The Great Cretaceous Walk Takes a Rest

About six weeks ago, I shared the happy news of our discovering dinosaur tracks at Milanesia Beach, Victoria, which turned out to be the largest collection of polar dinosaur tracks known in the Southern Hemisphere. Those tracks were found during the month-long excursion (May-June 2010) along the Victoria coast that inspired the start of this blog. And although we found heaps more trace fossils, the tracks constituted out most important scientific find. So even though we have a but more science to do, this is as good of a time as any with this blog to say, “Catch you later” and make a transition both geographical and temporal.

The Great Cretaceous Walk has been very, very good to me. But it’s time to take a pause in all of the walking and talking about the Cretaceous of Australia, and look closer to home (Georgia) and at this time in the present (otherwise known as “now”). Photo by Tom Rich, and taken on May 28, 2011 (Day 2) of our month-long field survey of the Cretaceous trace fossils of Victoria.

Fossil Collectors and Academic Paleontologists: Grudge Match, Love Fest, or a Little of Both?

In July of 2010, while in the small outback-Queensland (Australia) town of Boulia – mentioned in a previous entry – I was reminded through one simple question about a huge cultural and communicative gap dividing many people otherwise connected through their mutual love of fossils. The question, posed to me by Dick Suter, an extraordinary fossil collector who lives in Boulia, was: “Do you have a Ph.D.?” I have heard this question before in both the U.S. and Australia, and it is almost never asked out of curiosity, but to pick a fight. This time was no different, as I sensed his inquiry was tinged with antagonism. I braced myself, and said, “Yes.”

Here I am, having a cordial conversation with fossil collector Dick Suter (right) of Boulia (Queensland, Australia) at the Stone House Museum. He was a great guy and had lots of paleontological experiences to share during our visit with him, for which we were grateful. Just don’t tell him you’re a paleontologist and have a Ph.D. Photo by Ruth Schowalter.

Dreaming of Dinosaur Dreaming

Humans like to celebrate anniversaries during their lifetimes in fives and tens, which I like to think is a direct reflection of a much longer evolutionary heritage. For instance, why fives and tens, and not, say, threes or sevens? Look at your hands and feet, count your fingers and toes, and see what totals you get for each appendage (yakuza excluded). These numbers are a result of our having descended from synapsids (“mammal-like reptiles”) that likewise had five digits on each end of four limbs. In fact, all mammals are synapsids, and the last common ancestor synapsids shared with dinosaurs and other egg-laying reptiles was more than 300 million years ago. Humans and most other mammals don’t lay eggs (albeit, some placental mammals like to hatch from eggs), but a few still do – monotremes, such as platypuses and echindnas – thus demonstrating a lingering trait of this reptilian ancestry.

So it was this week that I was reminded of a five-year anniversary, the evolutionary history of mammals, and our long-lost connection to dinosaurs, thoughts that all coincided as they were triggered by remembering the Dinosaur Dreaming dig site in Victoria, Australia.

No, these people are not incarcerated and carrying out their sentences by cracking rocks all day in the summer sun. They actually are: volunteers at the annual Dinosaur Dreaming dig site in coastal Victoria, Australia; looking for fossils of Cretaceous dinosaurs, mammals, turtles, and other animals; and very much enjoy doing this. Really.

Of Min Min Lights and Ichthyosaurs

As loyal readers know from previous entries, following field work in Victoria, my wife Ruth and I went on a paleontologically themed “drive-about” (as opposed to walkabout) in western Queensland last July 2010. We started in Townsville, and went west from there (after all, going east would have put us in the Coral Sea). We then paused for a fun day and night in Hughenden, followed by three glorious days and nights in Winton. Where to go next for a married couple in pursuit of more knowledge about fossils and their role in inspiring the human imagination in Australia? Well, how about Boulia?

An artistic recreation of Cretaceous ichthyosaurs frolicking like dolphins at the Stone House Museum in Boulia, Queensland (Australia), thus providing a good example of how convergent evolution influences art: mural by Rona Thoragood (1997). For more about intersections between paleontology and art in outback Queensland, check out Ruth Schowalter’s (Hallelujah Truth’s) musings here and here.

