Teeth 
I see you want the teeth section better explained.

The idea is that tetrapods that grows slowly (i.e reptiles) continue to grow in maturity. Both the steadily increasing size of the jaws and the wear and tear imposed by a long life dictate continued change of teeth. Mammalian teeth being complex, replacing teeth requires quite a bit of resources, and as anyone having children of pre-school age can attest to, it is also a lot of bother (try eating an apple without your front teeth!). Thus, for the fast-living, high energy demanding life of insectivorous mammals, tooth replacement is kept to an minimum (i.e two setts, a trait retained in their descendants). How do you propose going about explaining it without making it a disproportionally large part of the article? Or is it so important it should be a large part?