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.

Discovering the Dinosaur Tracks of Milanesia Beach

(In my previous entry, I described the start of a day in the field – June 14, 2010 – at Milanesia Beach, Victoria (Australia), just hours before Tom Rich, Greg Denney and I discovered the largest assemblage of polar dinosaur tracks in the Southern Hemisphere. In that entry, I also pointed out how few dinosaur tracks had been documented in Victoria before then, which also meant very few polar dinosaur tracks had been found in the Southern Hemisphere. This background gave some context on why this find is a big deal, paleontologically speaking. So, would you like to want to learn how these tracks were discovered? Then read on.)

As Tom Rich, Greg Denney, and I walked down Milanesia Beach the morning of June 14 2010, my thoughts were about the dearth of dinosaur tracks found thus far in Victoria, Australia. Geological research of these Cretaceous-age rocks had been going on for more than 100 years, and paleontological studies there had been particularly intense during the past 30 years. Yet during that time, only four definite dinosaur tracks had been discovered in all of the extensive Cretaceous outcrops of coastal Victoria. Moreover, all of these were individual prints, with no dinosaur trackways showing at least two sequential steps. The previous three weeks of field work Tom and I had done along the coast seemed to bear out this notion that dinosaur tracks were rare here, even scarcer than their bones.

Nonetheless, I also tried to shake a premonition, experienced only a half hour after arriving at Milanesia Beach, that we might find dinosaur tracks there. Rest assured, this hunch was not inspired by séances, Ouija boards, psychic-pet hotlines, or any other forms of necromancy. Instead, it was based on our seeing the physical sedimentary structures and small invertebrate trace fossils (burrows) that told me we were looking at the former deposits of river floodplains. These environments would have been perfect for preserving dinosaur tracks. Regardless, I reminded myself to just be a cold, clear-headed, objective scientist: you know, a pessimist.

 A few more of the dinosaur tracks of Milanesia Beach, Victoria (Australia). Three size categories were there: small, medium and large, all made by three-toed theropod dinosaurs. Greg Denney found the ones shown here, which he discovered by recognizing how this rock matched another one with dinosaur tracks that I had found just a few hours before. Please buy him an adult beverage next time you see him, slap him on the back, and say, “Good on ya, mate!”

The Dinosaur Tracks of Milanesia Beach: Part I

Because of the sparse and uneven record of dinosaurs in Australia, their fossil footprints are more valuable here than anywhere else on Earth.

- Thomas H. Rich and Patricia Vickers-Rich, A Century of Australian Dinosaurs (2003).

The Preamble

Dinosaur tracks are hard to find. This humbling realization struck me during the third week of a month-long field excursion in May-June 2010, while doing field work along the craggy coast of Victoria, Australia. Why was I there, engaging in such an apparently fruitless quest? Paleontologist Tom Rich of Museum Victoria had invited me to look for trace fossils made by dinosaurs and other Cretaceous animals that might be preserved in the rocks of Victoria. Yet as was often the case with looking for fossils of any kind, there were no guarantees of success. He and I had already searched more than a hundred kilometers of coastal cliffs and platforms east of Melbourne, and were then working our way through sites west of there.

Here are four three-toed dinosaur track,s preserved on a block of sandstone at Milanesia Beach, Victoria (Australia). They’re faint, but there – look closely for all four. These tracks were probably made by small theropods on a river floodplain during a polar summer about 105 million years ago, when Australia was close to the South Pole. On June 14, 2010, I discovered the block that contained these tracks, and a few hours later, Greg Denney found another block with more tracks. This is a big deal, as they represent the greatest number of polar dinosaur tracks found in any one place in the Southern Hemisphere. It’s enough to make you want to do a happy dance. Scale bar in photo (lower left) = 10 cm (4 in).