Diving Down Under in the Cretaceous Sea

Cyclone Yasi - the massive tropical storm that hit Queensland, Australia last week – was a Category 5 hurricane, with winds well in excess of 250 km/hr (> 150 mph) at one point. Once it reached that place where the land meets the sea, it smashed a large area from Cairns to Townsville, its eye passing over Mission Beach, then Tully, places I have visited twice with study-abroad students from Emory University. The cyclone continued inland, bringing high winds and heaps of rain to communities inland that normally stay dry: Hughenden, Winton, Richmond, Boulia, and Mt. Isa. As expected, entire beaches vanished, coastal forests were torn apart, and property damage was excessive. Fortunately, though, very few people were injured, a direct result of excellent emergency preparedness by the Australian people and government.

The path of Cyclone Yasi (top), compared to a paleogeographic map of Cretaceous Queensland (bottom). Sometimes the sea comes back to visit, however briefly and horrifically. Cyclone track map is from Wikipedia Commons, and paleogeographic map was in the Museum of Tropical Queensland, Townsville, Australia, a place that was hit hard by Yasi just last week.

Why Eat a Rock? Gastroliths (‘Stomach Stones’) as Trace Fossils

During the past 30 years or so, trace fossils – such as tracks, burrows, nests, toothmarks, coprolites (fossil feces), and so on – have been steadily gaining more respect and recognition in paleontology. I would like to think this is a direct result of my dedicated “ichnoevangelism,” in which I have attempted to convert The Great Unwashed who fail to see the paleontological truth inherent to trace fossils, but the world of paleontology is much bigger than the Church of Ichnology (so far). Nonetheless, despite this overall increase in enlightenment, one type of trace fossil still causes some recalcitrant non-believers to turn gazes elsewhere and ignore their scientific worth. Those would be gastroliths, otherwise known as “stomach stones.”

Gastroliths extracted from the interior of a Cretaceous elasmosaur (a large, long-necked marine reptile) in central Queensland, Australia. Specimens are at the Stonehouse Museum and collected by “Dinosaur” Dick Suter in Boulia, Queensland. I know, they just look like a bunch of rocks, not trace fossils. Please read on, and prepare to learn.

A Trace Fossil by Any Other Name

Seemingly everyone – but especially five-year-olds – can enthusiastically rattle off the genus or species name of their favorite dinosaur or other prehistoric animal. “Tyrannosaurus rex!” “Triceratops!” “Dimetrodon!” But I will bet a six-pack of my favorite adult beverage that 99% of people – kids and adults alike - cannot name a single trace fossil in the same way. And even if they did, could you imagine anyone applying the same vigor and gusto reserved for body fossils as they shout out the names of trace fossils? “Ophiomorpha nodosa!” “Eubrontes! “Celliforma!”

Wow, look! It’s Thalassinoides in Early Cretaceous rocks of Victoria, Australia! I absolutely love that trace fossil! Wait, come back – where are you going? Was it something I said?

Who Made the Three-Toed Dinosaur Track?

In paleontology, occasionally a scientific hypothesis rules for several decades or more and enters the public realm, becoming part of popular lore. Nonetheless, science is always changing, which means that what we took for granted as a “true” story can be upended in a way that surprises everyone, perhaps even the paleontologists doing the revising. Such is the situation with the “giant-stalking-theropod-dinosaur-causing-a-dinosaur-stampede” story of the Lark Quarry dinosaur tracksite in Queensland (Australia). This tale has been reigning for more than 30 years and is known worldwide by paleontologists and laypeople alike, but now faces a makeover in the light of new evidence.

Here are some dinosaur tracks from Queensland, Australia. The dinosaurs that made them had three toes on their rear feet, and walked only on those two feet (bipedally). So were these from theropod dinosaurs or ornithopod dinosaurs? Don’t know? Then I guess you’ll have to read more, won’t you? Display is at the Museum of Tropical Queensland in Townsville, Queensland (Australia). Note the stylish sunglasses (lower right) for scale.

The Mystery of Lark Quarry

One of the most famous dinosaur tracksites in the world – Lark Quarry Conservation Park in central Queensland – is protected from the elements of the Australian outback by a beautiful, spacious, and environmentally friendly building. But how comfortable would it be to spend a night there, alone with the dinosaur tracks? I was about to find out, having been accidentally locked in, and just after the departure of the last tour of the day.

Lark Quarry has gorgeous dinosaur tracks, and lots of them. But would you sleep with them?

Why Dinosaur Tracks Matter

As an ichnologist, I have often witnessed and noted the contrasting enthusiasm of someone finding a dead body, versus finding clues that tell a story, but lack a body. No, I am not writing about a scene from some lurid U.S. crime show on TV (CSI, NCIS, Bones, ad nauseum).

