The Hindu Business Line : Following the fossil tracks

IT is when time seems not to move as fast as you would like it to — as during days devoted exclusively to Planning Commission rather than doing Departments — that one tends to think about the past. Perhaps, I pressed the time machine a bit too hard, so there is this story about flying dragons of the Triassic period that I glean from what's `forthcoming.'

Rewind to some 220 million years ago when reptiles took to the skies, competing with insects swarming around. They were the first vertebrates to fly, David Unwin would inform in his upcoming book, The Pterosaurs from Deep Time, from Pi Press (www.pipress.net) .

There's another title, Human Bones, on the publisher's site and it seeks to combine "expert knowledge of biomechanics and evolution with engaging discussion of aesthetics and philosophy concerning our most surprisingly important organ." But let me fly back to the pterosaurs that had "a wingspan of 39 feet," wider than an F-16 fighter, as www.nationalgeographic.com would educate.

The author, Unwin, is the Curator for Fossil Reptiles and Birds, Museum of Natural History, Humboldt University, Berlin. He is the caretaker of the world's most famous fossil, Archaeopteryx, I learn from a Pi communiqué. It seems pterosaurs were originally thought to be flying dinosaurs, but Unwin explains that these were "closer cousins to extinct marine reptiles" than related to dinosaurs. You can't find them now because the last of the pterosaurs disappeared about 65 million years ago, which still means they were around for about 150 million years ago, as some quick math would show.

"They were warm blooded, laid eggs, and may have raised their broods like birds," is no first-hand account you'd appreciate, but is what the author deciphers from fossils he found in Western Mongolia. "These successful animals were brightly coloured, spread widely around the globe, and evolved into far more species than previously thought."

Going "on the spoor of the pterosaur," Unwin observes that fossil tracks are "wonderful." Because, "each one is like a tiny movie with its own little story of movement, behaviour, meetings and meals."

Tracks would also tell you if these winged wonders walked on two legs or four, whether they stood on their toes or were flat-footed. But the track record of those who went for these tracks, the `palaeoichnologists,' has been a story of false starts. For instance, what some 19th century scientists found as pterosaur tracks "proved to belong to horseshoe crabs," because at the end of the trail there was "the occasional body"!

Similarly, in the 1950s, another expert, William Stokes, found a "well-preserved track" in Arizona, with "nine sets of hand and footprints made by a flat-footed animal walking on all fours."

But then, about three decades later, his theory that the track belonged to the pterosaur was discounted, because by then the idea was that pterosaurs were bird-like, and stood on their hind limbs with "arms tucked up against the body."

Okay, what was the track that Stokes found in the 1950s? Two other scientists worked on the puzzle and concluded that they were made by an Upper Jurassic crocodile. Believe it or not, I'm already able to see some big croc tracks on the highway, but if I were to track them, it's quite likely that I end up at some politician's door! Which is why I guess pterosaurs would have flown and fled rather than perished.

SayCheek@TheHindu.co.in