Cruising the Cretaceous of Queensland: Student Edition

Earlier this month – July 4-8, 2011 – was my third time to see the wondrous Cretaceous fossils of Queensland, Australia. But it was my first with university students in tow to share in that paleontologically inspired excitement. Our trip together to outback Queensland was during the third week of a five-week program for Emory University students taking a study-abroad program in Australia, taught by me and my good friend (and oh yeah, colleague) Steve Henderson from Oxford College of Emory. We did this trip to give them a taste of what life was like in the modern-day outback and 100 million years ago during the Cretaceous Period, when theropod dinosaurs like Australovenator wintonensis (“Banjo”) likely chowed down on hapless ornithopod dinosaurs, and the whopping pliosaur Kronosaurus queenlandicus was ruling the inland seaway that covered much of the area we saw during our trip.

Paleontological innocents abroad, about to get acquainted with the past lives of outback Queensland. And who could resist posing with a life-sized recreation of the large ornithopod dinosaur Muttaburrasaurus langdoni, located in Hughenden, Queensland? Well, OK, I told them their grades depended on it, so they quickly got into the spirit of things.

The Dinosaur Tracks of Western Australia May Go Extinct

You really have to want to visit Broome and nearby environs in the Kimberly region of Western Australia, because it’s a long ways from nearly everywhere else in the world. Even of the Australians I’ve met, relatively few have been there, despite Broome’s beautiful beaches, camel rides on those beaches, a wonderful open-air theater (the oldest In Australia), pearling history, longtime connections to Asian culture, small-town feel, and charming locals. Oh, and its dinosaur tracks, which of course was one of the reasons why I was motivated to go there with my wife Ruth in 2009.

Anyone up for some “ichnotourism”? At low tide near Broome (Western Australia), you can see some of the biggest dinosaur tracks in the world, made by sauropods about 130 million years ago. Or, you could put a gas-processing plant on top of them and build a port, which will generate absolutely no ichnotourism, stuff up the local environments, and if anything drive people away from the area. Hmm, tough choice: (A) short-term profits benefiting a few people and causing lots of collateral damage, vs. (B) preserving a world-famous natural resource, coastal environments, and cultural heritage that will continue to give back tourism dollars to the local community in perpetuity. Not to bias you, but I’m going with (B). (BTW, lovely wife Ruth for scale.)

Keeping Track of Fossil Tracks

The fossil thieves drove their sport ute into the Western Australia outback in the middle of the night, confident that no one would see them. Just to make sure, though, they turned off their headlights the last kilometer before their destination, using moonlight to keep their tires on the unsealed road. Once at the site, they used torches (flashlights) to search the ground, and quickly found what they were seeking. They pulled out a portable rock saw from of the back of the vehicle and cut through the 120-million-year old sandstone, the abrasive sound masked by nearby waves crashing during high tide. The sandstone bed was thick, but split evenly along its bedding plane so the thieves were able to use a lever bar to pry up each square. These blocks were heaved onto the truck bed; blankets were used to cushion them below and cover them above. The perpetrators got into the truck and sped away from the site, well before the first rays of the morning sun revealed the newly made and oddly square holes in the rock. They had just taken some of the few stegosaur tracks known from the geologic record, and they had stolen these from aboriginal tribal land. It was both a crime against the state and a grave insult to the people who regarded these tracks as part of their heritage.

Nice dinosaur track you got there. It’d be a shame if something happened to it. Track is from a large theropod dinosaur, preserved in Early Cretaceous sandstone of Western Australia. Please don’t take it, legally or otherwise.

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 Case of the Mistaken Dinosaur

Like all stories in paleontology, that of Lark Quarry – a world-famous dinosaur tracksite in Queensland, Australia - starts in the geologic past; in this instance, during the Cretaceous Period, about 98 million years ago. The cast of this tale consisted of about 150 dinosaurs, played by:

• One species of a large herbivorous dinosaur (an ornithopod), who was a mere bit actor, making a cameo appearance before the main act.