A crime scene in progress, where one fossil collector turns on another, either in a jealous rage over a recently discovered Cambrian trilobite, or (more likely) because the ichnologist (right) will not stop complaining about the lack of trace fossils in the rocks.

Instead, this is about the excitement that surrounds the discovery of a bone, shell, or other body fossil in the field, and how that interest stands in direct contrast to the discovery of a trace fossil, which may have been made by the very same animal that owned the body part.

Now, this is not to put down bones, shells, impressions, carbon films, or other fossils that reflect former bodily remains of plants and animals. I am likewise very happy to find body fossils, and become excited for my fellow paleontological practitioners when they uncover these, too. After all, let’s say you crack open a rock with a hammer, and that rock splits to reveal the remains of a once-living, once-breathing, once-reproducing, once-feeding (well, you get the idea) plant or animal. Then dig this (pun intended): yours are the first human eyes to see it since it shuffled its mortal coil and became one with the earth. How could any feeling human being not be excited by that thrill of discovery?

Paleontology in practice is an inclusive science, though, in which its participants ideally employ a combination of body fossils, trace fossils, and chemical fossils to reconstruct life before humans. Body fossils, appropriately enough, consist of body parts, and hence represent direct evidence of ancient life. Trace fossils normally do not include any body parts and are the products of behavior; these fossils are best represented by tracks, trails, burrows, nests, feces, toothmarks, scratchmarks, and other forms of indirect evidence. Chemical fossils consist of ratios of elements that tell you something was alive just before its elements were incorporated into an examined rock, such as stable isotopes of carbon (no, I will not explain that – but you can read about it here) or certain compounds called biomarkers.

So when given this list of possible fossils, which do you think paleontologists work with the most? Yes, you’re right: body fossils. Accordingly then, the paleontologists who receive the greatest public accolades for their finds are those who discover or describe body fossils. OK, so of these body fossils, which ones get the most attention from that same adoring public? Why yes, you’re right again: dinosaurs! Granted, an occasional fossil fish or mammal sneaks into the bright, shiny media spotlight, but a single dinosaur bone, especially of a large carnivore, can generate thousands of headlines, Facebook status updates, Tweets, and other digital shockwaves.

A single dinosaur bone – a pelvic bone, specifically – from the Cretaceous of Victoria, Australia that got a wee bit of public recognition recently. Why yes, it belongs to a large carnivore: why did you even have to ask? Image from Roger Benson of Cambridge University, and published by National Geographic. (And for you Yanks out there who refuse to use the metric system, 30 cm = 12 inches.)

On the other hand (or foot), a single track belonging to a dinosaur, especially of a carnivorous one, can also get some attention, but its fame may not last as long. For example, once I had found a couple of (not-so-good) large theropod tracks at the Dinosaur Dreaming dig site in Victoria, Australia in 2006, dig crews thereafter were on the alert for other tracks. So they started looking for something they previously did not think was there. (You never know until you look, even if sometimes you still haven’t found what you’re looking for.) And what do you know, they found one, and it was from a large theropod dinosaur.

A single dinosaur track, probably of a large theropod dinosaur, found by volunteer Tyler Lamb at the Dinosaur Dreaming dig site in February 2007. And I mean, at the site, only a few meters away from where they were digging for dinosaur bones. Volunteers had been walking over it for about 14 years and had not noticed it, because, you know, it wasn’t a body fossil. Scale = 10 cm (4 inches).

Once a body fossil of a large carnivorous dinosaur was unveiled three years later, though, this track was not mentioned at all in news reports as previous evidence of large theropod dinosaurs living in that area at about that time. How fleeting the fame.

No, I’m not jealous of body fossils and the flashbulbs, red-carpet walks, bling, and swag bags they receive: I just want equal time for trace fossils. Consequently, in recent years I have been acting more and more as an “ichnoevangelist,” trying to convert the Great Unwashed who have not felt the daily transformative power of trace fossils in their lives. (As for paleontologists who study chemical fossils: sorry, you’re on your own.) I have even created my own “religion,” The Church of Ichnology, which has its holy trinity of Substrate, Anatomy, and Behavior (amen). (More will be said about that topic in a future post. But for now, also file away that this “church” requires drinking, dancing, and lots of cursing about body fossils.)

