Some more turtles for The Big Book (Patreon)

I've managed to find time to do a few more turtles for The Big Book (the gigantic reptile chapter of which is still far from finished). For starters, we have the extant, remarkable Leatherback - one of my favourite turtles. My illustration is based on photos, of course. When we come to extinct stem-turtles... well, it took a fair bit of work to get their proportions and anatomy right. The most archaic turtle shown in the montage above is the Triassic Eunotosaurus africanus, a broad-bodied  reptile from the Middle Permian of South Africa known from several specimens, the best of which give us a good guide to its overall form. It didn't have a carapace or plastron, but its weirdly wide body made it difficult to depict. The banded pattern is completely speculative.

The swimming turtle that doesn't have an obvious carapace is the Triassic Odontochelys. I went to some trouble to get the proportions right - but it looks terrible and I don't like it. I think it's the hindlimbs in particular that made it look wrong. Some artists have shown the bony plastron of this animal as if its bones would have projected in the live animal, but they would presumably have been well embedded in soft tissue. Giving the animal sufficient soft tissue to cover the plastron made it wider and chubbier than I was expecting (I also thought that the tail would look longer... turns out it isn't so long, proportionally), the final result being vaguely reminiscent of living softshells (these proved the inspiration for the colour scheme).

Finally, also new here is the stem-turtle Proterochersis, a more 'turtle-like' turtle than the other two archaic forms we've just seen. The shell and scute pattern of this animal is well known (and well described and figured in a 2018 paper by Tomasz Szczygielski et al.); I combined this with the skull and skeletal information of other archaic turtles to produce the reconstruction you see here. Proterochersis would appear, from shell form, to have been terrestrial, so the look I gave for its scutes, and colour scheme, is based on that of living terrestrial turtles, like box turtles.

Having done these new illustrations, I wanted to see what all the ready-to-go turtles look like when thrown together into the same montage. Here's the result...

There are still a few more to do, but the end is in sight.

I hope you found this of interest. Thanks as always for your support. I soooooo want to finish this goddam book...