synapsid
Americannoun
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synapsids
plural
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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
The researchers, including co-authors Graeme Lloyd and Christian Kammerer, found that the story of synapsid evolution wasn't one of "survival of the small and unspecialized."
From Science Daily ● Oct. 5, 2023
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 Richard C. Fox
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
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 that they have a single opening in the skull.
From Textbooks ● Jan. 1, 2015
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