Tribosphenida is a group (infralegion) of mammals that includes the ancestor of Hypomylos, Necrolestidae, Aegialodontia and Theria (the last common ancestor of marsupials and placentals plus all of its descendants).
Tribosphenida is a group (infralegion) of mammals that includes the ancestor of Hypomylos, Necrolestidae, Aegialodontia and Theria (the last common ancestor of marsupials and placentals plus all of its descendants).