Jurassic World’s Trailer Traces

One of the most momentous events of the post-Jurassic world happened last week with the online release of the official trailer for the upcoming movie Jurassic World. Yet within mere hours of its release, a great wailing and gnashing of teeth arose from dinosaur nerdom, as professional paleontologists and fervent paleo-fangirls and paleo-fanboys alike jumped onto it like a ravenous pack of naked, oversized, bunny-handed velociraptors (or deinonychosaurs: whatever).

Jurassic-World-ToothOwen (Chris Pratt): “Looks like a large theropod dinosaur tooth.” Claire (Bryce Dallas Howard): “That’s not going to tell us anything. Why don’t you look at its toothmarks right next to you?” That’s just one small sample of how I would rewrite the Jurassic World script from an ichnological perspective, neatly repairing its reputation as a scientifically accurate film while retaining blockbuster entertainment value. (This still image and all others in this post were stolen shamelessly from the Jurassic World trailer.)

You see, this trailer – which lasted for all of 161 seconds – contained 257 scientific inaccuracies, which comes out to about 1.6 errors/second. OK, maybe I just made up that number, much like how some people make up movie plots, scripts, and characters. Nonetheless, the trailer had scenes depicting featherless theropods, elephant-skinned sauropods, and a non-dinosaur mosasaur that was far too big, had a frill on its back, and a non-forked tongue. It’s almost as if these were genetically recreated monsters, and not the original animals from the Mesozoic Era. Oh, the waste! Oh, the humanity!

Anyway, let’s talk about something that really matters, like traces. As far as I know – and like many others on the Internet, I plan to stay ignorant of anything that might add to my present knowledge – not one of those paleo-critics, or even the critics of the paleo-critics, mentioned the totally awesome and epic traces shown in this trailer. This egregious oversight once again reinforces my oft-asserted point that ichnology is the Rodney Dangerfield of paleontology.

So that’s why I’m here, to enlighten the masses and convert y’all to the Church of Ichnology, where there’s no tithing, dancing and drinking are required, and you can leave the church any time you feel like it. I’ve also covered this beat before, having reviewed the ichnology of Jurassic Park, which was an entire movie, not just a trailer. Even better, I know a little bit about dinosaur ichnology, having just written a book on that topic (Dinosaurs Without Bones, if you must know).

What traces in are in the trailer, you ask? The first ones shown are at 1:39, revealed with a shot panning up a concrete wall. There on the wall are sets of three more-or-less parallel scratches, some straight and some curved. The scratches vary in lengths, and a few cross-cut each another. In one set the scratches are not parallel, but form more of a fan pattern.

Jurassic-World-Wall-Scratches-1I knew it was worth sitting through the first 1:30 of this trailer – check out those scratch patterns!

Of course, the preceding picture means little to an ichnologist unless it has a scale. I mean, were these from Compsognathus, or something a lot bigger? Fortunately, at 1:47, Chris Pratt provides a means of comparison by placing his hand on one of the scratches, and it looks like his three middle fingers approximate the width of that mark.

So let’s assume his hand proportions are about 1.4 times the size of mine, a supposition that can only be tested by the two of us having a beer together. (Hey, it could happen.) Accordingly, we will name this conversion factor the Chris Pratt Manual Ratio™ (CPMR). My three middle fingers bunched together are 5 cm (2 in) wide, which, after multiplying it by the CPMR, would make this scraping about 7 cm (2.75 in) wide. The spaces between the scratches seem to be about twice as wide, or 15 cm (5.5 in). This would make the entire set – three scratches and the two spaces between them – 51 cm (20 in) wide. These are twice as wide as some of the biggest known theropod dinosaur tracks. Or, as I like to say whenever I encounter grizzly-bear scratches on trees: “That ain’t no squirrel.”

Jurassic-World-Wall-Scratches-3Put your hands on the traces, and feel their healing power and redemption! Repeat the Holy Trinity of the Church of Ichnology with me: Substrate, Anatomy, and Behavior! Amen, brothers and sisters!

Based on my detailed study of these traces for at least two minutes (perhaps less), as well as Chris Pratt’s concerned gaze following these scracthes up the wall, I am interpreting them as traces made by three claws on the feet and hands of its tracemaker, with the wider sets coming from feet and the narrower ones from hands. Overall, these traces would be anatomically appropriate for theropod dinosaurs, many of which had three digits on its feet and hands with sharp claws. Moreover, this would have been a theropod dinosaur with impressively endowed forelimbs, sufficient for helping to pull it up a wall (sorry, T. rex).

Big-Three-Toed-Foot-With-Claws-Jurassic-WorldWhy, that looks like an enormous three-toed foot with robust claws on their ends, and in motion as it chases the presumed protagonist of Jurassic World. Who could’ve predicted that, based on mere ichnologically based foreshadowing?

The behavior of the tracemaker can also be interpreted by looking for where the “feet” traces cross-cut the “hand” traces on the wall. This pattern would have been made by an upward movement of the tracemaker as it climbed the vertical surface. In short, these are escape traces, and they were made by a very large theropod-like dinosaur. To his credit, Chris Pratt’s character (“Owen”) totally got this.

Jurassic-World-BonesChris Pratt isn’t just a Guardian of the Galaxy and a dinosaur handler: he’s also an ichnologist. (By the way: what’s with the bones behind him that don’t have any toothmarks on them? And why aren’t my paleontologist friends outraged about that unforgivable error?)

