Slow Worms at Wormsloe

Posted on October 21, 2014 by TMartin

Every time I visit the Georgia coast, traces that have been there all along make themselves apparent to me for the first time. One would think these personal discoveries would stop happening after more than fifteen years (on and off) of going to that coast and studying its traces, especially after writing a 700-page book about them (Life Traces of the Georgia Coast). Nevertheless, they happen, and when they do, these insights underscore the importance of doing regular field work in the same places. However familiar it might seem, there’s always something different you missed previously while there. So before each trip to the Georgia coast, I make sure to become wide-eyed and expectant, rather than jaded and bored.

Mysterious trails in a sandy road, crossing and re-crossing paths. What could have made them? And why so many? If curious, read on. If not, I’ve heard there are some Web sites with pictures of cats that require your viewing. (Photo by Anthony Martin, taken at Wormsloe Historic Site, Georgia.)

The latest example of this exercise in place-based humility happened just a little more than a week ago during a short time at Wormsloe Historic Site, south of Savannah, Georgia. Sarah Ross, the President and Director of the Wormsloe Institute for Environmental History, invited me there to give a nature walk and talk to guests at a private event on the evening of Saturday, October 11. After the walk and talk (which was a big success), we all watched lovely and enlightening story-telling by a local Gullah/Saltwater Geechee performance group (The Saltwata Players), had a delicious dinner, partook in great conversations fueled by nice wine, and I got to sell and sign copies of the book I mentioned earlier. In short, the proverbial good time was had by all.

My wife Ruth and I stayed in a guest cabin on the grounds of the former plantation that night; in morning, I got up just before dawn to start tracking and otherwise looking for traces. In the dimness, only a few raccoon and deer tracks stood out on the sandy roads, as well as a pile of scat that had been inside a feral hog only a few hours before. A nearby salt marsh beckoned, and because the low tide had exposed its banks, I walked out onto a nearby dock for better views of its exposed surfaces. The dark mud was pockmarked by thousands of holes, most belonging to mud-fiddler crabs and other burrowing invertebrates that call this place home.

A small part of the salt marsh at Wormsloe Historic site where it abuts the maritime forest, and during low tide. See all of those holes in the foreground? I wonder what those might be?

Each and every one of these holes is the burrow of a small marine-adapted animal – fiddler crabs, polychaete worms, and more. In other words, an ichnologist’s dream come true. (Photos by Anthony Martin.)

Less than a hundred meters from this dock is the home of Craig and Diana Barrow. Mr. Barrow is the ninth-generation heir of Wormsloe, but donated its grounds to the state of Georgia so that it could become a natural laboratory for researchers studying its environmental history. Ruth and I were acquainted with the Barrows from two previous visits to Wormsloe, and Craig – a great outdoors enthusiast – had eagerly given us personal tours of the woods, fields, and marshes on the property.

Having hunted for most of his life, Craig is a good tracker, and we’ve had in-depth discussions on animal-track forms, trackway patterns, aging of tracks, scat, and related topics. I find these conversations refreshing. Academic hierarchies, journal articles, impact factors, grant amounts, and other dull concerns become meaningless when you’re in the field with experienced naturalists. Here are some traces. Let’s learn.

Thus as the dawn light started to illuminate the maritime forest, I was not surprised to see Craig already outside his home, and to have him enthusiastically invite me to hop onto a golf cart with him to go look for tracks. He had already been out earlier on one of the sandy roads near his house and spotted three red foxes, so he wanted to check on whether their tracks were there, too. Within minutes, we arrived at the spot where he saw the foxes, and we quickly confirmed his sighting by identifying their fresh tracks in the loose sand on the road.

That was also about when Craig asked me a question that I answered wrong at first, then corrected once I gathered more data. You know, like any good scientist should. His question was “What’s this?”, and he was referring to a thin, shallow, and meandering groove in the sand. “Beetle trackway,” I answered instantly, without looking too closely. Then I squatted to show him the tiny tracks that would be on each side of the groove, where I imagined the beetle had dragged its abdomen.

Oh look, a beetle trackway, and right next to the tracks of a red fox (Vulpes vulpes)! How exciting! Gee whiz, I gosh-darn love science! Isn’t it neat? Wait a minute: what’s that earthworm doing at the end of a beetle trackway? (Photo by Anthony Martin, taken at Wormsloe Historic Site.)

That’s when I realized there were no tracks on either side of the groove. This was a trail made by a legless animal. “Wait a minute, this isn’t from a beetle,” I said. “Maybe a worm?” And by “worm,” I meant earthworm, but my small amount of experience with identifying earthworm traces made me a little uncomfortable with elaborating further on that idea. After all, I didn’t want to appear too ignorant about such common animals, and ones I had written about in both my book and on this blog (Of Darwin, Earthworms, and Backyard Science and Darwin, Worm Grunters, and Menacing Moles).

Fortunately, an earthworm saved me from further embarrassment by having the decency to be at the end of one of these trails, moving and otherwise actively demonstrating how these traces had been made. With our eyes and brains properly (and instantly) trained by this association between trace and tracemaker, Craig and I glanced around us. We were rewarded for looking, and promptly became astonished. The road was criss-crossed with hundreds of earthworm trails for as far as we could see, and most of them had living worms at their ends.

Even better, a few of these trails connected to open, small-diameter vertical burrows. My second insect-biased mistake of the morning was to initially identify these burrows as the shafts of halictid bee burrows. However, too many earthworm trails connected directly to these holes. Again, like any good scientist should in the face of contradictory evidence, I changed my mind. These traces were also from earthworms, and showed where the earthworms exited their subterranean homes.

Earthworm burrow marking exactly where it left its home for the surface world, and intersecting a trail. (Photo by Anthony Martin, taken at Wormsloe Historic Site.)

What really surprised me, though, was the length and complexity of the trails. These were not simple meandering paths, but complicated records of earthworm decision making. These worms may have been slow, but their traces certainly weren’t dull.

This trail was made by one earthworm that moved from right to left. The pointed grooves on either side of the main trail are from where its “head” and “tail” ends probed the sand.

Here’s an earthworm in action, moving from right to left. Compare this to the next photo to see how movement of both its forward and rear ends changes the trail, putting newer traces on top of the previously made ones.

See what I mean? Small but multiple movements from both ends of a worm – as well as its middle – make this much, much more than just a “worm trail.” So don’t be calling it that. (Photos by Anthony Martin, taken at Wormsloe Historic Site.)

Yes, I know, there’s a bigger question that looms over all of this ichnological minutiae: Why were so many worms on top of the ground, instead of in it? What could have caused hundreds of them to leave their homes and risk the perils of dehydration and predation at the surface?

I speculated aloud that their mass stranding might have been related to vibrations imparted to the road. After all, Charles Darwin had noted how earthworms reacted like this to subsurface vibrations, associating these with their mortal enemies, burrowing moles. This was independently verified by “worm grunters” of the Appalachians, who took advantage of earthworm-mole co-evolution to get bait for their fishing. Craig backed up my idea by saying that he had grated the road the previous day. So perhaps the vibrations from his vehicle and activities had persuaded the earthworms to come up and out of the ground.

Later, though, I wondered whether another much larger stimulus had invoked such aversive reactions in the earthworms, one that persisted for more than a day after the road had been grated. What else could have done this, impelling these earthworms to flee, much like urban hipsters sensing the first few notes of a nearby Justin Bieber concert, and leaving spilled PBR’s in their wake?

Then it came to me. A full moon that weekend had caused higher tides than normal in the area, ranging from 2.6 to 2.9 m (8.5-9.6 ft). As a result, saltwater probably crept high enough in the soil profile to trigger a collective reaction in the earthworms, which do not fare well once salty water starts filling their homes. Yes, that would do it.

Hi, terrestrial earthworms. Remember me? I’m a salt marsh with 2.5-3 m high tides, right next to where you live.

Assuming this hypothesis is correct, what we saw there on that sandy road of Wormsloe Historic site was a great example of a marine ecosystem forcing animals living in a terrestrial ecosystem to drastically change their behaviors. Best of all, these animals made a suite of traces that reflected this sudden change in their behaviors. If preserved in the fossil record, such trails and burrows might even be recognizable to geologists and paleontologists, some of whom are quite fond of calling every invertebrate trace fossil a “worm burrow” anyway.

All in all, this field experience at Wormsloe taught me a lesson about keeping my senses open to noticing and wondering about traces wherever I go, as should you, gentle readers. Look for those moments when the worm has turned: they will teach you something new.

Vestiges of Home

Posted on September 23, 2014 by TMartin

I first became a scientist in my backyard. This path to life-long inquiry began when I was four years old, as soon as my family moved to a larger house, and one with a larger yard. This small, outdoor patch of land with a few large trees, bushes, and grass soon became my field area, laboratory, classroom, and all-purpose place for conducting experiments in nature. Even better, my proclivity for observing this world outside of myself was encouraged – or at least tolerated – by my mother and father.

At the time, I had no idea just how important of a role this backyard and parental support would play in my scientific career. Yet now I look back on it with a mix of gratitude and wistfulness, especially as both of my parents have departed this earth I have studied for most of my life.

Here’s where I first learned science by going into the field. Back in the day, people – including my parents – called it a “backyard.” (Photograph by Anthony Martin.)

Indiana was an odd place for a natural scientist to develop in the 1960s. I recall how kids in public schools there and then were encouraged to study and pursue careers in science. However, this was mostly because of the “space race,” in which the U.S. was competing against the U.S.S.R. to see who could first land on the moon. I loved space, staring at the moon, planets, and stars, and I watched Star Trek (the original series, of course), dreaming of some day traveling in space. Science fiction stories became an outlet for me as well. Weekly trips to the public library meant checking out books by Arthur C. Clarke, Ray Bradbury, and other sci-fi writers who expanded my perspectives and kick-started my imagination with worlds far different from those I could experience in the Midwest.

Yet science fiction wasn’t the only subject that put me on a first-name basis with librarians as I checked out stacks of books. There were two other topics that supplemented my learning, namely dinosaurs and insects. Although the study of dinosaurs had not yet gone through its major scientific revolution of the 1970s, these animals still loomed large in my and other children’s inner worlds. “Tyrannosaurus rex! Stegosaurus! Brontosaurus!” we kids would shout gleefully at one another, or at bemused adults. Books with artistic recreations of dinosaurs and the occasional movie starring dinosaurian protagonists – such as The Beast from 20,000 Fathoms, The Valley of Gwangi – fed our fancy, too.

Photo of the original mural of Charles Knight’s ‘Triceratops and Tyrannosaurus‘ (1927), which is in the Field Museum of Natural History in Chicago, Illinois. While growing up, I saw this image many times in books, and it inspired both my artistic and scientific leanings. (Photograph by Anthony Martin.)

Still, no matter how hard I imagined, I could not see a tyrannosaur in my backyard, let alone watch it stalk and devour its prey. In contrast, insects and other animals with jointed legs delivered Tennyson’s “nature red in tooth and claw,” and much more. For about nine months of any given year during my childhood, starting in the spring, I could step out the back door of my house and watch ants, bees, wasps, butterflies, moths, spiders, and praying mantises. Plant-insect interactions in particular – such as pollination, herbivory, and wound responses in plants – drew me in, teaching me those ecological principles long before I ever heard the words “pollination,” “herbivory,” and “wound response.”

Roses blooming in the front yard of my Indiana home in August 2014, attracting a pollen-gathering carpenter bee (probably Xylocopa virginica). Female carpenter bees leave exquisitely crafted traces in wood, boring into them to make brooding cells, which they provision with pollen balls. The rose bush was originally planted by my father in the late 1970s. (Photograph by Anthony Martin.)

Insect damage on the leaf of an apple tree in the backyard of my Indiana home in August 2014. The leaf mine (left) was probably caused by a different insect from the one that made the incision along the leaf margin just to its right. Notice the brown discoloration in the leaf, a trace of its response to these injuries and its healing. My father planted this apple tree, but I’m not sure when: maybe also in the late 1970s. (Photograph by Anthony Martin.)

