Synapsida[a] is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant reptiles and birds).

Much more than mammals! The mammals of today are but one branch of the Synapsida, a great vertebrate group with a 300 million year history.

In mammal: The evolution of the mammalian condition …therapsids, members of the subclass Synapsida (sometimes called the mammal-like reptiles), generally were unimpressive in relation to other reptiles of their time.

In traditional taxonomy, the Synapsida encompasses two distinct grades successively closer to mammals: the low-slung pelycosaurs have given rise to the more erect therapsids, who in their …

Note: in evolutionary terms, the mammals are entirely within the Synapsida. Their status as a separate class is traditional Linnaean taxonomy: as a clade they are a sub-group of the Therapsida.

May 16, 2023 · Biology definition: A synapsid refers to any animal belonging to the clade group Synapsida. Synapsids are believed to have descended from the earliest amniotes. Their front teeth are distinct from their back teeth, they have limbs under the body, and they have a temporal fenestra (the temporal aperture on the sides of the skull).

Aug 6, 2023 · What are synapsids? Synapsids are an evolution of amniotes that once resembled reptiles, but developed a temporal opening on the side of the skull. Mammals are the only extant synapsid.

Sep 30, 2020 · Synapsida comprises mammals and all extinct taxa more closely related to mammals than to reptiles including birds. Synapsids form a distinct evolutionary lineage from reptiles.

Synapsida (=Theropsida) Evolution The Theropsids or "beast (mammal) faces" constitute an evolutionary lineage that developed a special opening, the synapsid arch, for attachment of jaw muscles, giving a superior bite and permitting adaptive radiation during the late Carboniferous.

A recent, compromising position (see Benton 2004) has the class Synapsida as intentionally paraphyletic, constituting a grade of animals from the earliest split with sauropsids to the arbitrary division with its daughter class, Mammalia.