Any other traces in the trailer? Oh yeah, and it’s a good one. At 1:51, Bryce Dallas Howard (“Claire”) picks up a hardhat that clearly was not hard enough to prevent serious brain leakage in its former wearer. The trace is a sharply defined gouge that nearly cleaves the hardhat into two half-hats. This trace is either from a claw or tooth, but because it’s by itself, I’m going to surmise it was from a single strategically employed claw. How wide was the claw? We can figure that out by using the Bryce Dallas Howard Pollex Ratio™ (BDHPR) of 1.0, which assumes her thumb is the same width as mine, 2.2 cm (0.9 in). (Yes, I have petite thumbs. You have a problem with that?)

Based on this unit of measurement, the split seems to be at least three times her thumb width, or minimally 6.6 cm (2.6 in) wide. Which, incidentally, is about the same width as the scratches left on the concrete wall, which I also interpreted as coming from claws, and which neatly connects the escaped “dinosaur” to this heinous act committed on what was no doubt an out-sourced employee who did not have health insurance. Coincidence? No, it’s ichnology!

Jurassic-World-Hardhat-PunctureHey, this hardhat is defective! Let’s check the warranty. Yup, sure enough: “Does not cover hybrid dinosaur attacks.” But at least we got a cool trace out of it.

So despite all of the problems my paleontological colleagues justifiably noted for the dinosauroid animals depicted in the trailer, I am encouraged that Jurassic World will have enough ichnology in it to persuade me to leave a buttock-shaped impression on my theater seat in June 2015. But there had better be tracks, nests and feces in it, otherwise you’ll see my footprints going straight out of the theater.

(For other “ichnology at the movies” posts by Yours Truly, also check out The Ichnology of Pacific Rim and The Ichnology of Godzilla.)

Vestiges of Home

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.

Backyard-Home-IndianaHere’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.

Charles-Knight-PaintingPhoto 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-Pollination-Bee-HomeRoses 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.)

Leave-Insect-Feeding-TracesInsect 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.

Dad-Then-LaterMy 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.

Dad-Back-From-War-with-MomHappier 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.

Victoria-Coast-CretaceousIn 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.

Flagpole-ClimbingThat’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.

Climbing-Pine-TreeMy 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.

Insects-Then-NowOne 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.

Mom-Honeymoon-OutcropMy 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.

Mom-Then-LaterThe 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 88th birthday.

Decatur-Book-Festival-Dedication-MomMe 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.

Mom-Me-Then-LaterFirst 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

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.

Grizzly-Bear-Scat-Montana-Ants-1Had 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 19th 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.

Bear-Treeing-PersonLewis 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.

Grizzly-Bear-Tracks-MontanaLeft 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?

Grizzly-Bear-Scat-Montana-Ants-2See 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.)

Montana-Ant-Nest-2Ant-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.)

Montana-Mound-Nest-Ants-CloseupClose-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.

Grizzly-Bear-Ant-Predation-PitsEver 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

(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.

Tony-Martin-Searching-Fossils-Two-MedicineThis 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.

Geologic-Anticline-Two-MedicineOriginally 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.)

Geologic-Fault-Two-MedicineIt’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.

Fossil-Plant-Root-Traces-Two-MedicineThese 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.)

Horizontal-Burrows-Two-MedicineThese 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.)

Vertical-Burrows-Two-MedicineThese 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.)

Limulid-Tracks-Two-MedicineThese 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.)

Fossil-Cocoons-Two-MedicineOne 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.)

Fossil-Cocoon-in-situ-Two-MedicineThis 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.)

Dinosaur-Bone-Two-MedicineA 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.)

Fragmented-Dinosaur-Bone-Two-MedicineThis 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.)

Adult-Hadrosaur-Track-Two-MedicineHere’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.)

Hadrosaur-Track-in-situ-Two-MedicineWhat 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.)

Hadrosaur-Coprolite-Two-MedicineCheck 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-MedicineYou’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.)

Eggshell-Fragments-Two-MedicineThe 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.)

Find-Dinosaur-Eggshell-Two-MedicineCan 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.

Seven-Samurai-PaleontologyThe 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

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?

Wasp-Digging-Burrow-Tybee copyWhoa, 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.)

Cretaceous-Wasp-Burrow-Pupal-ChamberWhy, 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.

Egg-Mountain-Digging-2A 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.

Troodon-Nest-StructureHere’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.

Troodon-Nest-with-Eggs-MartinMy 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.

Troodon-Egg-ClutchBottom 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-Cocoons-MontanaFossil 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.

Stictia-BurrowMy 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.

Cretaceous-Wasp-Burrow-Pupal-Chamber-2Close-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.

Martin-Fossil-Cocoons-MontanaA 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

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.

Tony-in-the-FieldSee 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.

Egg-Mountain-Digging-2 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.

Maiasaura-Nesting-Site 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.)

Two-Medicine-Formation-OutcropI 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.)

Hadrosaur-Track-Two-MedicineA 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.

Fossil-Cocoons-MontanaInsect 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.

Fun-With-Field-Work-MontanaThis 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.)

