31 July 2013

Pterosaurs deserve a place in the sun

Pterosaurs deserve a place in the sun

Large as life, model pterosaurs fly over modern-day humans (Image: Peter Macdiarmid/Getty)

The first animals to evolve powered flight have long been eclipsed by our insatiable appetite for dinosaurs. Let’s hear it for the pterosaurs

FROM lost worlds to flying dragons, pterosaurs have always been the stuff of legend. The reality is hardly less amazing. Pterosaurs were the first vertebrates to evolve powered flight. Before they died out with the dinosaurs 65 million years ago, they were the largest animals to fly, with wingspans of more than 10 metres.

Pterosaurs deserve a place in the sun

For years they have been outpaced by discoveries of good dinosaur fossils, and dino-mania. Good books are also few and far between, so Mark P. Witton’s Pterosaurs is most welcome.

The other exception, The Illustrated Encyclopedia of Pterosaurs by Peter Wellnhofer, makes for an interesting contrast. Wellnhofer is the German palaeontologist who did much to revive research in the field. His book opens with a fictional description of an encounter with a living pterosaur, borrowed from Arthur Conan Doyle’s The Lost World. The dust cover shows pterosaurs flying gracefully, but scuttling awkwardly on high cliffs before they leap into the air.

Twenty-plus years on, and Witton updates the picture with a book that is as amply illustrated as the Encyclopedia. Witton, a palaeontologist at the University of Portsmouth, UK, paints as well as he writes. His dust cover sets the scene: a striking pterosaur soars in a red sky, while on the ground a group of them stand on all fours with folded wings – as comfortable on land as in the air.

This is part of a new view of pterosaurs emerging from fossil discoveries and research tools and techniques that make the most of the few pterosaur fossils that exist. We know of between 130 and 150 species so far, compared with more than 900 well-established dinosaur genera.

The best pterosaur fossils come from well-known deposits such as Germany’s Solnhofen limestone. The first pterosaur was found there decades before a fossil of Archaeopteryx, the first bird. Another rich bed is China’s Yixian formation, famous for its feathered dinosaurs. Yixian also sports crow-sized pterosaurs and Darwinopterus, which made the news in 2011 because the first pterosaur egg was found beside it.

These finds teach us a lot. Small juvenile pterosaurs, for example, showed that they could fly when their wingspan was only 10 to 20 per cent that of an adult’s. Modern bats and birds must grow to near adult size before flying. As for launching, biomechanical studies now suggest pterosaurs used a two-stage leap: small hind limbs thrust off first, then longer front limbs pushed up and unfolded into wings that lifted them up.

In careful prose, Witton lays out the spectrum of pterosaurs, from the small and birdlike, to the giant azhdarchids, with wingspans of 10 or 11 metres. Why grow so large? Because “they could”, he writes: being large saves energy and protects against predation.

The joy of Pterosaurs is how it brings long-extinct animals to life. This is a remarkable achievement because pterosaurs looked so very different from their nearest living relatives, birds and crocodiles. Their furry, leathery wings stretched from arm to leg (or between front and back limbs), so like bat wings, they behaved differently from feathered wings. And many pterosaurs had heads larger than their torsos. Some lived like today’s sea birds, vultures or waders; others have no modern counterparts.

“Pterosaurs evolved into very different forms from their living relatives, birds and crocodiles”

Witton makes you work for your reward. With little biology, I struggled with his anatomical terminology. But his explanations and diagrams shed vivid light on the most intriguing creatures that ever flew, and in richer detail than even Wellnhofer could have managed just two decades ago.


Mark P. Witton

Princeton University Press

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