A Rauisuchian Montage # 1 (Patreon)

One of the many sections of the giant reptile chapter of The Big Book that needs finishing is the rauisuchian one. What are rauisuchians? They're the large group of crocodile-line archosaurs that include predatory, quadrupedal, deep-headed forms as well as a variety of sail-backed and bipedal taxa, some of which were omnivorous, herbivorous or bipedal. They're a tremendously exciting group, in part because they seem to have evolved dinosaur-like body plans long before dinosaurs themselves did. While the text for the relevant section needs work, the illustrations do too, so I've finally decided to start making progress on the planned montage I need. 

For no particular reason, I started by reconstructing the shuvosaurid Effigia from the Rhaetian (Late Triassic) of New Mexico, an animal which caused quite a sensation when first published in 2006... a toothless, bipedal, superficially theropod-like crocodile-line archosaur about 2 metres long. The reconstruction here was based on the proportions of the reconstruction provided by Nesbitt and Norell in 2006....

I added a keratinous rhamphotheca, the sort of scalation you'd expect for a croc-line archosaur, and a hypothetical colour scheme based on that of large terrestrial lizards. There's some uncertainty about how many fingers the animal has; I opted to go for four.

The other animal here is Arizonasaurus, a ctenosauriscid from the Middle Triassic of Arizona. I used Nesbitt's reconstruction from 2007. I was surprised to discover that the skull - which is not completely known (the dentary and partial maxilla are the best bits) - must have been proportionally quite large. The sail was presumably covered in scaly skin and hence I resisted the urge to give it that 'thin-skinned' look that artists often given the sails of sail-backed animals. I also went for a conservative, standard skull shape, typical for the rauisuchian group. The scalation is, again, guesswork based on what's typical for croc-line archosaurs; the colour scheme is based on what looks reasonably for an animal of open woodlands, and I looked at tegus while creating it.

So that's TWO of these animals done so far! I have many more to do. I did previously illustrate an aetosaur (which is not a rauisuchian but a close cousin) and an animal meant to be Postosuchus or something similar. But they're not good enough anymore, and I need to illustrate new ones. Here they are...

Come back soon to see how this montage develops. Here are photos which show the illustrations above coming together...