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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 ?
Some of these genes are also crucial in digit formation in amniotes, a group including reptiles, mammals and birds but not amphibians.
A prominent example of this coordination is found in the gastrulation of amniotes, where Brachyury (Bra), a transcription factor, is synchronously and transiently expressed in a localized population, the Primitive Streak (PS).
Statements that birds are dinosaurs are as silly as claiming that mammals are synapsid reptiles, or that all amniotes are amphibians.
This early tetrapod could be the earliest example of a reptile and explain the origin of amniotes, all vertebrates that belong to reptiles, birds and mammals.
The fact that nearly all living mammals have eye shapes that appear 'nocturnal' by comparison with other amniotes [mammals, reptiles and birds] is a testament to the strong influence that evolutionary history can have on modern anatomy," said Chris Kirk, associate professor of anthropology at The University of Texas at Austin.
Introductory Sentences: "The question presents a statement Improved Student Application that birds and mammals are amniotes with (l)-(2)-(3) Guided whose embryos are supported by extra- Reflection embryonic membranes.
These lines - incremental lines of von Ebner - are present across all amniotes, and record daily dentin deposition.
2007) and McKenna and Farrell (2009) indicate that the four living suborders of beetles diverged in the Permian, when early amniotes, conifers, and others groups of terrestrial organisms, including other insects (Labandeira and Sepkoski, 1993), were also diversifying.