‘Dinosaurs Without Bones’ Leaves Its First Marks

Life Traces of the Georgia Coast was published just a little more than a year ago, which as far as authoring goes, seems like yesterday. (Well, unless you’re James Patterson.) Yet as of now, it’s now my second-most recent book.

Dinosaurs-Without-Bones-BookHey, look: it’s a book. How about that? (Photograph by the person whose name is on the cover.)

So I’m proud to announce today is the official launch date of my latest book, Dinosaurs Without Bones: Dinosaur Lives Revealed by Their Trace Fossils (Pegasus Books). What’s it about? Yeah, I know, the main title implies the existence of invertebrate or incorporeal dinosaurs. But the subtitle makes clear that it’s all about the fossil record of dinosaurs apart from just their bones: tracks, nests, burrows, toothmarks, gastroliths, feces, and much more. It’s not only the first comprehensive book written about dinosaur trace fossils, it’s my first overt attempt at popular-science writing in book form. How was it for me? Great fun, and I hope readers feel the same about it.

In a sure sign that authoring might be addictive, I started writing Dinosaurs Without Bones before the publication of Life Traces of the Georgia Coast. The latter book took nearly four years to complete, from proposal to holding that rather hefty volume in my hands. In contrast, I wrote and illustrated Dinosaurs Without Bones in just a little over a year, starting in the summer of 2012 and finishing in December 2013.

This marsupial-like gestation for Dinosaurs Without Bones can be attributed to several fortunate factors coming together, such as my having written two editions of a college textbook on dinosaurs (Introduction to the Study of Dinosaurs, 2001, 2006), writing about dinosaur trace fossils in a 2010-2011 blog (The Great Cretaceous Walk, now defunct), having the fresh experience of writing Life Traces of the Georgia Coast, and the freedom to write with a popular audience in mind. Write? Right.

Although today seems like a firm starting point for its availability to readers, it’s actually been in an incremental “soft launch” during the past few weeks. For example, my publisher made it available for sale by Charis Books in Atlanta, Georgia when I gave a talk to the Atlanta Science Tavern at their annual Darwin Day Dinner on February 9. Other people have told me via Facebook, Twitter, and in person that their pre-ordered copies had already arrived last week. Then just last week, I had a bit of a coming-out party for the book at the annual Science Online 2014 meeting, where it was among the featured new science books, which were all given away in a raffle to lucky meeting participants.

Dinosaurs-Without-Bones-Book-Paleontologist-BarbieMy colleague Paleontologist Barbie, happily posing next to Dinosaurs Without Bones during its first big public viewing at the Science Online 2014 meeting last week in Raleigh, North Carolina. (Photograph by the author again. Unfortunately, Paleontologist Barbie’s arms, much like those of a tyrannosaur, are too short for her to do a selfie.)

I know what you’re thinking: Where can I buy this book? (Your second most likely question is: Does it mention cats? The answer is yes, several times.) If you do get the book and read it, please let me know what you think of it, either via Twitter (@Ichnologist), its Facebook site, e-mail, or most retro of all, in person. Here’s a list of suggested means for acquisition:

  • Your local independent bookstore. Tell the owner I sent you.
  • Order it directly from Pegasus Books here.
  • Order it from Powell’s Books here.
  • Order it from Barnes and Noble here.
  • Order it from that online business that’s trying really hard to make all of those other just-mentioned businesses go extinct. (And I ain’t naming it, because that gives it more power.)

Thanks, hope you like it, and happy tracks, trails, nests, and burrows to you.

 Pertinent Bibliography

Martin, Anthony J. 2014. Dinosaurs Without Bones: Dinosaur Lives Revealed by Their Trace Fossils. Pegasus Books, New York: 460 p.

A Good Bird Track is Easy to Find: Flannery O’Connor, Her Birds, and Their Traces

Authors of books are sometimes lucky enough to get people interested enough in both them and their books. Even better, these authors are sometimes invited to talk about their books to a receptive audience. Yet I’ll bet few authors get the opportunity to talk about their books with fellow book lovers while also standing on the front porch of a great American author. Even less probable is that the author of a natural history book – one related to paleontology, no less – would somehow have to relate his or her work to a deceased author best known for her Southern Gothic fiction.

It’s a sign! Upon my arrival at Andalusia Farm, the former home of Flannery O’Connor, this sign greeted me at the door, reminding me why I was there. It was fun to think that during Flannery O’Connor’s life, this is how she might have announced a lecture at her place, using a sheet of paper with words, posted on her door. (For the sake of imagination, just ignore that the notice was created and printed by person using a couple of 21st century devices.) Photograph by Anthony Martin.

This past Sunday, I was just so fortunate and challenged, having been invited to speak about my new book, Life Traces of the Georgia Coast, at Andalusia Farm, the former home of famed American writer Flannery O’Connor. Andalusia is located just north of Milledgeville, Georgia, and despite many previous trips to Milledgeville, this was my first visit to Flannery O’Connor’s former haunts. The house and grounds are in a formerly rural setting, its clay-laden driveway just off a busy highway and directly across from a chain hotel. Yet her house is still surrounded by more than 500 acres of forest, streams, and a pond; the pond is visible from the front porch of the house. These natural areas are what attracted me to coming, and provided an avenue for connecting themes of my book with this place.

A view of the main house at Andalusia Farm, where Flannery O’Connor spent more than a third of her life. Her bedroom, where much of her writing also happened, is just to the left after passing through the front porch. Photograph by Anthony Martin.

