Of Sacred Mules and Sauropod Tracks

Legends and storytelling are an intrinsic part of being human. Given this statement, you might then also think of myths and other stories you’ve heard throughout your life. Which were the most memorable, and why? With such remembrances, your next step may be to do something else that is very much a part of being human, which is to wonder whether that myth or story holds some lesson applicable to real life. Whether a story is an accurate account of reality is beside the point, as its imparted teachings are sometimes more important than factual accuracy.

Avelino-Sauropod-TracksModern scientists say these depressions in a tilted rock surface near Sesimbra, Portugal were made by sauropod dinosaurs in soft sediments during the Jurassic Period more than 150 million years ago. But what if you lived in this area during the 14th century? How would you explain these depressions? While you’re thinking about that, here’s another question: If I hadn’t told you these were dinosaur tracks, would you even know they were tracks? (Photograph by Anthony Martin.)

Yet, what if reality and scientific reasoning – with the latter thriving on a spirit of disproof – rudely intrudes on a good story, disrupting its original intent? In such instances, a legend previously regarded as literal truth may lose its narrative power, as we begin to doubt not just its details, but also its intent. Can anything useful be salvaged from a myth when skepticism assaults faith? Should we completely reject parables once we know foxes do not talk about grapes, sour or otherwise?

Less than two weeks ago I visited a place where the basic facts of a long-held legend had been disproved, yet a lesson from it remains. The place is Cabo Espichel, marked by a lighthouse, church, and small chapel on a plateau high above rocky cliffs along the southwest coast of Portugal. Cabo Espichel is about a 90-minute drive from the modern metropolis of Lisbon, yet it felt far more remote, and very much connected to a medieval past.

Cabo-Espichel-OutcropsA view of Lagosteiros Bay from the top of Cabo Espichel. Also check out those gorgeous outcrops of tilted Jurassic and Cretaceous rocks! Gee, I wonder what trace fossils might be in them? (Photograph by Anthony Martin.)

The legend associated with that place concerns a 14th century visitation there by someone named Mary, who is also known by many other names: Saint Mary, Mary of Nazareth, Blessed Virgin Mary, Our Lady, The Madonna, or very simply the Mother of Jesus. Given the Catholic culture that is very much still a part of the Iberian Peninsula, her purported arrival to Portugal there was (and still is) considered a blessing and a ringing endorsement of Christianity there. Accordingly, the church complex is called the Santuário de Nossa Senhora do Cabo Espichel (“Sanctuary of Our Lady of Cape Espichel”).

Cabo-Espichel-ChurchIchnologists approaching the Santuário de Nossa Senhora do Cabo Espichel, Portugal, not on the way to confess their sins (that would have taken way too long), but to see the small chapel behind it, as well as some great coastal outcrops of Mesozoic rocks. So you might say they were there for a different type of worship. (Photograph by Anthony Martin.)

How did Mary get to Portugal from the Middle East? Given the absence of airlines then, she and the Baby Jesus traveled by boat. Once the Mother and Child reached the shore of Lagosteiros Bay below Capo Espichel, a giant mule carried them up the steep rock faces of Cabo Espichel. This scene came in a vision to two men in the area, who shared the same dream of her arrival on the same night. In a splendid example of confirmation bias, their testimony was taken quite seriously by the local populace and beyond, and has endured since.

Sauropod-Tracks-Cabo-Epsichel-3Cliff face below the present-day chapel and church at Cabo Espichel, with well-exposed and tilted bedding planes of sedimentary rock. This would have been the most likely route for a mule (giant or otherwise) to have accessed the top from Lagosteiros Bay. Photo is a still taken from an online edited drone video titled “Cabo Espichel – Dinosaur Trackway Adventure.” Related to the question asked in the previous caption: Huh, I wonder what those depressions on the rock face might be, how they relate to the legend, and the title of that video?

In commemoration of this momentous event, the church and chapel – the latter called Ermida da Memória (Chapel of Memory) – were built near the precipice. Portuguese royalty hosted annual feasts there, and many pilgrims put it on their spiritual “bucket list” as a must-visit place. Today, it is still visited by devout Catholics, who may be imagining themselves walking on the same holy ground trodden by Mary and her miraculous mule.

Ermida-da-MemoriaThe Ermida do Memória seen from afar on Capo Espichel. Imagine it in the darkness of night, when suddenly a glow comes from the bay below. Inside this light, the head of a giant mule appears, and as more of its body emerges from the cliff edge, you see Mother Mary astride it carrying the Baby Jesus, accompanied by an aerial escort of angels and the most beautiful music you’re ever heard in your life. OK, Guillermo de Toro, I just wrote the scene for your next movie: the rest is up to you. (Photograph by Anthony Martin.)

So where did this legend come from: crazed fishermen who had spent one day too many at sea, villagers imbibing enthusiastically on local vinho verde, or clergymen overcome by ecclesiastic visions? No, this story actually had evidence backing it up. All one had to do is get in a boat just offshore, and you could see for yourself enormous footprints in the rocks leading from the sea to the top of the cliff at Cabo Espichel.

Sauropod-Tracks-Cabo-Espichel-1They’re a little tough to see from this far out, but the big white arrows help. The “mule tracks” are on tilted strata just above the bay, and compose diagonal-walking patterns. (Photo taken as still from video Cabo Espichel – Dinosaur Track Adventure. I would have prefaced that information with “Spoiler Alert,” but you did read the title of this post, right?)

Sauropod-Tracks-Cabo-Espichel-2A closer view of a rock surface with the diagonal-walking pattern clearly defined, accentuated by vegetation growing in the depressions. Don’t believe me that these are from the same site? Look up “Cabo Espichel, Portugal” on Google Earth™, scan the rock surfaces just north of the chapel, and see them for yourself. (Photo again is still taken from video Cabo Espichel – Dinosaur Trackway Adventure.)

These tracks, people said, marked where the weight of the mule pressed into the rocks. Even better, some of these tracks formed patterns clearly made by four-legged animals, and individual tracks were crescent-shaped, resembling the feet of mules or other horse-like animals. As a result, one name applied to this place is Pedras de Mula, which translates as “Rocks of the Mule,” although Pegadas de Mula (“Tracks of the Mule”) is also applied.

Every good story also needs images, and this one has a particularly noteworthy visual aid. The building of a chapel on the site in the 16th century contains tile artwork commemorating this divine calling; however, the tile was probably made later, in the 18th century. Although the chapel interior is closed to the public, a open slot in its door afforded a glimpse of this depiction, aided by the zoom lens on my camera. Like any good illustration, the story is neatly encapsulated in the tiles: Mother Mary and The Baby Jesus riding on a mule, with angels in tow and stunned onlookers properly prostrating.

Pedras-de-Mula-118th century tiled artwork inside the Ermida do Memória depicting the legend of Mary’s visitation of Cabo Espichel. To all artists out there (and I’m one of you), the original creator of this work is unknown, hence image credit cannot be assigned here. (Photograph by Anthony Martin.)

Centuries later, ichnology happened. Beginning in the mid-1970s, geologists and paleontologists realized that the Mesozoic rocks of Portugal, including those at and near Cabo Espichel, held dinosaur tracks. This consciousness has been affirmed many times since, with discoveries of tracks belonging to a wide variety of Jurassic and Cretaceous dinosaurs: theropods, ornithopods, stegosaurs, and sauropods among them. Portugal is now rightly renown as one of the best places in the world to see thousands of well-preserved dinosaur tracks, all within just a few hours drive of one another.

Saruopod-Tracks-Cabo-Espichel-4A close-up of a dinosaur trackway – probably from a sauropod – on one of the rock surfaces at Cabo Espichel. As folks would say in my part of the U.S., “Those ain’t from no mule.” (Photo is still from video Cabo Espichel – Dinosaur Trackway Adventure.)

Vanda-Santos-Avelino-Sauropod-TracksDr. Vanda Faria dos Santos, Portugal’s premier dinosaur tracker, telling us about the sauropod tracks at the Avelino tracksite, just south of Cabo Espichel. Notice the abundant depressions on a tilted rock face, very similar to those at Cabo Espichel. (Photograph by Anthony Martin.)

Of these tracks, those of sauropods were the most relevant to the tale of Cabo Espichel. The majority of sauropod tracks in Portugal are very large, especially those of the rear-foot (pes), which can be about a meter long and nearly as wide. The front-foot (manus) impressions are smaller, but still approach a half-meter wide, and are crescent-shaped. You know, like those of a horse, or mule.

Sauropod-Manus-AvelinoFront-foot (manus) track made by a Late Jurassic sauropod preserved as a cresent-shaped depression at the Avelino tracksite near Sesimbra, Portugal. (Photograph by Anthony Martin.)