• Two species of small dinosaurs – one a theropod and the other an ornithopod – who made up most of the cast; and

• The star of the show, a tyrannosaur-sized theropod, who made a grand entrance toward its climatic finish.

The story is filled with dramatic flourishes, of a tranquil scene shattered by brutal carnivory, and of a quiet Cretaceous lakeshore becoming a killing ground. The former lakeshore, though, left no bodies, only tracks. So we have to reconstruct what happened there by using the oldest science known to humankind, ichnology: the study of modern and fossil traces.

A small sample of the 3,300 dinosaur tracks of Lark Quarry in Queensland, Australia, showing evidence for three species of dinosaurs that either walked or ran along a Cretaceous lakeshore 98 million years ago. Who made these tracks,  what behaviors do they represent, and how were the trackmakers’s behaviors related to one another? That is the mystery – and now the controversy - of Lark Quarry.

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!

Cretaceous Worlds of Queensland, Part V: Fossil Lives in Downtown Winton

After spending a night in the paleontologically delightful town of Hughenden, my wife and paleo-companion Ruth and I were off to Winton, about 215 km to the southwest.

I had visited Winton once before in 2007, but for only a day and night. Nonetheless, the trip there was so memorable (and why is another story), I had vowed to come back, and was eager for Ruth to visit it with me. Based on my all-too-short foray, I reckoned its combination of paleontology, bush poetry, cowboy culture, ample beer, and welcoming folks would be a winning blend for both of us. So we were prepared to stay a while to better soak up the unique flavors of this place.

We arrived in town early afternoon on Wednesday, June 30 2010, just after the start of the antipodal winter on a gorgeous blue-sky day, and promptly checked into the North Gregory Hotel. I had also stayed at the North Gregory during my previous trip, the main reason being that this was the site of where Waltzing Matilda was first performed in public, in 1895. Was this the original hotel, you ask? Well, no, and neither was its previous incarnation: three fires had wiped out three earlier hotels, including the original one. Hence the designation of this as the “site” where Waltzing Matilda was played. Place is important, as is memory.

The North Gregory Hotel, site of classic songs, fires, beers, paleontology, and other essential facts of life in the outback of Queensland, Australia. Photo is from Rita’s Outback Guide.

With only a few hours of sunlight left, we had a decision to make about our afternoon in Winton: Australian culture or Australian fossils? Our typical eclectic (or is it hedonistic?) attitude of “having our cake and eating it too” held sway, though, so we did both.

First we walked across the street to the Waltzing Matilda Centre, which claims that it is “the only centre devoted to a single song.” (I have little doubt that this assertion is correct, so you should likewise feel no urge to use “The Google” on “the Internets” to find out whether it is true.). The display there does indeed supply a thorough history of the composer Banjo Patterson and how Australia’s most famous song originated (like many songwriters, he was trying to impress a sheila). But Ruth was most impressed with a separate art gallery in the centre, which featured Australian-themed art from local artists.

The beauty of a small town like Winton is that we just had to walk back across the street to sate our thirst for paleontological knowledge. (Also beautiful was that beer could be had on both sides of the street.) The historic Corfield and Fitzmaurice Building, which used to be the town’s general store, is where you go to see fossils in downtown Winton. To see the largest dinosaur bones in Australia, which are coming out of the ground near there, you have to drive a little ways (about 15 km) east of town to the Australian Age of Dinosaurs, and to see a world-class dinosaur tracksite (Lark Quarry), you have to drive a lot more (about 100 km) to the south of Winton. (Do you think that’s enough foreshadowing of the next two blog entries?)

Dinosaurs, the North Gregory Hotel, and a bar! Winton has it all, including an abundant supply of XXXX. No, it’s not what you might first think, but as the Australian joke goes, “It’s how you spell ‘beer’ in Queensland.”

