Placentals are mammals. All mammals are vertebrates which means they do have backbones.
Yes
yo kitchen lol
Yes.
No there is more with backbones
an ugly tsamanian devil
Monotremes, marsupials, and placentals
Pigs do have backbones.
it has 2 backbones
No backbones
Because placentals are the largest number of mammals.
All snakes have backbones.
placenta which is between the mother and the embryo.