The Ichnology of Godzilla

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Other “Science and Godzilla” Posts

The Impossible Anatomy of Godzilla (Danielle Venton)

Godzilla Gets Bigger Every Year (Rhett Allain)

The Impossible Gait of Godzilla (Ria Misra)

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

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

The Science of Godzilla (Scott Sutherland)

The Science of Godzilla, 2010 (Darren Naish)

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

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

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

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

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

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

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

Dolf-Roland-IIW-BaselHow would you like to have your “Dolfing“? Inside or…

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Seilacher-Fossil-Art-2Seilacher-Fossil-Art-1Dolf Seialcher introducing Fossil Art to a gathering of ichnologists at Ichnia 2008 in Krakow, Poland. (Photographs by Anthony Martin.)

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

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

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

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

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

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

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

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

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

References

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

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

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

(This is the second in a three-part series honoring the memory of ichnologist-paleontologist-educator-artist Dolf Seilacher (1925-2014). For Part I, please go here.)

Dolf Seilacher and I crossed trails again in the fall of 1997, but through my initiative and in my backyard, here in Georgia. After the Evolutionary Biology Study Group at Emory University hosted a series of prominent biologists on the Emory University campus – such as George C. Williams, Richard Lewontin, and the Grants (Rosemary and Peter) – its director asked me which paleontologist we might bring to campus. Having invited theoreticians and lab-based or field biologists as our main guests, he wanted to give the members of our group more of a “deep time” perspective on evolutionary processes. So I immediately said, “Dolf Seilacher.”

Seilacher-Coca-Cola-EmoryDolf Seilacher in Melton’s App & Tap, a neighborhood pub near the Emory University campus that served both Coca-Cola (which has economic connections to Emory) and proper adult beverages, the latter necessary for fueling meaningful paleontological conversations. (Photograph by Anthony Martin, taken in Atlanta, Georgia 1997.)

I recall a few snobbish members of the group doubted that any paleontologist could be a real evolutionary scientist: after all, paleontologists don’t do “experimental work.” (Yes, I’ve actually heard this smug, self-important drivel emit from the mouths of proudly lab-bound neontologists, making Sheldon Cooper look downright open-minded by comparison.) I was also at a university that had jettisoned its Department of Geology only eight years previously, meaning I had little support in my on-campus academic community for hosting an earth scientist. However, Dolf had won the Royal Swedish Academy of Sciences Crafoord Prize just five years before, thus he qualified as prestigious enough for most of the doubters. (Needless to say – but it bears saying anyway – none of his prejudiced skeptics had similar honors.)

Fortunately, Dolf did not disappoint, and hosting him at Emory University was among the most intellectually exhilarating three days I’ve experienced in the past 24 years at my institution. I had him mostly to myself on his first day in Atlanta, but we were joined by fellow ichnologist and friend Andrew (Andy) Rindsberg for dinner, with both of us feeling as if we had the world’s best private tutor in ichnology for that brief time. The next day, Dolf did a lunchtime seminar for the Evolutionary Biology Study Group, then later that afternoon delivered a talk in a big room open to the entire university and the general public. For his last full day in Georgia, he insisted we take him out in the field to see some of the Ordovician-Silurian rocks in the northwest corner of the state. (Other than transferring planes in Atlanta’s airport, Dolf had never been to Georgia and wanted to see our trace fossils.)

His second day in Atlanta, he began his engagement with the Evolutionary Biology Study Group, which was composed mostly of biologists, anthropologists, and psychologists; Andy and I were the lone paleontologists there. The lunchtime seminar was held in a cramped room, and most people there were awkwardly holding flimsy paper plates weighed down by slices of cheap pizza. The overall mood was one of curiosity, as Dolf was a complete unknown to most people there. (Remember, this was 1997: “Googling” was still a year away from being anything, let alone a verb.)

His seminar topic was on fossil tracks, and he started with the classic historical example of how some Early Triassic tracks from Germany (named Chirotherium) had been badly misinterpreted by some of the greatest scientists of their time, such as Alexander von Humboldt, Richard Owen, and Charles Lyell. Later, with more scrutiny and the application of a few key ichnological principles, other scientists revealed what animals made them and how, which Dolf explained in his book Trace Fossil Analysis (2007, p. 6-7).

Seilacher-Chirotherium-AnalysisDolf Seilacher’s visual explanation for how the anatomy and dimensions of a tracemaker, its behavior, and the original substrate (a firm mud) all contributed to making a fossil trackway from the Early Triassic Period (about 245 million years old). He also included  explanations of previous interpretations for these tracks and when they were proposed (middle right), neatly summarizing the progression of the science done on these tracks. (Figure from: Seilacher, A., 2007, Trace Fossil Analysis, Springer, p. 7.)

Wrong-Way-Hands-Fossil-ArtA reproduction of the Early Triassic (about 245 million-year-old) rock slab with mudcracks and Chirotherium tracks, both preserved in convex relief as natural casts. I said “reproduction” because this is a epoxy resin cast made from a latex mold that was also colored to mimic the original rock. Does this sound like a work of art? Well, as a matter of fact, this was one piece in a show Seilacher conceived called Fossil Art. (Photograph by Anthony Martin, taken in Krakow, Poland in 2008.)

Once introduced, Dolf took off, and his audience went with him. In a lively, mesmerizing presentation, Dolf deftly interwove history of science with detective-like applications of ichnology, anatomy, sedimentology, and evolution, all delivered with his trademark enthusiasm, humor, and charisma.

In one memorable instant, he used his hands and arms to play-act the wrongly interpreted gait of the Chirotherium maker, in which this wretched imaginary animal had to cross its limbs as it walked. (Later, paleontologists figured out its so-called “thumb” was actually its outermost digit, thus erasing any need for the animal to cross-step.) He then pantomimed the more correct gait, again bringing across his points far more effectively than if he had used, say, a computer-animated reconstruction of the tracemaker. The audience was enthralled, enchanted, engaged, or whatever words science communicators use to describe what happens when a speaker is rhetorically kicking butt.

