Amniote vertebrates share a suite of extra-embryonic membranes that distinguish them from anamniotes. Other than that, however, their reproductive characteristics could not be more different. They differ in basic ectothermic vs endothermic physiology, in that two clades evolved powered flight, and one clade evolved a protective shell. In terms of reproductive strategies, some produce eggs and others give birth to live young, at various degrees of development. Crucially, endotherms provide lengthy parental care, including thermal and food provisioning—whereas ectotherms seldom do. These differences could be expected to manifest themselves in major differences between clades in quantitative reproductive traits. We review the reproductive characteristics, and the distributions of brood sizes, breeding frequencies, offspring sizes and their derivatives (yearly fecundity and biomass production rates) of the four major amniote clades (mammals, birds, turtles and squamates), and several major subclades (birds: Palaeognathae, Galloanserae, Neoaves; mammals: Metatheria and Eutheria). While there are differences between these clades in some of these traits, they generally show similar ranges, distribution shapes and central tendencies across birds, placental mammals and squamates. Marsupials and turtles, however, differ in having smaller offspring, a strategy which subsequently influences other traits.

中文翻译：

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不同的解决方案会导致羊膜生命树的巨大鸿沟具有相似的生活史特征

羊膜脊椎动物共有一套胚外膜，可将其与羊膜动物区分开。除此之外，它们的生殖特性没有什么不同。它们在基本的吸热和吸热生理上有所不同，因为两个进化枝进化出了动力飞行，而一个进化枝进化出了保护壳。就生殖策略而言，有些会产卵，有些会生出处于不同发育程度的年轻幼虫。至关重要的是，吸热会提供冗长的父母照料，包括热量和食物供应，而外热很少。可以预期这些差异将在数量繁殖性状的进化枝之间的主要差异中表现出来。我们审查了繁殖特征，育雏量的分布，繁殖频率，四个主要羊膜进化枝（哺乳动物，鸟类，乌龟和鳞茎）和几个主要子进化枝（鸟类：古颚虫，加卢安塞拉虫，纽瓦夫斯;哺乳动物：后生亚纲和Eutheria）的后代大小及其衍生物（年繁殖力和生物量生产率）。尽管这些进化枝之间在某些特征上存在差异，但它们通常在鸟类，胎盘哺乳动物和鳞状细胞中表现出相似的范围，分布形状和中心趋势。然而，有袋动物和乌龟的区别在于后代较小，这种策略随后会影响其他特征。尽管这些进化枝之间在某些特征上存在差异，但它们通常在鸟类，胎盘哺乳动物和鳞状细胞中表现出相似的范围，分布形状和中心趋势。然而，有袋动物和乌龟的区别在于后代较小，这种策略随后会影响其他特征。尽管这些进化枝之间在某些特征上存在差异，但它们通常在鸟类，胎盘哺乳动物和鳞状细胞上显示相似的范围，分布形状和中心趋势。然而，有袋动物和乌龟的区别在于后代较小，这种策略随后会影响其他特征。