Predation fascinated me, probably because death was such an inappropriate topic for children to discuss with their parents. This wasn’t the artificial, acted-out stuff of TV and movies, but was in your face, or rather, in front of your face. With mild shame now (and apologies to my Buddhist friends), I remember going into my backyard, picking up ants, and throwing them into wolf spiders’ ground webs. It was a repeatable experiment in which I could observe spider response-times to tactile stimuli, and it was real.

My backyard is also where I learned to sit still and wait. As soon as I spotted a praying mantis, it was only a matter of time before that magnificent, big-eyed head swiveled to lock onto a target, moved delicately toward it, and sprang its barbed arms forward to snatch and hold its squirming dinner, which it devoured alive. Who the hell needed TV, with sharks, lions, and polar bears, when you had this, and for free?

Ah, there’s that word, “free.” This connects to the main reason why my science leaned more toward field observations and less to indoor labs, a legacy that stuck. You see, my family was poor. I didn’t know this until other kids at school made fun of my shoes, which had holes in their soles, or my pants, which were too outgrown or ragged, or my haircuts, which looked odd because my mother cut it, and badly, but with good intentions, because haircuts done by barbers were just too expensive. Compounding this (and not coincidentally), my mother and father never went to college, and my parents struggled to maintain their traditional roles, for which they were ill suited to succeed.

My father was a veteran of World-War II, and late in his shortened life was diagnosed with PTSD (post-traumatic stress syndrome), which in the 1970s was labeled “shell shock.” This condition meshed all too well with his alcoholism, meaning he had trouble keeping down a job for more than a few years. His last paycheck came from working as a night-shift janitor at a Columbia Records distribution center in Terre Haute. This job ended once he began suffering from a series of serious illnesses that put him in and out of hospitals for the last 15 years of his life. Only 59 years old, he died in the summer of 1985, just a few months before I left for Ph.D. study at the University of Georgia.

My father at six months old (in 1927) and near the end of his life (circa 1982). His mother was still alive when the photo at the left was taken, but he never got to know her; she died when he was only two years old. During his last ten years of life, he developed a fondness for roses, cultivating them in our yard and bringing beauty to our home every year.

My parents were also Catholic, which in their time meant the only birth control they used was prayer. As a result, we had a big family, and I grew up with four brothers and one sister. But we were also reminded of unseen siblings, the ones who might have been. My mother was pregnant 13 times, with six successful births, but also six miscarriages and one stillbirth, meaning she bore more deaths than lives. Much later, I realized how this must have placed a profound emotional burden on her, even though she almost never mentioned it.

Judging from my mother’s affection for books and reading, I think she wanted to be an intellectual of sorts, perhaps even a scientist, or at least she wanted to learn and debate ideas with other people. This, however, was not possible when cleaning, cooking, shopping, paying bills, and otherwise taking care of six kids, all while constantly pregnant until she had her last child in 1962. Add to those demands a chain-smoking, alcohol-fueled, and narrow-minded husband who helped with none of those household tasks, followed by her being his in-house nurse and servant during the last 15 years of his life, and she didn’t stand a chance of reaching those ideals.

Happier times for my parents, soon after my father came home after his service in the U.S. Army during World War II, where he fought in the Pacific. It would be his only trip abroad, but it scarred him for the rest of his life, which affected everyone around him. My mother never traveled outside of the U.S. and stayed in the Midwest for nearly all of her life.

Given such a family history, I experienced class differences and situations in college and graduate school that perplexed and occasionally stung. Even now, despite having taught at an elite private university for nearly 25 years, I still wrestle with imposter syndrome, and with how much my background sets me apart from others in my rarified academic world.

For instance, many of my academic colleagues are second-generation academics, or otherwise come from more socially elevated or well-to-do (or at least middle-class) families, where they never had to worry about paying the bills in time and making it through the month. Moreover, most of the students I’ve taught over the years have almost never experienced such economic anxieties, either. Behind all of the science I do and teach, and all of my achievements, I still hold onto a nagging, debilitating fear of scarcity, and a secret shame of how my family was on welfare and used food stamps to buy groceries. The taste of government cheese still lingers.

In the 1960s, education seemed like a way to escape from the cycle of poverty, and that was the message I constantly received from my mother and father. Sadly, that message sometimes translated as, “Don’t be failures like us.” Later in life, I turned that little frown upside down when I traveled, met wonderful people, and made scientific discoveries, many of which happened whenever I did field work in places far away from that backyard in Indiana.

In grade school music class, I used to get in trouble for singing the chorus of Waltzing Matilda a bit too boisterously, which happened in between reading books about dinosaurs and insects. About 40 years later, I was walking along the coast of Victoria, Australia, looking for dinosaur tracks and insect trace fossils in the Cretaceous rocks there. Funny how that happens sometimes. (Photo by Ruth Schowalter.)

But here’s the thing about that whole “education helps people to escape from poverty” trope, one seemingly affirmed by my little personal story. This was much easier to do in the 1960s than today. The gap between the poor and rich in the U.S. today is the worst it’s been since the 1920s, with no sign of abating. People who wants to preach their faith-based mantra of “People just need to work harder to succeed” conveniently overlook that Horatio Alger was a second-generation Harvard man and Ayn Rand took government assistance. Also, an increased emphasis on student loans to pay for exploding tuition rates during the past 30 years has meant young, aspiring scientists may be starting their careers with crippling debt.

But here’s another thing: I was damned lucky because of my parents. Not despite them, but because of them. That’s what I say – and with considerable ferocity – every time someone tries to tell me (in a well-meaning way) how much my life reflects “the American dream.” For one thing, I grew up at a time when white boys were far more encouraged to go into science than African-American boys, or all girls. This accident of being born male, and in a family belonging to the dominant ethnic group of my culture, meant I benefited from the privilege of my gender and race, even as my socioeconomic background held me back.

That’s me, climbing a flagpole just outside my house when I was about seven years old, circa 1967. The rest of my family was standing below watching, cheering me on, and documenting the event. Little did I know at the time that other kids were told they couldn’t climb flagpoles, let alone make it to the top. Yes, that’s a metaphor. (P.S. The flagpole’s gone now.)

I also had lots of help along the way, such as financial aid and scholarships in college, and teaching assistantships in graduate school. This meant I didn’t have to take out student loans. Sure, I had less than $100 to my name the first month I began the teaching job I still hold (so far), but at least I began that job debt-free. Many of today’s aspiring scientists don’t have this luxury, and entrenched inequities related to gender and ethnicity continue to discourage careers in science for most Americans. Also, achieving a college degree today is nine times more likely if you come from an upper-income family than a poor one. It was never easy for poor people to become successful scientists, but it’s far, far tougher today. I was lucky.

Perhaps most importantly, though, I had parents who let me play outside and supported my learning science, however weird I must have seemed to them. I mean, staying out in the backyard for hours, flinging ants in spider webs, and watching praying mantises kill other insects? That was pretty strange, even in the 1960s. I even climbed trees in our backyard. I suspect that many of today’s “helicopter parents” would have forbidden a scrawny runt like me from going outside, let alone get my face close to spiders and insects, and handle unknown plants. Climbing trees probably would have involved first donning a series of ropes, carabiners, harnesses, padding, and a helmet, all while being supervised by a team of tree-climbing experts. Instead, like any arboreal primate should, I climbed those trees by myself, occasionally fell out of them, then got back up and climbed again. I was lucky.

My favorite climbing tree in my backyard, which I started scaling when I was about six years old, so it must be more than 70 years old now. It was great fun to see how far I could get up into it and explore, and I found much peace just sitting in its crooks, watching the world below. Notice in the close-up (right) all of the scars on the trunk, marking the sites of the low-hanging branches, which fell off the tree a long time ago. (Yes, that’s another metaphor.)

My parents also regularly took me to our modest public library, where I checked out many books, which I read, and sometimes re-read. After my grade-school teachers alerted them that I was showing talent as an artist, my parents also spent some of their meager cash to buy me crayons, pencils, paper, acrylic paints, oil paints, and canvases as birthday and Christmas presents. So I drew and painted, and nature was my inspiration for such creations. I still can draw well – and sometimes teach drawing to my students – because of what my parents did for me. I was lucky.

One of my earliest attempts at scientific illustration (left), coupled with one of my more recent efforts (right). The one on the left – clearly intended as a multi-part figure – shows some of the insects I observed in my backyard, as well as some of the ecological interactions they had as pollinators, predators, and prey. The one on the right is from Figure 5.4a in Life Traces of the Georgia Coast (2013, Indiana University Press, p. 192), and is the subsurface form of a nest made by Florida harvester-ants (Pogonomyrmex badius); scale bar = 25 cm (10 in).

As I do field work today, I silently thank my father for taking me on hunting and fishing trips, effectively planting the seeds for my present-day comfort with forests, streams, lakes, and other outdoor environments. On those hunting trips, I learned what little my father knew then about tracking animals, a skill that I honed later in life, and now one of my passions. On fishing trips, I watched the behavior and ecology of freshwater crayfish, which abounded in the streams of southern Indiana. I had no clue that more than 40 years later I would reconnect with that childhood interest in crayfish by discovering the oldest fossil crayfish in Australia. I also did a different kind of fishing by studying and interpreting fish trace fossils, such as a trail left by a bottom-feeding fish about 50 million years ago in Wyoming. Then I combined my childhood love of insects and dinosaurs by writing and publishing a paper about Cretaceous insect cocoons near dinosaur nests in Montana. I didn’t see an ocean until I was 20 years old, but last year published a 700-page book, Life Traces of the Georgia Coast, which I also illustrated myself. None of those things would have happened without my parents’ help early in my life. I was lucky.

My father and mother did what they could with what life dealt them, and my mother in particular. She was born in northern Illinois and lived there through the Great Depression during her childhood. While there, she met her high-school sweetheart, who some day would be the father of her six children. He went off to fight in a world war, she waited for him to return, and they married soon afterwards. They headed south to Terre Haute, and lived in one house, then another. The latter was her home for 50 years.

My mother on her honeymoon at Turkey Run State Park in southern Indiana, 1947. While looking through a photo album in 2012, I was delighted to see this photo, showing her when she was fully in love with my father, but also enjoying what must have been a glorious waterfall. Best of all for me, though, it has an outcrop of Late Carboniferous (Pennsylvanian) Period deltaic sandstones in the background.

My mother outlived my father by nearly 30 years and got to see how her love of books, reading, and encouragement of my learning came back home to her. In 2001 and 2006, it was with much pride I mailed her each edition of a textbook I wrote and published (Introduction to the Study of Dinosaurs). In the preface to Life Traces of the Georgia Coast, I pointedly thanked her and my father for cultivating a childhood life filled with books, art, and the outdoors.

The first and last photographs of my mother, when she was three years old (about 1929) and just last month, the latter photo taken by my brother Pat.

My mother died three weeks ago. The first stroke was toward the end of December 2013, and its treatment necessitated her going to a hospital, and then to assisted care. For the next eight months, she had a picture window that looked out onto a courtyard, where she watched the blooms, butterflies, and birds of what would be her last Indiana spring and summer. On August 26, she had a second and more deadly stroke, putting her in a coma that took away all of her speech, thoughts, and memories. After receiving emergency care in Terre Haute, she was evacuated by helicopter to an intensive-care unit in Indianapolis that same night. Six days later, she exhaled for the last time, less than a week shy of her 88^th birthday.

Me giving a talk about my most recent book, Dinosaurs Without Bones (2014) at the Decatur Book Festival last month. At the end of my talk, I dedicated it to my mother. Almost no one in the audience knew she was in a coma at the time, and none of us knew she would die three days later. (Photo by Ruth Schowalter.)