How did I know Dolf’s talk was a success? About five minutes into it, one of the most egotistical and pedantic curmudgeons in the Evolutionary Biology Study Group (who may or may not have been an anthropologist) turned to me and said with genuine delight, “This guy is terrific!” Yes, he was.

Later that afternoon, Dolf gave a lecture in a, well, lecture hall, with about a hundred people attending. For me, this was less exciting than his noontime talk because trace fossils and ichnology only figured briefly in its message. Instead, it was more about the “big picture” of evolution as reflected by the fossil record, with emphases on constructional morphology and biological structuralism, and connecting these to the evolution of animal behaviors. Some of these concepts – which I won’t even try to explain here – represented expansions on research by Dolf’s Ph.D. advisor, Otto Schindewolf. Nonetheless, he delivered a thought-provoking lecture, and enthusiastically answered a variety of questions when the time came.

Dinner at a Lebanese restaurant after the lecture was an opportunity to see yet another side of Dolf. For instance, soon after our party had been seated, he and the restaurant owner exchanged pleasantries (and jokes) in Arabic. I had forgotten that Dolf taught at the University of Baghdad early in his career and did much field work in Libya and other parts of the Middle East. The dinner – which included many field stories Dolf had experienced around the world – went well into the night, but did not hinder Dolf’s observation skills at the end of it.

As we exited the restaurant, he pointed to the cement on the doorstep and said, “Look, evidence of a former biomat, helping to preserve this footprint.” We looked down and saw where a shoe-clad human had stepped into the originally wet cement. But wrinkle marks around its edges – as Dolf explained – showed where plastic sheeting had been placed over the cement in a vain attempt to prevent people from stepping on it. It was a moment when we felt like Watson to his Sherlock.

Following his triumphant visit to the Emory campus in Atlanta, Dolf was then ready to experience something that really mattered, like trace fossils. The next day, we took him to northwestern Georgia to look at trace fossils in the Ordovician-Silurian rocks there, a mere 2.5 hour drive from Atlanta.

We had a varied group, composed of a few paleontologists – Andy Rindsberg, Sally Walker, and me – along with the director of the Evolutionary Biology Study Group (Michael Zeiler), a couple of evolutionary biologists and biology graduate students, and a few undergraduate students from one of my geology classes. Our only goal for the day was to see the I-75 Ringgold roadcut, which through its height, breadth, and gently tilted strata afforded an opportunity to stroll along its length, find many trace fossils, and put them into the context of changing environments from more than 440-430 million years ago.

Dolf-Seilacher-Ringgold-Georgia-1The start of the field trip with Dolf Seilacher to see Ordovician-Silurian rocks near Ringgold, Georgia. This photo was taken about 10 minutes before he took over the field trip, which immediately followed Andy Rindsberg and me getting “Dolfed.” (Photograph taken by Anthony Martin in November 1997.)

Andy and I were thrilled to have Dolf at this outcrop with us because we had done a lot of work there, and we wanted to show off what we had found. Andy studied the Ordovician and Silurian trace fossils there in an M.S. thesis done at the University of Georgia, and I completed a bed-by-bed analysis of its Upper Ordovician rocks as part of my Ph.D. dissertation, also at the University of Georgia. Because we worked for the same graduate advisor (Robert “Bob” Frey), Andy and I communicated well with one another, and we mostly agreed on what trace fossils were there and what they meant. Moreover, Frey had published a paper with Dolf in 1980 (well before he died in 1992). Thus Andy and I felt as if we were fulfilling an ichnological legacy by taking Dolf to see trace fossils that Frey had studied here in Georgia.

Dolf-Seilacher-Ringgold-Georgia-2A first sign that Andy and I were not leading this field trip: within minutes of arriving at the site, the group gathered around Dolf to listen to what he had to say about the Late Ordovician rocks under our feet and around us. Did I mention this was his first time there? (Photograph by Anthony Martin, taken near Ringgold, Georgia in November, 1997.)

Dolf-Seilacher-Ringgold-Georgia-3Probably my favorite photograph of Dolf, showing him in full lecture mode while surrounded by Late Ordovician rocks in northwest Georgia. His synapses also might have been firing double time because of the caffeinated beverage he picked up at a Golden Gallon convenience store just beforehand. (Photograph by Anthony Martin, taken near Ringgold, Georgia in November, 1997.)

When we got to our destination, we parked and walked a short ways to our first stop. Rather than going directly to the road cut, we first looked at big slabs of sandstone in a former quarry site. These sandstones were from the Late Ordovician Sequatchie Formation, and they made for wonderful teaching specimens, containing many fossil burrows, mudcracks, and reddish clay, all indicating formerly intertidal environments. However, Andy and I didn’t know what made the burrows. Little did we know (but we should have), we were about to find out.

After Andy and I gave a brief introduction to this site and a preview of what to expect at the outcrop, Dolf strolled over to a large slab of sandstone, and nonchalantly placed his hand over a bump on its surface. “This trilobite resting trace shows how they were well adapted to living in intertidal environments at this time…” he began.

Andy and I exchanged startled looks. “Trilobite resting traces?” we both said. In all of our years of field work at this site, we had found very little evidence of a trilobite presence. We also had never recognized a trace fossil showing where a trilobite dug into mud or sand in one place and left an outline of its body, a so-called “resting trace,” sometimes called Rusophycus.

That’s when we realized it. We’d been Dolfed. And on our own field trip.

Fortunately, we didn’t care. Dolf then went on to propose that the more common burrows in these rocks were also made by trilobites, but smaller ones. I’ve written previously about this trilobite-themed revelation and how Andy and I tried later to disprove it, only to find that Dolf was probably right. This served as yet another example of why experience matters in ichnology, and why we ichnologists should always listen to those who have it.

Dolf-Seilacher-Ringgold-Georgia-4Dolf in action, as he started to put together the story of how trilobites were burrowing on and into tidal flats more than 400 million years ago in a place we now call Georgia. Notice how Dolf was using pencil and paper to assist in his explanations of what was in front of us, no doubt drawing out his conclusions. (Photograph by Anthony Martin, taken near Ringgold, Georgia in November, 1997.)

