Mosasaurs step 1 (Patreon)

Still at work -- in the background -- on the book Ancient Sea Reptiles, and I've recently made some progress with the mosasaurs needed for the cladograms and such. Turns out that I need six images (since the cladograms will show all of Mosasauria, not just Mosasauridae alone). The animals here are (1) Pannoniasaurus, a tethysaurine; (2) Platecarpus, a plioplatecarpine; (3) Tylosaurus, a tylosaurine; (4) Phosphorosaurus, a halisaurine and (5) Mosasaurus, a mosasaurine. The animals were reconstructed following various skeletal reconstructions, and I decided to go with the idea - favoured by its describers - that Pannoniasaurus is plesiopedal... that is, in possession of 'primitive' limbs that were not flippers (the hydropedal condition). The big surprise is that tethysaurines might be surrounded in phylogeny by hydropedal mosasaurs... in which case Pannoniasaurus secondarily evolved a plesiopedal condition from hydropedal ancestors! I discuss this scenario in the book. I have to say that I'm not persuaded by it, but it's certainly an interesting argument.

On the subject of evolutionary relations, here are the animals arranged in a simplified cladogram. I still have to finish drawing the animal: two more to go!

That's it for now, thanks as always for support.