Abstract:
The group Anguimorpha represents one of the most unified squamate clades in terms of body plan, ecomorphology, ecophysiology and evolution. On the other hand, the anguimorphs vary between different habitats and ecological niches. Therefore, we focused on the group Anguimorpha to test a possible correlation between heart morphology and ecological niche with respect to phylogenetic position in Squamata with Sphenodon, Salvator, and Pogona as the outgroups. The chosen lepidosaurian species were investigated by microCT. Generally, all lepidosaurs had two well-developed atria with complete interatrial septum and one ventricle divided by ventricular septa to three different areas. The ventricles of all lepidosaurians had a compact layer and abundant trabeculae. The compact layer and trabeculae were developed in accordance with particular ecological niche of the species, the trabeculae in nocturnal animals with low metabolism, such as Sphenodon, Heloderma or Lanthanotus were more massive. On the other hand athletic animals, such as varanids or Salvator, had ventricle compartmentalization divided by three incomplete septa. A difference between varanids and Salvator was found in compact layer thickness: thicker in monitor lizards and possibly linked to their mammalian-like high blood pressure, and the level of ventricular septation. In summary: heart morphology varied among clades in connection with the ecological niche of particular species and it reflects the phylogenetic position in model clade Anguimorpha. In the absence of fossil evidence, this is the closest approach how to understand heart evolution and septation in clade with different cardiac compartmentalization levels.
摘要:
就身体计划而言,安吉莫拉集团代表了最统一的角化进化枝之一,生态形态学,生态生理学和进化。另一方面,不同的栖息地和生态位之间的物种变化。因此,我们专注于Anguimorpha小组,以测试心脏形态与生态位之间可能存在的相关性,这些相关性涉及带有Sphenodon的鳞茎的系统发育位置,救世主,和波戈纳作为外群。通过microCT研究了所选的鳞翅目物种。一般来说,所有鳞龙都有两个发育良好的心房,房间隔完整,一个心室被室间隔分为三个不同的区域。所有鳞翅目的心室都有致密的层和丰富的小梁。致密层和小梁是根据该物种的特定生态位发展的,夜间代谢低的动物的小梁,比如Sphenodon,Heloderma或Lanthanotus更大。另一方面,运动动物,比如瓦兰尼德或救世主,心室分隔被三个不完整的隔膜分开。varanids和Salvator之间的差异在于紧凑的层厚度:监测蜥蜴较厚,可能与哺乳动物般的高血压有关,和室间隔的水平。总之:各个进化枝之间的心脏形态与特定物种的生态位有关,它反映了模型进化枝Anguimorpha的系统发育位置。在没有化石证据的情况下,这是最接近的方法如何了解不同心脏分隔水平的进化枝的心脏进化和分隔。