Just before this second stroke, I flew up to Indiana to see her, and we spent some time with our extended family, but also some quiet moments talking together, just mother and son. During this visit, I told her how much I appreciated everything she had done for me. We got to say goodbye to one another. We were lucky.

Today I am a trace of my mother’s and father’s love and care, and a trace of my home and backyard in Terre Haute, Indiana. Given more luck, I’ll be around for a while longer, leaving more traces of my own, and in many more places. Thank you, Dad. Thank you, Mom. You did good.

First and last photos of my mother with me, separated by more than 50 years. As you can see from both pictures, my disposition hasn’t changed much. And thanks to Mom, it probably won’t.

High Plains Anteater

Posted on August 22, 2014 by TMartin

Every time I travel away from home, I make a point of looking at the ground. The main reason for this seemingly odd behavior is to make sure I detect traces of whoever else might be living in my temporary neighborhood. This ichnological practice came in handy last month while I was doing field work in the high plains of central Montana. Located just east of the front range of the Rocky Mountains, this area – which happens to have some lovely Late Cretaceous trace fossils – is also prime real estate for grizzly bears.

Had we found this in the woods, it would have answered just one specific question. But because it was in the high plains of Montana, it generated a lot more questions than answers. (Photograph by Anthony Martin, taken in central Montana.)

Grizzly bears (Ursus arctos) are the largest land carnivores in North America. The earliest written records describing grizzly bears came from Meriwether Lewis and William Clark, who traipsed through this part of Montana with their expedition in the early 19^th century. After several encounters, they soon verified that this species was much tougher than they had presupposed, often taking more than ten shots from then-modern rifles to kill. To make matters worse, it had a low tolerance for upright bipeds traipsing, skipping, sashaying, or dosey-doeing in its territory. Moreover, these bears possessed the means to enforce their you-no-go-here zones. There’s something about weighing 300+ kg (700+ lbs), having powerful limbs ending in huge claws, big teeth, an ability to run more than 50 kph (30+ mph), and an aggressive attitude that persuasively argued for people to avoid them whenever possible.

Lewis and Clark thought they were badasses because they carried boom sticks, but Mr. Chocolate soon showed them why grizzlies were the Mongos of the animal kingdom: shooting them sometimes got them mad. (Image is originally from Sargent Patrick Gass’s journal and borrowed from Frances Hunter’s American Heroes Blog, co-written by Mary and Liz Clare.)

So although the area where I did field work in Montana is world famous for its dinosaur nests and other fossil evidence, modern grizzly-bear traces there also mean I associate this place with these animals. For instance, I’ll never forget my first morning there in 2000, when – while walking to an outcrop I’d be studying by myself for the next six days – I encountered fresh grizzly tracks in one of the arroyos. These traces readily explained why I heard a pack of coyotes making a racket the night before, while also invoking mild anxiety in this petite paleontologist once I realized the surrounding environment lacked any trees or other means of escaping an angry grizzly.

Left rear-foot track of an adult grizzly bear, left in the muddy sand of an arroyo next to a Cretaceous outcrop where I did field work in 2000. Notice the length of its claws, which left marks well in front of its toes. Photo was taken about four days after I had seen them freshly made my first day in this area of Montana. (Photograph by Anthony Martin.)

This time, with 14 more years of tracking experience behind me, I felt a little more confident about detecting grizzly-bear tracks and other sign, and looked forward to seeing these traces, but not their tracemakers. Thus I was pleased when my field companions and I found several-weeks-old evidence of a grizzly during my first morning there. Yet these traces were not tracks. Instead, they consisted of scat bearing (sorry) some never-before-seen items (for me, anyway), accompanied by nearby feeding signs that directly connected to another trace made by another animal.

So let’s first talk feces. Based on its size alone, we quickly determined that this deposit was from a grizzly bear, as the two pieces collectively were about 15 cm (6 in) long and about 5 cm (2 in) wide. Nearby coyote scat nearby gave some perspective: although 20 cm (8 in) long, it was only 2 cm (0.8 in) wide, indicating a much smaller anal diameter. However, that wasn’t the largest grizzly scat I’d ever seen, which made us think that maybe it was from a young bear.

But was really puzzled us was the contents of the scat: it was full of ants and grass stems. Despite none of us being entomologists, let alone myrmecologists, we recognized the red-and-black ant parts in the scat were from an ant common there in the high plains, and probably some species of Formica. Colonies of this ant built nests with prominent domes at the ground surface, which are composed of a mixture of soil and grass stems. Hmm, ants and grass stems: what could it mean?

See all of those orange and black bits in this scat? Those are ant parts that passed through the digestive tract of a grizzly bear. Notice these pieces are accompanied by lots of plant fibers, which must have provided some healthy roughage. (Photograph by Anthony Martin, taken in central Montana.)

OK, you already got it: this scat was evidence of a grizzly bear that ate ants. But the grass also showed that this grizzly ingested a lot of plant debris along with these yummy insects. This implied that it must have been chowing down on the top of an ant nest, scooping up insects and grass stems indiscriminately, like it was dining on an ant salad. Furthermore, knowing how ants tend to defend attacks on their nests, they probably swarmed upward in great numbers and straight into this grizzly bear’s mouth, unwittingly aiding its efforts. (Incidentally, an insectivorous member of our field crew had been tasting these ants just minutes before we found the scat and independently confirmed their delectable qualities.)

Ant-nest mound in the field area composed mostly of grass stems, and probably made by a species of Formica. Scale is a size 8 1/2 (men’s) boot. (Photograph by Anthony Martin.)

Close-up of the ants in the colony moving in and out of a nest entrance, in between all of the grass stems. Also, check out those black abdomens and reddish-orange thoraxes and heads, which we now know don’t change color much after spending time inside a grizzly bear. (Photograph by Anthony Martin, taken in central Montana.)

So how did we know that the grizzly was “scooping” (using its paws) instead of simply mashing its face into the nest like it was competing in an ant-eating contest at a grizzly-bear fair? Ah, that was the other trace evidence. Only a couple of meters away from the scat were two big pits. These pits showed exactly where the ant-eating grizzly had used its big-clawed paws to rip into a couple of nests. While taking into consideration the needed residence time of ants in a grizzly gut, we figured this bear had already raided a nest somewhere else and pooped here, or it came back to this place for seconds the next day. Either way, it left a little calling card for us bipeds and any other mammals in the area, warning us to stay away from its ant stash.

Ever wonder what a grizzly-bear-ant-eating pit looks like? Wonder no more, here’s two of them. The one on the left was about a meter (3.3 ft) across, whereas the one on the right was closer to 1.5 m (5 ft) wide. (Photograph by Anthony Martin.)

What was very gratifying about these traces is how they reflected the same sort of insectivorous bear behaviors I had discerned in black-bear traces in forests of Wyoming and Idaho. The big difference, though, was in the types of insects and substrates. Insect-eating bears in forests rip open rotten logs for their fodder, which mostly would hold wood-eating beetle grubs; this behavior leaves huge gouges and scatters wood chips around the feeding site. Without trees, the same behavior means digging into the soil, and after different insects, such as moths and ants, and the traces will be large pits like the ones we saw.

So how would traces like these look in the fossil record? Better yet, how would our knowledge of these grizzly-bear traces help us to test whether any dinosaurs did similar behaviors, such as tearing into Mesozoic ant or termite nests and feasting on these little protein-rich treats?

Well, you’re lucky that I’m the person asking such rhetorical questions, because I just happened to have talked about about this in my most recent book, Dinosaurs Without Bones. Based on their anatomies, dinosaurs accused of ant- or termite-eating behaviors include a few unusual theropods, such as alvarezasaurs and therizinosaurs. Very simply, dinosaur trace fossils of insectivory would be analogous to what we saw with these grizzly-bear traces in Montana. Lacking dinosaur skeletons with insect parts in its gut region, trace fossils might include coprolites containing abundant ant parts, accompanied by sediments or plant debris from their nests. Even better would be a fossil ant or termite nest with visible damage matching the claws or other body parts of these suspected dinosaurs.

Have paleontologists ever found such two-for-one ichnological specials? Not yet, but given an awareness of modern insect-eating animals and the traces – some of which are next to Mesozoic rocks – I have every confidence that we’ll discover find them some day.

Fossil Visions in the Two Medicine

Posted on August 4, 2014 by TMartin

(This post is the third in a series of three about my field work on the trace fossils of the Late Cretaceous (75 million-year-old) Two Medicine Formation, which I just completed a week ago. My previous two posts, which mostly explain the scientific importance of this field work, are Tracing the Two Medicine and Burrowing Wasps and Baby Dinosaurs.)

Looking back on three weeks of field work in the Late Cretaceous Two Medicine Formation, one of the realizations I had was how long it took before I could see more of what was there. The most frustrating part of this realization, though, is also knowing that I still missed plenty. This mix of satisfaction and unease is the duality that often accompanies the birthing and honing of search images, a visual training that enables paleontologists to find the fossils we want to find whenever we walk around a field site and look.

This outcrop of the Late Cretaceous (75 mya) Two Medicine Formation in central Montana is chock-full of fossils, but you might not know that from just looking at this picture. That means you have to get out onto the rocks and look closely for them, but first make sure you have the right search images for finding them. (Photograph by Ruth Schowalter.)

The Two Medicine Formation in particular presents a major challenge for cultivating search images because of the variety of fossils in it. Moreover, most of these fossils require very different search images. For example, over my three weeks of prospecting, I looked for the following fossils:

Plant root traces
Invertebrate burrows and tracks
Insect cocoons and pupal chambers
Dinosaur tracks
Dinosaur nests
Dinosaur eggshells
Dinosaur coprolites
Dinosaur bones
Dinosaur toothmarks (on dinosaur bones)

I also found a few other fossils I didn’t expect to find, but there they were. This happenstance served as a good reminder that simply going out into the field with a bullet-point checklist of what you think you’ll find (like what you just read) isn’t good enough. In other words, you also need to see what’s there, rather than just what you expect to be there.

On top of looking for these fossils, I’m a geologist, too. This means I also paid close attention to the rock types in the Two Medicine Formation – sandstones, mudstones, conglomerates, limestones – and their physical sedimentary structures – such as cross-bedding or graded bedding. Moreover, Two Medicine strata in the field area are not necessarily in their original horizontal positions, but instead are bent, tilted, and faulted in places. This is where training I had in structural geology – the study of how rocks were deformed – came in handy.

Originally horizontal sedimentary strata were bent upward into a fold, which we geologists normally call an anticline. In such folds, the fossils in the center of the fold are geologically older, whereas the fossils on the outside of the fold are younger. That is, unless the strata were overturned, in which case we’d call it antiformal syncline, then the fossils would have the opposite age relations. Thank you for teaching this, structural geology professors! (Photograph by Anthony Martin.)

It’s not my fault, so we’ll blame the Two Medicine Formation for this breakage of sedimentary rocks. Based on how it looks like the fault block on the right moved up relative to the one on the left, I think this is a reverse fault, which – like the anticline and almost everything else on earth – was caused by plate tectonics. (Photograph by Anthony Martin.)

Thus whenever I stepped into the field each day, I had to rapidly switch, combine, or otherwise tap into different types of vision. I’ve often jokingly referred to my ability to spot traces and trace fossils in the field as “ichnovision” (my most likely comic-book hero superpower), and my geological training means I’m using “geovision.” Yet in the Two Medicine Formation – a rock unit world-famous for its dinosaur bones and eggs – I also had to use “osteovision” (seeing fossil bones) and “oovision” (seeing fossil eggshells). These forms of fossil vision are tough for me, as I never see dinosaur bones or eggshells in the southeastern U.S., which is where I spend most of my time in the field.

So just to give you an appreciation of what it was like during my three weeks of looking for fossils in the Two Medicine Formation, here are a few photos and brief descriptions of some fossils I found. To be sure, there was much more than this, but at least I can share these for now so you can begin to see through my eyes.