Despite what looked like a small place from the outside, we were impressed with what awaited us inside, all for just a small entrance fee: a nice collection of local fossils (many Cretaceous), and a locally produced diorama that recreated an event from the Cretaceous Period, 95 million years previously, recorded in the aforementioned dinosaur tracksite south of town.

“Excuse me! Pardon me! We really must be going!” There’s something about a large theropod walking through your neighborhood that invokes a bit of anxiety in a wee dinosaur.

The diorama in the Corfield and Fiztmaurice Building represents a labor of love, depicting in dramatic detail the interpreted scenario of the Lark Quarry tracksite. In it, the artisans reproduced the probable environment (a muddy lakeshore), a few representative dinosaurs that made the tracks – including one very imposing (and rather portly) theropod – and a bunch of dinosaur tracks, looking as if they were made yesterday, when actually they were made sometime in the past few years.

Dinosaur tracks, recreated in downtown Winton and representing tracks from a large number of small dinosaurs, with the real thing (a dinosaur tracksite) about 100 km south of town. I wonder why most of those tracks are heading in the same direction?

The diorama even include a bit of speculation (as far as I know) that one of the small ornithopod-dinosaur trackmakers slipped and fell into the mud, leaving it vulnerable to victimization, whereupon the large theropod set upon it in a most rapacious way. In other words, it got eaten.

Bloody hell – all me mates left me here in the mud for that theropod! (Too late, this small ornithopod discovers that there’s no mateship in the Cretaceous.)

Other than the diorama were fossils, and perhaps the most impressive is a sauropod femur in a display case, which I recall belongs to the sauropod dinosaur nicknamed “Elliott.” This prodigious bone was set alongside the femur of an adult bull (Bos taurus, male version). Considering the cowboy culture of the area, this made for a brilliant contrast, easily understood by nearly any visitor educated in bovine anatomy.

That’s not a femur.

That’s a femur!

But there was much more than dinosaurs here for a paleo-enthusiast to marvel. How about fossil plants? There were some of those, and as a great two-for-one special that pleased this ichnologist very much, a Cretaceous fossil leaf had a leaf mine preserved in it, where a larval insect burrowed below the leaf cuticle as it chowed down on some yummy mesoglea. How cool is that? These sorts of trace fossils can lend to insights about the original ecosystems in which the dinosaurs lived.

It’s a body fossil (a deciduous-tree leaf) and it’s a trace fossil (the leaf mine in the leaf, indicated by the arrow), coming from Cretaceous rocks of Queensland.

Some trace fossils on display that were not from the Cretaceous, but much more recent (I suspected Pleistocene) were labeled as “Sea Wasp Eggs. Leftopius duponti. Loc. S. Aus.” Yet they looked very much like some insect trace fossils I had seen from Argentina, like beetle pupal cases. So I took this picture and looked up the name later (yes, using “The Google” on “The Internets”), and was gratified to see that they were indeed pupal chambers, they are interpreted as the works of the Pleistocene weevil Leptopius duponti, and they have been reported from South Australia and northern Queensland.

“Sea-wasp nests”? No on all of those words, but they’re still very interesting trace fossils. These were made by Pleistocene weevil larvae, and found in South Australia and northern Queensland.

And even though dinosaurs were the paleontological stars of this exhibit, I was pleasantly surprised to see the skeleton of an old (but not quite a fossil) northern hairy nosed wombat (Lasiorhinus krefftii) on display, nicknamed the “Winton Wombat.” This wombat became famous within the Australian paleontological community when its bones were found in between some sauropod dinosaur bones at a dinosaur dig site near Winton.

The “Winton Wombat,” a northern hairy nosed wombat that burrowed down next to some dinosaur bones and died in its burrow just so it would confuse some paleontologists a few thousand years later. Cheeky bugger.