Dolf-Seilacher-Ringgold-Georgia-5Dr. Sally Walker, getting a close look at the bedding-plane surface of the sandstone, which is loaded with natural casts of mudcracks. But wait: what’s that blurry, whitish bump in the lower left corner?

Dolf-Seilacher-Ringgold-Georgia-6Why, that’s a trilobite resting trace, the first ever found in this formation and locality. Thanks for the Dolfing, Dolf. (Both photographs by Anthony Martin, taken near Ringgold, Georgia in November, 1997.)

Seilacher-Trilobite-Resting-Trace-DrawingDon’t quite see the trilobite resting trace fossil, and you think it’s a just a random bump on that rock surface? Here’s an illustration by Dolf that should help to enlighten. Take a look at the left-hand side of this figure with his depictions of trilobite resting traces, then look again at the photograph of the “random bump.” Yes, that’s right: you’re wrong. And you know what? It’s perfectly fine to be wrong in science. Just make sure you learn from your mistakes. (Figure from: Seilacher, A., 2007, Trace Fossil Analysis, Springer, p. 39.)

The rest of the field trip seemed almost anti-climatic after Dolf’s discovery, but it was still quite enjoyable. We left the quarry site and walked along the roadcut itself for the next few hours, stopping to look at whatever caught our attention. Its titled strata meant were were going forward in geologic time, from oldest to youngest (Middle Ordovician –> Early Silurian). This provided a nice lesson for the geological novices in our group in how to interpret changing environments through time. We found more trace fossils, and even a few body fossils, giving everyone plenty of paleontological stimulation to get them through that day and beyond.

Dolf-Seilacher-Ringgold-Georgia-7Dolf Seilacher, master ichnologist and consumate teacher. We will greatly miss his pointing out the obvious to the oblivious. (Photograph by Anthony Martin, taken near Ringgold, Georgia in November, 1997.)

When it came time to leave, we walked out with Dolf, feeling exceedingly grateful for his requesting this trip. Later, we joked with him about the success of his “first visit to Georgia.” Alas, we did not know then that it would also his last. Nonetheless, what remains are the provocative thoughts and methods he imparted on so many of us during his brief time here, no doubt inspiring future generations of paleontologists, ichnologists, and all others interested in learning about the wondrous history of the earth.

Seilacher-Ringgold-14A group picture following our field trip with Dolf Seilacher to northwest Georgia in November 1997 (and much gratitude to whoever suggested it and took it). For me (far right, big hat), the road behind us seems to symbolize a trail he blazed for us to follow. Thanks for all of the cognitive traces, Dolf: may they continue to reach into the fossil record.

Reference

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

 

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

Every paleontologist has a Dolf story. Or at least it seems that way, especially for the past couple of weeks. One-by-one, like feather-duster worms poking their heads out of burrows, these stories have all emerged since the paleontological community heard the sad news that Adolf (Dolf) Seilacher died on April 26, 2014.

This manifestation of Dolf connecting with so many paleontologists over multiple generations symbolizes his ultimate and most lasting trace as a scientist and teacher. During his 89 years with us, he observed, discovered, pondered, argued, and argued more over the evidence that life left in the rocks of the past 600 million years or so. Much of this evidence is preserved as trace fossils, the vestiges of animal behavior that imparted their former presence as burrows, trails, tracks, feces, or other signs of life that almost never connect to their undoubted makers. Although Dolf was no slouch when pontificating on the bodily remains of ancient animals, either, it was with trace fossils where he truly excelled.

Seilacher-Ringgold-Georgia-TeachingAdolf (“Dolf”) Seilacher in his natural habitat, teaching students and professors alike when in the field. Notice how he was using paper and pencil as tools, which were instrinsic to his teaching methods. (Photo taken by Anthony Martin at Ringgold, Georgia in November 1997; Dr. Sally Walker (right) for scale.)

Dolf is often acknowledged as the founder of modern ichnology, the study of traces and trace fossils. Through this science, he could divine the original intents and purposes of trilobites, worms, clams, snails, shrimp, fish, pelycosaurs, dinosaurs, and many other former denizens of the earth. He accomplished this Sherlockian feat through the careful examination of ancient animals’ signatures, or the jots and tittles in those signatures: miniscule clues he reconstructed as entire manuscripts or symphonies that spill their secrets to those who pay heed. Dolf’s marvelous ability to spin fossil gold from carbonized straw is most of what inspired the many stories we paleontologists tell about him, although his personality was intrinsically linked to this, too (more on that later).

Nonetheless, what was truly remarkable about how Dolf worked his ichnological magic was his use of such old-fashioned methods. What were his primary tools for observing? His eyes, brain, pencil, paper, and drawing: no laser scanners (let alone “laser cowboys”), CT imaging, digital photogrammetry, rotating 3-D visualizations, or other modern technological tools were necessary for what he did. If someone had a time machine, they could have inserted Dolf into the late 19th century among the naturalists of those days, and he would have blended. Paradoxically, though, we 21st century paleontologists remember him as someone who surpassed all of us with his observational and intuitive skills. In this sense, he was a reminder of the readily available and valuable means we already possess that allow us to make sense of our planet and its vast history.

Dolf-Drawing-Zoophycos

The Hand of Dolf, drawing onto a Middle Jurassic trace fossil (Zoophycos) to teach me and others how it was made by worm-like animal on a deep seafloor about 170 million years ago. (Photograph taken by Anthony Martin in Switzerland, 2003.)

Field-Notebook-Dolf-DrawingA composite trace (drawings plus writings) made by Dolf and me. The central figure is a visual explanation he drew for me, showing how one could figure out whether the Zoophycos-making animal was moving down below the sediment surface (protrusive) or moving up (retrusive) as it burrowed. Under his watchful eye, I then parceled out the details below. Field notes and drawings done on July 16, 2003, at the outcrop indicated in Switzerland.

Still, Dolf vigorously disagreed whenever anyone praised him as an “artist,” insisting he was a mere illustrator. With all due respect to his memory, he was wrong on this, and most of the paleontological community likewise rejected such statements. He was a fine artist and scientist, inseparably partnered in one person.

