The main characteristic shared by mammals, and which makes them distinct from other vertebrate groups, is that they suckle their young on mothers' milk. This is the main characteristic mammals share.
Also unique to mammals is the fact that they have fur or hair.
As with all mammals, the echidna feeds its young on mothers' milk.
a Shared ancestral characteristic a shared primitive characteristic
A key characteristic shared by all gymnosperms is the fact that they all make seeds. Another shared characteristic is that they do not make flowers.
Mammal.All mammals feed their young on mothers' milk. This is the defining characteristic of a mammal, and it is a characteristic not shared with any other vertebrate.Mammals include placental mammals, marsupials and monotremes (egg-laying mammals).
a characteristic---- usually a homologous structure----shared by all organisms in a group
They all cause disease.
The common characteristic shared by all organic substances is that they contain carbon atoms bonded to hydrogen atoms.
Trick question. Remember the Duck Billed Platypus is classed as a mammal, and gives birth with eggs.
have a trochophore
It is rephrased as mammals are homeothermic animals .
Having hair is a characteristic of all "mammals."
They are all vertebrates.