A detailed field study of the tracks at Cabo Epischel, done by Martin Lockley, Christian Meyer, and Vanda Santos in 1993 and published in 1994, confirmed that the “mule tracks” at Cabo Epsichel were indeed those of sauropods. The original surfaces were of soft sediment and horizontal; only later did a combination of cementation and plate tectonics harden and tilt these rocks, with coastal erosion finally rendering their current appearance. Moreover, ten sauropod trackways on one of the bedding-plane surfaces there recorded the herding movements of seven smaller sauropods (juveniles) and three larger ones (adults), all of them walking in more-or-less the same direction. These results thus made the site scientifically famous, as it was one of the first convincing examples of family herding behavior in sauropods demonstrated from their footprints.

Lockley-et-al-Sauropod-Track-Map-Cabo-EspichelTrackway map of bedding plane at Cabo Espichel in article by Lockley, Meyer, and Santos (1994). The map shows parallel smaller (juvenile) sauropod trackways (numbers 1-7), followed by two larger (adult) sauropod trackways (numbers 8-9); another adult trackway is not on this figure, but was below the other two.

Here’s the full edited aerial-drone video linked previously, Cabo Espichel – Dinosaur Trackway Adventure. The video credit only says “rlage3,” so if the person/people who produced this would just let me know who you are, I’m more than glad to give full attribution. In the meantime, thanks much for providing such a nice overview of this beautiful and ichnologically rich area!

This situation with competing stories is where ichnology excels, as it is also a science based on storytelling. Granted, the story told by ichnologists is radically different from the one first accepted by the 14th century people of Portugal, or those since who have accepted the faith-based explanation for the tracks. On a personal note, I’m ex-Catholic; hell, I was an altar boy, went to a Catholic college for my undergraduate studies, and my mother was a more devout Catholic than most pontiffs. Thus I have much empathy for how people of faith (especially Catholics) feel about such things. So if pilgrims still chose to believe the tracks of Cabo Espichel were made by a giant mule bearing Mary and Jesus, and this fills them with joy, I’m cool with that. Just don’t tell me our science is wrong.

So now I will leave you with two provocative thoughts. The first is that the tile artwork in the chapel is the first known illustration of dinosaur tracks. Is it a scientifically accurate, to-scale, 3-D rotating digital model of a dinosaur trackway? No, but it’s still an illustration, and even though its interpretation does not qualify as science, it clearly shows a large, diagonal-walking trackway pattern on an inclined cliffside at Cabo Espichel. Let that sink in for a second: an 18th century artist must have seen dinosaur tracks on a bedding plane somewhere in that area, and faithfully reproduced them in a recognizable pattern.

Pedras-de-Mula-2Close-up of tile artwork in the Ermida da Memória, connecting the trackway pattern to a mule, but which we now can be sure was inspired by the trackway of a Late Jurassic sauropod dinosaur. (Photograph by Anthony Martin.)

The second thought is that although the interpretations of this trackway might differ radically, what they share is true: These impressions in the rock were made by enormous, walking, four-legged animals. How many modern people today, their eyes no-doubt glued to their 21st-century devices, would stumble in such tracks, possibly never recognizing their connection to animal life? So rather than make fun of the people of Portuguese past, or whoever else must have observed the tracks preserved in the rocks of Cabo Espichel, we should celebrate those who recognized these depressions as traces of life. In this sense, then, the faith-filled people of the past were doing their own form of ichnology in Portugal, centuries before we modern ichnologists walked in the same place.

Afterword: Many other paleontologists and science historians have written about the discovery of the first known sauropod tracks in Portugal, so I will not repeat nor summarize their contributions here. Instead, I’ve included the following bibliography. Many thanks to Drs. Vanda Santos, Paulo Caetano, Carlos Neto de Carvahlo, and Joana Rodrigues for teaching other ichnologists and me about the long ichnological history of Cabo Espichel.

Further Reading

Atunes, M.T. 1976. Dinossáurios Eocretácios de Lagosteiros. Ciéncias da Terra (UNL), 1: 1-35.

Atunes, M.T. 1990. Dinossáurios em Sesimbra e Zambujal – Episódios de há cerca de 140 milhões de anos. Sesimbra Cultural: 12-14.

Chure, D. 2012. Sacred birds, lucky rhinos, and The Virgin and the sauropod. Land of the Dead (blog), January 7, 2012.

Lockley, M.G., Meyer, C.A., and Santos, V.F. 1994. Trackway evidence for a herd of juvenile sauropods from the Late Jurassic of Portugal. Gaia, 10: 29-40.

Lockley, M.G., Novikov, V., Santos, V.F., Nessov, L.A., and Forney, G. 1994. “Pegadas de mula”: an explanation for the occurrence of Mesozoic traces that resemble mule tracks. Ichnos, 3: 125-133.

Santos, V.F. 2008. Pegadas de dinossáurios de Portugal. Museo Nacional de História Natural da Universidade de Lisbõa, Lisbõa, 123.

 

Tracking That Is Otterly Delightful

Writing about a place, its environments, and the plants and animals of those environments is challenging enough in itself. Yet to write about that place and what lives there, but without actually being there, seems almost like a type of fraud. Sure, given a specific place, I could read everything ever published about it, watch documentaries or other videos about it, carefully study 3-D computer-rendered images of its landscapes, interview people who have spent much time there, and otherwise gather information vicariously, all without experiencing it directly. But then is my writing just about the shadows on the wall of the cave?

River-Otter-Tracks-Sapleo-Beach-1What do you see in this photo? I see fine quartz and heavy-mineral sand, originally parts of much larger rocks and forming parts of the Appalachian Mountains. I see the sand blowing down a long beach, but pausing to form ripples. I see a river otter galloping alongside the surf, slowing to a lope, then a trot, then back to a lope and a gallop. I see a brief rain shower, only about two hours after the otter has left the beach. (Photo by Anthony Martin, taken on Sapelo Island, Georgia.)

This pondering, of course, brings us to river otters. Yesterday, while on the third of a four-day writing retreat to Sapelo Island on the Georgia coast, my wife Ruth and I spent nearly an hour tracking a river otter along a long stretch of beach there. Had I read about river otters and their tracks before then? Yes. Had I watched video footage of river otters? Yes. Had I written about river otters and their tracks before then? Yes. Had I seen and identified their tracks before then? Yes. Had I seen river otters in the wild for myself? Yes, yes, and yes.

But still, this was different. When I first spotted the tracks on the south end of a long stretch of Cabretta Beach on Sapelo, I thought they would be ordinary. Granted, finding otter tracks is always a joy, especially when I’ve seen them on stream banks in the middle of Atlanta, Georgia. (Seriously, folks: river otters live in the middle of Atlanta. How cool is that?) And because Sapelo only has a few humans and is relatively undeveloped, your chances of coming across otter tracks on one of the beaches there isn’t like winning a lottery. But still.

Otter-Tracks-Lope-Pattern-SapeloRiver otter (Lutra canadenis) tracks in what I (and some other trackers) call a “1-2-1” pattern. For gait, that translates into a “lope,” which is typical for an otter. In this pattern, one of the rear feet exceeds the front foot on one side, but the other rear foot ends up beside that same front foot; one front foot is behind. If that second rear foot lags behind the front foot, then it’s a “trot,” but if it exceeds the front foot (both rear feet ahead of both front feet), then that’s a “gallop.” Also, check out the wind ripples beneath the tracks, and raindrop impressions on top of them. (Photo by Anthony Martin, taken on Sapelo Island, Georgia; photo scale in centimeters, with the long bar = 10 cm (4 inches))

What made these tracks different was that they went on, and on, and on. These otter tracks spoke for the otter, saying in no uncertain terms that walking, trotting, loping, and galloping on a beach was the only thing it had on its schedule that morning. For nearly a kilometer (0.6 miles), we followed its tracks in the sandy strip of land between the high-tide line on the right and low coastal dunes on the left.

River-Otter-Tracks-Sapelo-Beach-2

Follow the river otter tracks for as far as you can in this photo. Then, when you can’t see them any more, decide where it went. Does that sound like a challenge? It probably would be if you’ve only written about tracking otters, but it can be tough for experienced trackers, too. (Photo by Anthony Martin, taken on Sapelo Island, Georgia.)

The tracks were only a few meters away from high tide, but sometimes turned that way, vanished, then reappeared further down the beach. This told us the otter was out close to  peak tide that morning (between 6-8 a.m.) and was mixing up its exercise regime by occasionally dipping into the surf. Raindrop impressions on top of the tracks confirmed this, as the tracks looked crisp and fresh except for having been pitted by rain. For us, rain started inland and south of there on the island around 10 a.m., but reached the tracks sooner than that. We were there about three hours after then, so the otter was likely long gone, on to another adventure. Nonetheless, we made sure to look up and ahead frequently, just in case the trackmaker decided to come back to the scene of his or her handiwork.

For those of you who are intrigued by animal tracks (and why would you not be?), I suggest you try following those made by one animal, and follow it for as long as you can. That way you can learn much more about it as an individual animal, rather than just its species name. In my experience, after tracking an animal for a long time, nuances of its behavior, decisions, and even its personality emerge.