So let’s say you love body fossils, especially of dinosaurs, and are amenable to an ichnological conversion; in other words, you’re paleontologically bi-curious. Why should you care about dinosaur trace fossils, and especially dinosaur tracks? Let me count the ways:

• Dinosaur tracks are typically found in the exact same place where a dinosaur was living. Where you see a dinosaur track, that’s where it was walking (or, less commonly, running). On the other hand, bodies and bones can be moved far away from where an animal actually lived. For instance, where I live, in the state of Georgia (U.S.A.), all dinosaur body fossils there have been found in Cretaceous rocks that formed in shallow-marine environments. Yet all dinosaurs lived in terrestrial environments. This means these dinosaurs died on land, then their bodies were washed out to sea, where their bones were finally buried.

Close-up of a surface of Cretaceous rock that used to be soft sediments deposited on a lakeshore about 98 million years ago, in Queensland, Australia. See any dinosaur tracks? If you do, then you know those dinosaurs were living on that lakeshore (however temporarily).

• Dinosaur tracks are far more abundant than their bones. My esteemed colleagues who study dinosaur bones and make regular appearances on Oprah (or, more likely, The Colbert Report) will begrudgingly concede this point if I press them on it. Dinosaur ichnologists just have lots more fossils to work with. Of course, when you think about it, it’s not even fair to make the comparison. After all, one dinosaur could have made tens of thousands of tracks during its lifetime, but it’s various body parts may or may not have made it into the fossil record. The odds are lopsidedly stacked in favor of a paleontologist finding dinosaur tracks, not bones. Epic win for dinosaur ichnologists!

Panorama of Lark Quarry tracksite in Queensland, Australia from the mid-Cretaceous age (about 98 million-year-old). See all of those indentations on the surface? Almost all of those are dinosaur tracks. Number of dinosaur tracks on this 210-square meter rock surface? About 3,300. Number of dinosaur bones on this same surface? Zero. I rest my case, however anecdotally.

• Dinosaur tracks are often in places where you don’t find their bones. Let’s say you’re a paleontologist and you want to find some dinosaur bones. So you start by looking at sedimentary rocks of the right ages, which would be from the Late Triassic through Late Cretaceous Periods, or about 225-65 million years old. You also want to look at rocks formed in the right environments, such as rivers or lakes. (Yes, I mentioned earlier how dinosaur bones might be in rocks formed in marine environments, but these are much more rare.) Lastly, you’d like a place with lots of exposed rock that is not covered by pesky vegetation.

 Why is this paleontologist (Tom Rich from the Museum of Victoria) looking for dinosaur bones along this dangerously slippery rocky platform inundated by smashing waves, and just below high cliffs that continually test gravitational theory by shedding excess boulders, which always seem to fall down instead of up? Could it be because these rocks represent the right age and right environments for dinosaurs, and are not covered by vegetation?

So let’s say you go down this checklist – check, check, check – and you still don’t find any bones. Well, you can blame this misfortune on the Great Goddess of Taphonomy, who decided that the dinosaur bones would not be deposited in those environments, or that they would be deposited, but have since been dissolved by acidic groundwater or otherwise had their elements recycled.

So you have places without dinosaur bones that really should have them? Start looking for dinosaur tracks instead. You just might find them.

• Dinosaur tracks can tell you exactly how a dinosaur was behaving on a given day. If you look at any given dinosaur bone, it can tell you something about how that animal lived. But this exercise often requires a lot of speculation, and usually fails to provide any “snapshots” of behavior on a given day in the Mesozoic Era, unless it has cool trace fossils in it, like toothmarks or carrion-beetle borings in it (which, incidentally, were not made by the dinosaur that owned the bone). In contrast, dinosaur tracks tell you the type of dinosaurs, their approximate sizes, how dinosaurs moved, how fast they were moving, when they stopped for a rest, if they had an injury, whether they were moving together, and other such important information that either supplements or surpasses information that can be gained from bones.

 See those big, round impressions in Cretaceous rocks of Western Australia (near Broome)? Those are sauropod dinosaur tracks, and they indicate a probable presence of titanosaurs in an area where their bones have not been found (yet). My wife Ruth (a.k.a. Hallelujah Truth), a true convert to the Church of Ichnology, gazes upon these tracks with genuine awe.

So now that all of you are members of the Church of Ichnology and believe in the restorative and redemptive value of dinosaur tracks, you will appreciate next week’s topic all the more: the mystery of Lark Quarry – one of the most important dinosaur tracksites in the world – and how it was originally interpreted, then recently reinterpreted. Best of all, it’s in central Queensland, mates. See you then and there, but in the meantime, happy tracking!

