This link is to a long, complex, semi-interesting talk on the convergence in evolution between large, highly evolved and specialized placental mammals, such as elephants and manatees large highly evolved and specialized marsupials such as kangaroos.


Convergent evolution

It seems that in many ways the kangaroo is just as specialized and well adapted as any other large mammal.

Would it be fair to say that the kangaroo, while perhaps more primitive reproductively, is less primitive than the most primitive placental mammals in other areas?