Trilobite-Grazing-SeilacherOne of many examples of how Dolf Seilacher was both a scientist and an artist, in which through drawing he interpreted a series of movements made by a trilobite along an Early Cambrian seafloor, more than 500 million years ago. (Figure from Seilacher, A., 2007, Trace Fossil Analysis, Springer: p. 27. If you support the unification of science and art, then you must get this book.)

Like all students of paleontology who took their first toddling steps in the 1970s-80s, I first learned of Seilacher through his papers. In those readings, I also soon realized the most effective way to discern the key points of his papers was to skip straight to his exquisite illustrations. Following a long tradition of German artist-scientists, such as Albrecht Dürer, he could accurately reproduce what might have been evident from a photograph of a trace fossil, or the specimen itself. Yet the salient qualities of a trace fossil were somehow more deeply understood – and thus better communicated – through his drawing of that specimen. His illustrations often impelled a viewer to take a second, third, or fourth look at a trace fossil, prompting more learning and often provoking marvel at what he perceived.

In some instances, he “cheated” in his drawing by using a camera lucida. This is a clever device that, through a prism, projects the image of a subject onto paper, where its proportions and details can be traced and thus captured accurately by the person drawing it. However, in Dolf’s drawings, his tracings were often fortified and embellished with dramatic black-and-white contrast rendered by pen and ink. Even better, these so-called “illustrations” were used as launching points for interpretive drawings that presented provocative explanations for how a trace fossil was made. Sometimes he even added a whimsical touch to these figures, such as placing a little windmill next to the cross-section of a marine-invertebrate burrow. Was this science, or was this art? Yes.

When did I first meet Dr. Adolf Seilacher, a person many other paleontologists and I would later casually call “Dolf”? It was on a Geological Society of America field trip in Cincinnati, Ohio, in the fall of 1992. In retrospect, I was extremely lucky with that first meeting to watch him perform his expertise – and it was always a performance – in the field, rather than the sterile confines of a convention hall or conference room.

On this field trip, we paleontologists were looking at outcrops in the Cincinnati area, which bear some of the best Late Ordovician fossils (about 445 million years old) in the world. Among these fossils are brachiopods, bryozoans, snails, clams, crinoids, and other animals – such as trilobites – that have no living relatives today. You can walk up to most of these outcrops, close your eyes, and scoop up a handful of these fossils. I had also done my M.S. thesis in this area, so it was a trip back to familiar territory, and some of the fossils felt like old friends: I mean, really old friends.

Yet thanks to Dolf, these body fossils were not the stars of the field trip that day. When we went to an outcrop with numerous U-shaped burrows preserved in its limestones – trace fossils the field-trip leaders called Rhizocorallium – I witnessed his scientific process at work. After we had all listened to the field-trip leaders give their interpretation of the burrows, he sat down next to one of these trace fossils, and for about 10 minutes, he quietly drew in his field notebook. Gradually, some of us gathered around to see what had attracted his attention and we watched him draw. Once he had a critical mass for what he considered an adequate audience, he began sharing his thoughts, a didactic lecture accompanied by more drawing as he explained his conception of how the burrows were made by small animals living in a shallow sea hundreds of millions of years before that moment.

Rhizocorallium-Zoophycos

A field-trip memory expressed through drawing: my recollection of what Dolf Seilacher illustrated in his field notebook in October 1992 while explaining a 445-million-year-old burrow and how it was made. The burrow is the main U-shaped structure, and the lines in between are spreite, showing where the former location of the animal’s burrow. In my illustration here, the animal – either a small arthropod or worm – adjusted its burrow downward into the sediment, then to the right. The behaviors recorded here may have been from the animal feeding, reacting to changes in the surrounding sediment, or a combination of ecological cues.

“You see, this so-called ‘Rhizocorallium’ is just the beginning of a Zoophycos,” he said with his patented Teutonic confidence mixed with professorial charm. He then drew more in his field notebook to show what he meant, a slow-motion visualization that delivered his lesson unambiguously. In his estimation, the U-shaped burrow, which had curved lines showing where the animal had moved it, was only the start of a more complex feeding probe. In Dolf’s assessment, one trace fossil (what ichnologists would call Rhizocorallium) could have thus easily merged into another form, one we would then assign another name (Zoophycos). This was a clarifying moment for me as a young scientist and educator about the communicative power of drawing. As a result, I have tried to use drawing in my research articles, books, and teaching ever since.

Based on this sample of one, I did not know then that Dolf’s “hijacking” of field trips was a time-honored tradition for him. Moreover, I did not know then that nearly every paleontologist who had ever disagreed with him, or presented a hypothesis he somehow found lacking, was running the risk of being subjected to an intense and aggressive interrogation that over the years was nicknamed “Dolfing.”

Dolf-Roland-IIW-Basel-2“Dolfing” in action, in which Dolf Seilacher would ask a series of penetrating questions as a follow-up to a helpful statement informing the “Dolfee” that she/he is completely wrong about everything ever. And just to show how no one was excused from potential “Dolfing,” regardless of their accomplishments and seniority, here he is subjecting Dr. Roland Goldring (1928-2005) to this treatment, just like he would have done to a well-meaning but woefully misguided graduate student. (Photograph by Anthony Martin, taken in Basel, Switzerland in July 2003.)

This harrowing critique was equal opportunity, in that he applied it to graduate students, senior professors, and everyone in between. For Dolf, getting the science right was far more important than honoring silly academic hierarchies. Although “Dolfing” occasionally caused discomfort in those getting “Dolfed,” these lopsided personal lectures often resulted in more details emerging, clearer explanations, and deeper understanding about a paleontological problem, meaning both the “Dolfer” and “Dolfee” learned more in the process. “Dolfing” became such a badge of honor, graduate students even wished for it to happen (“I’ve been Dolfed!”, they would say excitedly after surviving such an encounter.) One paleontologist friend of mine – after a colleague and I described “Dolfing” to her – said wistfully, “Oh…I want to be Dolfed!”

