The Strange Lives of Polar Dinosaurs

How did they endure months of perpetual cold and dark?

(Cheryl Carlin)
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On a balmy Sunday morning in early March, I'm on a beach in southern Australia looking for ice—or at least traces of it. It's summer in the Southern Hemisphere, and most of the beachgoers sloshing through the rising tide or walking their dogs are wearing T-shirts and shorts. Tom Rich, a paleontologist at Museum Victoria in Melbourne, leads the way along the low, tawny cliffs that crowd the shoreline. Rich is 66, with a stubbly silver beard, sparse gray hair and slanting eyebrows that give his face a sad, world-weary look. He was raised in Southern California and Texas but has spent his professional life in Australia. During more than three decades down under, he's picked up Aussie citizenship and plenty of the country's colorful lingo, but his accent remains stubbornly American. "I sound like I just got off the plane," he says.

This part of the coast, known as Flat Rocks, is near the resort town of Inverloch, about a two-hour drive southeast of Melbourne through farms and woodland parched by more than a decade of drought. Rich stops next to a pile of rubble at the base of a cliff. "That's it," he says. Partly buried by flakes of battleship-gray rock is a telling geological formation. Tongues of dark tan sediment droop into the lighter-colored layer below. The formation is called a "cryoturbation" and was caused when once-frozen clay sank into an underlying layer of sand during a thaw long ago.

Snow and ice are rare in this part of Australia today. But evidence from Flat Rocks and other nearby sites confirms that a little over 100 million years ago, "it was bloody cold around here," as Rich puts it. Though about a third of Australia now lies within the tropics, back then the continent sat about 2,000 miles south of its current position, snuggled against Antarctica. Southeastern Australia probably had a climate similar to that of Chicago, if not Fairbanks.

All the more surprising, then, that dinosaurs thrived here at that time. Think "dinosaurs" and you probably conjure up behemoths trudging through sweltering swamps or torrid tropical forests. But Rich and other scientists working in Australia, Alaska and even atop a mountain in Antarctica have unearthed remains of dinosaurs that prospered in environments that were cold for at least part of the year. Polar dinosaurs, as they are known, also had to endure prolonged darkness—up to six months each winter. "The moon would be out more than the sun, and it would be tough making a living," says paleontologist David Weishampel of Johns Hopkins University.

The evidence that dinosaurs braved the cold—and maybe scrunched through snow and slid on ice—challenges what scientists know about how the animals survived. Although Rich wasn't the first to unearth polar dinosaurs, he and a few other paleontologists are filling in the picture of how these animals lived and what their environments were like. Recent research might also shed light on two of the most disputed questions in paleontology: Were dinosaurs warmblooded? And what killed them off?

Every year from late January to early March, Dinosaur Dreaming—the polar dinosaur project led by Rich—descends on the shore near Inverloch. The sound you hear as you walk up the beach toward the dig is the clinking of hammers on chisels. Kneeling around flat-topped beach boulders that serve as improvised workbenches, a dozen or so volunteers pound on lumps of gray rock. Several wear this year's fashion statement, a T-shirt that reads "Mammalia: Popcorn of the Cretaceous" and shows a bipedal dinosaur clutching two ratlike mammals in one paw and tossing another toward its gaping, toothy mouth.

Down in the "hole," a knee-deep gash near the waterline marked off by a circle of fluorescent pink construction netting, another group is using a rock saw and chisels to dislodge blocks the size of loaves of bread. These chunks will also go under the hammer.

At a folding table in the lee of the cliffs, Lesley Kool is triaging the finds brought in by the rock-breakers. Kool started out as a volunteer on Rich's first dino excavation in 1984. She knew little about dinosaurs, but she trained herself to be an expert preparator—the person who winkles fossils out of the rock without smashing them to dust—and developed a knack for identifying fossils. Now she runs the dig. She can tell you that the brownish chunk you hoped was the dinosaur find of the century is really a commonplace bit of fossilized turtle shell.

The crew she supervises includes a smattering of students, a retired literature professor from Tucson, a vacationing manager from an auto parts maker and the owner of an environmental cleanup service who can't stop bursting into song. Most of them come back year after year. They say they return for the camaraderie—and the chance of making a discovery. "It's an addiction for which there is no cure," says Nicole Evered, 68, who has worked on the Flat Rocks dig since it started.

Here the stereotypical image of the fossil hunter sprawled in the dust, unearthing a gigantic dinosaur bone with only a whisk broom and dental picks, doesn't apply. The fossils are too small, too fragmentary and too scattered. In more than 20 years of digging at various places in southern Australia, Rich and his crew have discovered only three articulated specimens, with bones connected as they were in life.


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