For example, this otter was mostly loping (its normal gait), but once in a while slowed to a walk or trot, or sped up, when it galloped. In short, the tracks showed enough variations to say that the otter was likely reacting to stimuli in its surroundings, and in many different ways. What gave it a reason to slow down? What impelled it to move faster? Why did it jump into the surf when it did, and why did it come out? Or, do otters just want to have fun?

River-Otter-Gallop-Pattern-SapeloGallop pattern for a river otter, in which both of its rear feet exceeded the front feet, making a group of four tracks. In this instance, the group defines a “Z” pattern when drawing a line from one track to another, but gallops sometimes also produce “C” patterns. Notice also how the groupings are separated by a space with no tracks. This is also diagnostic of a gallop pattern: the longer the space, the longer the “air time” for the animal, when it was suspended above the ground between when its feet touched the ground. (Photo by Anthony Martin, taken on Sapelo Island, Georgia.)

Now I realize that discerning a “personality” and “moods” of a non-human animal based on a series of its tracks might sound like a little too “woo-woo” and “New Agey” for my skeptical scientist friends to accept, followed by jokes about my becoming a pet psychic. As a fellow skeptical scientist, I’m totally OK with that. In fact, I will join them in making fun of people who try to tell us that, say, they know what a Sasquatch was thinking as it strolled through a forest while successfully avoiding all cameras and other means of physical detection.

But here’s what happens when you’ve tracked a lot (which I have) and made lots of mistakes while tracking, but later corrected them (ditto). Intuition kicks in, and it usually works. For instance, at one point in following this otter, I lost its tracks on a patch of hard-packed sand. (Granted, I should have gotten down on my hands and knees to look closer, but was being lazy. Hey, come on, I was on a writer’s retreat.) So I then asked myself, “Where would I (the otter) have gone?” and looked about 10 meters (30+ feet) ahead in what felt like the right place. There they were. This happened three more times, results that led me to conclude this was almost like some repeatable, testable, falsifiable science-like thing happening. So there.

River-Otter-Tracks-Sapelo-Beach-2-LabeledOK, remember when I asked you to follow the river otter tracks for as far as you could in this photo, and when you couldn’t see them any more, decide where it went? If not, go back and re-read it and look at the photo again. If you have, then look at the red arrow, backtrack to the footprints in the foreground of the photo, then go forward. Do you see how the tracks are staying in the subtly lower area, just left of the slightly higher sand piled on the plant debris? Keep picking out those low areas, and you’ll end up where the arrow is pointing. After all, if I were an otter, that’s where I would go. (Photo by Anthony Martin, taken on Sapelo Island, Georgia.)

Oh yeah, regarding my main topic sentence: What’s all this have to do with writing about a place? Well, because of that otter and its tracks, I now understand at least one otter much better than before, and feel like I can write with a little more authority about otters in general. You know, like what you just read.

Otter-Tracks-Lope-Pattern-Sapelo-2Do you understand this river otter and its place a little better now, thanks to it leaving so many tracks while it enjoyed a morning at the beach, and because I tracked it for such a long time, and then wrote about that experience in that same place? Please say “yes,” as I want to keep writing about stuff like this. P.S. Thanks to Sapelo Island, this river otter, and my wife Ruth for teaching me so much yesterday. (Photo by Anthony Martin, taken on Sapelo Island, Georgia.)

Ballast of the Past

While strolling through the beautiful and historic city of Savannah, Georgia last week, I made sure to pay attention to the thousands of time machines below my feet. Yes, I know, everyone other than geologists stubbornly refer to these objects as “rocks.” Fortunately, though, we earth scientists don’t have to limit our imaginations by using such simplistic labels. These pieces of a pre-human past all have stories to tell of their origin, and sometimes they even connect to our treatment of one another as human beings.

Ballast-Stones-Street-Wall-SavannahA street on the north edge of Savannah, Georgia leading down to the Savannah River, composed of rocks from afar. How did these rocks get there, and what stories do they tell us about themselves and us? (Photo by Anthony Martin.)

Temporal considerations aside, the rocks of Savannah don’t really belong there. This is especially true for those on the north end of town cobbling the roads and reinforcing walls next to the Savannah River. A quick glance at these stones by the geologically informed reveals how these are all foreign to this part of Georgia. Sure enough, most are from across the Atlantic Ocean, with the majority probably originating in the British Isles. Yet they also have been part of Savannah history for at least a few hundred years. What are they, how did they get there, and why are they there?

Studying-Ballast-Stones-SavannahA fine example of how rocks and a geologist (me, in this instance) get along just fine, especially when that geologist kneels in their presence. Note also the stone walls on either side of the street, which also figure into the origin story of these stones. (Photo by Ruth Schowalter.)

These are ballast stones, which filled the holds of ships during the 18th and 19th centuries as they sailed across the Atlantic Ocean from England. Were these ships exporting rocks to eager colonists who wished to collect nostalgic (and solid) reminders of their former homelands? No, ballast stones were used to keep ships weighted down, which helped to stabilize them as they moved across seas both calm and rough.

Once a ship reached Savannah – which began as a British settlement in 1733 – its crew would dump its rocky cargo and replace its relatively uneconomic value with goods grown in Georgia, such as rice, cotton, and indigo. Those economic commodities then went across the ocean, where they were used for food (rice) or textiles (cotton and indigo). Meanwhile, the ballast stones were repurposed as durable materials for the streets, walls, and houses along the Savannah River, as well as in some of the older homes in the historic district of Savannah.

The rocks on the streets and in the walls of Savannah are amazingly varied, reflecting the geological diversity of the United Kingdom and perhaps other places. (Admittedly, I haven’t done an exhaustive literature search on this topic yet: This is only a blog post, y’all.) Igneous, metamorphic, and sedimentary rocks are all represented, but perhaps the most common type I saw was basalt, which is a black, fine-grained extrusive (volcanic) igneous rock.

Ballast-Stones-Savannah-Close-UpA nice sample of the geologically diverse rocks composing a street in downtown Savannah, Georgia. Geologists glancing at this photo will no doubt spot representatives of the Holy Trinity of Lithology in this assemblage: Igneous, Metamorphic, and Sedimentary. Amen! (Scale = size 8 1/2 shoe (mens); photo by Anthony Martin.)

Ballast-Stone-Basalt-SavannahA good example of vesicular basalt, an igneous extrusive (volcanic) rock that formed from hot magma that cooled at or near the surface of the earth, and nowhere near present-day Savannah. The “vesicular” part of its name is from vesicles formed by gases in the magma, evidenced by those little holes in the rock. (Photo by Anthony Martin.)

However, I also saw intrusive (plutonic) igneous rocks, at least one of which was intruded by basalt, defined by a clean, black band cutting across the older rock. Sedimentary rocks included sandstones, some of which were placed parallel to their original bedding, fitting like bricks in some of the walls above the street.

Ballast-Stone-Basalt-Crosscutting-Intrusive-SavannahForget paper and scissors: This time, rock cuts rock. The black band is a basalt dike, which is cutting across the coarser-grained igneous rock, which may be a pegmatitic granite. Based on the simple principle of cross-cutting relations, the basalt is geologically younger than the pegmatite. (Photo by Anthony Martin.)

Ballast-Stone-Sandstone-SavannahAs a sedimentary geologist, I’m always happy to see a sedimentary rock, and this one was no exception. This sandstone had some low-angle cross-bedding, which was likely made by the sorting of sand, moved and deposited by water millions of years ago. (Photo by Anthony Martin.)

At least a few sedimentary rocks even contained fossils, such as a limestone with gorgeous length-wise and cross-sections of crinoid stems. This one was probably from the Carboniferous Period, from more than 300 million years ago. It was next to another limestone containing what looked to me like cyanobacterial or algal structures, called oncolites. Such rocks were common earlier in the Paleozoic Era, say, 450-500 million years ago.

Ballast-Stones-LimestonesLimestones from another land, but now paving a street in Savannah, Georgia. The one on the left bears what I think are algal structures called oncolites, and the one on the right has nicely preserved crinoid parts. Where are they from, and what are their geological ages? I can only answer “Great Britain” for the former, and “Paleozoic” for the latter. But I suspect the oncolititic limestone is older (Cambrian) than the crinoidal limestone (Carboniferous). At any rate, these rocks are not from the Savannah area, which is composed of sands and muds from much more recent rivers and tides.

Ballast-Crinoidal-LimestoneA close-up of that crinoidal limestone, with the length-wise section of a crinoid stem (center bottom) and cross-sections of their columnals throughout. (Photo by Anthony Martin.)

So like most normal people, you are probably wondering how these ballast stones relate to ichnology. For instance, do any of the sedimentary rocks contain trace fossils? Maybe, although I didn’t see any really convincing ones. Only one rock of the many I examined had some possible vertical burrows, exposed as holes in a sandstone cobble.