It was with much pleasure, then, that I got to watch “Dolfing” happen again during a field trip to the Cretaceous-Paleogene stratigraphic boundary in Recife, Brazil in 1994. This was when the “end-Cretaceous meteorite” hypothesis was still debated fiercely at professional meetings, with both proponents and skeptics fighting over the evidence. Preceding the field trip was a morning symposium on this contentious topic, much of which dealt with the 65-million-year-old boundary exposed at a nearby outcrop we would see later that afternoon.

In this session, one of the geologist speakers referred to a “massive” deposit of limestone as a tsunamite (a deposit formed by a meteorite-induced tsunami), which we were all supposed to see on the field trip. As soon as this speaker finished and the question-answer period began, Dolf sprang to his feet and declared, “You realize, of course, that if we find one burrow, it will completely negate your hypothesis.” Very simply, an animal would not have continued burrowing blithely on and in the ocean sediments while a gigantic sea wave washed over it. The speaker, taken aback by Dolf’s confident pronouncement, simply repeated that the deposit was “massive,” meaning it lacked any defined layering (bedding), and had no burrows. Ichnologists know better, though, as we sometimes translate “massive” as “There’s no bedding because it’s been completely burrowed, you ichnologically ignorant geologist!”

Dolf’s statement turned out to be a prophetic one. Later that afternoon, we field trip participants walked along the outcrop, looking at the layer of limestone interpreted as a meteorite-induced “tsunamite.” Sure enough, within ten minutes of inspecting, I found a burrow. Acting as a field-trip troll, I called out, “Oh Dolf, look what I found!” He came over and confirmed that yes indeed, it was a burrow, he quickly spotted dozens more, and the rest of the field trip was his for the taking. Many of the participants on the trip sat back and watched the fireworks, enjoyed the show, and we very nearly applauded at the end. Although I felt a little sorry for the field-trip leaders, it served as a good reminder that all you need is one burrow (or its factual equivalent) to upset a hypothetical apple cart.

Seilacher-Brazil-Outcrop-Cretaceous-Boundary

Dolf Seilacher (left) delivering the intellectual equivalent of a bolide impact while standing in front of an outcrop containing evidence from the Cretaceous-Paleogene boundary. (Photograph by Anthony Martin, taken in 1994 near Recife, Brazil.)

After such a memorable conference and field trip, when would Dolf and I cross trails again? Not until 1997, and through my initiative and in my backyard, here in Georgia. But that story is worth its own post, one I promise to tell next time.

(To Be Continued)

Reference (Which is Also Quite Likely the Best Book Ever Done on Trace Fossils That Also Includes Some Incredible Artwork):

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

‘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.

Recent Signs of Life

Following a flurry of dozen posts in December 2013 loosely inspired by The 12 Days of Christmas, this site has been morbidly silent, a veritable vacuum of verbosity. This was probably a good thing, as my life has been occupied by a few other tasks and events, and will be in the near future. So in the proud tradition of Buzzfeed and other Web sites that rely on enumerated click bait for their traffic, here are the top five reasons why I haven’t been blogging lately.

5. I finished writing a book. Titled Dinosaurs Without Bones: Dinosaur Lives Revealed by Their Trace Fossils (Pegasus Books), I’ve been working on it since the summer of 2012, and I’m now holding it in my hands, which is a sure sign that it’s done. Overall, I’m very pleased with how it came out, and even more pleased that it’s out and available for others to enjoy reading. What’s it about? Just re-read the title, but if you’re still not quite sure, I guess you’ll have to get the book and read the whole thing.

Dinosaurs-Without-Bones-BookHere’s a trace of what I’ve been thinking and writing since 2012. Hope you like it. (Photograph by Anthony Martin, taken at home.)

4. I taught a field course in the Bahamas. Once every two years, I organize and teach a field course for Environmental Sciences students at my university. This course, which lasts about 10 days, is held during winter break at the Gerace Research Centre on San Salvador Island, Bahamas. Yes, I know, you’re thinking the following: “Can I go?” “Do you need a field assistant?” “That must be nice!” “Poor baby!” [the last of these said sarcastically]. No offense, but I don’t think you would last a day in this course. (Yes, you. And especially you.) It’s a physically demanding course, with land- and water-based field work every day, along with nighttime lectures and discussions, and that happens all before everyone walks 3 km to the nearest bar. Nonetheless, it’s a wildly successful course, in which my initially scared-of-the-outdoors-and-anything-alive-or-dead students are transformed into something approaching field-hardy scientists by the end of their time on the island. I’ll write separately about our latest experiences in an upcoming post, so be looking for that.

Outdoor-Classroom-BahamasOnce every two years, this is my classroom. Notice how I even got a student to teach everyone else that day. Not seen in this photo? Fruity drinks with paper umbrellas. (Photograph by Anthony Martin, taken on San Salvador Island, Bahamas.)

3. I gave my first public talk about the new book. First, let me heap some praise on one of the most awesome organizations in the Atlanta area, the Atlanta Science Tavern. With nearly 4,000 members, the Atlanta Science Tavern organizes several science-related talks and events held each month, they’re involved in the upcoming Atlanta Science Festival, and in charge of the Science Track at the Decatur Book Festival, all of which I reckon makes them a force to be, well, reckoned with. Anyway, they invited me to speak about my book as part of their annual Darwin Day Dinner event last month, and I happily complied. It was also great fun being the warm-up act for paleobotantist (and friend) Dr. Melanie DeVore, who spoke later that evening taught us about Darwin’s connection to the “abominable mystery” surrounding the evolution of flowering plants.

2. I co-wrote and submitted a research paper. Sometimes when I’m on San Salvador Island and teaching my students in the field, we make discoveries. So when someone tells you matter-of-factly that teaching and research rarely converge, this pronouncement can be, like, totally falsified when you’re teaching outside of a classroom. Which is to say, outside.

