Guess the retrosaur

An old, old sight, and yet somehow so young.

Finding time to blog has been more-or-less impossible of late. In the effort to keep things ticking over, I thought I'd post this quick painting as a prelude to a post I hope to have together soon. The image is, technically speaking, a piece of palaeoart, but shows a very, very dated interpretation of a fossil species. Retropalaeoart, if you will.

Question is, what is the main animal in this image? I'm not aware of any similar depictions of this taxon (which doesn't mean they don't exist, but they're probably rare) and several colleagues have already struggled to work out what this is meant to be. I'm not going to reveal the answer just yet, but feel free to leave guesses below in the comment feed. Note that the literature used to inform this reconstruction is rather vague on many anatomical details, so a fair bit of interpretation and imagination were used to put this together. That said, the identity of this animal is not that obscure, and I'm sure many readers will quickly grasp what I'm attempting to do here. The first person to guess correctly wins the satisfaction of being the first person to guess correctly.

Hopefully, the answer will be revealed in the next couple of days. Good luck!