Amniote - Wikipedia
WEBAmniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial and semiaquatic vertebrates. Amniotes evolved from amphibian ancestors during the Carboniferous period and further diverged into two groups, namely the sauropsids (including all reptiles and birds ) and ...
Amniotes - Definition, Characteristics and Evolution | Biology …
WEBApr 17, 2019 · Amniotes Definition. Amniotes are vertebrate organisms which have a fetal tissue known as the amnion. The amnion is a membrane derived from fetal tissue which surrounds and protects the fetus. The amnion can be found within the egg, as in lizards and birds, or the amnion can simply enclose the fetus within the uterus.
Amniota | Vertebrates, Tetrapods & Mammals | Britannica
WEBAmniota, a group of limbed vertebrates that includes all living reptiles (class Reptilia), birds (class Aves), mammals (class Mammalia), and their extinct relatives and ancestors. The amniotes are the evolutionary branch (clade) of the tetrapods (superclass Tetrapoda) in which the embryo develops.
The Animal Encyclopedia: Amniotes - Amniota - ThoughtCo
WEBUpdated on January 31, 2018. Amniotes (Amniota) are a group of tetrapods that includes birds, reptiles, and mammals. Amniotes evolved during the late Paleozoic era. The characteristic that sets amniotes apart from other tetrapods is that amniotes lay eggs that are well-adapted to survive in a terrestrial environment.
15.13: Introduction to Amniotes - Biology LibreTexts
WEBFeb 28, 2021 · Amniotes are a clade of tetrapod vertebrates comprising the reptiles, birds, and mammals. Amniotes are characterized by having an egg equipped with an amnion, an adaptation to lay eggs on land or retain the fertilized egg within the mother.
29.4A: Characteristics of Amniotes - Biology LibreTexts
WEBOct 31, 2023 · The amniotes include reptiles, birds, and mammals; shared characteristics between this group include a shelled egg protected by amniotic membranes, waterproof skin, and rib ventilation of the lungs. In amniotes, the shell of the egg provides protection for the developing embryo and allows water retention while still being permeable to gas …
15.5: Amniotic Animals - Biology LibreTexts
WEBJul 31, 2022 · Characteristics of Amniotes. Figure 1. The key features of an amniotic egg are shown. The amniotic egg is the key characteristic of amniotes. In amniotes that lay eggs, the shell of the egg provides protection for the developing embryo while being permeable enough to allow for the exchange of carbon dioxide and oxygen.
Introduction to Amniotes | Biology for Majors II - Lumen Learning
WEBIdentify characteristics of amniotes. Amniotes are a clade of tetrapod vertebrates comprising the reptiles, birds, and mammals. Amniotes are characterized by having an egg equipped with an amnion, an adaptation to lay eggs on land or retain the fertilized egg within the mother.
Introduction to the Amniota - University of California Museum of ...
WEBInside the egg are a series of fluid-filled membranes which permit the embryo to survive: the amnion, allantois, yolk sac, and chorion. Surrounding and protecting the embryo is the amnion, filled with amniotic fluid, and providing the embryo with a stable fluid environment. The allantois performs two very important functions for the embryo ...
Evolution and Phylogeny of Amniotes | SpringerLink
WEBJan 1, 2024 · Amniotes (Amniota) form a monophyletic group that encompasses the last common ancestor of living mammals and reptiles, and all descendents of that ancestor. They are characterised by the possession of an amniote egg (or at least amniotic membranes in live-bearers) that contains the essentials for embryo development, but is …
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