A sign telling about the recent history of Andalusia. Sadly, it does not include any mention of the Alleghanian Orogeny that contributed to the Piedmont Province there, nor does it inform visitors about the maximum extent of the Cretaceous and Eocene seaways just to the south, nor does it acknowledge the former presence and effects of the Pleistocene megafauna that used to live there. But I suppose all of that would have required a much bigger sign. Photograph by Anthony Martin.

O’Connor is much revered in the Southern U.S. and elsewhere, a loyalty that stems partly from the fact that she was indeed a terrific writer of Southern-inspired literature – consisting of short stories, novels, and essays – and partly from a wistful longing of “If only”: namely, if only she had lived longer. Born in Savannah, Georgia in 1925, she traveled to what was then called State University of Iowa (now the University of Iowa), where she earned an MFA, and soon afterwards began her illustrious writing career. In 1951, she was diagnosed with the same disease (lupus) that killed her father while he was still relatively young. She lived with this debilitating condition for the next 14 years, the last 12 of which were at Andalusia. She was only 39 years old when she died in 1964.

So how did I become a character in a Flannery O’Connor story? I blame it all on a paleobotanist friend of mine at nearby Georgia College and State University, Dr. Melanie DeVore, who suggested to me several years ago that I come to speak at Andalusia about my upcoming book. “Why?” was my first response. After all, as a long-time resident of Georgia, I was embarrassed to admit that I had read very little of O’Connor’s works until just recently. I also could not figure out how the plant and animal traces of the Georgia barrier islands could be related to a Southern author whose home was just above the fall line, between the Piedmont and Coastal Plain provinces of Georgia. Even the Cretaceous seaway from 70 million years past had not washed onto the landscape of O’Connor’s home. Thus I felt hard-pressed to come up with a way for my book to be relevant to her literary contributions and a sense of place.

Still, Melanie continued to encourage me to think about it. Admirably enough, she was trying to find ways in which natural scientists might contribute their perspectives to the considerable scholarship behind O’Connor’s works and the popular appeal of her former home. So I delved into O’Connor’s biographies, and searched for an ichnological connection between what she did and my interests. This is when I found the key, the theme that united: birds.

It turns out that O’Connor was a great lover of birds, and the thought that perhaps she had too many birds never occurred to her during her last years at Andalusia. Peafowl were her favorites for many reasons, some of which she explained ever-so-eloquently in several essays, including one of her most well-known works of non-fiction, The King of Birds. Domesticated birds also abounded on her property, including chickens, ducks, geese, and swans, all part of her avian menagerie. At one time, she evidently owned more than a hundred peafowl, a daunting number when one considers the vociferous qualities of these birds.

A peacock in a spacious enclosure just outside of Flannery O’Connor’s home, graciously displaying his tail feathers for us. See those feet? We’ll take a closer look at those soon. Photograph by Anthony Martin.

One of two peahens in the same enclosure, not nearly as resplendent and gaudy as her male companion, but still a very attractive bird. Of course, I was looking at her feet too, thinking about the tracks she would make, and how these might differ from those of the peacock. Photograph by Anthony Martin.

O’Connor’s earliest few minutes of fame were also bird-related, and established her life-long association with oddities of the South. When she was only five years old, she somehow taught a chicken to walk backwards. This feat attracted a film-reel company (Pathé News), which sent a crew from New York to Georgia to record this atypical avian mode of locomotion. The film reel, shown in theaters in 1932, also parodied O’Connor’s childhood accomplishment by reversing the film for other walking domestic animals, making these animals also appear to also walk backwards.


It’s one thing to read about Flannery O’Connor and her backwards-walking chicken, but it is another to actually see an original film about it. In the reel, she is mistakenly identified as “Mary O’Connor,” but no matter, as it was a start to her enduring fame for inventing quirky actions, plots, and characters reflecting the off-kilter cultures of her Southern environs. Incidentally, just how would you tell the difference between tracks made by a chicken moving forward or backwards? Maybe that should be the topic of a future post…

O’Connor’s link to paleontology was an oblique one, in that (as far as I know) she did not express any interest in it as a subject. Nonetheless, she was a great admirer of paleontologist, Jesuit priest, and philosopher Tielhard de Chardin, and the title of one of her anthologies, Everything That Rises Must Converge (1965), came directly from one of his writings. Also, in an “if only” moment of my own during my talk on O’Connor’s porch, I wondered what sort of fiction or essays would have come out of O’Connor had she lived long enough to learn that birds are actually living dinosaurs, and hence she had unwittingly surrounded herself with the progeny of those Mesozoic monsters.

Oh yes, my talk on O’Connor’s porch. How did that go? Fantastically. Because of the gorgeous weather that day, Craig Amason, my host and executive director of the Flannery O’Connor-Andalusia Foundation, thought that we might hold the discussion on the screened front porch, rather than inside in one of the more spacious rooms of the house. I was all for this idea, partially for its atmosphere (I mean, how cool would it be to talk about Flannery O’Connor with some of her fans on her front porch?), but also because we planned to have everyone walk on the trails with us later, looking for tracks and other traces of the animals that live there. Melanie and I had already scouted the trails in the morning and found a few surprises, so we knew that part of the program would be great fun, too: might as well get them halfway outside already by being on the porch. Fortunately, all of the dozen or so people who showed up also approved of this plan, which was helped in no small part by a heaping helping of cookies and soft drinks, enticing them to stay right there on the porch for a spell, and perhaps even relax in a rocking chair.