Ballast-Stone-Trace-Fossils-SavannahA sandstone with some good candidates for trace fossils, in which the holes may be cross-sections of vertical burrows. It may even have a U-shaped burrow, which looks like a little dumbbell when viewed from above (upper right). Sadly, out of all the rocks I saw on the street, I didn’t see any others like this, so I wasn’t able to test my hypothesis any further. (Photo by Anthony Martin.)

But there is another trace here, one much larger and more conceptual than what can be discovered in a single stone. Think of how these ballast stones collectively represent a human trace, tangible evidence of a grand transference of geological heritage from one continent to another.

From more of a moral perspective, however, these ballast stones are also a trace of slavery. The labor of enslaved people – abducted from their homes in western Africa and, like ballast stones, packed into cargo holds on ships and taken to a foreign land – produced the agricultural goods that went back in ships to Europe.

Although slavery was at first banned from Savannah, it was allowed soon after its founding (starting in 1750) and continued after American independence in the latter part of the 18th century. Savannah one of the most productive ports in the world for the shipping of rice and cotton during the antebellum times in the 19th century, and the heinous exploitation of human lives continuing until the advent of the American Civil War in the mid-1860s. This meant more ships arriving over the years, still bringing their ballast stones, and taking back cotton, rice, and other fruits of this cruel labor. Meanwhile, slave labor was also used to construct many of the streets, walls, and homes in Savannah composed of ballast stones.

Ballast-Stones-Street-Walls-Savannah-2A Savannah street and walls, built with rocks from another land, and by people from another land, some of whom did not have a choice in building them.

So there would be far fewer ballast stones on the streets and in the walls of Savannah if not for this brutal part of English and American history. The legacy of these stones also links to the family lineages of millions of African Americans, whether they live in Savannah, other parts of Georgia, the U.S., or abroad. As we walk on these rocks in the streets of Savannah, I am mindful of how their physical weight later became an emotional one, one still carried by many of us as we view and walk on these traces of that past.

IMG_2738African American Family Monument, a bronze sculpture designed by Dorothy Spradley, on River Street in Savannah, Georgia. The foundation – which I think is  composed of more geographically appropriate granite from Elberton, Georgia – is inscribed with the following words by Maya Angelou (1928-2014), which, like the ballast stones, remind us of a past we might like to forget, but should not.

We were stolen, sold and bought together from the African continent. We got on the slave ships together. We lay back to belly in the holds of the slave ships in each others excrement and urine together, sometimes died together, and our lifeless bodies thrown overboard together. Today, we are standing up together, with faith and even some joy.

(For a bit more information about Savannah’s ballast stones, and to see them for yourself while visiting Savannah – which I highly recommend – visit the Historical Markers Database site at Savannah’s Cobblestones.)

Rooted in Time

As a paleontologist and geologist, time is always on my mind. Nonetheless, such musings do not always connect with millions or billions of years, the so-called “deep time” that earth scientists love to use whenever shocking people who normally ponder shorter time intervals used when, say, measuring the life of a fruit fly, or the length of a cat-themed video.

Still, sometimes other paleontologists and I also try to interpret brief time spans, such as a few minutes, hours, or years, but ones that elapsed millions of years ago. This is where ichnology comes in handy as a tool, as animal traces in particular – such as tracks or burrows – can give “snapshots” of animal behavior in the context of their original ecosystems. For instance, when I look at a limestone layer that was first laid down 95 million years ago and see burrows in that limestone, I think of it as soft, carbonate-laden mud with many small crustaceans digging into it. This is an instance of where imagination becomes a time machine, helping us to create evidence-based explanations that hopefully can be later honed with further scrutiny and re-imagining. When trace fossils are preserved as an assemblage in the sediments of that past ecosystem, whether it was a soil, lake bottom, or beach, the stories can be told in chronological order.

Throw plants into the mix, though, and they can screw up those linear-time stories to the point where you doubt every earth scientist when they tell a story about an ancient land-based ecosystem. Plants can occupy sediments that are hundreds, thousands, or millions of years old, and if their roots penetrate deep enough into these sediments, they may leave both remnants of their tissues and root traces. These geologically fresh root traces then mix with older animal trace fossils, conjuring the illusion of a contemporaneous community, all living happily together. Only a careful examination of the sediment, and which traces cut across which, would help to unravel the real story.

In the preceding video – taken more than four years ago on Sapelo Island on the Georgia coast – I tell such a cautionary tale of what happens when you assume that the animal and plant traces in an old sediment were made at the same time. (Spoiler alert: You would be wrong.)

For more about this relict marsh and the fascinating lessons we can learn from it, please read Fossils In Progress (which includes a short bibliography) and Teaching on an Old Friend, Sapelo Island. Both posts also discuss how to teach students some of these concepts of interpreting fossilization, paleoecology, and geologic time when in the field.

A Birds-Eye View of a Georgia Barrier Island

All scientists use tools when investigating how the natural world works. Yet as a traditionally trained field scientist – and an ichnologist – I’ve always been wary of adopting anything more complicated than field notebooks, pencils, tape measures, hand lenses, and cameras. Granted, I did add GPS units to my equipment list starting about 12 years ago and now consider these location-finding devices as standard (and essential) field gear. Still, if you told me even a year ago that I would happily welcome the services of flying robots while tracking alligators on the Georgia barrier islands, I would have smiled and said, “Yes, and Bud Light is my favorite beer.” (Just to clarify: It is not, nor will it ever be.)

Drone+VultureNeed a better overhead view of barrier-island ecosystems with identified locations, and don’t feel like waiting for the latest satellite photos? I suggest strapping a camera and GPS unit onto a vulture and training it to take pictures while simultaneously recording waypoints. Or, have an aerial drone do the same for you, which will do a much better job, while also not annoying the vulture. (Photograph by Anthony Martin, taken on St. Catherines Island, Georgia.)

So here I am, ready to buy everyone a round of their favorite beverage (perhaps Kool-Aid) in celebration of my being wrong. Earlier this year, an Emory colleague of mine – Michael Page – convinced me that an aerial drone might be a good tool for getting overhead views of ecosystems on the Georgia barrier islands. So as soon as Emory purchased a new, state-of-the-art drone in early 2015, Michael and I plotted to take it to St. Catherines Island for its first real field test in March 2015.

Drone-1Yeah, I know, it’s not New Horizons, but this drone is still a pretty nifty piece of field equipment, and I’m glad to have added it to my ichnology utility belt. (Photograph by Anthony Martin, taken on St. Catherines Island, Georgia.)

The last time Michael and I were on St. Catherines Island together was two years ago, when we had a group of Emory students help us map gopher tortoise burrows and alligator dens there. (That was fun.) We’ve also been working with a few other colleagues at Georgia Southern University to describe the gopher tortoise burrows and alligator dens on St. Catherines Island over the past few years. So Michael and I figured we could use the drone to aid in this research, starting with the gopher-tortoise burrows.

Perhaps the most persuasive point Michael made about the drone’s potential value was its winning combination of built-in GPS and high-definition video camera. This meant we could instantly map (“georeference”) gopher-tortoise trails between their burrows, as well as the burrows themselves. The latter were easily visible from the wide, white, sandy aprons just outside burrows entrances, and sometimes even show up in satellite photos of the area. The big difference with using a drone versus satellite photos, though, would be in their ‘real-time” capture of these traces – rather than a randomly taken satellite image – while also having much better resolution.

Tortoise-Burrow-ApronSee that hole in the ground? That’s a gopher-tortoise burrow. See those breaks in the grass to the left and right in the foreground, and elsewhere? Those might be trails that connect this burrow to others in the area. How to map all of them? Call in the drone! (Photograph by Anthony Martin, taken on St. Catherines Island, Georgia.)

GT-Aprons-Trails-SCICan you see gopher tortoise traces from space? Surprisingly, yes. Not only are burrow aprons visible in this GoogleEarth™ photo (denoted by the arrows), but also trails connecting some of the burrows. Although if you find yourself squinting and turning your head sideways to see these, you’ll understand why sending up a drone with a high-resolution camera might be a better way to map these traces. (Image taken from a presentation I gave at the 2011 annual meeting of the Geological Society of America in Minneapolis, Minnesota.)

Most of the gopher-tortoise burrows are in a broad, flat area on St. Catherines that used to be pasture land, but is now being restored to the tortoises’ long-leaf pine-wiregrass ecosystem. This re-located tortoise population has done quite well here, and because of its isolation on St. Catherines, it’s an example of one that does not face as many human-related problems as their compatriots on the Georgia mainland. Its remote location also helped us with trying out the drone, as we didn’t have to worry about it dodging buildings, power lines, or gawking locals, all of which might have complicated its flights.