These odd-looking structures weathering out of an outcrop in the Two Medicine Formation had variable diameters, central cores filled with calcite, and branched in places. I’m fairly sure these are fossil plant root traces, but they were the only ones I saw like them during three weeks of field work. So I remain a little skeptical of my identification, and remain open to their being some geological features I’ve just never seen before then. (Photograph by Anthony Martin.)

These are longitudinal sections of horizontal burrows in a sandstone, showing off their beautifully expressed internal structures called meniscae. Meniscae are formed by burrowing invertebrates – such as beetle larvae or cicada nymphs – that pack their burrow with sediment behind them as they move. This means the convex side of the meniscae points in the direction the animal was moving. Go ahead, apply that principal and see what you figure out for yourself. (Photograph by Anthony Martin.)

These are more invertebrate burrows, but they’re vertically oriented, meaning you only see their circular cross-sections when you look at the top bedding-plane surface of this sandstone. Notice how some of them are open but others are filled with sandstone. The open ones were filled with mud originally, but that softer sediment has since weathered out, leaving them hollow. (Photograph by Anthony Martin.)

These are invertebrate tracks, and they form a distinctive enough pattern that I recognized them as a trackway, where the trackmaker (probably a freshwater horseshoe crab) turned. But they’re also preserved in positive relief (“sticking out”) because the original traces were filled with sand, which made a natural cast of the tracks. Think about how you have to reverse your concept of tracks to recognize these. (Photograph by Anthony Martin.)

One of my main research interests in the Two Medicine Formation is its insect trace fossils, which include some of the best-preserved fossil insect cocoons I’ve ever seen in the geologic record. See where the patterns of their original weaves? These cocoons were likely made by wasps – or something acting very much like wasps – 75 million years ago. I usually prospected for these cocoons by looking for their distinctive oval shapes on the ground, then looked more closely for the weave pattern. (Photograph by Anthony Martin.)

This is what a fossil insect cocoon looks like in an outcrop. Sometimes a burrow would be connected to the cocoon, showing where the original mother insect dug a brooding chamber for its intended offspring. (Photograph by Anthony Martin.)

A rare piece of dinosaur bone that actually looks like a bone, even to an untrained eye. Although this one is white, the dinosaur bones in the Two Medicine Formation varied wildly in their colors. So spotting these fossils was more a matter of looking for both a shape and texture that translate into “bone.” (Photograph by Anthony Martin.)

This is more what most dinosaur bones looked like when I found them in the field area. You probably spotted the big chunk right away, but how about the smaller ones that tend to blend in with the non-dinosaur-bone rocks around them? (Photograph by Anthony Martin.)

Here’s another example of how fossil tracks are not like modern ones in size, shape, and how it’s preserved. This is a three-toed dinosaur track (probably made by a hadrosaur), but it was originally made in mud, then sand filled in the track-sized hole to make a natural cast, which 75 million years later weathered out so that it’s sitting by itself on the eroded surface of a mudstone. What’s the scale? My boot’s a size 8 1/2 (men’s). Yes, I felt a little inadequate. (Photograph by Anthony Martin.)

What does a natural sandstone cast of a dinosaur track look like when it’s still in outcrop? Look for a lump on the bottom of a sandstone bed. From a side view, you might then see a couple of “toes” pointing in one direction, like in this one: the central toe is to the left and one of the outer toes is on the side, clser to you. Note how the sandstone bed also has a few open invertebrate burrows in it, too. Ichnobonus! (Photograph by Anthony Martin.)

Check out this big piece of, well, dinosaur coprolite. These trace fossils contained blackened (carbonized) wood fragments that originally passed through the gut of a dinosaur (probably a hadrosaur), and were later cemented by calcite. But you had to look at them doubly, because some of these trace fossils included their own trace fossils made by insects, namely dung beetle burrows. (Photograph by Anthony Martin.)

Field-of-Feces-Two-Medicine You’ve heard of ‘Field of Dreams’? This is a ‘Field of Feces.’ The ground here is adorned with dinosaur coprolites, which are weathering out of the mudstone and breaking apart on the surface. This serves as a good example of how once you know what the dinosaur coprolites look like in this area, you’re less likely to just walk by them, singing “Where Have All the Coprolites Gone?”. (Photograph by Anthony Martin.)

The Two Medicine Formation is famous for its dinosaur eggs and babies, but even more common than those are bits and pieces of dinosaur eggshells. These show up as black flakes on ground surfaces and sometimes in a rock, which you then must distinguish from all other black flakes that are not dinosaur eggshells. (Photograph by Anthony Martin.)

Can you find the dinosaur eggshell in this photo? I’ll bet the answer was “yes,” but I made it a little easier for you by cropping the photo, placing the eggshell near the center of the image, and oh yea, showing you what typical eggshells look like in the previous photo. Now think about detecting this bit of eggshell from a standing height and while walking. (Photograph by Anthony Martin.)

After viewing the photos and reading the descriptions, do you think you could recognize each of these fossils if you were somehow magically transported to the Two Medicine Formation in Montana?

The likely answer to that question is, maybe, maybe not. For instance, despite all of my previous paleontological and geological field experience, it took me about two weeks of being in the field before I started accurately identifying dinosaur bones and eggshells. This humbling situation gave me a renewed appreciation for the people who regularly work in the Two Medicine Formation, but also imparted a lesson about taking the time to learn from misidentified burrows, cocoons, coprolites, bones, and eggshells in it. Most things I saw in the Two Medicine were not these fossils, meaning my ways of seeing had to become more discriminating over time.

Thus given enough practice and “dirt time” seeking fossil in the field and correcting your mistakes – preferably with an expert peer-reviewing your finds beside you – the fossil visions will come to you. Then, next thing you know, you start noticing more of what you didn’t see before, expanding your consciousness of the lives that preceded your own.

* * *

Many thanks to Dr. David Varricchio for inviting me to be part of his NSF-sponsored research project in the Two Medicine Formation this summer, and by extension, my deep appreciation to Montana State University and Museum of the Rockies for their logistical support at Camp Makela. May it have many more successful field seasons.

The Seven Samurai of paleontology at Camp Makela, ready for action in the Two Medicine Formation of central Montana. These ruffians/malcontents/Guardians of the Cretaceous Galaxy are otherwise known as (left to right): Ulf, Jared, me, Ashley, Emmy, Paul, and Eric. (Photograph and choreography by Ruth Schowalter.)

For more about these people and other human connections between the paleontological research that took place in the Two Medicine Formation – and told from a non-paleontological perspective – go to Cretaceous Summer 2014, which had links to four blog posts done on site by my wife Ruth Schowalter. Also be sure to check out Brad Brown’s blog post from the Burpee Museum of Natural History about his experiences at the field site, Just What the Doctor Ordered: Two Medicine Delivers High Biodiversity in a Low Profile Area.

Burrowing Wasps and Baby Dinosaurs

Posted on July 21, 2014 by TMartin

Anyone who knows a little bit about dinosaurs knows that some of them made nests, took care of their young, and that their parenting skills must have been more like birds, rather than most reptiles. If pressed, most dino-enthusiasts can further say this concept is exemplified by two dinosaurs, the large ornithopod Maiasaura and the small theropod Troodon, both of which lived at the same time and place, 75 million years ago and in what we now called Montana.

But what animals lived beneath the nests and feet of those dinosaur parents and their babies? What behaviors did these animals express 75 million years ago? Would the behaviors of these animals have resembled those of ones living today, or did they reflected evolutionary dead-ends? And did these animals also take care of their young?

Whoa, check out this female Carolina sand wasp (Stictia carolina), energetically digging an inclined burrow into a Georgia coast dune! Why is she digging a burrow? To make a brooding chamber for her babies (larvae), who will hatch from their eggs and chow down on paralyzed prey stuffed into that chamber by their thoughtful mama. Gee, I wonder if any wasps did this in the geologic past? (Photograph by Anthony Martin, taken on Tybee Island.)

Why, yes, they did. That’s a fossil cocoon connected to an inclined burrow, reflecting a behavior much like that of modern sand wasps, but preserved in the Late Cretaceous Two Medicine Formation of central Montana. (Photograph by Anthony Martin.)

The answers to these questions are, in order: insects (wasps and beetles; most likely), burrowing and reproduction; they behaved very much like modern insects, and they likely did take care of their young by making brooding chambers and leaving food for their offspring. In my experience, these revelations surprise many people, who may not be aware of how many of the insects we live with today are descended from insects lineages that shared the same ecosystems with dinosaurs throughout the 165-million-year history of the latter animals.

This summer, for me to learn more about life underground way back then, I had to go to the same site in central Montana where our understanding of dinosaur parenting became better defined, but also where I first learned how insect parenting related to dinosaur parenting. Where I am now is the same general location where the first known dinosaurs nests in North America were found in the late 1970s by Jack Horner and his friend Bob Makela (mentioned in my previous blog post).

One of the most productive and interesting of these nest sites, which are all in the Late Cretaceous Two Medicine Formation, was informally dubbed “Egg Mountain.” The “Egg” part of the moniker is easy to understand, but the “Mountain” part is more of an exaggeration, as it’s an isolated and modest hill on the high-plains landscape of central Montana. Anyway, I’m working there now, along with a dedicated crew of rubble pickers being led by the ever-intrepid Dr. David Varricchio.

A snapshot of science in process at Egg Mountain in central Montana. Dr. David Varricchio (center, with jackhammer) has been leading an NSF-sponsored study of the fossils at this site, with the hope of understanding more about nesting dinosaurs and the animals that lived around them. Rubble pickers for scale. (Photograph by Anthony Martin.)

So why would an ichnologist like me care about a site that is famous for its mere body fossils, consisting of many dinosaur eggs, eggshells, and bones? I’ll start with three words: dinosaur nest structure. This is where the first known dinosaur nest structure – which is a trace fossil – was recognized. The structure was a rimmed depression about the size of a kiddie pool, but a little more shallow. In the center of this depression was a clutch of eggs belonging to the small theropod Troodon. The width of the nest was perfect for accommodating an adult Troodon, which probably sat above the egg clutch to protect and incubate it.

Here’s the first known dinosaur nest structure, as it looked soon after its discovery in the mid-1990s. The rim is composed of limestone, but originally was soil compacted and shaped by either one or both Troodon parents. The white part is plaster of Paris covering the egg clutch, which was aligned with the dead center (pun intended) of the structure. Tape measure shows 1 m (3.3 ft). Photograph was probably taken by David Varricchio, and is from Varricchio et al. (1999), Journal of Vertebrate Paleontology, v. 19, p. 91-100.

My artistic recreation of this same rimmed Troodon nest structure with its egg clutch in the middle. The inner part of the structure – inside the rim – is about a meter wide. (Artwork by Anthony Martin, from Dinosaurs Without Bones (2014), which you should buy so I can better afford to do more research like this and blog about it for you.)

What’s even better about this find – ichnologically speaking – is how the parent dinosaurs must have moved the eggs after the mother laid them, and then partially buried them upright in soil. These eggs are elongate, which means they would have reclined if laid by a mother Troodon. Instead, they were nearly vertical, which means either the mother or father dinosaur manipulated these eggs after they emerged from the mother dinosaur. Thus this orientation is also a trace fossil of parental dinosaurs that were greatly increasing the chances their future offspring would stay alive.

Bottom view of the Troodon egg clutch from that nest structure, with these elongate eggs in nearly vertical positions, and aligned along a central axis. These arrangements of the eggs are trace fossils, too. Want to see this clutch for yourself? It’s is on display in the Museum of the Rockies in Bozeman, Montana. (Photograph by Anthony Martin.)

Now let’s leave dinosaurs for a moment and talk about something that really matters, like insect trace fossils. What is well known by those who have worked at Egg Mountain is that the dinosaurs there were not alone. Just below the dinosaurs’ nests, egg clutches, and feet were insects, and lots of them, shown by numerous cocoons. In a few places near Egg Mountain, these exquisitely preserved cocoons – most with their spiraled weave patterns still visible – are so common, you can close your eyes and scoop up a handful of them.

