As noted on here before the first pterosaur specimen to be discovered was rather special and wonderfully detailed and complete. While obviously comparative anatomy was still a developing field in the 1700’s and there were still thousands of exotic and bizarre animals to be discovered or at least studied properly that we now somewhat take for granted (like giraffe or platypus) one would have hoped that the scientists of the day (Cuvier aside) would have recognised it as a reptile.
I’ll happily admit that it doesn’t look much like a ‘typical’ reptile but then, it doesn’t look much like a bird or a mammal either, but with only these two groups known to have produced flying species at the time, the comparison was perhaps inevitable. Certainly there were some bizarre theories flying around at the time for the true nature of pterosaurs, even after other specimens and other species were known. While most of them died a quiet death (with the exception of Harry Seeley’s ‘bird ancestors’ hypothesis which persisted, if only by himself, into the 1900’s) there were still occasionally new interpretations put forward or old ones revived.
One of the most famous (and indeed most reproduced) is that of Edward Newman from 1843 where he suggested that pterosaurs were actually flying marsupials. And here it is in its rather limited glory. One thing to note which is quite common with these kinds of pictures (and indeed of much palaeoart both in the past and, irritatingly / worryingly in the present) is just how many things are fundamentally different to the actual bones. OK, if he thinks they are furry and had little ears then fine, add fur and give them ears – you can’t see otherwise in the skeleton (even if you can infer it if you realise it’s a reptile). BUT you can’t just make the head half the length of that of the body, or make all the toes the same length, or add extra fingers when this is clearly not seen in the fossil (though the ones in the background look far more pterodactylus-y). These kinds of things happen and it’s a horrible conflagration of ignorance or wilful manipulation in most cases. Anyway, enjoy it for what it is, an interesting, if largely now irrelevant part of palaeontological history.