Let’s Talk Dinosaurs

It’s November. It’s cold. Dinosaurs are cool. So, I mean, why not?

Science | by Gregory Beatty

Imagine being alive at some point in humanity’s distant past and stumbling across a dinosaur fossil — the femur of a 45-metric tonne Brachiosaurus, say, or a Triceratops skull with its protruding horns and protective shield. What the hell would you make of that?

Even today, we have a hard time wrapping our heads around dinosaurs, though our understanding of them has grown by leaps and bounds. Still, a lot of myths and misconceptions linger.

“Dinosaurs are very popular, which is great!” says Royal Saskatchewan Museum palaeontologist Emily Bamforth. “It’s been wonderful for palaeontology that they’re such a hot topic. But with that there do come misconceptions about, first, what constitutes a dinosaur; but also, what dinosaurs were.”

Dino-mania Through The Ages

There are all sorts of myths and legends about dragons, sea serpents and other bizarre creatures. Ever wonder where they originated?

“A lot had to do with prehistoric creatures,” says Bamforth. “People would find these fossils and not know what kind of animal they came from, so they would build a story around that.”

By Victorian times, people knew that dinosaurs had once roamed Earth, but our understanding of what they were like was still limited.

“Because dinosaurs were a foreign concept, people had no idea what they looked like,” says Bamforth. “So the first reconstruction of dinosaurs in the mid-1800s was of these big, lumbering lizards. The Iguanodon, for example, looked like a giant iguana, because that was the framework they were using.”

Scholarly analysis of dinosaur fossils was underway by the 18th century. Fossil hunting reached a frenzy in the late 19th century when two American palaeontologists, Edward Drinker Cope and Othniel Charles Marsh, engaged in a “fossil war”. They were so eager to collect fossils and best their rival that they used dynamite to blast them out of rock.

In 1854, the first display of “lifelike” dinosaur sculptures — the aforementioned iguanodons —  opened at London’s Crystal Palace Park. The mold was big enough to fit a 21-person dinner party inside, which, yes, actually happened on New Year’s Eve, 1853.

Writers, and later filmmakers, were quick to incorporate dinosaurs into their stories. Jules Verne’s Journey to the Centre of the Earth (1864), and the movie Missing Link: A Prehistoric Tragedy (1915), are two early examples.

“Pretty much as soon as filmmakers could bring dinosaurs to the silver screen they were there,” says Bamforth. “Movies such as One Million B.C. were huge hits. Audiences really wanted to see these monstrous creatures from the past interacting with people which, of course, has no scientific basis. But that was the foundation of these original movies.”

So yeah, more myths and misconceptions. Still, considering the daunting nature of palaeontology as a science, some of our confusion  can be forgiven.

Not prehistoric humans and dinosaurs co-existing, though. That’s just whack.

Palaeo Puzzle

When dinosaurs first emerged around 235 million years ago, most of Earth’s land was clumped into the supercontinent Pangaea. It began to break up into our current continents around 175 million years ago. Dinosaurs lived through that and survived until around 66 million years ago, when an asteroid slammed into the Gulf of Mexico, unleashing toxic environmental conditions that caused a mass extinction.

Like other animals, dinosaurs, when they died, would’ve been eaten by carnivores and scavengers, or else simply decomposed. Special conditions are required for fossils to form, so they’re not common. Even when they did form, they were vulnerable, over many millions of years, to weathering and destructive geological forces. On top of that, scientists gotta find ’em.

So physical evidence in palaeontology is often fragmented and not easy to obtain.

“Whenever I take people through the gallery either in Eastend or Regina I like to point out that what they see with the mounted skeletons is the very end product,” says Bamforth. “Our big T-Rex ‘Scotty’ in Eastend, for instance, was found about 25 years ago. The excavation took three field seasons, plus two seasons after that to clean up the quarry.

“It took almost 20 years to prepare the skeleton. It was then shipped to Ontario where it was molded and cast. So there are literally hundreds, if not thousands, of person-years that went into that skeleton.”

Birds Baby!

So what, exactly, is a dinosaur?

“There are set criteria palaeontologists use to classify them,” says Bamforth. “Pterodactyls and other pterosaurs aren’t dinosaurs. They belong to a different group of [flying] reptiles. The same is true of the mosasaurs and plesiosaurs that lived in the ocean.

“They lived at the same time, but aren’t dinosaurs. So that’s one of the biggest misconceptions — that every large, prehistoric lizard was a dinosaur.”

With the proviso that palaeontology, as a science, is always evolving, the consensus now is that when the asteroid struck, dinosaurs didn’t go extinct. Instead, they’re all around us.

“Biologically speaking, birds are dinosaurs,” says Bamforth. “They are the direct descendants of a bipedal, carnivorous group of dinosaurs called theropods. So instead of being lizard-like, reconstructions today are much more bird-like — even the way they hold themselves and their forelimbs, or having feathered crests and tails.”

Palaeontologists are also re-evaluating previous assumptions about dinosaur behaviour, says Bamforth.

“A classic example is the oviraptor. Literally, that means ‘egg thief’. When they found a skeleton associated with eggs, they assumed it was stealing eggs and that dinosaurs would just bury and leave their eggs the way a lot of reptiles do today.

“It wasn’t until later when they were looking at the embryos that they realized they were oviraptor eggs, and that the oviraptor was sitting on the nest incubating. So that says something about the parental behaviour of dinosaurs — that it’s far more bird-like than reptilian.”

China & Technology

China is a vast country, and when it started opening up to the West in the 1980s, palaeontologists were able to study its extensive fossil collection, which helped cement the “birds are dinosaurs” theory.

Recent advances in imaging and information technology have helped palaeontologists and scientists in related fields such as biology, geology and chemistry, says Bamforth.

“One example is the synchrotron, which my colleague Ryan McKellar is using to image insects in amber. Even five or 10 years ago, we didn’t have those technologies. And they’re shedding light on some age-old questions.

“Another technique being used now is to look at the development of chicken embryos to try to understand dinosaur evolution. It’s an entirely new field called evolutionary development or ‘evo-devo’. It just came out in the last few years, and it’s fundamentally shifting the way we think about dinosaur evolution.”

While Marsh and Cope used dynamite to extract their fossils, palaeontologists today have access to sophisticated processing techniques that enable them to study soft tissue remains such as larynxes, muscles and feathers.

“That’s provided us with a lot of insight into dinosaur physiology,” says Bamforth. “We know now, for example, that female dinosaurs had an egg-laying bone the same as female birds. Those insights are really important to help us understand dinosaurs as animals.”

Bio-mechanical modelling is yet another advance. It enables palaeontologists to test different theories about how dinosaurs might have moved.

Throw in a growing global data-base of fossils and other paleobiological data, and palaeontology is rapidly advancing as a science these days.

Still, those pesky myths persist.

Mix & Match

Bamforth mentions the old trope of two iconic dinosaurs such as the T. Rex and the spine-plated/spike-tailed Stegosaurus squaring off in a fight.

“Dinosaurs were around for about 150 million years,” says Bamforth. “There were groups that lived during the Triassic, then an entirely different suite of dinosaurs lived during the Jurassic, which was the next period, then there was yet another suite in the Cretaceous.

The Triassic, Jurassic and Cretaceous periods make up the Mesozoic Era, which lasted roughly 186 million years, ending 66 million years ago. .

“The Stegosaurus is a Jurassic dinosaur, while T-Rex was only around for the very last days of dinosaurs. So they never would’ve met,” says Bamforth.

The same way humans have never met living dinosaurs. Aside from birds, that is.

The break-up of Pangaea introduced a geographic barrier too, says Bamforth.

“We got more of what’s called provinciality in dinosaurs. A good example is the Allosaurus. It’s a large, T-Rex-like theropod. They’ve been found in lots of places because they were around when Pangaea was breaking up.

“That’s opposed to something like a T-Rex, which came along after the continents broke up, so it’s only found in a relatively small area in North America.”

Jurassic Park?

In the Jurassic Park movies, dinosaur DNA recovered from mosquitoes trapped in fossilized amber is used to clone dinosaurs for an island amusement park It remains strictly science fiction, says Bamforth.

“DNA, as a molecule, breaks down after about 100,000 years. So structurally, it just doesn’t last that long.

But could we someday make dinosaurs, or at least a reasonable facsimile?

“If they were going to recreate Jurassic Park today, what they might do is try to re-evolve a chicken embryo into a dinosaur by switching back on all the genes that were repressed. If you knock out a certain gene in chick embryos, for example, they’ll grow teeth.

“The dinosaur would be a theropod, so it would be bi-pedal and carnivorous. It wouldn’t be a true dinosaur though — it would be a freak chicken with teeth and a bony tail.”

So now you’re up to speed on dinosaurs. As for what future discoveries might hold for us, Bamforth says it’s hard to know.

“I always like to tell people that where we are in our understanding of dinosaurs is just one step along a continually evolving path. In 10 or 20 years, some of our ideas could completely change, which is part of what makes the science so interesting.”

Certain often-gargantuan ancient reptiles are kinda cool, too. ❧


Sidebar

What’s Wrong With This Picture?

There’s something wrong with Planet S’ cover. Quite a few somethings, actually. Puty’s drawing is a paleontological train-wreck surrounded by a tire fire. Here’s an incomplete list of the scientific inaccuracies the artist put into his drawing, we can only hope deliberately. See more? Tell us about them on this story’s page at planetsmag.com!

CRETASSIC PARK The plated dinosaur Stegosaurus lived in the late Jurassic period, going extinct about 150 million years ago. Tyrannosaurus didn’t show up until the late Cretaceous, about 82 million years later.

DINOSAURS AREN’T LIZARDS They didn’t drag themselves around like iguanas or crocodiles and they didn’t have floppy tentacle-tails. Tyrannosaurus didn’t have a forked tongue like a snake. Puty’s stegosaurus is a nice shade of purple, though. But what’s up with that Pteranodon? It looks like something from Dungeons & Dragons.

NO NEANDERTHALS Dinosaurs and cavemen didn’t exist at the same time. Creationists who say otherwise are either liars or arrogant morons who think they’re smarter than scientists (they’re not). Also: Stegosaurus was a herbivore, so he wouldn’t eat cavemen even if they WERE on the menu.

TWO-FINGER TYRANT Tyrannosaurus only had two fingers. Two. We WILL fight anyone who says different. /Stephen Whitworth