Clancy, Matilda, and Banjo: Australian Dinosaurs, Living Large

“Discoveries are the currency of science.” When I heard renowned biologist and Pulitzer-Prize winning science author E.O. Wilson say these words several years ago during a visit to Emory University, I have reminded myself since of how the continuing discoveries of dinosaurs and other fossils probably reflect the most cost-effective way for science to progress. And when it comes to paleontology, few places in the world have yielded better “bang for the buck” than Australia.

“G’Day! My name is Banjo. I have come here to chew bubblegum, and kick bum. And I'll all out of bubblegum.” Fantastic artwork by Travis Tischler, Australian Age of Dinosaurs.

The Australian Age of Dinosaurs is Now

What is happening right now in Australia with dinosaurs is akin to another time and place on the other side of the world: the 19^th century and the American West. 

The Great Ocean Road(cuts)

After three days of rain, high winds, and waves, a break this morning (Saturday) in at least one of those three impediments – rain – meant that we could get out to see a few Cretaceous outcrops and look for trace fossils.

Just a little bit of white water along the coast: no worries, mate.

To avoid waves and wind, though, the outcrops would have to be along the Great Ocean Road in Victoria. The Great Ocean Road is the Australian answer to Highway 1 in California, as both roads are famous for their fantastic views of where rocks meet the sea. The Great Ocean Road was begun just after World War I as a tribute to the men who served in that war, who were rewarded by being given the job of building the road. (Not to worry, they were paid for this work, and I’ll bet it was a vastly improved experience over fighting in the trenches of World War I.) The road was started in 1919 and finished in 1932, an amazing feat of Australian engineering and hard work that should not be neglected in your thoughts as you turn corners while driving and gasping at the amazing scenery along the way.

Perhaps the most spectacular geologic site visible off The Great Ocean Road is The Twelve Apostles, a series of seastacks eroded from Miocene marine limestone, located about a 1.5-hour drive west of Apollo Bay.

The Twelve Apostles, now more like the 7.5 Apostles, subject to further revision as long as shoreline erosion continues (which it will).

These seastacks and others in the area comprise a major tourist attraction, with day tours from Melbourne taking people there daily so they can take pictures of one another in front of vertical pillars of stratified Miocene limestone. (I mean, when you put it that way, who could resist?)

Nonetheless, we went east of Apollo Bay this morning, and pulled off into small roadside parking areas wherever a tasty roadcut beckoned. After about 11 days of field work on coastal outcrops in Victoria, this roadside geology felt more like home to me. Much of the geology I have done in the Appalachians, including for my Ph.D. dissertation in the late 1980s, has been on roadcuts. The mud puddles, grassy areas separating me from the rocks in places, random spider webs, and paranoia about getting hit by a car, all while staring up at an expanse of rock, all felt cheerfully familiar.

A Great Ocean Road(cut) of Cretaceous shale and sandstone, inspiring memories of Appalachia, but not quite the same.

A few big differences popped into my head, though, reeling me back to this place and time. One was that I could hear the roar of ocean waves below the road, a sound I have never heard anywhere in my field work in the southeastern U.S., and you would not have been likely to hear in that area since the Eocene Epoch (more than 50 million years ago). Just a few minutes ago, while writing this, I heard a kookaburra let loose its distinctive loud, raucous call, which you are most likely to hear in the southeastern U.S. by watching an old Tarzan movie.

Also, and most strangely, while I scrutinized the outcrops for trace fossils, not a single disparaging epitaph was shouted by passing motorists, nor did anyone honk a horn, let alone throw a half-consumed bottle of Bud Lite at me. Even the bicyclists who rode by smiled and cheerfully said “G’Day” before peddling on, instead of grimly ignoring me as they no doubt fantasized of being Lance Armstrong (or fantasized about Lance Armstrong, with the distinction thus made). This country is very nice to geologists, although I’m sure a few people driving by privately thought I had a ‘roo loose in the paddock.

Oh yes, one more important point to keep in mind was the message of the following sign:

This sign is clearly intended for American visitors who are driving their rental cars straight from the Melbourne airport to the Twelve Apostles. Sadly, it suffers from the fatal flaw of assuming that these Americans: (a) read; and (b) care. For me, I required constant reminding about this reversal of expectations for the directions of oncoming cars alongside this narrow road (“Great” refers to the gorgeous sights along it, not its width). Three quick turns of the head – right, left, then right again – followed by a mad dash across the road, was the best way to safely accomplish this sort of field work.

