synapsid
noun
any of a subclass Synapsida including mammals and their extinct relatives and having one temporal opening on each side of the skull.
synapsids
-
pluralof synapsid.plural
The grammatical form denoting more than one person, place, thing, or idea.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Unable to warm themselves in the sun, these small, vole-like synapsids began burning calories to generate heat.
From The Wall Street Journal ● Nov. 13, 2025
The area's rust-colored rocks date back to the early Permian period more than 270 million years ago and contain the fossilized remains of ancient reptiles, amphibians and sail-backed synapsids, the precursors to modern mammals.
From Science Daily ● Mar. 21, 2024
Hellert created a massive family tree of the synapsids, the group of animals of which mammals are the last surviving members.
From Science Daily ● Oct. 5, 2023
These synapsids, he added, “are more closely related to us than any dinosaur or other reptile.”
From New York Times ● May 22, 2023
Mammals are synapsids, meaning that they have a single opening in the skull.
From Textbooks ● Jan. 1, 2015