Fossil insect cocoons from the Two Medicine Formation and a locality near Egg Mountain. The cocoons on the left and right are ichnological two-for-one specials: the left one has a partial burrow attached to it, and the right one has an emergence trace (top) from where the adult insect said goodbye to its cocoon 75 million years ago. (Photograph by Anthony Martin.)

In an article I coauthored with David Varricchio in 2011, we concluded that most of these insect cocoons were likely from burrowing wasps, and the rest may have been from beetles. The trace fossils reflect a unexpectedly modern behavior in these Cretaceous wasps, which dug inclined tunnels that led down to enlarged brooding chambers. These insects laid eggs in the chambers and stocked them with provisions, which may have been paralyzed prey, such as other insects or spiders. Later, larvae hatched in the chambers, ate whatever Mother Wasp left for them, made cocoons around themselves once they decided to stop being so larval, pupated, burst out of their cocoons when they became adults, and emerged on the surface.

My simple depiction of a burrow and pupal chamber made by the solitary Carolina sand wasp (Stictia carolina). These traces consist of inclined tunnels that end in enlarged chambers, the latter of which accommodate eggs, food, and eventually larvae and cocoons. Scale = 10 cm (4 in). (Illustration by Anthony Martin, which is in Life Traces of the Georgia Coast (2013), which you should buy so I can better afford to do more research like this and blog about it for you.

Close-up of the burrow end – filled with sediment, but now rock – leading to a cocoon, still preserved in its pupal chamber in the Two Medicine Formation, from about 75 million years ago. Compare this to my illustration of a typical modern sand-wasp burrow, especially the end part of it. Notice the resemblance? (Photograph by Anthony Martin.)

However, most of the fossil cocoons in the Two Medicine Formation did not make it past the pupal stage. How do we know this? Because some of these outcrops have thousands of cocoons that are perfectly preserved as beautiful ellipsoids, with no sign that an adult insect emerged from them. One of the axioms of paleontology is that each animal’s tragedy of the past can some day fulfill a paleontologist’s dreams. Thus these thousands of dead Cretaceous wasps are providing me with much joy this summer, as I study these trace fossils for more clues about their lives and how they related to the ecosystems they shared with adult and baby dinosaurs.

A picture of one happy ichnologist, who is giving thanks for all of those insects that died and had their burrows and cocoons fossilized in the Two Medicine Formation for him to study. Thanks, insects! Thanks, geology! (Photograph taken by Ruth Schowalter in central Montana.)

But here’s what really cool about Egg Mountain: it has both dinosaur nests and insect nests, implying that wherever these insects nested, so did the dinosaurs. As a result, their co-occurrence gives us a glimpse of the ecology of those places at that time, a window into the past landscapes in which they lived and bred. This makes sense when you imagine how both these dinosaurs and insects wanted to keep their eggs out of water, so they placed them in high-and-dry areas, such as well-drained soils well above the water table. So as we gather more information from this site, we get ever-better insights in the cycles of life for both Cretaceous insects and the dinosaurs that happened to live in their world.

Tracing the Two Medicine

Posted on July 15, 2014 by TMartin

Field scientists have to get into the field. If they don’t, they get cranky, narrow-minded, and – worse of all – feel like frauds. What’s the cure for this malady? Getting into the field.

See that smile? That’s a field scientist, who is out standing in his field. (Photograph by Paul Germano.)

This is the first summer since 2008 in which I did not have to edit or write a book. From 2008 to 2012, I was writing and editing Life Traces of the Georgia Coast (2013, 692 pages), and from 2012-2013, my literary efforts were devoted to Dinosaurs Without Bones (2014, 460 pages) So with these two books behind me and none in the making now, along with three merciful months off from my “day job” of being a college professor, I had few excuses for not getting outside to see some rocks and fossils this summer.

So it was with much joy when my long-time friend and fellow paleontologist David (Dave) Varricchio asked me earlier this year if I’d be interested in coming out to Montana to do some field work with him this summer. Even better, I’d get to do paleontological field work with him in the Late Cretaceous Two Medicine Formation (~75 million years old) at “Egg Mountain,” a paleontologically classic area near Choteau, Montana. I said yes, have been here for a week now, and it’s been glorious.

To look for traces, sometimes you have make your own traces. Here’s this summer’s Montana State University field crew excavating at Egg Mountain, where they’re looking for dinosaur bones and eggs, while also cataloging trace fossils like insect cocoons and burrows. If you’re looking for Dr. Varricchio, he’s the one in the middle with the jackhammer. (Photograph by Anthony Martin.)

The main reason why the field site is called “Egg Mountain” is because it and other places in the area are where the first known dinosaur nests in North America were discovered by Jack Horner and Bob Makela in the late 1970s and early 1980s. They further uncovered evidence that at least one dinosaur here – the large hadrosaur Maiasaura peeblesorum – had extended parental care, taking care of its young in their nests well after hatching.

Later in the 1990s, Dave and his colleagues showed that the small theropod Troodon formosus made rimmed ground nests and arranged it eggs carefully in these nests. This combination of body fossils (bones and eggs) and trace fossils (nests and egg arranging) changed many of our views of dinosaurs, rendering their behaviors much less like reptiles and more like birds.

Sometimes I hear paleontology referred to as a “historical science,” but it also has its own human history. This marker and several others in the field area mark where some of that history was made, with the discovery of the first known dinosaur nests in North America. (Photograph by Anthony Martin.)

I love waking up to the Two Medicine Formation in the morning. And there’s no shortage of trace fossils to discover in it with each waking day. (Photograph by Anthony Martin.)

A natural sandstone cast of an adult hadrosaur, weathered out of the surrounding softer mudstone that – in the absence of bones – serves as a visual reminder of who lived in this area. (Photograph by Anthony Martin.)

I had been to this site three times before – 2000, 2008, 2009 – but each of those were short visits, the longest lasting only a week. This time, I would get to stay for as long as three weeks, which allows for plenty of time to better document the invertebrate and vertebrate trace fossils here. So far, I’ve only published one paper with Dave based on previous work in the Two Medicine Formation, which was on some of the insect trace fossils near the nest sites. These trace fossils gave valuable clues about how these insects lived, and in the same ecosystems as the nesting dinosaurs, which I’ll happily cover in detail in my next blog post.

Insect burrow with pupal chamber (left) and two insect cocoons, one of which has a “hatching window” where the adult insect left the cocoon. Look closely and you’ll see the original silk-weave pattern still on the cocoons, which are preserved as finely crystallized calcite. (Photograph by Anthony Martin.)

So with one week of field work done, I’m happy to report that plenty of trace fossils have revealed themselves to us, and I have every expectation that more will be found in the next two weeks. And this, boys and girls, is why I am a field scientist and paleontologist: to experience that joy of discovery that happens in the same places where the plants and animals of their ecosystems breathed and died 75 million years ago. Field work never fails to take me back in time, to when those animals behaved in ways that left their traces for us recent arrivals on this earth to appreciate with wonder.

This is my office for the next two weeks. Not bad, huh? I could get used to this, and plan to. (Photograph taken by my camera, which was set on an automatic timer.)

(For another introduction to this field work, here’s a blog post done cooperatively with my wife Ruth, who will be joining me here at the field site in just a few days.)

Tracking Tybee Island

Posted on June 30, 2014 by TMartin

Plan to be surprised. That’s my adopted attitude whenever I’m on a developed barrier island of the southeastern U.S. coast and looking for animal traces. When primed by such open-mindedness, I’ve found that looking beyond the expected – or listening for the whispers below the shouts – can sometimes yield traces of the unexpected.

A beach-to-dune-to-fencing-to-vacation-home transect on the south end of Tybee Island, Georgia. Not much for an ichnologist or any other naturalists to learn here, right? Try, try again. (Photograph by Anthony Martin.)

Last month, just a couple of days after a successful book-related event in Savannah, Georgia (described here), my proximity to the Georgia coast meant I had to get to the nearest barrier island, which was Tybee Island. However, a challenge presented by Tybee – and the one that causes most coastal naturalists to run away from it screaming – is its degree of development.

Actual footage of a cephalopod ichnologist reacting to the news that a field trip would go to a developed barrier island. P.S. Octopus tentacle prints would make for the coolest trace fossils ever. (Source here.)

Accordingly, Tybee Island also has large numbers of people, especially on a pretty weekend during the summer. Granted, the development is not so awful that Tybee no longer has beaches and marshes. But it does have enough paved streets, houses, vacation rentals, hotels, restaurants, shops, and other urban amenities that you can easily forget you’re on a barrier island.

An oddly shaped beach on the south end of Tybee Island, molded by a combination of a seawall, big blocks of igneous rock, fences, boat wakes, and oh yeah, waves, tides, and sand. Better than a shopping mall, for sure, but it takes some getting used to for naturalists who do their field work in less peopled places. (Photograph by Anthony Martin.)

Tybee’s beaches are also “armored” with rip-rap and seawalls, which were placed there in a vain attempt to keep sand from moving. (On a barrier island, this is like telling blood it can only circulate to one part of a body.) Moreover, its modest coastal dunes rely on fencing as a half-buttocked substitute for healthy, well-rooted vegetation holding the sand in place. The sand in those dunes also looks displaced to anyone acquainted with Georgia-coast dunes on undeveloped islands. This is because that sand really is from somewhere else, having been trucked in from somewhere else and dumped there for beach “renourishment.” There’s also not much of a maritime forest there, or freshwater ponds. So yeah, I guess those cranky naturalists have a point.

Another view of the south end, showing the sharp vertical drop between the beach and dunes because of the seawall between them. The rocks (foreground) probably didn’t help much, either. (Photograph by Anthony Martin.)

Ergo, a pessimistic expectation I had before arriving on Tybee is that it would have a barrage of human and dog tracks, a tedium only punctuated by human-generated trash, all of which would assault and otherwise insult my ichnological senses. Fair or not, this prejudice kept me away from Tybee when I was doing field research for Life Traces of the Georgia Coast, and I stayed off St. Simons Island for a while, too, before succumbing in 2009. (I’m glad my wife Ruth convinced me to visit St. Simons – and I’ve been back several times since – but the interesting ichnology of St. Simons is the topic of another post.)

But then again, there was the matter of honoring the all-American right to convenience. Tybee Island is only about a 20-minute drive from Savannah, and you could drive there thanks to a causeway that connects the island to the mainland. Plus I had been to Tybee several times with students on field trips, and knew that lots could be learned there if I put a gag on my cynicism. I even had a research question, wondering how many ghost crab burrows would be in the dunes there compared to other Georgia barrier islands.

So thanks to the Hartzell Power Couple™, who were hosting Ruth and me in Savannah for the aforementioned book event, we were in their car on a Saturday morning and soon found ourselves walking on the south end of the Tybee, checking out its dunes and beaches, and (of course) their traces.

Fortunately, my question about the ghost crab burrows was answered within a few minutes of arriving at the south-end beach. Sure enough, we spotted a few of these distinctive holes, sand piles outside of the holes, and ghost-crab tracks scribbled on the dunes. Their traces weren’t nearly as common as on other undeveloped islands, but still, there they were.

Ghost crab burrows really do exist on developed barrier islands: whoa! Although it’s still a good question about their relative abundance on a developed Georgia barrier island versus one that’s barely altered, like nearby Wassaw Island. Sounds like some science needs to be done on that. (Photograph by Anthony Martin.)

But here’s the coolest thing we saw, ichnologically speaking. The dunes also had little holes that were about the width of a pencil, with crescent-shaped openings and fresh sand aprons just outside these holes.

What have we here? A little hole in the dunes with some freshly dumped sand outside of it. The game’s afoot! (Photograph by Anthony Martin.)