Was this a creationist dream come true, where modern mammals and dinosaurs lived at the same time, then were mixed together by a Noachian flood just before burial? Well, as we like to say in the southern U.S.: “Not just no, but hell no!” Here’s a really simple explanation, in three parts: (1) wombats are very good at burrowing; (2) this wombat burrowed down to the level of some 95-million-year-old dinosaur bones near the surface (which, as a matter of fact, is where they are found today); and (3) the wombat died in its burrow. Or, a miracle occurred. Your pick.

So what was next on our quest for furthering our paleontological education in the Winton area? How about a visit to the most exciting recent development in Queensland paleontology, the Australian Age of Dinosaurs Centre? See you there next week!

The theropod track on the sign would not lie: when you’re in Winton, you’re on Australia’s Dinosaur Trail.

Cretaceous Worlds of Queensland, Part II: In Town in Townsville

As loyal readers may already know (and new readers will learn in the remainder of this sentence), The Great Cretaceous Walk literally ended in late June 2010, but continues metaphorically as an exploration of the Cretaceous worlds of Australia: kind of a “walkabout through time.” The actual walking was done over Cretaceous rocks exposed in Victoria (such as here, here, and here), but more inwardly directed ambulating in the Cretaceous past happened in Queensland, Australia and well north of Victoria.

To see the Early Cretaceous rocks and fossils of Queensland, though, requires covering more than a few kilometers, bringing home the “variety show” that is Australia, well exemplified by just an easy day of travel in this expansive country. On such a day, my partner in paleontological pursuits (Ruth Truth) and I flew from the modern metropolis of Sydney (New South Wales) to Townsville, Queensland in just a few hours.

We went from there to there, and all in just a few hours. However much we complain about airport security, long lines, and expenses, this is the miracle of modern jet travel. Show it a little wonder, and stop whinging so much.

Townsville, Queensland from the air, with its beautiful shoreline and prominent inselberg – Castle Hill – overlooking the city. What’s an inselberg? Read on.

Nonetheless, this short trip entails a considerable change in both latitude and attitude. Townsville is a thoroughly modern town on the Queensland coast, but ensconced in a semi-tropical setting that instantly seduces, rendering the most frenzied city-dweller to sluggard status as soon as you step outside of its charmingly small airport.

Accommodations in Townsville, Queensland are not in the Cretaceous, but some days it feels like it. And that’s a good thing.

Because we were traveling during Australia’s winter – thus neatly missing the record heat of a Georgia summer – the change from the colder (albeit lovely) environs of Sydney to the embracing warmth of Townsville, accentuated by its organic briny smells of the Coral Sea and the squawks of cockatoos, was like taking, a long, slow sip of a craft beer. Which we did as soon as we arrived in downtown Townsville. (Who needs metaphor when you can have reality?)

Ruth and I had been in Townsville before, and have a fondness for it because I have spent more time here than any place else in Australia other than Melbourne. Why? In two previous visits, in 2006 and 2007, I co-taught Emory University study-abroad programs here, hosted on the lush and gorgeous campus of James Cook University. The courses offered in this program were evolutionary biology and ecology of invasions: invasive species, that is. Queensland is a fantastic place to learn natural history in general, and of Australia specifically, which is why I keep coming back to it, sometimes with students in tow, sometimes not.

It’s a jungle out there whenever you take a stroll across James Cook University (JCU) in Townsville: a very nice place to teach American uni students and observe a little bit of Australian nature on the way to and from class.

Modern theropods loose on the JCU campus! (Above) Stone-bush curlews (Burhinus grallarius), which I have seen pack-hunting during the night, but sometimes are out during the day. Make sure you look for the one hiding behind the eucalyptus tree: clever girl! (Below) A laughing kookaburra (Dacelo novaeguineae), a fierce carnivore with a raucous laughing call. P.S. It’s not a bloody monkey, mates!

But what of the Cretaceous in Townsville? Alas, there are no outcrops of such rocks in the area, and the most prominent geologic feature in the area is an igneous intrusion (now evident as a monadnock or inselberg) called Castle Hill (see the photo of Townsville above, and taken from above).