By mid-day, the rain began again, but six extensive outcrops had been surveyed. Almost no trace fossils were seen, but it was well worth the effort. After all, the best geologist is the one who sees the most rocks, and it was a privilege for this Yank to get a closer look at the rocks along the Great Ocean Road.

At the end of the rainbow is a Cretaceous trace fossil of unparalleled beauty and exquisite charm. Problem is, it’s underwater.

Dinosaurs Down Underground, Part I

(Field work has temporarily ceased for the past two days because of intermittent rain, occasional high winds, and powerful waves that are causing seawater to cover up the beautiful Cretaceous along the coast here in Victoria. In the meantime, here is the first part of a two-part series on burrowing dinosaurs.)

Why am I here in Victoria, Australia, when perfectly fine and extensive outcrops of Cretaceous rocks are in the western U.S.? Heck, Cretaceous rocks are even in southern Georgia. From Atlanta, I could drive just a few hours to see those, instead of flying to Los Angeles and dealing with the hellish nightmare of LAX, just before squeezing myself in between two fellow anonymous travelers for the 15-hour flight to Melbourne, then recovering from jet lag for a few days after that, which is only cured by alternating consumption of fine Australian coffee drinks with beers. (OK, so the last part isn’t so bad.)

There are several reasons why I traveled more than halfway around the world to see the rocks here, versus just staying put in Georgia. One is that most of the Cretaceous rocks in Georgia are covered by an invasive creeping vine called kudzu, which is so bad, it inspires the geologists there to consider bringing back the much maligned (but probably just misunderstood) defoliant Agent Orange. Most Cretaceous rocks in southern Georgia are also weathered to the point where people living there just call it “dirt.”


Kudzu (Pueraria montana), covering the landscape, trees, houses, and slow-moving children in Georgia, and the bane of geologists there and elsewhere in the southeastern U.S., giving good reason to fly for more than 24 hours to see a decent amount of Cretaceous rock containing some tasty trace fossils.

Most importantly, though, the Cretaceous rocks in Georgia were formed in shallow-marine environments. Now, I personally hold no animosity against marine environments (not even mild scorn), and in fact have done several studies of trace fossils made by critters that formerly lived in shallow- and deep-marine environments. But if you want to study how dinosaurs, mammals, insects, and their companions really lived during the Cretaceous – and I do – then you’d best look at rocks formed by freshwater river sediments.

Sure enough, sediments of former rivers, lakes, and other inland environments were responsible for making the Cretaceous rocks here in Victoria. When we stand on these rocks, we sometimes share the same spot where a dinosaur stood, a mammal scurried, or an insect conducted insect business, which mostly consisted of feeding itself or making more insects. But still, it’s pretty neat to know that these rocks are the remnants of environments shared by those and other animals.


A very happy me, taking notes on many geological and paleontological observations of Cretaceous rocks in Victoria, Australia, which is all made possible by their not being covered by kudzu.

So that’s a few reasons for being here. The one of the most important reasons is that this is one of only two places in the world where dinosaur burrows were interpreted. And I was connected to both of those interpretations.

“What’s that?”, you say. “Dinosaur BURROWS?” Just in case you've never heard of such a thing, and you somehow imagine a tyrannosaur emerging from a hole the width of the Holland Tunnel, don't feel bad. This is still a new concept in dinosaur paleontology. The first firm evidence for burrowing dinosaurs wasn’t found until 2005. The second place was about, as the lorikeet flies, in Cretaceous rocks about 20 kilometers (12 miles) from where I’m sitting right now. This place is called Knowledge Creek: more about it soon.

Although no scientific clues for burrowing dinosaurs existed before 2005, Tom Rich and Patricia (Pat) Vickers-Rich proposed burrowing as a behavioral strategy for Victorian dinosaurs in a paper in 1988. So why did they make such a silly statement, with seemingly no data to back it up? Well, if you recall from a previous post or two of mine, the environments here were near the South Pole 105-120 million years ago, and it got chilly, especially during the winters. Tom and Pat further reasoned that the small dinosaurs living in this area could not have migrated – that required too much energy – so the simplest way for them to survive a polar winter would have been to stay in burrows. Lots of modern critters do this in polar environments, including polar bears, so why not dinosaurs?

Were there any burrowing dinosaurs? Yes. The first known burrowing dinosaur from the geologic record was discovered in Cretaceous rocks of western Montana in 2005, although it was not revealed to the scientific community until 2007. This dinosaur was named Oryctodromeus cubicularis, which literally means, “digging runner of the lair.” It was a small ornithopod dinosaur that lived about 95 million years old, and it had several anatomical traits showing it was well adapted for burrowing.