Dr. Bruce Gentry of Georgia College and State University, having just bought a copy of my book, opens it to take a look inside. Dr. Gentry is a scholar of Flannery O’Connor works and heads the Flannery O’Connor Studies Program at Georgia College and State University, in nearby Milledgeville. Meanwhile, I’m in the background, gesturing grandly to the delicious cookies on the table next to me while also introducing everyone to the topic of bird tracks and sign. Photograph by Melanie DeVore.

A sample of our front-porch chat about Flannery O’Connor and her birds, in which I point out the close resemblance between a rooster’s feet and those of a peacock. Although the peacock tracks would have been noticeable larger than those of her chickens, their overall forms would have been nearly the same, with three long thin toe-prints pointing forward, one shorter one pointing backward, and all four ending with clawmarks. Video footage by Craig Amason, exceutive director of the Andalusia-Flannery O’Connor Foundation.

A close-up of a rooster’s feet. Think about the tracks this would produce, whether walking forward or backwards. Rooster was known as “Tom” (R.I.P.), formerly owned by Carol Ruckdeschel on Cumberland Island, Georgia. Photograph by Anthony Martin.

Now compare the rooster’s feet to those of this peacock at Andalusia Farm, and you’ll see for yourself how close they are to one another in their overall form, despite the rear digits being hidden in this photo. I could not help but think that O’Connor, while seeking the pleasure of the company provided by her birds, also saw thousands of similar-looking peacock and chicken tracks every day she went outside. Photograph by Anthony Martin.

The talk itself was mercifully brief on such a fine day, with tracks and other sign awaiting us. So I simply expressed my gratitude for being there with all of us gathered in this special place, talked about Flannery O’Connor’s love of birds, and jumped into a speculative discussion of what tracks she might have seen every day on the farm. My presentation was decidedly low-tech, in which my only visual aids were paper print-outs of bird tracks and feet and a couple of my illustrations from the book, which were of bird-track categories and nests. These were supplemented by my acting out birds motions (walking, mostly), demonstrating how these behaviors would result in certain trackway patterns. One of these, much to the amusement of audience, was of a peacock doing its little circular and sideways-stepping dance, which was followed by my asking them to imagine the trackway patterns that would have resulted from such courting.

I also did a short reading from my book that introduces the topic of bird tracks, which fairly drips with admiration for the complexity of behaviors captured by such traces, thus hopefully echoing O’Connor enthusiasm for birds. Many questions were asked and observations of bird behavior offered, a give-and-take that I thoroughly enjoyed in the role of a “guide on the side” rather than a “sage on the stage” (or a “torch on the porch”). Once done, we had a short break for people to buy my book (thanks, y’all!), then walked onto a nearby trail to look at what the wild animals had left us the previous few days.

This outing was enjoyable, a bit of a treasure hunt and an eye-opening experience for many of how much animal activity is embodied by their traces in a typical Piedmont forest and its water bodies. Some of the traces I had seen earlier in the day while out scouting with Melanie, but we saw more, such as previously missed raccoon tracks and woodpecker sign. The highlights included the discovery of fresh (less than 12-hour-old) beaver tracks on one of the stream banks. This delighted several people, who told me that beavers had supposedly moved out of the area years ago, so they were pleased to know that at least one was back in the neighborhood. I was also excited to find coyote scat on the trail, which inspired earthy, amusing comparisons between the territorial markings of mammals in the wild versus those of corporate board members and academics (which, not surprisingly, are not so different in practice).

Coyotes just can’t help themselves: where we see a human footpath, they see an advertising opportunity. Here I excitedly point out an example of coyote scat, which had been strategically placed in the middle of the trail so that all other mammals would know this was her/his territory. You know, just like you might see happen in a professional meeting. Photograph by Melanie DeVore.

Fresh beaver tracks on a stream bank! This was a happy find, as it demonstrated that at least one beaver was in the area, following a nearly five-year absence of their species. These tracks show the beaver turned to its right and walked down the bank and into the water; look for the large rear-foot track to the left, and the tail dragmark in the middle. Swiss Army knife is about 6 cm (2.4 in) long. Photograph by Anthony Martin.

Once this short, ichnologically-infused hike was over, people thanked me and bid goodbye, but a few of stayed behind to take a gander at the peafowl, which were in a large enclosure just behind O’Connor’s house. One male and two females are kept there, and our timing was impeccable, as the male was in full display mode, feathers fully erect and dazzling as he strut about the grounds, while the peahens stayed in the background, mildly impressed or nonchalant. (“Oh yes, he does that all of the time,” I imagined them thinking, mildly bored.) Nevertheless, as far as we non-avian bipeds were concerned, he was indeed the king of birds.