Tortoise-Burrow-Drone-PilotsAlmost ready for take-off! Drone pilots/wranglers Alison Hight (left) and Michael Page (right) look for a flat place near a staked gopher-tortoise burrow for setting down our “eyes in the sky.” (Photograph by Anthony Martin, taken on St. Catherines Island, Georgia.)

This was the drone’s maiden voyage on St. Catherines Island, taking off from the gopher-tortoise field. It did just fine. (Video footage by Anthony Martin, taken on St. Catherines Island, Georgia.)

Drone-Above-Tortoise-FieldThe drone pilots doing a great job, sending the drone around the gopher-tortoise field for a spin. (Photograph by Anthony Martin, taken on St. Catherines Island, Georgia.)

This flight was a big success, in that the drone went up, took lots of video and photos while in the air – all of which was georeferenced – and it came down without crashing. So we decided to try it elsewhere. That’s when we remembered the Atlantic Ocean was only about 500 meters away on the eastern edge of St. Catherines, with a lengthy beach, salt marshes, storm-washover fans, tidal creeks, and a bluff of Pleistocene sand with maritime forest on top of it. So off we went, and we did Flight #2 over the storm-washover fans, salt marshes, and tidal creeks near the north end of the island.

Drones (much like me) operate well in places with wide-open spaces that involve Georgia beaches. Check out how quickly it disappears from view once in the air. (Video footage by Anthony Martin, taken on St. Catherines Island, Georgia.)

Following this flight, we decided to send the drone father north to survey the bluff from just offshore. This was probably the most exciting flight, as we watched it go out to sea, then fly parallel to the shore, with its camera trained on the coastline.

Drone-Yellow-Banks-Bluff-1Michael setting down the drone on a almost-flat surface as Alison prepares it for take-off. The yellow yardstick serves as an easily visible scale that can be used to estimate ground-level distances. (Photograph by Anthony Martin, taken on St. Catherines Island, Georgia.)

Off we go, into the wild blue yonder. (Video footage by Anthony Martin, taken on St. Catherines Island, Georgia.)

Drone-Yellow-Banks-Bluff-3Bringing it back home. Look for the spot near the top-center of the photo for our “hand lens in the sky.” (Photograph by Anthony Martin, taken on St. Catherines Island, Georgia.)

Coming in for a soft landing, which is much preferred over the other type of landing. (Video footage by Anthony Martin, taken on St. Catherines Island, Georgia.)

So following these inland and coastal successes, which clearly were applicable to studying gopher tortoises and coastal geology, it was time to try using the drone to look at the apex predators of the island – alligators – and their traces. The next day,while scouting areas further to the south for alligator dens and tracks, we paused on a causeway cutting through a salt marsh. Because the marsh was at low tide, its mudflats were exposed, which allowed a few big animals to walk across it and leave their tracks, and for us to see these tracks.

At least two of the trackways were from alligators, made distinctive by their sinuous tail drags, arcing footprints, and belly drags. I suspect the other trackways were from feral hogs, but I couldn’t tell for sure because they were in squishy mud beyond my carrying capacity. Which is to say, I would have quickly immersed myself in this environment had I gone any further out. Gee, if only we had some way to photograph those trackways from above, better helping us to see their lengths, patterns, and directions.

Alligator-Trackways-MarshA salt-marsh mudflat at low tide, with low marsh and a patch of forest (hammock) in the background. See the alligator trackway to the left, where the alligator turned? Look in the middle and you’ll see two more trackways that are probably from feral hogs, and another curving trackway to the right that is from another alligator. (Photograph by Anthony Martin, taken on St. Catherines Island, Georgia.)

Drone-Landing-Salt-MarshWhy wade into waist-deep salt-marsh mud to track an alligator when you can stay safely (and cleanly) on dry land, telling a drone what to do? (Photograph by Anthony Martin, taken on St. Catherines Island, Georgia.)

So it was time for another flight, and the drone’s first alligator-track-mapping mission, which I’m pleased to say was a success. One example of that success is conveyed by the following photo, which made me gasp when I first saw it. There were the two alligator trackways and the two hog trackways, but also two not-so-clear trackways I had missed and a clear view of where the hogs had dug along the marsh edge. This photo similarly evoked a collective “Ooooo!” when I showed it to an audience the next week at the Southeastern Section meeting of the Geological Society of America meeting in Chattanooga, Tennessee. My talk was a progress report on the alligator dens of St. Catherines Island, but I threw in this photo toward the end of it to show how drones might help with some of our tracking alligator movements through difficult-to-access environments on the island.

DCIM100MEDIADJI_0100.JPGOK, you’re probably wondering by now how good those photos and videos taken by the drone might be, and whether or not any useful science can come from them. See that guy in the lower center of the photo? That’s me, pointing to each of the two alligator trackways, with the yellow yardstick providing an additional scale to the left. Notice also the probable feral hog trackways in the middle and fainter ones to the right, as well as the “hogturbation” (rooting disturbance caused by hogs) in the upper left of the photo. As an ichnologist, I was pretty darned pleased by this picture, and I want more like it. (Photograph by The Aerial Drone, taken on St. Catherines Island, Georgia.)

Lastly, I was also happy to see that drones have their own ichnology, in that they make flight traces. I’ve been long fascinated by flight traces – called volichnia by ichnologists – and have done my best to describe these in modern birds of the Georgia coast, as well as bird flight traces in the fossil record. Given the right substrate, anatomy, and behavior, the take-off and landing traces of birds and other flighted animals can preserve well enough for us to interpret them for their true nature.

Now, to do the same for a drone requires knowing how they have vertical take-offs and landings, using rapidly moving rotors. This means air will be pushed down onto the substrate directly underneath the drone, then dissipated abruptly outside that zone. The result would be a sem-circular depression slightly more that the maximum width of the drone, and one that would look very much the same whether made by a take-off or landing. The difference would be in the timing of the landing-pad traces: if obscured by the depression, then it was taking off, but if they are impressed on the depression, then it was landing.

Drone-Making-Landing-TraceDrone coming in for a landing, already pushing aside pine needles on the forest floor and making its landing trace. (Photograph by Anthony Martin, taken on St. Catherines Island, Georgia.)

Drone-Landing-Trace-2Drone landing trace, minus the drone. Do you see the square pattern in the middle of the oval depression? That’s the outline of the drone, defined by its landing gear. (Photograph by Anthony Martin, taken on St. Catherines Island, Georgia.)

So now we know that a drone can be used for conservation biology, coastal geology, behavioral ecology, and – most importantly – ichnology. How about art? Yes indeed. Once we got back to the Emory campus, Michael handed over the footage to Steve Bransford, a skilled videographer employed by Emory and founder of Terminus Films. Given all of the drone footage, he snipped out the boring parts (always a good thing to do), added a few maps at the start to orient the viewers, put in a soothing soundtrack, and basically created an aesthetically pleasing and extraordinarily educational video. So we submitted it for consideration as an video in the peer-reviewed online journal Southern Spaces, which was founded at Emory University. Much like an aerial drone on an unobstructed coastline, it sailed through peer review and is now available for viewing by all who have an Internet connection.

St. Catherines Island Flyover from Southern Spaces on Vimeo. Never mind the stern message: just click on the link or the video and it will play. Once it does start playing, please watch it on a big screen, sit back, and enjoy the ride. Also be sure to read the accompanying article linked to the peer-reviewed online journal Southern Spaces.

What’s aerial adventures await us next? We’ll see, as we have plenty of visual information and data to process from our previous visit. But for now we can be pleased to have shown the value of an aerial drone as both a scientific instrument and a means for engaging our senses with soaring imaginations.

Acknowledgements: Many thanks to the St. Catherines Island Foundation for its support of our research on St. Catherines, and to Royce Hayes and Michael Halstead for their assistance on field logistics. We also appreciate the expert piloting of the drone by Alison Hight while on St. Catherines. Steve Bransford did a fantastic job with creating the video for the Southern Spaces article, which should win the Georgia equivalent of an Oscar. Input from the editor of Southern Spaces, Allen Tullos, improved our article accompanying the video, and we are grateful to the staff of Southern Spaces for their quality service in putting this video and article online. And as always, many thanks to Ruth Schowalter for her help and support, in and out of the field.

Emory News (July 15, 2015): Drone Offers Stunning Aerial Views of Georgia’s St. Catherines Island.

Rewilding a Jurassic World

(Author’s note; The following post is a republished article of mine, originally published on June 12, 2014 by The Conversation and later republished by The New Republic, The Guardian, Quartz, and several other online news sources. However, this post is an embellished version, in which I include a paragraph on dinosaur microbiomes omitted from the original, and it uses my personal photographs and captions to illustrate its points about dinosaur paleoecology. So you might say this is the “director’s cut.” Many thanks to The Conversation editor Nick Lehr for helping turning my rough prose for the original article into one more readable for a general audience.)