Profile view based on preserved bones and a close-up portrait of the “digging dinosaur,” Oryctodromeus cubicularis, from 95 million years ago in what we now call Montana, yet another place that lacks kudzu and has great exposures of Cretaceous rocks. Illustrations by Lee Hall.

Very luckily, this dinosaur was also found in a fossil burrow of the right size, and was entombed with two of its partially grown offspring. Remember, in science we like to have multiple lines of evidence to support our hypotheses, so to have both trace fossil and body fossil evidence, especially with multiple specimens, and all in the same place, was very nice indeed.


Artistic rendering of an adult Oryctodromeus cubicularis and its OH THEY’RE SO DARNED CUTE offspring (soon to be dead and fossilized) in a den made by the adult dinosaur. Artwork by very skilled paleoartist Mark Hallet, done for a special issue of National Geographic, May 2008.

The second piece of evidence for burrowing dinosaurs was “just” from trace fossils, and no bones were involved. During my first visit to Victoria in May 2006, I noticed a couple of odd structures in an outcrop of the Otway Group (from about 105 million years ago) at a foreboding place Knowledge Creek. (Yes, even its name is laden with symbolism, evoking thoughts of the River Styx – not to be confused with the ‘80s band Styx, of course.) This was less than a year after Oryctodromeus had been discovered, although this dinosaur had not yet been announced to the world. One of the Knowledge Creek structures, though, almost perfectly matched the size and shape of the burrow associated with Oryctodromeus.

Wait a minute: how did I know that then, in 2006? Oryctodromeus and its burrow were still unknown to the scientific community, and the paper describing it would not be published until early 2007. Was I clairvoyant, really good at guessing random ideas, or (most likely of all) spiritually inspired by The Flying Spaghetti Monster?

The short answer is, none of the above: I had inside knowledge. At the time, I was part of the research team working on Oryctodromeus, and had seen and studied its burrow only eight months beforehand, which looked almost exactly like the Knowledge Creek burrow. It was a coincidence that, much like Glenn Close’s character in Fatal Attraction, would not be ignored. (All right, I must admit that I didn’t then pursue the dinosaur burrows in a murderously vengeful way after having an affair with them. So perhaps it was more like Pee Wee’s Big Adventure.)

To make a long story short, one of the big reasons why I am here is to look for more evidence of burrowing dinosaurs in Victoria. But for my faithful readers to better understand the science that preceded that decision, in my next post I’ll provide a brief history of how this whole idea of “burrowing dinosaurs” came together in just the past few years.

(Three peer-reviewed scientific papers that show either end of the “dinosaurs living in burrows” idea are:

(1) Rich, P.V., Rich, T.H., Wagstaff, B.E., McEwen-Mason, J., Douthitt, C.B., Gregory, R.T., Felton, E.A., 1988. Evidence for low temperatures and biologic diversity in Cretaceous high latitudes of Australia. Science, v. 242, p. 1403–1406;

(2) Varricchio, D.J., Martin, A.J., Katsura, Y., 2007. First trace and body fossil evidence of a burrowing, denning dinosaur. Proceedings of the Royal Society of London, B, v. 274, p. 1361–1368;

(3) Martin, A.J. 2009. Dinosaur burrows in the Otway Group (Albian) of Victoria, Australia, and their relation to Cretaceous polar environments. Cretaceous Research, v. 30, p. 1223–1237.)

Getting Wet in Cretaceous West

Geologic field work can be a great equalizer, erasing the artificial hierarchies all too often imposed by academia and other institutions. As one geologist I know puts it: when you’re out with a group of geologists in the field and it starts raining, you’re all getting wet, Nobel Prize winners and undergraduate students alike.

That’s why, when I do field work in a new place, I welcome the assistance of experienced, enthusiastic, and energetic local people, regardless of whether they have academic training in geology or not. There is a relief in knowing that no one has to talk about where they went for their Ph.D., who they worked with, where they published their latest papers, what grants they’ve received recently (and their amounts), and other such metrics that all become meaningless when you’re getting wet together.

