Abstract:
Turbinals are key bony elements of the mammalian nasal cavity, involved in heat and moisture conservation as well as olfaction. While turbinals are well known in some groups, their diversity is poorly understood at the scale of placental mammals, which span 21 orders. Here, we investigated the turbinal bones and associated lamellae for one representative of each extant order of placental mammals. We segmented and isolated each independent turbinal and lamella and found an important diversity of variation in the number of turbinals, as well as their size, and shape. We found that the turbinal count varies widely, from zero in the La Plata dolphin, (Pontoporia blainvillei) to about 110 in the African bush elephant (Loxodonta africana). Multiple turbinal losses and additional gains took place along the phylogeny of placental mammals. Some changes are clearly attributed to ecological adaptation, while others are probably related to phylogenetic inertia. In addition, this work highlights the problem of turbinal nomenclature in some placental orders with numerous and highly complex turbinals, for which homologies are extremely difficult to resolve. Therefore, this work underscores the importance of developmental studies to better clarify turbinal homology and nomenclature and provides a standardized comparative framework for further research.
摘要:
鼻骨是哺乳动物鼻腔的关键骨骼元素,涉及热量和水分保存以及嗅觉。虽然鼻甲在某些群体中是众所周知的,它们的多样性在胎盘哺乳动物的规模上知之甚少,跨越21个订单。这里,我们调查了每个现存胎盘哺乳动物的一个代表的鼻骨和相关薄片。我们分割并分离了每个独立的鼻甲和薄片,并发现了鼻甲数量变化的重要多样性,以及它们的大小,和形状。我们发现鼻甲数量差异很大,从拉普拉塔海豚的零开始,(Pontoporiablainvillei)在非洲灌木象(Loxodontaafricana)中约为110。胎盘哺乳动物的系统发育过程中发生了多次鼻甲损失和其他收益。一些变化显然归因于生态适应,而其他人可能与系统发育惯性有关。此外,这项工作突出了鼻甲命名的问题,在一些胎盘顺序与众多和高度复杂的鼻甲,其中的同源性极难解决。因此,这项工作强调了发育研究对更好地阐明鼻甲同源性和命名法的重要性,并为进一步研究提供了标准化的比较框架。