Like many moviegoers this summer, I plan to watch Jurassic World. And because I’m a paleontologist, I’ll cheer for the movie’s protagonists (the dinosaurs) and jeer at the villains (the humans). But no matter how thrilling this movie may be, one question will plague me throughout: where are the dung beetles?

Jurassic-Morrison-Landscape-Walters-Kissinger-CarnegieThis mural depicts theropod dinosaurs (foreground) and sauropod dinosaurs (background) as part of a Late Jurassic ecosystem about 150 million years ago. OK, so this ecosystem has some producers (plants), primary consumers (herbivores, the sauropods), and secondary consumers (carnivores, the theropods). What’s missing from this picture that would be needed to make this a real, functioning ecosystem? If you said “Dung!” and “Dung beetles!,” you’re on the right track. (Mural by Robert F. Walters and Tess Kissinger (Walters & Kissinger) at the Carnegie Museum of Natural History, photograph by Anthony Martin.)

Dung beetles – which are beetles that eat and breed in dung – would be only one of many ecological necessities for an actual Jurassic World-style theme park. Yes, cloning long-extinct dinosaurs is impossible. But even if dinosaur genomes were available, the animals couldn’t simply be plopped anywhere.

So for the sake of argument, let’s say an extremely wealthy corporation did manage to create a diverse bunch of dinosaurs in a laboratory. The next step in building a Mesozoic version of Busch Gardens would be figuring out how to recreate – and maintain – the dinosaurs’ ecosystems. Accomplishing this goal would require a huge team of scientists, consisting (at minimum) of paleontologists, geologists, ecologists, botanists, zoologists, soil scientists, biochemists and microbiologists.

Such a team then would have to take into account countless interacting factors for the dinosaurs’ recreated habitats. And perhaps they could take a page from rewilding efforts that are currently taking place throughout the world.

In a memorable scene from the original Jurassic Park, paleobotanist Dr. Ellie Sattler examines an impressive heap of an ill Triceratops’s feces to look for digested remains of a toxic plant.

One of my favorite scenes in Jurassic Park (1993), when Dr. Ellie Sattler (played by Laura Dern) affirms her Ph.D. (= “Piled Higher and Deeper”) by unhesitatingly plunging her hands into a massive pile of Triceratops feces. Please note her sensible footwear, suitable for running away from theropods planning to add her to the local food web.

Here, the filmmakers touched on a key challenge for recreating an environment from a different geologic period. Many modern plants have evolved defenses against herbivores, which include toxins that can swiftly impair any animal that hasn’t adapted to them. Consequently, a time-traveling Triceratops would be taking a big risk with every visit to its local salad bar.

Paleobotanists could try to solve this problem by cataloging fossil plants that lived at the same time as plant-eating dinosaurs, before picking out descendants of those plants that are still around today. Still, plant lists will never be good enough to say whether or not a Triceratops, Stegosaurus, or Brachiosaurus ate those plants or if they could eat their descendants.

The same might hold true for carnivorous dinosaurs, which – for all we know – may have been picky eaters. For instance, although some Triceratops bones hold tooth traces of Tyrannosaurus, there’s no way to be sure a genetically engineered Tyrannosaurus would eat an equally inauthentic Triceratops (even if it were organic and free-range).

Triceratops-Tyrannosaur-Toothmarks-2 copyDid tyrannosaurs ever eat Triceratops? Oh yeah, and with gusto. Tooth trace fossils in Triceratops hip bones (red arrows) happen to match the dental records of Tyrannosaurus rex, which lived as the same time (Late Cretaceous, 65-70 million years ago) and place (western North America) as Triceratops. Also think about how much meat was covering that hip bone, which means the Triceratops must have been dead when this tyrannosaur was helping to recycle its body into the ecosystem. (Specimen in Museum of the Rockies and photograph by Anthony Martin.)

Yet another food-related dilemma is that we also are not quite sure how most dinosaurs digested what they ate. For instance, many modern animals – from termites to humans – require a suite of gut bacteria to break down and assimilate nutrients from food. Even if microbiologists somehow successfully recreated the microbiome of a dinosaur, how would you prevent it from acquiring modern gut parasites? Dinosaur coprolites (fossil feces) tell us that some dinosaurs had gut bacteria and parasites: but how to engineer the right bacteria and exclude the wrong parasites?

So despite a century of dinosaur flicks portraying tyrannosaurs and other predatory dinosaurs gratuitously munching humans, one bite of our species – or other sizable mammals – might make them sick. In other words, there’s no accounting for taste.

The lack of dung beetles in that same scene with Dr. Sattler also may have explained why the Triceratops’s feces were piled so high. We know from fossil burrows in dinosaur coprolites that dung beetles fed on dinosaur droppings at least 75 million years ago. Similarly, Late Jurassic dinosaur bones from nearly 150 million years ago hold the traces of carcass-eating insects.

Hadrosaur-Coprolite-Dung-Beetle-BurrowsA large, 75-million-year-old coprolite – attributed to the hadrosaur Maiasaura – filled with digested plant debris, but also with dung-beetle burrows. One burrow is sliced length-wise and runs diagonally (upper right to lower left), and another is in cross section and pointed toward you (upper right). Specimen is from the Museum of the Rockies but was part of a traveling display at Fernbank Museum of Natural History in the late 1990s. (Photograph by Anthony Martin.)

Termite-Borings-Dinosaur-Bone-DNMLate Jurassic (about 150 million-year-old) dinosaur bone with insect borings, which are credited to carcass- and bone-eating insects that used these bones for food or breeding soon after the dinosaur was dead. Specimen on display at Dinosaur National Monument near Vernal, Utah. (Photograph by Anthony Martin.)

This makes sense: wastes, bodies and other forms of stored matter and energy must be recycled in functioning modern ecosystems. Accordingly, to maintain the productivity of these dinosaurs’ ecosystems, animals that perform essential services to the ecosystem would need to be introduced. These include pollinators, such as bees, beetles and butterflies, as well as seed dispersers, like birds and small tree- and ground-dwelling mammals. Thus Masrani Global – the imaginary corporation tasked with creating Jurassic World – should have added entomologists (insect scientists), ornithologists and mammalogists to the career opportunities page on its mock website.

Can we learn anything useful from such fanciful reconstructing of long-gone ecosystems, where large animals once roamed? Sure. In so-called “rewilding” projects, imagination meets real science. These projects, which attempt to restore ecosystems by closely mimicking their previous iterations, often include reintroducing locally extinct animals.

Perhaps the most famous and successful of such rewilding projects began just after the release of the original Jurassic Park. In 1995, wolves were reintroduced to Yellowstone National Park. Although admittedly not as exciting as releasing a pack of velociraptors into the woods, the reintroduction of wolves – which had been extirpated from the area earlier in the 20th century – had a dramatic restorative effect.

Wolf-Tracks-Lamar-YellowstoneIf you looked for these tracks in Yellowstone National Park before the original Jurassic Park came out in 1993, you would have been disappointed. They’re from gray wolves (Canis lupus) and are signs of a now-thriving population of these apex predators reintroduced to the Greater Yellowstone Ecosystem in 1995, which has since caused big changes there. (Photograph by Anthony Martin.)

After the wolves gorged on elk – which, without predators, had overpopulated the region – riverine foliage grew more lushly. This prevented erosion and expanded floodplains, which gave beavers a better habitat to get to work damming rivers. A similar experiment is taking place in Europe, where increased numbers of large carnivores, such as wolves, bears and lynxes, are reshaping their ecosystems closer to their original states.

Bolstered by these successes, rewilding proponents have even proposed reintroducing elephants, lions, cheetahs and other animals to parts of North America as ecological proxies to mammoths, American lions and American “cheetahs” that lived only a little more than 10,000 years ago in those areas. Given the much shorter elapsed time since their extinction, enough similar species today and no need for genetic engineering, a “Pleistocene Park” – Pleistocene being the geological epoch that was about 2.5 million to 11,700 years ago – would be far easier to achieve than a Jurassic World (while also being more alliterative).

Pleistocene-Park-YellowstoneYou want a “Pleistocene Park”? Here’s a start, with herds of large primary consumers (Bison bison, otherwise known as “bison”) and grasslands in Yellowstone National Park, which overlap in range with secondary consumers wolves and grizzly bears. Now just add some elephants, lions, cheetahs, and a bunch more dung beetles, and you should be set. Wait a minute: you say the National Park Service wouldn’t approve of that? Oh well, one step at a time. (Photograph by Anthony Martin.)

So to any corporations out there that are thinking of making such a park, do us a big favor: whatever you do, don’t forget to include dung beetles.

Flight of the Quahogs

Let’s try a science-education experiment. Give a child a live clam and ask, “Can this animal fly?” and I predict her or his answer – accompanied by much giggling – will be “No!’ But if you ask, “Can you fly?”, the answer may change, especially if this child has already flown on an aircraft. So of course humans can fly, but to do this, they require machines, paragliders, or other technological aids in order to move through the air and – this is important – arrive on the ground safely.