For example, on December 30, while with my students at an coastal limestone outcrop on San Salvador, my student teaching assistant (let’s call her “Meredith”) pointed to some features and said, “Hey Dr. Martin, are these ___________?” To which I replied, “Why yes, I think those are ______________!” (I’d be glad to tell you what they are, but first they have to go through peer review.) So in the past few months, I wrote a draft of a short research paper reporting the find, “Meredith” added her editing suggestions, and we submitted it to an open-access journal for possible publication. But what was really neat about this discovery was that we shared it with the other students in the field, right then, right there, and used it as a teaching lesson on what you should do when making a potential fossil discovery in the field. Take that, false dilemma!

Wave-Innundation-San-SalavdorWhat is life, but a coastal limestone outcrop with a paleosol that is daily immersed by tides and inundated by waves, awaiting discovery of its hidden trace fossils, which are revealed by those same tides and waves? And by the way, watch out for those waves. (Photograph by “Meredith” – which may or may not be her real name – and taken on San Salvador Island, Bahamas.)

1. I’ve been teaching (more so). No matter how much it might pain pundits who love to bash those unproductive academics for their non-existent class loads, cushy tenure, exorbitant pay, and – most galling of all – academic freedom, I’ve been teaching 40+ students this semester in two classes, advising a senior honors-thesis student, and helping other students pick out courses for study-abroad programs. Incidentally, I’m also not tenured, my pay is far lower than that of the aforementioned pundits make, and I have no academic freedom (see previous statement about lack of tenure).

For a good summary list of what professors actually do in their jobs, read this. But if you’re one of those people who won’t have your mind changed by evidence-based reasoning, then by all means go back to watching your favorite cable-news show and watch people shout at one another about how climate change is a hoax, whether or not mermaids and Megalodon (or, better yet, a mermaid-eating Megalodon) really do exist, and other fascinating fare. Regardless, I’ve had fun teaching these two classes, although I’m guilty of putting off grading the Bahamas field-course reports. Que sera, sera.

0.5. (Bet you thought you were done, didn’t you?) I attended two conferences in the past few weeks. The first conference is one that meets only once every five years, the North American Paleontological Convention. It’s normally a wonderful conference, and this one – held in Gainesville, Florida and hosted by attended by about 500 paleontologists of all types – was no exception. Indeed, it’s one of the few times we can get micropaleontologists, paleobotantists, invertebrate paleontologists, vertebrate paleontologists, taphonomists, and even ichnologists under the same roof. Other than learning heaps from my paleontological ilk, I presented a talk summarizing Cretaceous trace fossil research I’ve done with colleagues in Victoria, Australia since 2006, and other colleagues of mine at the North Carolina Museum of Natural Sciences and I co-authored a poster about Ediacaran fossils in North Carolina.Paleontologist-Barbie-NAPCHere’s that poster on Ediacaran fossils from North Carolina, coauthored with Patricia Weaver and Chris Tacker from the North Carolina Museum of Natural Sciences. Notice it’s also undergoing peer-review by our hero, Paleontologist Barbie. Is there nothing she can’t do? (Photograph by Anthony Martin, taken in Gainesville, Florida.)

The other conference, still fresh on my mind, was Science Online 2014, which was held in Raleigh, North Carolina last week. It was my first time to this conference, and my main reason for going was to promote my book, which was on display there and being given away to lucky attendees in a raffle. But I also had the nice fringe benefits of meeting many very nice (and very smart) folks from the science-communication community who I had only known previously through digital media, while also learning much about online-science communication during sessions on a variety of topics. From what I gathered, a good time was had by most.

What’s coming up in the next future? Plenty! For one, Dinosaurs Without Bones is officially released this Thursday, May 6, 2014. So I’ll probably have something to say about that. Ta-ta for now, and thanks for reading about my latest signs of life, which may or may not preserve in the fossil record.

On the 1st Day of Ichnology, My Island Gave to Me: 1 Sea Star Gliding

The last of my holiday-inspired series of photos depicting traces from the Georgia barrier islands is of one most people will see only rarely, but is a glorious one to spot. It is the trail left by a lined sea star (Luidia clathrata), best observed on the lower parts of sandy beaches.

Sea-Star-Moving-SapeloA beautifully expressed trail left by a lined sea star (Luidia clathrata). The sea star itself is only about 10 cm (4 in) across, but its trail shows how far it traveled, from its initial “resting” spot to where you see the tracemaker itself. (Photograph by Anthony Martin, taken on Sapelo Island.)

Sea stars make such trails when stranded on the lower part of a beach by a high tide. Once exposed, especially under a summertime sun, they can either dry out quickly or become easy prey for a wandering seagull. If they’re fortunate enough to be on or otherwise near a saturated sand, they’ll bury themselves by moving their hundreds of tube feet underneath them. This makes a sort of localized quicksand around them, and they will sink into the sand, which normally solves their dual problem of dehydration and predation. However, the resulting trace this makes is a star-shaped bump on the sand surface, which to many seagulls still translates as “food.” Many times I have seen and photographed spots on beaches where a gull was practicing its own form of ichnology, where it walked straight to a buried sea star, plucked it from its temporary resting spot, and took it somewhere else to eat.

In this photo, though, the sea star had an even greater challenge when it was left on a sandflat. It was dumped by a high tide onto a part of the beach with a thin layer of wet sand overlying a more firmly packed sand. This meant that the sea star’s tube feet could only get it so far down into the sand, having been stopped by the hard, packed layer underneath. So its only other choice was to move laterally along the wet sand, which it accomplished through a combination of tube feet and arms, causing it to glide through and on top of the sand.

My interpretation of this behavior is that the sea star was desperately seeking moisture – whether a softer, wetter sand or a submerged area – and that this journey was more likely to ensure its survival than to simply sit and wait for the next tidal cycle. Considering that sea stars have been around for more than 450 million years, I can only assume this behavior worked quite well for at least of few of this species’ ancestors. Thus I would not be surprised at all by the discovery of trace fossils matching the form and intent of the modern traces shown here.

Meanwhile, let’s give thanks for how lucky we are to see them and understand the meaning of these and other traces being made by Georgia-coast animals every day. Each vestige is a lesson in natural history, beckoning us to learn more about the evolutionary processes that led to what we observe now.

