Here we have the dermal scute of a a 75 million year old crocodile!
Dermal scutes are pretty cool. Not quite scales, not quite bone, or keratin, scutes are layer upon layer of these features, that together compose a sort of armour. Scutes are primarily used for protection, whether from predators, or from inter species battles over mates and territory.
Examples of animals with dermal scutes are the pangolin, the turtle, the armadillo and the crocodile.
Dermal scute fossils are helpful because they give us a better idea of what animals looked like, in the same way that fossilized skin imprints help.