Shattered-Quahogs-Pier-Jekyll-IslandFor clams that try to fly, they end up with more than shattered dreams. How did these clams (Mercenaria mercenaria, also known as quahogs or “hard clams”) end up doing Humpty-Dumpty impressions on a wooden pier? Please read on. (Photograph by Anthony Martin, taken on Jekyll Island, Georgia.)

In a similar way, clams can fly. They just need a little help from other animals that can fly and willingly give them a temporary lift from the earth they and their molluscan relatives have known for all of their evolutionary history. Compared to most of our forays into the air, though, these flights are much more limited. Clam aerial exploits are brief and mostly vertical, with little time for them to appreciate the view from above or otherwise experience unusual sensations. They go up, then they come down, and fast.

Clams do not have landing gear. So they can hit the ground hard, especially if their free fall happened after a lengthy trip up into the air and the ground surface is hard: think of a sandflat at low tide, a paved parking lot, or a wooden boardwalk. A a result, the most common end to clam flights is a shattered shell, which is quickly followed by the demise of the clam as it is consumed by the very same animal that bestowed it with flight, however brief and self-serving.

Impact-Trace-Seagull-Clam-DropTraces of a unidirectional vertically oriented clam flight (otherwise known as “falling”) that did not end well for the clam, but worked perfectly for the flying animal that took it for a ride. Notice the impact trace on the hard sandflat, outlining the ribbed shell of the clam (probably Dinocardium robustum) and bits of shell. Most of the probably-still-alive-but-definitely-dying animal  was dragged off to a nearby spot so that its soft parts could be eaten by the same perpetrator that took it for a ride. (Photograph by Anthony Martin, taken on Sapelo Island, Georgia.)

So just what flying animals do such dastardly deeds, taking hapless clams up for a ride, only to drop them to a certain death? By now the gentle reader has probably figured out birds are responsible for this blatant bivalvicide, and some may have already known that seagulls are the most likely culprits. In some coastal areas and during low tides, some seagulls fly over exposed sandflats and mudflats, searching for the outlines of clams buried below the surface. These avian ichnologists then swoop down, land, pick up the clam with their beaks, take off, and then once high enough, they drop them, serving up instant raw clam on the half (or quarter, or eighth) shell. Typically all that is left is a jigsaw puzzle of clamshell pieces and the seagull perpetrator’s footprints, but with the latter only evident on muddy or sandy surfaces amenable to preserving tracks.

Seagull-Tracks-Eaten-ClamIchnological evidence of who killed the clam, provided by the tracks a laughing gull (Larus altricilla).The other half of the shell was broken by its falling onto the sandflat elsewhere, then the gull carried its clam on the half-shell to a more scenic place for its meal. (Photo by Anthony Martin, taken on Little St. Simons Island, Georgia.)

I found this behavior so compelling that I started my book Life Traces of the Georgia Coast (2013) with a story about a laughing gull (Larus altricilla) and the traces of its unwitnessed predation on an Atlantic cockle (Dinocardium robustum), seagull behavior on the Georgia coast. I was not the first person to note this method of clam-smashing by seagulls, as it has been documented by other scientists in parts of the U.S. and abroad, and has been caught on video. Amazingly, though, despite more than 15 years of visiting the Georgia coast, I had never actually witnessed seagulls dropping clams. instead I had only performed post-mortem forensics, in which I would find broken clamshells on hard sandflats accompanied by seagull tracks, telling tales of murder most fowl.

Video footage of a western gull (Larus occidentalis) picking up a clam, flying up about 10 meters (> 30 feet), and dropping it onto rocks to crack it open. After this doesn’t work the first time – and after shooing away a potential clam-stealing rival – it tries again, and is presumably successful. It’s almost as if this gull is using a scientific methodology, isn’t it? (The videographer is only credited as ‘Trisera’ on the YouTube page, and I don’t know where it was filmed, but suppose it’s on the western coast of the U.S.)

Seagull-Cockle-Predation-DiagramHere’s the first illustration a reader will see in my book, Life Traces of the Georgia Coast (2013, Indiana University Press), which I drew to provide a visual forensic analysis of how an Atlantic cockle met its demise at the hands of – er, I mean, wings and bill of – a laughing gull. Part (a) depicts the gull landing after recognizing the outline of the cockle from the air, stopping, and extracting it from the sandflat. Part (b) shows where the cockle was dropped and broken successfully, accompanied by the gull landing and trampling the area as it enjoyed its clam dinner.

This meant I was more than overdue to get visual confirmation of gulls killing clams, which was finally granted just a few weeks ago during a recent trip to Jekyll Island (Georgia). It was the day after I had given an invited talk at the annual meeting of The Initiative to Protect Jekyll Island environmental group, and while my wife Ruth and I were relaxing before leaving the island, but of course were also observing whatever nature we could.

In that spirit, and while sitting on a deck on the west side of the island and looking at a mudflat (in between swatting sand gnats), we noticed a seagull flying about 10 meters (>30 feet) above a wooden pier. At one point, it paused its ascent, and we saw an object fall from its mouth and down toward the pier. Thunk! We clearly heard the impact of the object correlate with what we saw, and with much excitement realized that we had just witnessed seagull clam-cracking for the first time.

Jekyll-Island-Mudflat-Dead-Clams A mudflat replete with mud snails (probably Ilyanassa obseleta), grazing away and making gorgeous meandering trails on the western side of Jekyll Island (Georgia). But wait, what are those big white chunks on the same surface?

Dead-Clams-Mudflat-Jekyll-IslandWhy, look at that: hard clams (Mercenaria mercenaria) in an unnatural state, i.e., disarticulated, broken, and dead on the surface of the mudflat. These clams normally burrow into and live under the mud, and usually manage to stay intact if they stay below the surface. The pieces of clams here must have bounced off the wooden pier, which is casting a shadow in the lower right-hand side of the picture. (Both preceding photographs by Anthony Martin and taken on Jekyll Island, Georgia.)

What was most surprising to me about this broken-shell assemblage on the pier was how it was represented only by the hard clam, or quahog (Mercenaria mercenaria). These thick-shelled clams are quite common in sparsely vegetated muddy areas of salt marshes, burrowing into the mud and connecting their siphons to the surface so that they can filter out suspended goodies in the water during high tides. During low tides, however, they become vulnerable to avian predation. Despite being “hidden” in the mud, somehow the seagulls spotted them from the air, landed next to them on the mudflat, and pulled them out of the mud. They then used the nearby pier as an anvil, and the clam’s hard, thick shell unwittingly became its own hammer when they hit the pier after falling from a fatal height.

Shattered-Quahogs-Jekyll-Pier-MartinThe horror, the horror: a clam killing “ground,” thoughtfully supplied by humans for seagulls in the form of a long, hard, wooden pier. (Photograph by Ruth Schowalter and Yours Truly for scale, taken on Jekyll Island, Georgia.)

OK, now it’s time to think about broken clams and deep time. If you found such an assemblage of broken shells of the same species of thick-shelled clams in a geologic deposit, how would you interpret it? Would you think of these broken shells as predation traces, let alone ones made by birds? Which also prompts the question, when did seagulls or other shorebirds start using flight and hard surfaces to open clams? Did it evolve before humans, and if so, was it passed on as a learned behavior over generations as a sort of “seagull culture”?

All of these are good questions paleontologists should ask whenever they look at a concentration of broken fossil bivalves that are all of the same species, and overlapping with the known geologic range of shorebirds. In short, these may not be “just shells,” but evidence of birds using gravity-assisted killing as part of their predation portfolio.

Tales of Trails by Seahorse Tails

I’ve always been a big fan of aquariums. Having grown up in the landlocked Midwest and not seeing an ocean with its bountiful life until I was 20 years old, I am still drawn to the old-school charm of big tanks filled with salt water and populated by exotic fish and other sea critters. These environments, however artificial, never fail to inspire awe and wonder. Even better, they often teach me something new and relevant each time I pay closer attention to what they hold.

Seahorse-Making-Resting-TraceA seahorse, of course, is not a horse. But that’s not the only way seahorses differ from horses, in that they leave trails instead of tracks. Intrigued? Yeah, me too. (Photograph by Anthony Martin, taken at the UGA Aquarium, Skidaway Island, Georgia.)

Nonetheless, I also have a “problem,” which manifests itself whenever I’m at an aquarium, walking along a beach, sitting on a park bench, driving down a  road, or, well, conscious. As an ichnologist, I’m constantly looking for animal traces. Then once found, I study these traces carefully so that they may inform me whenever I see similar traces in the fossil record. But because I’m a land-dweller and rarely have the opportunity to snorkel or scuba-dive, aquariums come in handy for observing traces of aquatic animals I might not often see. Particularly helpful are aquariums in which the people caring for them were kind enough to include sand on their bottoms (the aquariums, that is).

