[Antoninus]

Those look like crocodylians.

One is, one ain't. The one that ain't is Eryops, a giant amphibian which existed about 300 million years ago. The other one is of a modern caiman.

My point is, it's relatively easy to misidentify two fossils that very far divergent--even when we have full skulls or skeletons (which is the exception, not the norm). Granted, a trained paleontologist is going to be a lot better at it than you or I, but they're still prone to mistakes and have made many of them over the past century.

[<1/1,000,000th%]

I was close. The eryopidae are part of temnospondylii which is part of the stegocephalian group with the amniota of which the diapsids are a sub-group (whew).

I agree with you in the cases where there is little fossil evidence. Where significant fossil evidence is available, molecular biology is confirming almost all of the groupings.