FIrst off, I like how the plates and spines are not coloured in at all, indicating they actually are legitimate dinosaur fossils or that they simply materialised.

Second, the purported identies just don’t check out at all. 

The arms and legs of Stegosaurus don’t resemble any “pachyderms”, alive or dead - they have the wrong number of digits, for one. Elephant hands and feet each have five, hippo hands and feet each have four, and rhino hands and feet each have three. Stegosaurs had five fingers and four toes, and the structure of them doesn’t resemble any mammals (stegosaur hands have two hoofless digits, not seen in any of these animals).

Crocodilians tend to be fairly flat animals, and their tails are no different. Their tails don’t really resemble those of stegosaurs:

You’d also be extremely hard-pressed to find a mammal with a torso anything like that. For one, check the number of neck vertebrae - in almost all mammals, the number is seven or fewer (with the one exception being the three-toed sloth, which has 8), while this animal has at least 13. Its hips are also entirely wrong for a mammal - the three bones of our hip tend to be well-fused, with a very expanded illium (upper bone) that results in them looking very little like dinosaur hips. You can see that in this elephant skeleton: