synapsid
Americannoun
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Any of various amniotes with one temporal opening on each side of the skull. Synapsids emerged in the late Permian Period and were characterized by carrying their limbs under their body and developing front teeth that were different from their back teeth. One group of synapsids, the therapsids, gave rise to the mammals.
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This finding provides important context for a key step in synapsid evolution.
From Science Daily ● Feb. 22, 2024
They found a major shift in synapsid jaw function roughly 270 million years ago linked to a significant shift in predatory behaviour that has important implications for the evolution of our earliest ancestors.
From Science Daily ● Feb. 22, 2024
Julius and I endeavored to surprise and delight readers with our interpretation of how this giant synapsid might have looked walking through Late Triassic–era Poland.
From Science Magazine ● Jan. 10, 2020
An early synapsid with extensive soft tissue preservation.
From Scientific American ● Jul. 23, 2017
In the course of synapsid evolution leading to mammals, the temporal presumably became the main muscle mass acting in adduction of the lower jaw.
From The Adductor Muscles of the Jaw In Some Primitive Reptiles by Fox, Richard C.
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
At some points, larger synapsids were the ones that survived, and the winners weren't just generalist insect-eaters.
From Science Daily ● Oct. 5, 2023
Life on land throughout the Permian Period, which lasted from about 298 million to 252 million years ago, was dominated by synapsids, the evolutionary precursors to mammals or protomammals.
From New York Times ● May 22, 2023
Mammals are synapsids, meaning they have a single opening in the skull.
From Textbooks ● Jan. 1, 2015
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
