noun
- a group of vertebrate animals characterized by having a single temporal opening in the skull behind each eye socket, including mammals and their extinct relatives
Usage: scientific; paleontology
Examples
- Synapsids first appeared in the late Carboniferous period.
- Modern mammals are the only surviving synapsids.
- Early synapsids included the sail-backed Dimetrodon.
- The fossil record shows synapsids dominated before the rise of dinosaurs.
- Scientists study synapsid skulls to understand mammalian evolution.
- Therapsids were advanced synapsids that gave rise to mammals.