Amniotes in a sentence

All anapsid skulls lack a temporal opening, while all other extant amniotes have temporal openings (although in mammals the hole has become the zygomatic arch ).

Amniotes acquired new niches at a faster rate than before the collapse and at a much faster rate than primitive tetrapods.

Amniotic eggs, however, have internal membranes that allow the developing embryo to breathe but keep water in. Hence, amniotes can lay eggs on dry land, while amphibians generally need to lay their eggs in water.

By contrast, all amniotes (mammals, birds and reptiles) have twelve pairs of cranial nerves. citation Close-up of frog's head showing eye, nostril, mouth and tympanum.

Different authors linked these groups either to lepidosauromorphs Gauthier J. A. (1994): The diversification of the amniotes.

Environmental sex determination preceded the genetically determined systems of birds and mammals; it is thought that a temperature-dependent amniote was the common ancestor of amniotes with sex chromosomes.

Indeed, since the sinus venosus is incorporated into the right atrium in amniotes, it is likely homologous with the SA node.

In the majority of vertebrates, the mesonephros persists into the adult, albeit usually fused with the more advanced metanephros ; only in amniotes is the mesonephros restricted to the embryo.

Like other amniotes, turtles breathe air and do not lay eggs underwater, although many species live in or around water.

Other amniotes (non-amphibian tetrapods) have cranial nerves similar to those of humans.

The collecting ducts from each cluster of nephrons usually drain into an archinephric duct, which is homologous with the vas deferens of amniotes.

The earliest amniotes were superficially lizard-like, but had solid, box-like skulls, with openings only for eyes and nostrils, termed the anapsid condition.

These two nerves only became discrete nerves in the ancestors of amniotes (non-amphibian tetrapods). citation Diagrammatic view of the cranial nerves of the horse.

They are superficially similar to reptiles but, along with mammals and birds, reptiles are amniotes and do not require water bodies in which to breed.

Ureotelism appears to be the ancestral condition among primitive amniotes, and it is retained by mammals, which likely inherited ureotelism from their synapsid and therapsid ancestors.

Very shortly after the first amniotes appeared, a lineage called Synapsida split off; this group was characterized by a temporal opening in the skull behind each eye to give room for the jaw muscle to move.