Amniotes 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 amphibious stem tetrapod ancestors during the Carboniferous period .

羊膜动物 （Amniote）是一群四足 脊椎动物 ，包括合弓类动物（ 哺乳类 与 似哺乳爬行动物）与 蜥形类 （含爬行动物、鸟类）。 羊膜动物藉由产卵、胎生等方式繁衍，胚胎由 多层膜 来保护。 在 真兽类 哺乳动物，更演化出 羊膜 来包覆胎儿。 羊膜动物与 两栖动物 的差异在于保护胚胎的膜，与缺乏幼体变形为成体的阶段 。 羊膜动物由产卵、胎生等方式繁衍，胚胎由多层膜来保护。 羊膜动物与两栖动物的差异在于保护胚胎的膜，缺乏幼体变形为成体的阶段。 [2] 根据较广泛的 …

羊膜動物 （学名： Amniota）是 脊椎動物 的一个 演化支，其特征是 胚胎 在发育过程中会形成 胎膜，使其可以在远离 水体 的 陆地环境 进行 繁殖。 羊膜动物与不具备胎膜的 两栖动物 一起组成了代表 陆生 脊椎动物的 四足总纲。 与 半水生 的两栖动物不同，羊膜动物在其 生命周期 中的任何一个阶段都不用 鳃 进行呼吸，可以 产下 有 外壳 保护的硬体 卵 （蛋），或将 受精卵 保留在母亲体内发育直到产下能够主动 进食 的幼崽（胎生）。 这与需要在水中或潮湿环境中产下软体卵的 …

2019年4月17日 · 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, 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 …

2024年6月30日 · Amniotes, a diverse group of vertebrates, share several key characteristics that set them apart from other animals. One defining feature is their ability to lay eggs with an amniotic membrane, allowing them to colonize a variety of terrestrial habitats.

2018年1月31日 · 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 …

2025年1月12日 · Amniotes, including reptiles, birds, and mammals, are characterized by the presence of an amniotic egg, which protects the developing embryo from dehydration. They also have a more advanced and efficient respiratory system than amphibians, enabling them to inhabit a wider range of environments.

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.

2021年2月28日 · 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.