A close-up look of another hole very similar to the previous one. I wonder what could have made this? Oh well, I guess we’ll never know. Unless you read more, that is. (Photograph by Anthony Martin.)

I was pretty sure what made these, but as a scientist, I needed more evidence. So after pointing out the holes to my companions (Ruth and the Hartzell Power Couple™), we stood in one place and waited a few minutes. That’s when one of the tracemakers arrived.

Behold, the mystery tracemaker revealed! Check out that incredible digging! She’s got legs, and knows how to use them! (Photograph by Anthony Martin.)

Hypothesis confirmed! I predicted these were wasp burrows, and after watching several flying around the dunes, landing, walking up to and entering the holes, digging energetically, and emerging (repeat cycle), this was all of the evidence I needed. The wasps were some species of Stictia (sometimes nicknamed “horse-guard wasps” because they prey on horse flies). Moreover, these were female wasps making brooding chambers, little nurseries where they were going to lovingly lay eggs on paralyzed prey as a form of parasitoid behavior. (P.S. I absolutely adore parasitoid wasps, and you should, too.)

Up-close view of the same wasp burrow shown above. Oh, she’s in there, all right. See those sand grains getting kicked out of the burrow? (Photograph by Anthony Martin, taken on Tybee Island.)

In our too-brief time there on Tybee, we also saw feral cat tracks in the dunes. This is a common trace on developed islands, especially where people live year-round. Sometimes these are from pets that residents let roam free, but more likely these are made by the descendants of escaped cats that then breed in the wild.

Feral cat cats on dune sands, probably a day old at the time the photo was taken, eroded by wind and rain (see the raindrop impressions?). How to tell cat tracks from little foo-foo dog tracks? Cats make round compression shapes, a three-lobed heel pad, and rarely show claws. (Photograph by Anthony Martin, taken on Tybee Island.)

Another possible trace from a feral cat was an opened bird egg we found on the dunes. Admittedly, I’m quite the ichnological novice when it comes to egg traces, and can’t tell for sure whether this one was from predation (by a cat or other egg predator) or from hatching. But some clues are there, such as nearly half of the eggshell fragments adhering to the inside of the shell, instead of being absent.

Is it a birth trace or a death trace? Empty bird eggshells always present such questions. (Photograph by Anthony Martin, taken on Tybee Island.)

Down on the beach, one of the most common (and hence easiest) traces to find on Tybee or any other developed island with clam or snail shells washing up on their shores are predatory drillholes made by moon snails, the lions of the tidal flat. Sometimes these shells also have smaller holes, which are made by clionid sponges. Shells can thus bear the histories of life-and-death and life-after-death.

These shells are looking a little bored. (Yes, that’s a pun, albeit not a very good one.) The clam shell on the left was bored by a clionid sponge, and the three shells on the right were made by moon snails, probably Neverita duplicata. (Photograph by Anthony Martin, taken on Tybee Island.)

Once we were off the beach and walking on a paved road to where the car was parked, the ichnology didn’t stop then, either. In front of the car was a tree with some beautifully expressed rows of yellow-bellied sapsucker drillholes in its trunk.

What can I say, I’m a sucker for sapsucker holes. (Photograph by Anthony Martin, taken on Tybee Island.)

So can you still do ichnology on Tybee Island, or other developed barrier islands, for that matter? Looks like…

So next time you go on that beach vacation to Tybee, Jekyll, St. Simons, or other developed barrier islands, may you likewise be pleasantly surprised on your ichnological endeavors. Good luck!

Ichnology in the Beer Garden of Good and Evil

Posted on June 23, 2014 by TMartin

For reasons unfathomable – but ultimately forgivable – I had never talked about my 2013 book Life Traces of the Georgia Coast in the lovely and historic city of Savannah, Georgia. There were many reasons for me to go there, preach the gospel of traces, and otherwise enlighten its citizens about the Holy Trinity of Ichnology (Substrate, Anatomy, and Behavior – amen, brothers and sisters!). For one, Savannah is not only the largest city in Georgia along its coast, but also has inspired many writers as a place. Even better, a good number of people there are keenly interested in the nearby ecosystems and non-human life inhabiting the Georgia coast. So it made sense to visit and plug my book, which, despite having been out for more than a year, was regrettably unknown to most people in Savannah. Yeah, I know, some other book got in the way during the past year, but still.

Who could resist the winning combination of science and beer? Here’s the sign we put out at Moon River Brewing Company in Savannah, Georgia as a siren call to those who might have wandered by. Lettering by Savannah artist Betsy Cain and trace fossil icons (theropod track on the left and a U-shaped burrow on the right) by me. (This photograph and all but the last were taken by Ruth Schowalter.)

With the help of well-connected friends there (who I hereby dub The Hartzell Power Couple™), we arranged for a book-related event in Savannah at a downtown microbrewery – Moon River Brewing Company – and placed it in their new outdoor beer garden. (Sorry bookstores, museums, and universities, you just can’t compete with that.) A local independent bookstore, The Book Lady Bookstore, helped out by selling my more recent (and much more reasonably priced) dinosaurian-themed book. But I also brought copies of Life Traces of the Georgia Coast for anyone interested in getting it for a bargain from the author. Major bonus: all conventional author traces in these books (otherwise known as “autographs”) are always accompanied by my original drawing of a trace.

Chatting with the locals, including (left to right), environmental activist Ann Hartzell, my two most recent books, me, and an anonymous geologist (right) who stopped by to talk about geology and paleontology. How can you tell he’s a geologist? Note the voluminous but mostly empty stein just behind him.

Advance publicity for the event was excellent, too, exceeding the expectations of most authors who wistfully hope that more than five people hear about their book-related event. For instance, Leslie Moses, a reporter for the local newspaper (the Savannah Morning News) wrote an article about my book, which included a nice photo of me standing (appropriately enough) on the Georgia coast. A reporter for the free weekly paper (Savannah Connect), Jessica Leigh Lobos, also conducted a delightful interview with me, in which I got to connect (get it?) both Life Traces of the Georgia Coast and Dinosaurs Without Bones via their common theme of ichnology enriching our otherwise mundane lives. Yet another reporter, Mary Landers (again for the Savannah Morning News) wrote a fun announcement about the event in which she alluded to my recent blog post about Godzilla’s tracemaking abilities. So let’s just say I felt loved by the local media, and the Hartzell Power Couple™ were able to bring in lots of their environmental-artistic-cool friends to attend the event, too.

Savannah environmental artist Betsy Cain graciously offered her calligraphy skills for the sign advertising the event, to which I later added my artistic depictions of trace fossils (see the photo at top for our finished masterpiece). In the background, The Hartzell Power Couple™ set up the much-needed-and-appreciated sound system I later used to project ichnological bon mots.

My talk at the beer garden wasn’t the usual formal slide show (i.e., Death by Powerpoint) we academics are expected to give almost by reflex nowadays. Instead, it was a totally different format adapted to the given circumstances. A lack of screen and projector, along with the outdoor setting and a nearby busy (and loud) city street, ensured that this would not be like any other talk I’d given about either book. Fortunately, at the urging of my ever-so-wise wife Ruth and the amazing resourcefulness of The Hartzell Power Couple™, I was able to get a microphone and speaker to speak over the urban din. But what to say, and how to say it without the support of pictures and oh-so-mesmerizing-and-persuasive bullet points?

A good example of how science education is wherever you take it: Thursday evening at the Moon River Brewing Company beer garden in Savannah, Georgia.

Thus I decided to make this book presentation more of a lively piece of performance science, rather than a lecture. It was part informative – with “elevator speeches” about each book on why they mattered, punctuated by brief (less than two minutes) readings – and part interactive. The latter was mostly improv, in which I asked audience members to shout out the name of their favorite Georgia-coast animal, followed by my acting out that animal’s tracemaking behavior, then describing what traces they would make from such behaviors. Alligator! Ghost crab! Sandhill crane! Fiddler crab!

“Look at my claw!” There’s nothing like a good fiddler-crab dance to warm up a crowd.

Science authors, if you’re going to talk about your book in public, always make sure you have one as a prop so you can hold it up and say, “Have you heard the good news?”

Babies dig ichnology.

Based on feedback from those there and my own perceptions of audience reactions, I thought the event went great. Not only did I have a good time, we even sold a few books. But something else that happened, and it was something that advocates of public-science outreach might note. I witnessed a subtle transformation in the people who were there at the beer garden just to have dinner, chat, and drink beer (and not necessarily in that order). First they ignored the “show” going on beside them, but soon they ended up listening, getting interested, and next thing you knew, they were (gasp) learning science.

Afterwards, two science enthusiasts (mother and son) check out my books. One of those books went home with them, and may have later contributed to even more sciency goodness.

Ultimately, I hope my example introduced the Savannah community to the concept of a science tavern, which has been fantastically successful in Atlanta and is being adopted in several other U.S. cities. A key component of the Atlanta Science Tavern’s success, though, is making sure scientists are on board with being clear, lively, original, and fun with their science. As much as this paleontologist hates to admit, beer can only take you so far.

Somehow a copy of Donna Tartt’s The Goldfinch ended up in the same box holding copies of my book Dinosaurs Without Bones. Seizing a teaching moment, I explain with my hand how this literary juxtaposition was completely appropriate, because goldfinches are dinosaurs, and their feet (and hence their tracks) show this ancestor-descendant relationship.

So for all of you science authors out there who love public outreach about the science and the beer you love, please flatter me through imitation and try this on for yourself, then let the rest of the world know how it went. Think of it as an experiment that requires much repeating. If it doesn’t work, don’t do it again. If it mostly works, then revise it based on suggestions by your peers (the audience, that is). It it works fantastically, do that again. Repeat until science is shared and beer mugs run dry. Good luck!

Many thanks to: Ann and Andrew Hartzell (left) for hosting Ruth and me (right) during our fun time in Savannah; Ruth for all of her expert photographic documentation and loving support; Joni Saxon-Giusti and Chris of The Book Lady Bookstore; Brandi Cockram of the Moon River Brewing Company; Savannah reporters Jessica Leigh Lobos, Leslie Moss, and Mary Landers; Betsy Cain; Robin Gunn; Sarah Ross; Craig Barrow; and all of those folks in the beer garden who didn’t expect to get some science on a Thursday night out in Savannah. Hope it happens again to you soon.

The Ichnology of Godzilla

Posted on May 23, 2014 by TMartin

Upon learning that Godzilla would be making its way back onto movie screens this summer, my first thought was not about whether it would it would serve as a powerful allegory exploring the consequences of nuclear power. Nor did I wonder if it would be a metaphor of nature cleansing the world’s ecological ills through the deliberate destruction of humanity. Surprisingly, I didn’t even ponder whether the director of this version (Gareth Edwards) would have our hero incinerate Matthew Broderick with a radioactively fueled exhalation as cinematic penance for the 1998 version of Godzilla.

Instead, my first thought was, “Wow, I’ll bet Godzilla will leave some awesome tracks!” My second thought was, “Wow, I’ll bet Godzilla will leave some awesome bite and claw marks!” My third thought was, “Wow, I’ll bet Godzilla will leave some awesome feces!” All of these musings could be summarized as, “Wow, I’ll bet Godzilla will leave awesome traces, no matter what!”

Godzilla: King of the Tracemakers. (Image and most others here from the movie were taken as screen-capture stills from the official trailer here and modified slightly for your science-learning pleasure.)

So as an ichnologist who is deeply concerned that movie monsters make plenty of tracks and other traces whilst rampaging, I am happy to report that yes, this Godzilla and its kaiju compatriots did indeed make some grand traces. Could they have made traces worthy of ichnological appraisal, ones that could be readily compared to trace fossils made by Godzilla’s ancestors? Yes, but these traces could have been better, and let me explain why.

[Minor spoilers follow, not least of which include the not-surprising news that The King of the Monsters prevails in the end, inevitably setting up a sequel in which I sincerely hope Godzilla and his rivals make more easily defined traces.]