Further Information

Luidia clathrata: Lined Sea Star. Encyclopedia of Life.

Links to Previous Posts in This Theme

On the 12th Day of Ichnology, My Island Gave to Me: 12 Snails Grazing

On the 11th Day of Ichnology, My Island Gave to Me: 11 Plovers Probing

On the 10th Day of Ichnology, My Island Gave to Me: 10 Beetles Boring

On the 9th Day of Ichnology, My Island Gave to Me: 9 Molluscans Hiding

On the 8th Day of Ichnology, My Island Gave to Me: 8 Crab Legs Walking

On the 7th Day of Ichnology, My Island Gave to Me: 7 Lizards Looping

On the 6th Day of Ichnology, My Island Gave to Me: 6 Hatchlings Crawling

On the 5th Day of Ichnology, My Island Gave to Me: 5 Bivalves Drilling

On the 4th Day of Ichnology, My Island Gave to Me: 4 ‘Gators Denning

 On the 3rd Day of Ichnology, My Island Gave to Me: 3 Ghost Shrimp Pooping

On the 2nd Day of Ichnology, My Island Gave to Me: 2 Otters Running

On the 2nd Day of Ichnology, My Island Gave to Me: 2 Otters Running

On this Christmas of 2013, I thought that the second-to-last post of my “On the __th Day of Ichnology” series would be a gift, one speaking of the beautiful harmony we sometimes are so fortunate to see recorded in the sands of the Georgia barrier islands. The traces composing this gift are the tracks of a male-female pair of river otters (Lutra canadensis).

Otter-Tracks-St-CatherinesSynchronicity expressed in traces: a pair of river otters, running and turning together along a Georgia beach. (Photograph by Anthony Martin, taken on St. Catherines Island, Georgia; scale is about 10 cm (4 in) long.)

A normal gait for river otters is a lope, which registers as a 1-2-1 pattern, in which one rear foot is in front, a rear and front foot are next to one another, and a front foot is behind. However, in this instance, I think both otters were galloping, as it looks like both rear feet exceeded their front feet, and a well-defined space is in between each set of four tracks.

What really struck me about these tracks, and made me gasp with joy when I saw them, was their near-perfect symmetry and how they hint of one otter reacting to the other otter’s movement. I can’t say for sure right now what evidence lends to my discerning the following interpretation (sorry, fellow scientists). But my hunch is that the otter on the left was running just in front of the other, maybe separated by a body length at this point, and then turned just slightly to her/his left. The otter on the right was galloping to catch up, saw its partner turn to the left, and decided to turn her/his body in response to this change in direction. Notice how the gap between their trackways is narrowed just a bit, and how the tail of the second otter left an arc-like impression on the sand that points directly to the next set of tracks.

Such a gorgeous set of traces, left by a species we humans often revere (or envy) for its love of play! But I also found these tracks even more gratifying for how they told of two otters linked to one another, perhaps through play, but certainly through their mirrored behaviors, and how this in turn held up a mirror to ourselves. What interactive traces do we similarly leave in our lives? In which instances are we the otter on the left, leading the way and making decisions to change course? In which instances do we follow just behind and to the side of others, and run to catch up? Why do we sometimes lead, why do we sometimes follow, and what makes us come together? Thoughts for Christmas, thoughts for the end of this year, and thoughts for the start of a new year, bestowed by the symbolism of these traces.

Links to Previous Posts in This Theme

On the 12th Day of Ichnology, My Island Gave to Me: 12 Snails Grazing

On the 11th Day of Ichnology, My Island Gave to Me: 11 Plovers Probing

On the 10th Day of Ichnology, My Island Gave to Me: 10 Beetles Boring

On the 9th Day of Ichnology, My Island Gave to Me: 9 Molluscans Hiding

On the 8th Day of Ichnology, My Island Gave to Me: 8 Crab Legs Walking

On the 7th Day of Ichnology, My Island Gave to Me: 7 Lizards Looping

On the 6th Day of Ichnology, My Island Gave to Me: 6 Hatchlings Crawling

On the 5th Day of Ichnology, My Island Gave to Me: 5 Bivalves Drilling

On the 4th Day of Ichnology, My Island Gave to Me: 4 ‘Gators Denning

 On the 3rd Day of Ichnology, My Island Gave to Me: 3 Ghost Shrimp Pooping

On the 3rd Day of Ichnology, My Island Gave to Me: 3 Ghost Shrimp Pooping

Everyone poops. More specifically, every animal has to eat, converting this food into energy and otherwise applying it to bodily functions. As we also know through daily experience, this conversion is never 100% efficient. Thus waste is produced and excreted from all animal bodies, sometimes liquid, sometimes solid, or a mixture of the two.

And on the Georgia barrier islands, few animals are more visibly productive with their poop than ghost shrimp. So today’s photo and explanation celebrates those wondrous poopers of the Georgia coast.

Ghost-Shrimp-Pellets-Burrows-JekyllWe three burrows of Georgia coast are adorned with feces, showing that each of us is actively occupied by a ghost shrimp. In each burrow, the shrimp is probably just below the narrow aperture, doing a little housecleaning. (Photograph by Anthony Martin, taken on Jekyll Island, Georgia.)

I’ve written previously about ghost shrimp – otherwise known as callianassid shrimp – and the significance of their burrows to ecologists, geologists, and  paleontologists (linked under “Further Reading”). But I haven’t focused on one of their most important roles as ecosystem engineers, which is their prolific pooping of pellets.

These pellets are small, dark, perfectly shaped cylinders that, because of their resemblance to “chocolate sprinkles,” never fail to capture the attention of cupcake lovers as they stroll along Georgia beaches. (Now that you know what they are, please don’t eat them. Unless you like them, in which case, I’m never buying a cupcake from you.) However, aside from inspiring confectionery allusions, these pellets are extremely important in Georgia beach environments as sources of mud.