As a result, whatever Cretaceous rocks and fossils you might see there are in the Museum of Tropical Queensland, a lovely regional museum that neatly summarizes the natural history of this part of Queensland, including the Great Barrier Reef. To see the reef itself entails a 10-minute walk from the museum to a pier and a two-hour boat ride (or four-hours if you want to come back).

Among the displays is a fair-sized one about the Cretaceous rocks and fossils located a short drive west of Townsville. Did I say “fossils”? Yes, and best of all to an ichnologist, these included a few trace fossils along with the body fossils. Invertebrates are represented here, a few vertebrate remains, and even dinosaur tracks.

Some dinosaur tracks on display in the Museum of Tropical Queensland, preserved in a sandstone bed as natural casts, and accompanied by frustratingly little scientific information. Locality? Geologic age? Interpretations of the trackmakers and their environment? My photo was taken in 2006, though, so maybe this display has been updated since. In the meantime, feast your eyes on those tasty looking trace fossils! How many tracks do you see? How many different types of dinosaurs made them? What were they doing? And an added bonus: stylish field sunglasses for scale.

In recognition of the many small ornithopod (“hypsilophodontid”) dinosaurs whose bones keep popping up in the Cretaceous of Queensland and south of it in Victoria, the museum has a small reconstructed ornithopod on display for visitors to admire. I don’t recall which species it is supposed to represent, but it’s about the size of Leaellynasaura amicagraphica from Victoria, mentioned in some previous entries.

Aw, it’s such a cute little hypsilophodontid dinosaur! Can we take him home, mum? I promise I’ll feed him nothing but tree ferns and araucarian cones.

Body fossils include parts of former denizens from the Cretaceous seaway that cut through the eastern part of Australia about 100 million years ago. Cretaceous environments to the east and west of this seaway were where the dinosaurs roamed, but the Cretaceous sea was where dinosaurs had no say in how life was conducted.

The Cretaceous inland seaway of Australia, a great place to be alive. That is, until you got eaten by something else sharing the same seaway. Start studying the place names on the map, because we’re going to be talking about them in future entries. And yes, there will be an exam later. Display is at the Museum of Tropical Queensland.

Although the Cretaceous dinosaurs of Queensland are all the rage right now (understandably so), some of the most spectacular vertebrate fossils coming out of the outback, and just as captivating as dinosaurs, are marine reptiles. Ichthyosaurs and plesiosaurs were plentiful in the Cretaceous seas of Australia, and they likely preyed on abundant squid, fish, and each other.

Skull of the Cretaceous elasmosaur Woolungasaurus glendowerensis that probably ended up as lunch for something bigger, a supposition based on the puncture marks on its skull (arrow). This is a two-for-one special, paleontologically speaking: the skull is a body fossil, whereas the toothmarks are trace fossils of whichever sea monster chomped the elasmosaur’s face.

Also impressive are the recreations of these marine animals, which the museum has hung in aesthetically pleasing ways that give a sense of scale, and lends to imagining swimming in the same Cretaceous oceans (which would not last very long if you registered as “prey” in the search images of any of these animals).

The formidable Early Cretaceous pliosaur Kronosaurus queenslandicus, lurking above and waiting for tourists to come into view. Remember those toothmarks on the elasmosaur? We have a suspect in custody.

The plesiosaur (elasmosaur) Woolungasaurus glendowerensis, recreated in full, fish-eating view, and with Kronosaurus in the background (above), and ready for its close-up (below). She’s a beauty!

An ammonite and ichthyosaur, swimming together in harmony. Suspend disbelief for a moment and forget that these are, er, suspended. Sorry to have no species information, but they are very nice to look at, aren’t they?

So with this intellectual and visual information properly lighting up your cerebral hemispheres, we will go west, to central Queensland and the former sites of those Early Cretaceous landscapes and seas that held those varied and wondrous lives. See you next week, and in the Cretaceous of Queensland, Australia!