So last weekend, while leading a class field trip to the Georgia coast and after a wonderful boat ride to Wassaw Island and back, I eagerly joined my students in viewing a salt-water aquarium. This particular venue was the UGA Aquarium (UGA = University of Georgia, Athens) is maintained by the UGA Marine Extension Service (MAREX) on Skidaway Island, Georgia. Our visit was especially satisfying because we were there on a Sunday afternoon, when the aquarium is closed to the public. This luxury afforded us plenty of room and quietude, qualities that are rumored to enhance learning.

Within just a few minutes of entering the main room, one tank to the right caught my eye, and not just because of its pretty colors, but for its denizens and traces on the sandy bottom of that tank. It contained seahorses, fishes that are so odd compared to other fishes, we humans had to compare them to hoofed domesticated mammals. The best part of all, though, was that this tank had lots of intersecting grooves and circular imprints on its sandy surface, which no doubt had been made by the seahorses.

Seahorse-Making-TrailA seahorse (Hippocampus sp.) showing off its lack of swimming skills by moving along the sandy bottom of a tank. Gee, what are all of those meandering and intersecting grooves in the sand and circular imprints? I wonder what made those? Sorry, first guess doesn’t count. (Photograph by Anthony Martin, taken at the UGA Aquarium, Skidaway Island, Georgia.)

All seahorses are under the genus Hippocampus, which consists of more than fifty species. Evolutionarily speaking, they are ray-finned fish (actinopterygians) and share a common ancestor with pipefish and sea dragons (Sygnathidae). The oldest known fossil seahorses are in Miocene Epoch rocks, from about 13 million years ago. Besides their equine-like profiles, they are well known for their prehensile tails, which can either grasp onto algae, sponges, or corals, or curl up underneath them as they swim.

However, seahorses are never going to inspire bets at underwater race tracks, as they are among the slowest-swimming of fish, propelled mostly by tiny pectoral fins while moving upright. Still, they don’t need to be fast, as they are very successful predators, with about 90% accuracy in nabbing fast-swimming small crustaceans that get too close to their mouths. Seahorses also don’t need to swim away from larger predatory fishes that might wish to pick them from a seafood menu. Whenever seahorses attach to algae and corals, they sway in harmony with their temporary hosts, effectively blending in with their surroundings.

One point I keep in mind whenever visiting an aquarium, zoo, or other such enclosures is how these can alter so-called “normal” behaviors of their animals. In this instance, the smaller space of this tank, combined with little material for attachment, meant these seahorses were more likely to swim along its bottom then they might in an open ocean. Accordingly, they had made lots of traces in the sand: mostly undulating grooves, but a few circular impressions from their curled tails plopping onto one side or the other.

Seahorse-Making-Trail-2A seahorse making tail trails while swimming along the bottom of an aquarium. Notice how the trail would become less linear, wider, and more circular if the tail flops over to one side or another, involving a greater area of the curled end. (Photograph by Anthony Martin, taken at the UGA Aquarium, Skidaway Island, Georgia.)

Seahorse-TrailsA close-up of those trails left by swimming seahorses dragging their tails along a sandy surface. Also, check out the overlapping circular “plop” traces on the right, made by the curled part of the tail? (Photograph by Anthony Martin, taken at the UGA Aquarium, Skidaway Island, Georgia.)

What’s the take-home message of these observations for ichnologists, geologists, and paleontologists? That experience matters, as does questioning preconceived notions about what we might observe from the geologic record. Take a look at the preceding photo, and tell me – quite honestly – that your very first interpretation of the tracemakers would have been “fish,” let alone “seahorse.” Instead, I think nearly everyone (yes, me too) would have reached for the easiest answer, which would have been “worm trails,” similar to how geologists reflexively apply “worm burrows to anything small, tubular trace fossil they encounter at an outcrop. Wrong, wrong, wrong.

So next time when looking at rocks formed in marine environments – whether from the last 13 million years or much older – and these rocks host lots of “worm trails” on their surfaces, ask yourself who else could have made such trails, and how. Reach beyond easy and ordinary explanations, and imagine. Oh, and when you go to aquariums, don’t just look at their sea-life, but also the traces of the sea-life in them.

Acorns, Mighty Oaks, and Raccoons

Despite more than 15 years of visiting the Georgia coast, studying its traces, and taking students on field trips to its barrier islands, I always marvel at how each trip is different, bestowing new insights and lessons to both me and my students. So a trip there this past weekend was no exception, and perhaps the most intriguing phenomenon I encountered during it was of some “mere” scrapings in a sandy road on Wassaw Island, Georgia.

Raccoon-Scrapings-Acorns-WassawWho needs a Mystery Date when you can have a Mystery Trace? Here we have some enigmatic scrapings in a sandy road on Wassaw Island, Georgia. What could have made these, and why? (Photograph by Anthony Martin; scale in centimeters.)

Wassaw Island is a National Wildlife Refuge, and I’ve mentioned it before as the one island of the Georgia coast that most closely approaches the ideal of “pristine,” a label blithely applied to nearly any Georgia barrier island regardless of how much humans had modified their landscapes. Current estimates are that it Wassaw only about 600 years old, which means that Native Americans had barely populated it by the time the Spanish arrived in the 16th century. Thus whenever I teach my biannual Barrier Islands class, I like to include a field trip to Wassaw Island so my students can appreciate the close-to-natural state of its ecosystems. We then contrast their experiences there by visiting overdeveloped Tybee Island on the same weekend, giving my students the opportunity to think about “before and after” conditions of Georgia barrier-island ecosystems.

Even better for my students, our leader for the field trip to Wassaw was not me, but John “(“Crawfish”) Crawford, one of the most knowledgeable naturalists on the Georgia coast. Employed by the University of Georgia Marine Extension Service on Skidaway Island, John regularly takes groups on an open boat to Wassaw Island for day trips. These trips never disappoint for the sheer variety and richness of natural history learned along the way, whether on the boat trip there and back, or on the island itself. I’ve been to Wassaw four times with John as a guide, and each time with him have seen something novel there. (I mean, how often do you see a decapitated seagull?)

Wassaw-Interior-HikingInto the Woods, Wassaw Island style! With our intrepid guide (John “Crawfish” Crawford) leading the way into the maritime forest of Wassaw, my students were in for a world of discovery on this beautiful Georgia barrier island. (Photograph by Anthony Martin.)

Just one example from this most recent trip I’d like to share are traces I have never before seen, or, more likely, never before noticed. We encountered it while walking down a sandy road on Wassaw used more often by deer and alligators than humans. The traces were systematic and widespread scrapings of the top few centimeters of the road, some of which resolved themselves as curved to linear features with finer grooves in their interiors. Because they did not match the feeding traces of feral hogs (Sus scrofa) or nine-banded armadillos (Dasypus novemcinctus), I was intrigued. Who made these, and why?

Raccoon-Scrapings-Acorns-WassawJust in case you missed it the first time, here’s that photo again. Yes, this will be on the exam: why do you even ask?

A closer look revealed the traces were overlapping sets pf five evenly spaced grooves, corresponding with five thin-fingered hands. These could only belong to the most dextrous, industrious, and resourceful denizens of maritime forests and other environments on the Georgia coast, raccoons (Procyon lotor). When I queried John about these traces, he confirmed that not only were they made by raccoons, but also were a result of their “mining” the sand. The raccoons, using their front paws, methodically raked the loose sand to expose shallowly buried acorns dropped by the many old and mighty oaks lining the road, indulging in an all-you-can-eat acorn feast.

DSCN4416Close-up of the same mystery trace seen in the previous photo, but this time more groovy. Check out the curving, parallel set of five grooves (left) and the partial track (right), telling us that a masked bandit left its mark. (Photograph by Anthony Martin; scale in centimeters.)

Although raccoons are infamously omnivorous, in winter months they depend on acorns for much of their diet. Thus considering that the Georgia coast was still in winter, and that a sub-freezing cold front had just passed through the area a few days before, it was not surprising to see this evidence of extensive acorn foraging.

OK, time to replace my floppy coastal-geologist hat with my more stylish paleontologist hat to ask this question: Would such traces preserve in the geologic record, and if so, would they be recognizable for both the tracemaker (raccoon) and behavior (foraging)? Probably not for both, as the loose quartz-rich sand in a maritime forest would have few chances of being buried intact and cemented in a way that would “freeze” the details needed to discern both tracemaker and its intent. Yet these traces would lend some insights to interpreting disturbed zones in the upper parts of fossil soils, especially those that might have preserved acorns or other nuts in them.

So next time you’re in a maritime forest during the winter and come across some odd scrapings in the road, take a closer look and ask yourself a few questions about them. Who made them? Why did they make them? How do these traces relate to the broader ecology of the area? Would they be preserved in the fossil record, and if so, could we properly interpret them? Then ask yourself what you’ll find next time you go to the same place and look just a little bit closer.

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.)