Only two species of ghost shrimp are responsible for all of this mud dumping, the Georgia ghost shrimp (Biffarius biformis) and Carolina ghost shrimp (Callichirus major). Nonetheless, they make up for their lack of diversity through sheer numbers; look closely at most Georgia beaches at low tide and you will see thousands of little “sand volcanoes,” most with pellets. Nearly all of these represent a live ghost shrimp, down below your feet, burrowing, feeding, mating, and pooping.

After feeding on mud-rich organics in their burrows, these shrimp make and emit mud-rich fecal pellets, neatly shrink-wrapped by mucus. The shrimp can then collect these packets of poop and pump them out the tops of their burrows, an efficient form of waste disposal that keeps their homes clean. These pellets become the hydrodynamic equivalent of sand grains, rolling with the tides and waves and are commonly deposited in ripple troughs and other low spots on a sandy beach.

Eventually their mucus coverings break down and release the mud particles (silt and clay), but at least these sediments were deposited. This would almost never happen on its own because of tides and waves keeping it suspended in the water, and means that the mud would be much less likely to get recycled into coastal sediments, and Georgia coastal waters would be even muddier than normal.

So take note, geologists: those thin layers of mudstone you see in the troughs of a rippled sandstone that you might just label “flaser bedding” in your field notebook, then promptly forget? Those beds probably got there by something pooping in the ancient past. And for everyone else, give thanks for these gift-wrapped feces, and for what they do for Georgia coastal environments.

Further Reading

The Lost Barrier Islands of Georgia. Written by me, posted October 3, 2011.

Ghost Shrimp Whisperer. Written by me, posted May 20, 2013.

Links to Previous Posts in This Theme

On the 12th Day of Ichnology, My Island Gave to Me: 12 Snails Grazing

On the 11th Day of Ichnology, My Island Gave to Me: 11 Plovers Probing

On the 10th Day of Ichnology, My Island Gave to Me: 10 Beetles Boring

On the 9th Day of Ichnology, My Island Gave to Me: 9 Molluscans Hiding

On the 8th Day of Ichnology, My Island Gave to Me: 8 Crab Legs Walking

On the 7th Day of Ichnology, My Island Gave to Me: 7 Lizards Looping

On the 6th Day of Ichnology, My Island Gave to Me: 6 Hatchlings Crawling

On the 5th Day of Ichnology, My Island Gave to Me: 5 Bivalves Drilling

On the 4th Day of Ichnology, My Island Gave to Me: 4 ‘Gators Denning

On the 4th Day of Ichnology, My Island Gave to Me: 4 ‘Gators Denning

For today’s photo and explanation of traces of the Georgia barrier islands that beguile, I’ll turn to one of the more charismatic and well-known of  tracemakers, and what are among the largest traces of any animals on the Georgia coast. These would be alligators (Alligator mississippiensis) and alligator dens, respectively.

Juvenile-Alligators-Denning-SapeloSee those two big holes just above the shoreline of this freshwater pond? Those are alligator dens, large burrows that benefit them in many ways. And just to prove this point, these two dens have a pair of alligators hanging out at their entrances. Both alligators are only about 1 meter (3.3 feet) long, though, which means they’re way too small to have been the alligators that made these dens. So what’s going on here? (Photograph by Anthony Martin, taken on Sapelo Island, Georgia.)

I’ve written several times before about alligator dens on the Georgia barrier islands, and these are a subject of on-going research for me and several colleagues. So I won’t go on about them here, and instead will just focus on what this specific photo of these dens and alligators tells us.

The picture was taken in March, 2011, at the start of spring on the Georgia coast. Hence the alligators might have been just then coming out of dens after overwintering in them. However, notice the mismatch in sizes of the alligators compared to the den entrances. The dens are much too large for their denizens, implying that these are not their original makers, but instead are secondary occupiers, reusing these dens. I was also surprised to see five alligators – all about the same size – sharing dens. Yeah, I know, the title of this post says “four ‘gators denning,’ but you’re only seeing four of them in the photo; the one on the right had at least three I saw that day.

A little bit of background might help with understanding what was happening there and then. I’ve been revisiting this freshwater pond on Sapelo Island for nearly 15 years, and can confirm that these are the same dens. Sometimes I’ll see evidence of alligators actively using them, as in, I see alligators lying at their entrances, and alligators that retreat into these dens if they get too shy from all of the enthusiastic ichnologically inspired love I’m sending their way.

Sometimes those alligators have been large, full-sized adults with body widths only slightly smaller than den widths. Other times the alligators will be most modestly sized, like these. Regardless, this shows that once a den is made, it can be used by many alligators of varying sizes, over more than a decade, and possibly over generations.

Something else interesting about this photo? All four of the visible alligators – and the one you don’t see that’s in the den to the right – were about the same length. Along with their congregating in the same location, this is a hint that they might have been siblings, having hatched from the same egg clutch and grown up together in this pond. Even better, their mother might have raised and protected them there by using one or both of these dens. This means that alligator dens might be passed down in families and occasionally shared out of necessity by family members. You know, just like us. Amazed? If so, thank ichnology for inducing that sense of wonder.

Further Reading

Into the Dragon’s Lair: Alligator Burrows as Traces. Written by me, published on this blog March 15, 2012.

Deconstructing an Ichnology Abstract, with Alligators. Written by me, published on this blog October 19, 2012.

What a Big Momma Alligator in Her Burrow Tells Us about Dinosaurs. Written by me, published on the BBC’s Walking With Dinosaurs site November 20, 2013.

Links to Previous Posts in This Theme

On the 12th Day of Ichnology, My Island Gave to Me: 12 Snails Grazing

On the 11th Day of Ichnology, My Island Gave to Me: 11 Plovers Probing

On the 10th Day of Ichnology, My Island Gave to Me: 10 Beetles Boring

On the 9th Day of Ichnology, My Island Gave to Me: 9 Molluscans Hiding

On the 8th Day of Ichnology, My Island Gave to Me: 8 Crab Legs Walking

On the 7th Day of Ichnology, My Island Gave to Me: 7 Lizards Looping

On the 6th Day of Ichnology, My Island Gave to Me: 6 Hatchlings Crawling

On the 5th Day of Ichnology, My Island Gave to Me: 5 Bivalves Drilling