Answer to Question #235007 in Evolution for Pere

Question

The link between synapsids and aves, and the link between synapsid and mammals

Answer 1

The primary dichotomy within the amniotes is that between the Reptilia, or Sauropsida (see amniote groups above - turtles through to birds), and the Synapsida, thought to have diverged sometime during the Carboniferous.

Synapsids are a group of animals that includes mammals and every animal more closely related to mammals than to the other members of the amniote clade, such as reptiles and birds.The distinctive temporal fenestra developed in the ancestral synapsid about 312 million years ago, during the Late Carboniferous period.