The two definitive characteristics that make the platypus a mammal are: 1. It nurtures its young on mothers' milk. 2. It has fur. No other group of animals both these characteristics.
Mammals have several defining characteristics, two of which are commonly cited. First, all mammals have hair on their skin and teeth. Second, all mammals nurse their young through the secretion of milk from mammary glands.
We ARE mammals. Like all other mammals, humans are warmblooded vertebrates, have hair, give live birth, nourish babies with milk and spend sufficient time with our offspring before releasing them into the world.
No, porpoises are not dolphins. While these two animals are both mammals they vary in size, physical characteristics, and behaviors.
birds
Yes. Apes are mammals, and one of the defining characteristics of mammals is that they have hair.
Bats are not birds because they are mammals as they have the characteristics of a mammal. They have these characteristics which enable them to be classified as mammals. They are warm blooded, and they have fur.
If mermaids existed (which they don't) they would presumably be mammals. At least, most depictions of mermaids show them with obvious mammalian characteristics (specifically, obvious human characteristics; most mammals do not have large, permanent breasts).
One would be producing milk... The other is fur
It is cardiovascular.
An order of mammals similar to bats.
not all mammals have five fingers and pose able thumbs and our hands are not harry