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Any of numerous vertebrates of the group Amniota, characteristically having an amnion during embryonic development and including the reptiles, birds, and mammals.

[From New Latin amniōta, amniotes, from Greek amniōn, amnion (influenced by amniotic).]


(Zoology) any vertebrate animal, such as a reptile, bird, or mammal, that possesses an amnion, chorion, and allantois during embryonic development. Compare anamniote
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.amniote - any member of the Amniotaamniote - any member of the Amniota    
craniate, vertebrate - animals having a bony or cartilaginous skeleton with a segmented spinal column and a large brain enclosed in a skull or cranium
Amniota - higher vertebrates (reptiles, birds and mammals) possessing an amnion during development
amnion, amnios, amniotic sac - thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)
chorion - the outermost membranous sac enclosing the embryo in higher vertebrates (reptiles, birds and mammals)
References in periodicals archive ?
Several researchers have long considered the possibility that the superficially reptile-like features of this animal might tell us something about amniote ancestry.
Hylonomus lyelli, meaning "forest dweller", named in honour of his mentor and friend, Sir Charles, a century and a half later was proclaimed Nova Scotia's Provincial fossil and remains the earliest known amniote in the fossil record (Carroll 1964, 1970; Reisz 1997; Clack 2002).
It is probable that this better means of expelling carbon dioxide allowed these creatures to become fully independent from the water and contributed to the development of the amniote egg, which was integral to the transition from amphibian to reptile.
Taxonomic congruence versus total evidence, and amniote phylogeny inferred from fossils, molecules, and morphology.
After the recent discovery of mesosaur embryos, we can state with a high degree of confidence that embryo retention developed early in amniote evolution, given that mesosaurs are among the basal-most reptiles and that they date from the Early Permian around 280 million years ago," she asserted.
Two cases of triorchidism have been observed in a rare Malagasy tortoise, Geochelone yniphora (Mourgue 1989), suggesting the phenomenon occurs in at least three deep amniote lineages.
By double-clicking on a picture, the student views a pop-up window with a list of traits (eukaryotic cells, amniote egg, jaws, etc.
Unlike other mammals, monotremes, like the platypus, never evolved to give live birth, but instead lay eggs like their amniote ancestors.
Knowing how a basic amniote embryo ends up developing into something so radically different could shed light on turtle history, says paleontologist Michael Lee of the South Australian Museum at the University of Adelaide.
A time of forests, swamps, seed ferns, mosses, lycopods and the origin of the amniote egg.