Vertebrate Zoology - V. M. Konstantinov 2011

Chordates
Terrestrial, or Tetrapod, Vertebrates — Vertebrates with Embryonic Membranes

The group of higher vertebrates adapted to a terrestrial lifestyle comprises reptiles, birds, and mammals. Although some higher vertebrates are known to inhabit aquatic environments, all such cases are the result of secondary adaptation to Water. This is evidenced by numerous findings from paleontology, Embryology, and ecology.

All higher vertebrates exhibit internal Fertilization. They reproduce on land, with only a few viviparous species (such as cetaceans) reproducing in water. During embryonic development, higher vertebrates form specialized extraembryonic membranes. Because of one of these membranes—the amnion—higher vertebrates are referred to as amniotes, whereas lower vertebrates, which lack extraembryonic membranes during embryonic development, are called anamniotes. In egg-laying species, these embryonic membranes, together with the egg membranes, ensure that the embryo can develop in a terrestrial environment.



Last update: 13/08/2026

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