BATH, UK, March 15 (Reuters) — Pterosaurs — huge flying reptiles — were long thought to be in decline at the time the dinosaurs went extinct, but were actually diversifying and thriving, according to new fossil evidence. Nick Longrich, senior lecturer at the Milner Centre For Evolution and the department of biology and biochemistry at the University of Bath said: "What we found here is really pretty extraordinary, it's a remarkable fauna of pterosaur — giant winged cousins of dinosaurs, from the end of the age of dinosaurs. "And for a long time there's been a mystery about what happened to the pterosaurs. We don't have a lot of fossils from the end of the Cretaceous period when these things lived, and so it looks like these things might have been in decline, declining diversity and there's just a few species left when the asteroid hits and wipes out the dinosaurs and takes out the last of the pterosaurs with it. "The other possibility though is that pterosaurs might have been very diverse and we simply weren't seeing their fossils because they're extraordinarily rare. And so we stumbled across this amazing trove of fossils in Morocco, and we describe these fossils as representing half a dozen new species of pterosaur. "And we were also able to show that diversity is increasing; there is a wider range of sizes and shapes and ecologies of these things at the very end of the Cretaceous period when the asteroid hit. So they weren't going into a decline, they were actually staging a radiation and basically cut down in their prime. "Nothing has ever evolved to replace them, it's kind of remarkable that in 66 million years no bird has evolved that's as large as a pterosaur. And likewise if the asteroid hadn't hit, the birds wouldn't have been able to diversify because it's the extinction of the pterosaurs and archaic birds that live alongside them that lets moderns bird take off and diversify."