Early on in the movie – set in 1999 – a surface mine in the Philippines collapses. Drs. Ishiro Serizawa (Ken Watanabe) and Vivienne Graham (Sally Hawkins) are summoned to the site and quickly whisked underground. There they find a spacious chamber containing body fossils – bones or similar endoskeletal parts – of an enormous creature. Instantly, I began yawning. I mean, body fossils: how boring.

A bit of paleontology near the start of Godzilla, in which some of the humans (who are mostly irrelevant) find skeletal remains underneath a surface mine. Little do they know they’re about to undergo enlightenment and become ichnologists.

But then I sat upright in my seat when I realized – along with the screen scientists – that this chamber wasn’t a mere tomb, but also a place of rebirth: it was a hatching chamber. Views from inside and outside of the chamber then revealed the ichnological money shots of the movie, showing first an emergence burrow, then an emergence crater* connecting to a trail, the latter cutting a swath through the forest and leading directly to the sea. This was trace evidence of a yet-unseen monster that was very much alive, and one that was brooded and born in a subterranean terrestrial environment, but then moved to an oceanic environment.

Dr. Serizawa sees light at the end of the tunnel, and it’s not from an oncoming train, but something far worse. Still, it’s a cool example of an emergence burrow, so there was some consolation.

Kaiju emergence burrow connected with a kaiju trail, leading to the sea. So this is definite trace evidence of a heterometabolous animal, with different stages of its metamorphism (terrestrial egg –> marine larva) taking place in different environments. Unlike, you know, Gregor Samsa, who just stayed terrestrial.

A map of seismic signatures shown later in the film denoted where the animal burrowed in the seafloor from the Philippines to Japan, which would have made for one hell of a burrow. Why was this massive animal using so much energy to burrow to Japan? For some radiogenic sustenance, of course, which was conveniently located in a nuclear-power plant there. The “M.U.T.O.,” (= “Massive “Unidentified Terrestrial Object”) then caused a collapse of that power plant, thus qualifying as a feeding trace, rather than plate-tectonic-induced earthquake damage, which is what became the official story. That’s right, geophysicists: you’d better start studying some ichnology if you want to correctly interpret what’s causing those rapid releases of tensional energy that excite you so much. (I’m talking about earthquakes, you perverts.)

Anyway, people die, 15 years pass, families grow apart, blah blah blah, when the action finally returns to something that really matters, like monsters making traces. It turns out the Japanese government had been hiding the truth from the public, which, much like Tom Cruise, can’t handle it. The kaiju not only fed on a nuclear reactor in Japan, but also pupated there. As an example of how gigantic, deadly animal traces can be the real “job creators” in a modern economy, a huge industrial complex with hundreds of Japanese and American employees was monitoring the cocoon, with Drs. Serizawa and Graham as scientific advisors.

Who knew these actors – Ken Watanabe and Vivienne Graham – were actually playing ichnologists in the new Godzilla movie? Just about nobody, including them. (Photograph originally credited to Kimberley French, AP, and much reproduced elsewhere.)

The adult M.U.T.O. that emerged from the cocoon fractured the outer casing, broke through the steel cables that were supposed to restrain it, and immediately started making some tracks. So those are some mighty fine traces, and it was a pleasure watching them get made.

What about its tracks, though? Despite the kaiju’s blend of tetrapod and insect qualities, it had eight appendages and used six while walking – four forelimbs, two of which were wings, and two hindlimbs – making it hexapedal. Moreover, it used an alternating gait, similar to those used by pterosaurs or bats (if they had an extra pair of limbs, that is). Hook-like ends on the forelimbs would have made elongate impressions, and literally impressed a few panicked employees as the monster escaped. On the other hand, er, appendage, the hindlimbs looked as if they were terminated by flat-bottomed hooves. So if one were inclined to track this M.U.T.O, its trackway patterns might have looked like the following:

Hypothesized male (winged) M.U.T.O. trackway pattern, moving from left to right, showing normal walking that ends with take-off. Wing impressions are on the outside and angled, whereas the forelimb tracks are just inside the trackway, and the hindlimb tracks are closest to the midline. Take-off pattern is at the end, with wing impressions forward so that, like a giant pterosaur, it could “pole vault” for its launch. What’s the scale? Really big. (Illustration by Anthony Martin.)

Toward the end of this scene, we find out this kaiju was also flight capable, as it takes off from its former pupation site. Accordingly, it would have made both take-off and landing track patterns, which have been interpreted in the fossil record for pterosaurs and birds, but from nothing nearly as big. (Oh, how I dream of finding Queztalcoatlus take-off or landing tracks some day…) This switch from terrestrial to aerial locomotion is noted in one of the few funny lines uttered in the movie, when U.S. Navy Admiral William Stenz (David Strathairn) first refers to the kaiju as a M.U.T.O., but then updates the status of its behavioral ecology by saying, “It is, however, no longer terrestrial, as it is airborne.”

Later in the movie, another tracemaking M.U.T.O. emerges from its pupation site –a nuclear-waste repository in Yucca Mountain, Nevada – and proceeds to leave a trail of devastation through Las Vegas, which included killing lots of people who probably bet that wouldn’t happen to them.

Leaving Las Vegas, female M.U.T.O. style, with a well-defined trail in its wake, and perhaps knowing it should have taken a left turn at Albuquerque. Hey, U.S. military: I think it went that way!

This kaiju was female and much larger than the male, thus providing a great example of sexual dimorphism in tracemakers of the same species, as seen in horseshoe crabs (limulids) and many other animals. This meant its trackway width would have been correspondingly wider than that of the male, and its tracks larger. It also lacked wings, with the homologous pair of limbs used instead for walking. Consequently, the kaiju’s locomotion (and hence its tracemaking) was restricted to terrestrial environments, with no take-off or landing tracks. So if any more of these monsters came out of the ground, such ichnological knowledge might come in handy for the U.S. military (or recreational hunters) to know which gender of a M.U.T.O. pair they might be tracking.

Bioerosion trace (boring) made by M.U.T.O. as it encountered a human commerce-generating hive in San Francisco. Unlike most bioeroson structures, this is a locomotion trace, rather than a dwelling or feeding trace.

Other tracemaking done by the M.U.T.O.s included mastication marks on a Russian nuclear submarine and some ICBMs, a little bit of bioerosion when they walked through buildings, and – following some kaiju courtship and sexy time – a nest structure made in San Francisco (no doubt inspiring a new song titled I Left My M.U.T.O. Nest in San Francisco). The nest structure was in the style of those made by many shorebirds, looking like a scratched-out hollow, with the trivial differences of being hundreds of meters across, about a hundred meters deep, and composed of urban debris. The fertilized eggs were in the middle of the structure and attached to an ICBM, like a sort of atomic yolk sac. Overall, it was a tremendous nest structure, dwarfing those likely made by the largest known sea turtle, Archelon from the Late Cretaceous Period, which would have been a mere 10-15 m (33-67 ft) across.

OK, enough about the M.U.T.O. tracemakers. What about our beloved behemoth, The King of the Monsters, The Stomper with the Chompers, Godzilla? The movie – much like this review – held him back until about an hour into the story, only giving us teasing glimpses from photographs over the past 60 years. Sure, this was done deliberately to build suspense, but the title of the movie wasn’t M.U.T.O.s Making Traces (although it could have been, and I would’ve been fine with that). So I was more than ready for Godzilla to leave some tracks, bite marks, and other megatraces that would have made the world’s largest dinosaurs’ traces look puny by comparison.

Tracks on the left are of a sauropod dinosaur trackway in an Early Cretaceous (about 100-million-years-old) limestone bedrock in the Paluxy River of Texas. Tracks on the right are in rocks of same age and area, with left-side front- and rear-foot tracks; the stick is a meter long. For comparision, one Godzilla track would exceed the width of the river. (Both photographs by Anthony Martin, taken in Dinosaur Valley State Park, Texas; to read more about those tracks, go here.)

Did Godzilla leave any clearly defined tracks in the film? Oddly enough, no: imagine my disappointment. Such a glaring ichnological absence led me to believe that Godzilla tracks must not have been a high priority in director Gareth Edwards’s mind while making the film. This is also a rare instance of where the 1998 version of Godzilla surpassed the 2014 one, in that a few nicely outlined tracks were shown in the former.

Godzilla trackway made for 1998 movie, still visible on Oahu, Hawaii. Photo from http://the-american-godzilla.wikia.com/, credited to “Varg2000.”

However, had Edwards decided to add the scientific excitement that would have been induced by overhead views of Godzilla tracks, they would have looked a lot different from the 1998 ones. Although all movie versions of Godzilla have shown it as bipedal on land, the monsters’ feet have been different. For instance, the 1998 Godzilla tracks were definitely modeled after those of theropod dinosaurs, with three separated and forward-pointing toes adorned by sharp claws, albeit greatly up-scaled. According to a reporter in Hawaii who saw one of the Godzilla footprints, he estimated it was about 12 feet long (3.6 m). So using a footprint formula applied to theropod dinosaurs, where the footprint length is multiplied by 4.0, the hip height of that Godzilla would have been 48 feet (14.5 m).

For those of you who have a monster foot fetish, you’re in for a treat. This video shows nothing but close-ups of Godzilla‘s feet landing on and crushing stuff in the 1998 movie.

In contrast, the new Godzilla not only had a pedicure, but also a major foot makeover. Instead of three separate toes, this one has four toes scrunched together into more of an elephantine or sauropod-like configuration. It still has claws, but they look much more robust than those of the previous theropod-like feet of its predecessor, and more like those of a sauropod. Accordingly, Godzilla tracks from the 1998 movie versus the 2014 one would have been way different from one another. This means that a skilled movie-consulting ichnologist could have easily distinguished the two films just by glancing at tracks shown in each. (Mr. Edwards, please do keep me in mind if you need an ichnological advisor for Godzilla 2.)

(Right) Right-foot anatomy of 2014 version of Godzilla, nearly as wide as long and with four digits ending in stout claws. (Left) Hypothesized trackway pattern for present version of Godzilla, using its normal city-destroying gait. Notice its wide stance, like that of a certain retired U.S. senator. A tail drag-mark is not included in this diagram, but probably would have registered once Godzilla stood more upright, such as to kick some M.U.T.U. abdomen. (Both illustrations by Anthony Martin, but foot anatomy is composite drawn freehand from unattributed online photos, such as this one.)

Something important to also note about these trackways is the lack of any tail drag marks. This is because both the 1998 and 2014 Godzillas kept their tails off the ground, which aligns with modern interpretations of how theropod dinosaurs walked. The original Godzilla – and many sequels after it – showed it dragging a weighty tail behind it. This behavior would have left a deep groove in the middle of the trackway, perhaps with a slight undulating pattern caused by side-by-side movement. This would have looked sort of like an alligator or crocodile trackway, but with only right-left tracks, because Godzilla was walking more like some guy wearing a rubber suit.

Still taken from original 1954 Godzilla (Gojira), showing a bipedal trackway going from a terrestrial to marine environment. But also check out the prominent groove in the middle of the trackway, caused by a tail dragging behind it, and four forward-pointing toes on each foot.

What other traces would I have really liked to see Godzilla make, ones that would have made me stand up in the theater and scream “Ichnology for the win”? My #1 and # 2 choices, in that order, would have been urination marks and feces. In my latest book, Dinosaurs Without Bones (2014, Pegasus Books), I’ve written about trace fossils linked with dinosaur urination and defecation; dinosaur coprolites in particular are great trace fossils for showing what dinosaurs had for lunch millions of years ago. Alas, Godzilla performed neither excretory behavior in the movie, but that didn’t stop at least one scientist from speculating on how much urine this Godzilla would have produced.

So for my upcoming post, I’ll explore the possibility of a Godzilla urination trace. What mark would Godzilla have left if he got really pissed? Tune in next week, and in the meantime, enjoy seeing the movie. but now with an added ichnological perspective.

