synapsiiden
Synapsids are a major group of amniote vertebrates that includes all mammals and their extinct ancestors. The group is defined by a single pair of temporal fenestrae, or openings, in the skull located behind the eye socket. This anatomical feature distinguishes them from the diapsids, which have two pairs of such openings, and the anapsids, which have none.
The earliest known synapsids appeared in the Late Carboniferous period, around 312 million years ago. Initially,
Later, more mammal-like synapsids, known as therapsids, evolved. Therapsids showed increasingly mammalian characteristics, including more upright
Mammals themselves emerged from the cynodont lineage during the Triassic period. Despite the rise of dinosaurs,