Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic...

(/tɛˈtræpədə/). Tetrapods include all extant and extinct amphibians and amniotes, with the latter in turn evolving into two major clades, the sauropsids...

Pan-Amniota) is a clade containing the amniotes and those tetrapods that share a more recent common ancestor with amniotes than with living amphibians (lissamphibians)...

Sauropsida (Greek for "lizard faces") is a clade of amniotes, broadly equivalent to the class Reptilia, though typically used in a broader sense to also...

fluid is the protective liquid contained by the amniotic sac of a gravid amniote. This fluid serves as a cushion for the growing fetus, but also serves...

Like amphibians, amniotes are air-breathing vertebrates, but they have complex eggs or embryos, including an amniotic membrane. Amniotes include reptiles...

The primitive streak is a structure that forms in the early embryo in amniotes. In amphibians, the equivalent structure is the blastopore. During early...

the Taxonomic Position of Mesosaurs, and a Surprising Phylogeny of Early Amniotes" (PDF). Frontiers in Earth Science. 5: 88. Bibcode:2017FrEaS...5...88L...

Others prioritize the clade Sauropsida, which typically refers to all amniotes more closely related to modern reptiles than to mammals. The earliest known...

advanced reptiliomorphs (transitional between "amphibians" sensu lato and amniotes) positioned close to, but outside of the clade Amniota, though some recent...