Because pterosaurs aren’t dinosaurs. What they have been, though, is a puzzle, at least in terms of how the later, classic pterodactyl form evolved from earlier long-tailed pterosaurs. There are so many differences between them – from the pterodactyl’s characteristic skull (and the number of openings in it) and much shorter tail, to differences in ribs and a second flight membrane between the legs – that it’s hard to tell what path that evolution took.

But once again, it’s Chinese fossils to the rescue, as a new species – another transitional form, Creationists! – has been discovered. As published this week by the Royal Society, Darwinopterus modularis (“Darwin-wing”…er…”modular”) is the kind of transition that makes things obvious – it has all the skull and neck characteristics of a pterodactyloid, but the rest of its body is old-school, long-tailed pterosaur. It’s as though a mid-Jurassic pterosaur had a new haircut and the new ‘do was such a big hit that it eventually changed it’s whole wardrobe to match…

The exciting thing is that this doesn’t just help explain how one form changed into another, but is also evidence of modular evolution. Normally we think of evolution in terms of an individual trait changing over generations – a tail getting longer, teeth getting sharper, colouration getting brighter. In modular evolution, though, sets of complementary features evolve together at the same time – in this case, D. modularis doesn’t just have a head closer to that of a pterodactyl; it’s evolved all the numerous head and neck features of pterodactyls, while the rest of its body retains the characteristics of an earlier pterosaur. It hasn’t just had a haircut, it’s gone in for some piercings and facial tatts as well, but it’s still wearing the stodgy old business suit.

This story is also interesting in the way that some news outlets have done better with it than others. The Independent did quite well, but fell into a common misconception: “Carbon dating has shown that the fossils fall in the middle of the age range from 220 million to 65 million years ago”. The erroneous word here is “Carbon”; Carbon dating is useless for anything more than around 60,000 years old, and palaeontologists – certainly those working with dinosaurs – use other methods to determine the age of their finds. To the author and paper’s credit, this little error and several others have now been cleaned up; to even greater credit, they added a comment in the story to let readers know! (Probably because bloggers with quicker trigger fingers than mine had already been pointing to it…)

On the other hand, The Australian were much worse; they ran with a headline about “Flying Dinosaurs” – pterosaurs are flying reptiles, not dinosaurs – but then go one better by reporting that the fossil was “baptised” with its scientific name. Baptised? Really? I mean, christened, sure; that has currency as a synonym for “named”. But “baptised”? I expected the article to conclude with a social item inviting the reader to Darwinopterus‘ confirmation… The article lists Agence France-Presse as the source, but somehow I’m not sure this translation is entirely their fault…