synapsid — English Dictionary

Adjective

1. Pertaining to the class Synapsida of animals which have an opening low in the skull roof behind each eye, leaving a bony arch beneath each.

   Usage

   • not-comparable

   Examples

   We are synapsid tetrapods, a group of reptiles that almost went extinct 200 million years ago in competition with the better-designed dinosaurs.

Noun

1. Any animal (all mammals) of the class Synapsida.

   Synonyms

   stem mammal

Noun

1. extinct reptile having a single pair of lateral temporal openings in the skull

   Synonyms

   synapsid reptile

   Broader terms

   reptilereptilian