首页 > 分享 > 龟鳖目和镶嵌踝类主龙的皮肤盾血管演化：系统发生约束与生态生理适应。

龟鳖目和镶嵌踝类主龙的皮肤盾血管演化：系统发生约束与生态生理适应。

萌宠菠菠乐园
2025-10-30 15:43

Abstract

Studies on living turtles have demonstrated that shells are involved in the resistance to hypoxia during apnea via bone acidosis buffering; a process which is complemented with cutaneous respiration, transpharyngeal and cloacal gas exchanges in the soft-shell turtles. Bone acidosis buffering during apnea has also been identified in crocodylian osteoderms, which are also known to employ heat transfer when basking. Although diverse, many of these functions rely on one common trait: the vascularization of the dermal shield. Here, we test whether the above ecophysiological functions played an adaptive role in the evolutionary transitions between land and aquatic environments in both Pseudosuchia and Testudinata. To do so, we measured the bone porosity as a proxy for vascular density in a set of dermal plates before performing phylogenetic comparative analyses. For both lineages, the dermal plate porosity obviously varies depending on the animal lifestyle, but these variations prove to be highly driven by phylogenetic relationships. We argue that the complexity of multi-functional roles of the post-cranial dermal skeleton in both Pseudosuchia and Testudinata probably is the reason for a lack of obvious physiological signal, and we discuss the role of the dermal shield vascularization in the evolution of these groups. This article is part of the theme issue 'Vertebrate palaeophysiology'.

摘要

对活体海龟的研究表明，在闭气过程中，通过骨骼酸中毒缓冲，壳参与了对缺氧的抵抗；这一过程还伴随着软壳海龟的皮肤呼吸、经咽和泄殖腔气体交换。在鳄目恐龙的骨酸中毒缓冲中也发现了同样的情况，这些恐龙也被认为在晒太阳时会利用热传递。尽管这些功能多种多样，但其中许多都依赖于一个共同的特征：真皮盾的血管化。在这里，我们测试了在 Pseudosuchia 和 Testudinata 之间的陆地和水生环境的进化过渡中，上述生态生理学功能是否起到了适应性作用。为此，我们在进行系统发育比较分析之前，测量了一组真皮板的骨孔隙率作为血管密度的替代指标。对于这两个谱系，真皮板的孔隙率显然取决于动物的生活方式，但这些变化被证明主要受系统发育关系的驱动。我们认为，在后体皮骨骼的多功能角色的复杂性在 Pseudosuchia 和 Testudinata 中可能是缺乏明显生理信号的原因，并讨论了真皮盾血管化在这些群体进化中的作用。本文是主题为“脊椎动物古生理学”的特刊的一部分。