But that’s when my ichnologist hat popped onto my head, askance from its sudden appearance. Craig had told me earlier about the peafowls making a dust bath in the confines of their enclosure, and sure enough, there it was. It matched the width, depth, and shape of dust baths I had written about in Life Traces of the Georgia Coast, only for wild turkeys. Birds make dust baths for alleviating skin parasites, in which they hunker down in them, using their wings to distribute enough fine-grained sediment on them to smother the offending lice or other arthropods. Could such traces preserve in the geologic record, whether they were made by feathered dinosaurs, birds, or mammals? How could we recognize or distinguish these from other shallow depressions? And most importantly, did Flannery O’Connor ever see such dips in the landscape, and if so, did she know their meaning?

A dust bath made by peafowls, about 50 cm (20 in) wide on its longest dimension, and looking a little less dusty after several days of intense rain the preceding week. Still, this was a cool trace to see, and conjured some imaginative thoughts about these as trace fossils. (Peafowl feces extra in the pit: no charge.) Photograph by Anthony Martin.

Another ichnologically inclined thought occurred to me while there at the enclosure, and is worthy of further experimentation. How might we tell the male (peacock) tracks from those of the female (peahen)? Take a look at the following photo, and you tell me. Anything there that might leave a distinctive mark identifying the gender of its tracemaker?

Here comes the groom! Any aspect of this tracemaker’s anatomy that might leave traces telling you he was a boy bird? Photograph by Anthony Martin.

So from this day trip to Andalusia Farm, I was awed, inspired, and ever slightly more enlightened by it all, and hoped that a small amount of the same feelings had been experienced by others who participated in this special day. Still, I was also humbled, realizing how little I still know about Flannery O’Connor, why she connected so well with birds, bird traces and behavior, or how these traces might manifest themselves to us and grace us with wisdom as recognizable trace fossils made in a distant past. Hence from my time there and into my future, I will endeavor to keep in mind the words spoken by Dr. Block, a character of O’Connor’s in The Enduring Chill from the anthology, Everything That Rises Must Converge:

“Most things are beyond me,” Block said. “I ain’t found anything yet that I thoroughly understood.”

Acknowledgements: Many thanks to: my good and long-time friend Melanie DeVore for encouraging me to visit Andalusia to share my science and sense of wonder; Craig Amason for being such a gracious host; Bruce Gentry for his continuing contributions to teaching his students about the complex and varied dimensions of Flannery O’Connor, a great American writer; the people who showed up and made for lively company; and of course the birds and their traces, which will outlive all of us, no matter the lengths of our lives.

Further Reading

Elbroch, M. and Marks, E. 2001. Bird Tracks and Sign of North America. Stackpole Books: 456 p.

Martin, A.J. 2013. Life Traces of the Georgia Coast: Revealing the Unseen Lives of Plants and Animals. Indiana University Press: 692 p.

O’Connor, F. 1955. A Good Man is Hard to Find, and Other Stories. Harcourt, Brace and Company: 265 p.

O’Connor, F. 1965. Everything That Rises Must Converge. Farrar, Straus and Giroux: 320 p.

Simpson, M. 2005. Flannery O’Connor: A Biography. Greenwood Books: 152 p.

Deep in the Dinosaur Tracks of Texas

Given the continuing public mania over dinosaurs, and recent important discoveries of yet more exquisite specimens of feathered theropod dinosaurs discovered in countries far away from the U.S. (here and here), it is sometimes easy to forget what has long been known about these animals, and right here in my own “backyard” (globally speaking).

Need to see some of the best dinosaur tracks in the world, and you live in the southeastern U.S.? Guess what: you can seen them in Glen Rose, Texas. Not China, Mongolia, Canada, Utah, or some other far-off land inhabited by strange people with unusual customs, but Texas. Saddle up! (Photograph by Michael Blair, taken in Dinosaur Valley State Park, Texas.)

So on July 22, just to jog my memory a bit, I flew from Atlanta, Georgia to the Dallas-Ft. Worth (Texas) airport, and only a few hours later was gazing upon dinosaur tracks accompanied by the burrows of invertebrate animals, both trace fossils having been made more than 100 million years ago. It was a fitting welcome to Glen Rose, Texas, a place famous for its dinosaur trace fossils since the 1930s, and where dinosaurs were an integral part of its culture long before it was cool, hip, and contemporary elsewhere.

In Glen Rose, Texas, the dinosaur tracks are so abundant, you can choose whether to see these just outside of your hotel room, or go to the hotel jacuzzi and pool. Naturally, I chose both. (Photograph by Anthony Martin, taken in Glen Rose, Texas.)

So just how did I end up in Glen Rose, Texas, looking at Cretaceous dinosaur tracks and invertebrate burrows? I was lucky enough to be there as an invited participant in an expedition sponsored by the National Geographic Society. I say “lucky” because luck was certainly a part of it, a fortuitous connection made through my writing a book about the modern traces of the Georgia coast. James (Jim) Farlow, a paleontologist at Indiana-Purdue University Fort Wayne (IPFW) and an associate editor with Indiana University Press, reviewed the first draft of my book, but he was also in charge of this dinosaur-track expedition to Glen Rose. Evidently he was impressed enough about what I knew about invertebrate burrows (or at least what I wrote about them) that he considered me as a possible member for his team of scientists, field assistants, and teachers on this expedition.

Dr. Jim Farlow, the world expert on the Glen Rose dinosaur tracks, having a reflective moment at Dinosaur Valley State Park near Glen Rose, Texas. What’s with the broom? He and other people in the expedition used these to sweep river sediment out of dinosaur tracks submerged in the river. In 100° F (38° C) temperatures. On the other hand, I just described invertebrate trace fossils, which was more of a job, not work. (Photograph by Anthony Martin, taken in Dinosaur Valley State Park, Texas.)

