Blue Collar Scientist

Quick - have a look at these YouTube videos before some creationist cooks up a fraudulent DMCA copyright infringement claim to have these taken down.

Both videos explore phylogeny from the transitional fossil record in an interesting and compelling way, and set to some wonderful music.

Hat tip to Panda’s Thumb.

So I’m enjoying a low-pressure Saturday afternoon, clicking the “StumbleUpon” button, and it takes me to the Dinosaur Facts site - specifically, the page about Eudimorphodon. On that page I notice the following text:

The Eudimorphodon was a flying dinosaur that lived in the late Triassic period.

Now, I’m not an expert on dinosaurs. What I know about dinosaurs and carry about in my head would not be too much trouble to write down. But it seemed to me that Eudimorphodon was not a dinosaur, but in fact was a pterosaur. The picture certainly looked like that of a pterosaur. And I hadn’t really heard of non-feathered flying dinosaurs anyway. And one last objection - a flying dinosaur in the late Triassic? Not impossible, I suppose, but I don’t recall hearing of such a thing.

A quick look at Wikipedia seemed to confirm that Eudimorphodon is a pterosaur.

Now if there’s one thing that motivates me, it is finding errors. Having found this one, I decided to read the rest of the page. I read to the end and then I look at (what in print media would be called) the sidebar, which is titled Did you know, and which contains this gem:

Eudimorphodon was a pterosaur, not a dinosaur.

Er, ok then. Contradictory information on the same page just bugs me, but that’s the web for you. At least this time they had the right answer.

But here’s the thing. I don’t actually know what a Pterosaur is. Yes, I know that it is a flying Mesozoic reptile - I just don’t find that to be very meaningful. So I did a little web searching, and I quickly realized that for me, “what is a pterosaur” is answered not by the mantra about flying reptiles, not by their morphology, but by their phylogeny. Their phylogeny is not yet super-well established, which makes drawing firm conclusions chancy, but nevertheless cladograms exist. Looking for one led me to this image (from here):

So Pterosaurs are closer to the dinosaurs than crocodilians, but diverged before the dinosaurs originated. Nice. That’s actually a perfect answer - it tells me exactly why pterosaurs aren’t dinosaurs, and also suggests some attributes of Pterosaurs that it wouldn’t share with dinosaurs, or crocodiles.

So, why are we still using the mantra “flying reptile” to describe a Pterosaur? Phylogeny and phenotype together do a much better job, yes? Why do none of the benchmarks or standards used by the teachers I work with include cladograms? I’m sure this concept can and should be explained to 9-12 students.