A mammal it an animal that can only breath in air but does not have feathers like birds. Even Dolphins and Whales have to breath air, that is why they come to the surface so often, they can hold their breath much longer than a human can as well.
No
what are mammels that live on land called? they are called terresteral creatures
yes
Yes.
mammalogist
Yes they are.
Yes.
Yes.
No they have gills
yes
They were reptiles
is your crocoidiles referring to crocodiles and mammels referring to mammals?if so, crocodiles are not mammals they're reptiles..