Thus when Jim asked me last fall if I would be interested in joining them to describe and interpret the Cretaceous invertebrate burrows that occur with the dinosaur tracks there, I jumped at the opportunity. The Glen Rose dinosaur tracksites, most of which crop out in the Paluxy River bed in Dinosaur Valley State Park, are world famous for their quantity and quality, and they connect with an important part of the history of dinosaur studies. Going there, experiencing these tracks for myself, and better understanding their paleoecological and geological context would be of great benefit to me, my students, and of course, you, gentle readers.

Just to back up a bit, and clarify for anyone who doesn’t know why these tracks are so darned important, here’s a brief background. In November 1938, Roland T. Bird, an employee of the American Museum of Natural History and a field assistant to flamboyant paleontologist Barnum Brown (the guy who named Tyrannosaurus rex), saw large, isolated limestone slabs with theropod dinosaur tracks in a Native American trading post in Gallup, New Mexico. Upon inquiring about the origin of these tracks, Bird was told they came from Glen Rose, Texas. So he set out in his Buick for Glen Rose to see for himself whether these tracks were real or not, and whether there were any more to see in the rocks around Glen Rose. The theropod track set in the town bandstand – pictured below – was one of the first sites that greeted him, and Glen Rose locals told him about the tracks in the Paluxy River.

Glen Rose, Texas, the only place in the world where the town bandstand has an Early Cretaceous theropod dinosaur track on display. Wish I could also tell you about all of those little holes in the rock with that track, but I can’t right now. Nonetheless, rumor has it they are burrows made by small, marine invertebrates that lived at the same time as the dinosaurs. (Photograph by Anthony Martin, taken in Glen Rose, Texas.)

Bird had hit the jackpot, the motherlode, the bonanza, the surfeit, the, well, you get the point. Not only did the Paluxy River outcrops contain hundreds of theropod dinosaur tracks – many as continuous trackways – but also the first known evidence of sauropod dinosaur tracks.

A couple of beautifully preserved theropod tracks under shallow water in the Paluxy River. Note that the track at the bottom also has a partial metatarsal (“heel”) impression, and look closely for the digit I (“thumb”) imprint on the right. Scale is about 20 cm (8 in) long. (Photograph by Anthony Martin, taken in Dinosaur Valley State Park, Texas.)

Funny how those “potholes” in the limestone bedrock of the Paluxy River have oblong outlines and form regular alternating patterns, isn’t it? Well, them ain’t no potholes, y’all. They’re sauropod tracks, and were among the hundreds recognized as the first know =n such tracks from the geologic record. (Photograph by Anthony Martin, taken in Dinosaur Valley State Park, Texas.)

The discovery of sauropod tracks was as huge as the tracks. Up until then, sauropods were assumed to have been so large that they could not support their weights on land and spent most of their time in water bodies. These tracks said otherwise, that these sauropods were walking along mudflats along with the theropods. In short, the trace fossil evidence contradicted the assumed story about how these massive animals moved. After all, trace fossils are direct records of animal behavior, and if interpreted correctly, can tell paleontologists more about what an animal was doing on a given day than any amount of shells, bones, and yes, even feathers.

Sauropod tracks from the main tracksite in Dinosaur Valley State Park, Texas. The sauropod was moving away in this view, and the trackway pattern is a typical diagonal-walking one, right-left-right. In parts of this trackway, both the manus (front foot) and pes) rear foot registered, something Bird noticed in 1938, his observation accompanied by more than a little bit of excitement. (Photograph by Anthony Martin, taken in Dinosaur Valley State Park, Texas.)

The details preserved in these sauropod tracks are also astounding. Most sauropod tracks I have seen elsewhere, in Jurassic and Cretaceous rocks of the American West, Europe, and Western Australia, are only evident as large, rounded depressions that you would only know are tracks because they form diagonal-walking patterns. In contrast, the Glen Rose tracks include all five toe and claw impressions on the rear feet (pes) and full outlines of the front feet (manus). The original calcium-carbonate mud in the shoreline environments where the sauropods walked, similar to mudflats I’ve seen in the modern-day Bahamas, is what made this exquisite preservation possible. The mud had to be firm enough to preserve these specific details of the sauropods’ feet, but not so soft that the mud would collapse into the tracks after the sauropods extracted their feet.

Beautifully preserved tracks, manus (top) and pes (bottom). Note the five toe impressions in the pes, which along with its size confirms that these were made by a large sauropod. Meter stick for scale. (Photograph by Anthony Martin, taken in Dinosaur Valley State Park, Texas.)

One sauropod trackway, preserved with a theropod trackway paralleling and intersecting it, was actually quarried out of the river and taken to the American Museum. Once there, its pieces stay disassembled for years, before Bird helped with putting the puzzle pieces back together so that it could be used as part of a display there.

Archival video footage of Roland Bird and his field crew working on the dinosaur tracks in the Paluxy River near Glen Rose, Texas. More about this tracksite and its role in the history of dinosaur paleontology is ably conveyed by Brian Switek here.