Other “Science and Godzilla” Posts

The Impossible Anatomy of Godzilla (Danielle Venton)

Godzilla Gets Bigger Every Year (Rhett Allain)

The Impossible Gait of Godzilla (Ria Misra)

The Ever Increasing Size of Godzilla: Implications for Sexual Selection and Urine Production (Craig McClain)

Reviewing the Science of Godzilla for Plausibility and Imagination (Mika McKinnon)

The Science of Godzilla (Scott Sutherland)

The Science of Godzilla, 2010 (Darren Naish)

*Just as a cool astronomical-geological-ichnological-cultural aside, indigenous Australians first interpreted a meteorite impact structure in Wolfe Creek Crater National Park of Western Australia as an emergence crater made a great, burrowing snake. Some stories that involve traces seem to repeat themselves in our human history.

Life Traces of a Master: A Tribute to Dolf Seilacher (Part III)

Posted on May 16, 2014 by TMartin

(This is the third of a three-part series honoring the memory of paleontologist-ichnologist-teacher-artist Dolf Seilacher, who died on April 26, 2014. Part I of the series is here and Part II is here.)

After Dolf’s only trip to Georgia in 1997, I saw and talked with him a few more times, conversations that sometimes involved rocks and trace fossils in the field, but sometimes not. These times and places were in 2003 (Switzerland), 2004 (Argentina), 2006 (the far-off land of Philadelphia), and 2008 (Krakow, Poland).

Plenty of other ichnologists from around the world attended these meetings, too. Many of them I now consider as long-time friends, in which we get back for regular reunions to talk and argue about trace fossils, discussions that are normally accompanied by ritualistic consumption of significant volumes of libations. Almost always in such conversations, though, someone mentions the name “Dolf.” This then leads to animated discussions of his articles, remembrances of personal encounters with him (which usually involve some sort of strongly worded disagreement about a scientific idea), or telling stories about field trips, where Dolf noticed something extraordinary that everyone else had missed. In other words, even when Dolf wasn’t there, he was still present.

If invited to speak at a gathering of ichnologists, Dolf Seilacher was never shy about saying “yes.” Here he addresses participants of the 1st International Ichnological Congress (Ichnia), held in Trelew, Argentina in 2004. (Photograph by Anthony Martin.)

As opposed to his trip to Georgia in 1997, the 2003 meeting in Switzerland was more-or-less in Dolf’s backyard, a short trip from his home in Tübingen, Germany. This was the International Ichnofabric Workshop, a biannual meeting of ichnologists that’s been taking place since the 1990s in various trace-fossil-rich places throughout the world. I love these meetings because of their balance between time spent blabbing in conference rooms and time spent in the field, looking at trace fossils: typically three days inside, three days outside. Now that’s what I call “fair and balanced.”

How would you like to have your “Dolfing“? Inside or…

…outside? (Both photographs taken by Anthony Martin in July 2003, Switzerland.)

Many of the trace fossils we encountered on the field-trip portion of the workshop were originally from deep-marine environments, made 30-50 million years ago by invertebrate animals that lived in on ocean-floor sediments hundreds or perhaps thousands of meters below the surface. Later, when the Alps were uplifted by colliding plates, this oceanic-continental mashing transported the trace fossils, resulting in seemingly anomalous signs of life from a deep seafloor, but in alpine settings. Dolf was one of the world’s experts on deep-sea traces, and among the few ichnologists to have taken a submersible ride (DSV Alvin) to more than 3,500 m (11,500 ft) down, highlighted in the IMAX film Volcanoes of the Deep Sea (2003). So it was no surprise when our first encounters with these trace fossils in the field prompted him to share his considerable knowledge about them.

Although Volcanoes of the Deep Sea is a fine documentary film in its entirety, for now just watch the first three minutes here to see Dolf in the field, looking for deep-sea trace fossils and talking about his mistress, who he met on his honeymoon. (Spoiler alert: His “mistress” is a trace fossil, and a complicated one, named Paleodictyon.)

Dolf was clearly excited about sharing what he knew about the deep-sea trace fossils during our Ichnofabric Workshop in Switzerland. And he knew a lot. (Photograph taken by Anthony Martin in July 2003, Switzerland.)

The 2004 meeting in Argentina was a big deal for ichnologists, as this marked the first International Ichnological Congress, more briefly called Ichnia. More than a hundred ichnologists of varied interests, backgrounds, and nationalities gathered in Patagonia, Argentina, first for a glorious four-day field trip based out of Comodora Rivadavia, then for the congress itself in Trelew. Dolf joined us for the latter, and people who delivered talks in the sessions soon realized they were not going to leave the stage until Dolf asked them a question or made a comment about their work. At the time, he was 79 years old, but clearly was not ready to slow down teaching all of us.

A rare circumstance: three of the most significant ichnologists in the world leaving fresh and contemporaneous footprints in the same habitat. From left to right is Richard Bromley (Denmark), George Pemberton (Canada), and Dolf, who was accepting an award from the organizers of this Ichnia. Jorge Genise’s hands (left) for scale. (Photograph by Anthony Martin, taken in Trelew, Argentina in April 2004).

The 2006 meeting in Philadelphia was significant, as this was for a symposium in honor of Dolf’s long and successful career. Organized as a session within the Geological Society of America meeting, it attracted so many ichnologists that the symposium lasted the entire day. In our talk, Andy Rindsberg (mentioned in my last post) and I decided we would cover one of Dolf’s favorite topics, the traces made by animals when they stop, nicknamed “resting traces.” In planning our talk, we knew Dolf would appreciate some good-natured poking fun at his expense. So we decided to lampoon both his authority in our field and his penchant for smoking good cigars through the following two slides (shown here side-by-side).

Two slides shown in succession at the Seilacher symposium, held in the 2006 Geological Society of America meeting in Philadelphia, Pennsylvania. Translation on the right is “Sometimes a resting trace is just a resting trace,” and I think you can figure out the one on the left now. I don’t know the photo credit for Dr. Freud, but the one on the right was taken by Andy Rindsberg at the Seilachers’ home in Tubingen, Germany in 2006.

It was a success. Dolf was sitting in the front row while I gave my talk, and I’ll never forget his delighted smile when he saw the image of Sigmund Freud dissolve into his, with an almost perfectly mirrored pose.

The last time I saw Dolf was in Krakow, Poland, and at the second Ichnia meeting in 2008. His presence was doubly appreciated by all of us, as Jagiellonian University was also hosting – at the same time – Dolf’s pride and joy, the Fossil Art exhibit.

It’s a sign! Advertising the exhibit Fossil Art, that is. In this instance, the venue was at Jagiellonian University in Krakow, Poland, and in 2008. (Photograph by Anthony Martin.)

However, it was at this meeting where Dolf showed us a side we had almost never seen, but one that was completely appropriate for where we were. Alfred Uchman, the meeting organizer (and one of the world’s experts on deep-sea trace fossils), had asked Dolf to speak at the opening of the meeting on an ichnologically themed topic of his choosing. I don’t remember the main topic of his presentation, and the reason why for my faulty memory is because of what happened first.

Dolf began his talk with a deeply heartfelt and remorseful apology. In an awareness of both history and place, he told us how the grand room in which we were seated was where, in 1939, Jagiellonian University officials had handed over control of this esteemed institution – one of the oldest universities in the world and the intellectual home of Copernicus – to invading forces of Nazi Germany. Dolf, as a German citizen, a World-War II veteran who fought on the side of the Nazis, and who shared a first name with a certain genocidal dictator from Germany, expressed his shame and regret about what had happened in that place and then. I looked around the room and recall sensing the surprise we all felt at his expression of regret, but also its poignancy and sense of redemption. He then went on and delivered his scientific talk, but it had become one overshadowed by our realization of how horrific histories and inquisitive inquiries are shared facets of our humanity.

Then there was Fossil Art. I remember seeing the first iteration of this traveling display in Germany in 1994, then elsewhere. This exhibit consists of life-sized reproductions (epoxy resin casts) of rock slabs, most of which held gorgeously intricate and intriguing trace fossils, but some with body fossils and physical sedimentary structures, such as ripples and mudcracks. At this meeting, we were privileged enough to get a guided tour of the exhibit by Dolf himself, who gave an introduction to its purpose as a way of engaging our minds and senses with beautiful patterns in rocks, many of which were made by animals from millions of years ago.

Dolf Seialcher introducing Fossil Art to a gathering of ichnologists at Ichnia 2008 in Krakow, Poland. (Photographs by Anthony Martin.)

Many of these reproductions received fanciful titles, such as The Trilobite Circus of Penha Garcia and Witch Broomings, and are mounted like works of art, with carefully arranged lighting accentuating their features. These “slabs” also have Dolf’s written explanations in placards next to them, describing and interpreting their geological significance, but also marveling at their beauty. Is it art, or is it science? Yes. Anyway, I’ll just let these images speak for this masterful blending of natural, aesthetic beauty and scientific information.

Cambrian Beach Party II, representing trace fossils made by large slug-like animals on a beach about 500 million years ago. (Photograph by Anthony Martin, taken in Krakow, Poland in 2008.)

The Trilobite Circus of Penha Garcia, a collection of exquisitely preserved trilobite burrows from Portugal, preserved as natural casts. (Photograph by Anthony Martin, taken in Krakow, Poland in 2008.)

Trilobite Pirouettes, more natural casts of trilobite burrows, but showing looping and stopping (“resting”) behaviors. (Photograph by Anthony Martin, taken in Krakow, Poland in 2008.)

More ichnology meetings took place since then: the third Ichnia meeting in Newfoundland, Canada (2012), and the most recent International Ichnofabric Workshop in Çannakale, Turkey (2013). Dolf did not physically attend either meeting, which did not surprise anyone, as he was in his late 80s, and we were starting to hear stories about his failing health. Nevertheless, a day never passed without his name coming up in conversation. So although most of us had not seen him since 2008, his ideas, personality, and methods seemed permanently attached to us, akin to some of the fossils he had studied.

Now that Dolf is gone and we are left with his considerable life traces, what would be the best way for all of us to remember him? I suggest we do it through the flattery of imitation.

We are living in a time when science is very popular, even in the U.S., evident from TV shows like Cosmos and Your Inner Fish, as well as many clear and wonderfully written science books. A few people have even declared that we’ve entered a “golden age” of science communication. Yet basic scientific research is also under assault from anti-science political forces, ones that insist on alternative realities where opinions are given equal (or superior) weight when compared to factual evidence. Moreover, mainstream academia is currently undergoing an administratively led collapse from within, as U.S. universities move more toward a corporate model that places higher profits over discoveries, knowledge, and teaching.

Still, through Dolf Seilacher’s life and accomplishments as a scientist, teacher, and artist, he showed a way to side-step the current chaos. Through his practices, he demonstrated how nearly all of us can do science and make discoveries every day by simply using our senses, pencils, paper, and intellects. Just to be clear, this is not a call to Neo-Luddism, in which we abandon our precious iPads and laser scanners while chanting incantations honoring our pre-technological ancestors. Instead, it is one that asks us to rediscover these basic skills – observing, drawing, and imagination – for conducting science, discovering, learning, and passing on new-found insights to future generations. In short: be more like Dolf.

Danke und Auf Wiedersehen, Dolf, for the gifts you gave us, traces that will continue long after you have become part of the earth and life you so loved studying.

References

Seilacher, A. 2007. Trace Fossil Analysis. Springer, Berlin: 226 p.

Seilacher, A. 1997, 2008. Fossil Art. (Two versions of this book were published, one through the Royal Tyrell Museum of Palaeontology in 1997, which was 64 page long; the other was through CBM Publishing in Laasby, Denmark, and was 101 pages long. The latter book can be purchased here.)

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The Ever Increasing Size of Godzilla: Implications for Sexual Selection and Urine Production (Craig McClain)

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