Mammals have a pretty basic blueprint. Among other things, we give birth to live young, we’re warm-blooded, and, perhaps most obviously, we all have hair. (Yes, even dolphins.) But in the churn of natural selection, some mammals ended up with appendages that look like they should be found on a reptile, bird, or…
https://gizmodo.com/6-mammal-body-parts-that-look-like-they-were-stolen-fro-1846800976