Photos at the visitor’s center at Dinosaur Valley State Park, showing the sequence of clearing (left) and extraction (right) of the limestone bed containing the theropod and sauropod dinosaur tracks. (Photographs taken of the photographs, then enhanced, cropped, and placed side-by-side by Anthony Martin.)

A lasting trace today of Roland Bird and his field helpers from the 1940s, in which they took out a sauropod and theropod trackway from this place and transported it to New York City. (Photograph by Anthony Martin, taken in Dinosaur Valley State Park, Texas.)

Other than some of the best-preserved Early Cretaceous dinosaur tracks in the world, one other claim to fame for the Glen Rose area, and not such a proud one, is its attraction to evolution deniers, a few charlatans who used the tracks to promote what might be mildly termed as cockamamie ideas. You see, Glen Rose is also the site of the infamous “man tracks.” These tracks are preservational variants of theropod tracks that – through a combination of the theropods sinking into mud more than 100 million years ago and present-day erosion of the tracks in the Paluxy River – prompted some people to claim these were the tracks of biblical giants who were also contemporaries of the dinosaurs. (Perhaps this is as good of a time as any to start humming the theme music for The Flintstones.)

Rare documentary footage of humans and dinosaurs interacting with one another during the Early Cretaceous Period, or the Late Jurassic Period. Whatever. Note the inclusion of other seemingly anachronistic mammals, too, such as the saber-toothed felid Smilodon. Perhaps this footage could be included in the curriculum of some U.S. public schools, providing a formidable counter to the views of 75 Nobel laureate scientists. Then we’ll let the kids decide which is right.

I will not waste any further electrons or other forms of energy by continuing to flog this already thoroughly discredited notion, but instead will direct anyone interested to a thorough accounting of this debacle to some actual scholarship here, summarizing original research by Glen Kuban and others in the 1980s through now that have laid to rest such spurious notions. Speaking of Mr. Kuban, I was delighted to meet him for the first time during while in Glen Rose (we had corresponded a few times years ago). I was even more gratified to spend a few hours in the field with him, discussing the genuinely spectacular trace fossils there in Dinosaur Valley State Park with these directly in front of us. Again, I’m a lucky guy.

The expedition was scheduled in Glen Rose for three weeks during late July through early August, but with so many commitments for this summer, I could only carve out a week for myself there, from July 22-29. Fortunately, this was enough time for me to accomplish what was needed to do, while also having fun getting to know the rest of the expedition crew – teachers, artists, videographers, laborers – and enjoying wonderful discussions (and debates) with colleagues in the field. The people of Glen Rose were also exceedingly welcoming and accommodating to us: we felt like rock stars (get it – “rock”?), and were feted by local folks three nights in a row during the week I was there. Many thanks to these Glen Rose for the the exceptional hospitality they extended to our merry band of paleontologists, geologists, river sweepers, or what have you.

You can’t see it, but I’m standing in a sauropod dinosaur track, which is a little deeper than the rest of the river bed. You also can’t see the invertebrate burrows that are in the limestone bedrock, which is fine, because I can’t show them to you yet anyway. But be patient: you’ll learn about them some day. (Photograph by Martha Goings, taken in Dinosaur Valley State Park, Texas.)

I can’t yet say much more about what I did during that week, as all participants signed an agreement that National Geographic has exclusive rights to research-related information, photos, and video unless approved by them. But if you’re a little curious about the daily happenings of the expedition (which just ended last week), Ray Gildner maintained a blog that succinctly touched on all of the highlights, Glen Rose Dinosaur Track Expedition 2012.

Still, I can say, with great satisfaction, that I did successfully describe and interpret invertebrate trace fossils that were in the same rocks as the dinosaur tracks. Hopefully my colleagues and I will have figured out how these burrows related to environments inhabited by the dinosaurs that walked through what we now call Texas.

All in all, my lone week in the Lone Star State was a marvelously edifying and educational experience, one I’ll be happy to share with many future generations of students and all those interested in learning about the not-so-distant geologic past of the southeastern U.S.

Group photo from the Glen Rose Dinosaur Track Expedition 2012. Names of all participants can be found here, but in the meantime, just sit back and admire those Dinosaur World t-shirts everyone is wearing. (Photograph by James Whitcraft or Ray Gildner: they can fight over who actually took it. Although, the automatic timer on his camera took the photo, so maybe it should get credit instead.)

Further Reading

Bird, R.T. 1985. Bones for Barnum Brown: Adventures of a Dinosaur Hunter. Texas Christian University Ft. Worth, Texas: 225 p.

Farlow, J.O. 1993. The Dinosaurs of Dinosaur Valley State Park. Texas Parks and Wildlife Department, Austin, Texas: 30 p.

Jasinski, L.E. 2008. Dinosaur Highway: A History of Dinosaur Valley State Park. Texas Christian University, Ft. Worth, Texas: 212 p.

Kuban, G.J. 1989. Elongate Dinosaur Tracks. In Gillette, David D., and Martin G. Lockley (editors), Dinosaur Tracks and Traces, Cambridge University Press, Cambridge, U.K.: 57-72.

Pemberton, S.G., Gingras, M.K., and MacEachern, J.A. 2007. Edward Hitchcock and Roland Bird: Titans of Vertebrate Ichnology in North America. In Miller, William, III (editor), Trace Fossils: Concepts, Problems, Prospects. Elsevier, Amsterdam: 32-51.