So with that spirit in mind, I was very pleased that the beginning of our field work Monday in the Otway Ranges (“The Otways”) west of Melbourne – or what I am calling “Cretaceous West” – began with the help a local who fit all of the criteria just mentioned (experienced, enthusiastic, energetic), Greg Denney. Greg lives near Dinosaur Cove, just west of where we started our work at Apollo Bay, Victoria, and he does quite a bit of bushwalking and guiding around here. This, along with his curiosity about natural history, has resulted in much knowledge about the local plants, animals, and other valuable information that has absolutely nothing to do with academia or American Idol (which I sincerely hope is never broadcast in Australia).

Greg Denney, exhibiting the Australian trait of “mateship,” by helping Tom Rich across a tricky part of a Cretaceous outcrop.

His partner, Deb, owns and manages a bookstore in Apollo Bay, Galapagos Books. Both have been connected with Tom Rich through his previous work at Dinosaur Cove and other paleontological work in the Otways, and they are always eager to assist in whatever way they can when Tom or other paleontologically oriented folks come into the area.

Our plan that morning was to do a “car shuffle,” in which we took two vehicles to the intended destination of our walk, left one vehicle there (Greg’s), then took the other (ours) to the starting point. That way we would have a one-way trip for our walk, instead of backtracking over the rocky shore platform toward the end of the day, when the light was dwindling along with our energy reserves.

The starting point of the walk was at a carpark at Marengo, and the intended ending point was Blanket Bay, about 5-6 kilometers (3-4 miles) to the southwest along the coast. It didn’t quite work out that way, which is another reality of geologic field work: you always keep in mind how circumstances can change, and you just have to improvise, innovate, and adapt to whatever situation might present itself.

The ride to Blanket Bay first involved our winding through a beautiful, thick, lush eucalyptus forest of Otway National Park. Tom and I rode together in our vehicle as we followed Greg in his. During this ride, I recalled to Tom how during one previous time in this very same forest, I spotted a few koalas in the trees while speeding by in a car. Tom did not seem to believe me, so in the next 30 seconds or so, I pointed to one in a tree just in front of us, then four or five more in the next few minutes.

Behold: Koala the Forest Destroyer, which is also the most recent common ancestor of the deadliest and most dreaded animal in Australia, the "drop bear."

Turns out that this was really not an impressive feat of eco-magic on my part, as the koalas are very abundant here, and have taken over this part of the park, denuding and killing many of the eucalyptus trees. Greg informed me that this problem stemmed from a reintroduction of koalas to the area in the late 1970s that has since gone amuck. After all, even native species can outstrip their resources under the right set of conditions. So wherever we saw starkly white and barren eucalyptus trees, these were the places where koalas had eaten all of their leaves and deprived these trees of their way to make a living.

But enough talk about arboreal marsupials and their greedy ways. We were here for geology and paleontology! The three of us rode back together to Marengo, where we started out walk just before 11:00 a.m. Nearly five hours later, after traversing much Cretaceous rock along the shoreline and seeing some trace fossils – including some of the largest freshwater crustacean burrows I have seen anywhere – we were still kilometers away from Blanket Bay. We had grown tired, the sun was getting lower in the sky, a chill had suffused the air, and the waves crashing near us seemed just a bit more fierce.

Before and after photos: the first shows the start of the hike, near lots of beach houses in Marengo, the second near the end of our field work.

So Plan B went into effect. We were near well-marked access trails that connected to the shoreline, appropriately called “Decision Points.”

As the sign says, Elliot River, Decision Point 5. Note all of the graphic exhortations of peril, encouraging a hiker to turn back and just read about this trail.

Greg had brought a detailed map with him that showed all of the nearby trails, and he knew the area very well. So even though he and I each had good (and functioning) GPS units, we did not need these to figure out where to go: there’s no substitute for a fine map and the ability to read one. He also had a mobile phone, but to get reception he needed to go up one of the access trails to a carpark. From there, he called his partner Deb to ask for a ride. She came to the carpark with her sport-utility vehicle (“ute”) within a half hour of Greg calling, and soon we were speeding our way out of the forest, back to Marengo.

Rare, never-before-seen video footage of an Australian and Yank experiencing the ride out of Otway National Park on the back of a “ute.” No koalas were sighted along the way, but on the up side, neither were any “drop bears.”

Me on the back of the “ute” at the end of the ride, and back at our starting point in Marengo. Photo by Greg Denney.

During this coastal walk along the Cretaceous West coast, we also got wet together. At some point late in the afternoon, a big wave washed a sheet of water straight toward all three of us. Greg and I laughed as we ran away from it toward high ground: alas, to no avail, our boots became soaked. But it was a reminder of how field work can make us both equal and dependent on one another’s knowledge for making things work out right.