Breathing in a Box: Constraints on Lung Ventilation in Giant Pterosaurs
Breathing in a Box: Constraints on Lung Ventilation in Giant Pterosaurs
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DOI：
10.1002/ar.22839
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发表时间：
2014-12-01
影响因子：
2
通讯作者：
Elgin, Ross A.
中科院分区：
文献类型：
--
作者：
Geist, Nicholas R.;Hillenius, Willem J.;Elgin, Ross A.
翼龙是第一批实现主动飞行的脊椎动物，其中一些衍生形式达到了巨大的体型。不断积累的化石证据证实了早期的迹象，即这些飞行形态对大尺寸的选择导致了轻而坚固的骨骼，其特征是躯干的许多骨头融合在一起。然而，这一过程也对大型翼龙胸部的活动性增加了机械限制，这可能限制了肺部通气的选择。我们对最近提出的类似鸟类的肋胸骨泵送机制作为主要抽吸方式的建议提出了另一种假设。对大型翼龙的椎骨、肋骨、胸骨和胸带之间的关节进行分析表明，胸腔和胸骨的活动性有限。与现存羊膜动物的肺通气模式的比较表明，僵硬的胸部，加上可移动的胃和耻骨前骨，可能与大型翼手龙的肋外肺通气机制最一致，可能类似于鳄鱼样内脏移位系统 Anat Rec，297：2233-2253，2014。（c）2013 Wiley 期刊，公司
Pterosaurs were the first vertebrates to achieve active flight, with some derived forms reaching enormous size. Accumulating fossil evidence confirms earlier indications that selection for large size in these flying forms resulted in a light, yet strong skeleton characterized by fusion of many bones of the trunk. However, this process also added mechanical constraints on the mobility of the thorax of large pterosaurs that likely limited the options available for lung ventilation. We present an alternative hypothesis to recent suggestions of an avian-like mechanism of costosternal pumping as the primary means of aspiration. An analysis of the joints among the vertebrae, ribs, sternum, and pectoral girdle of large pterosaurs indicates limited mobility of the ribcage and sternum. Comparisons with modes of lung ventilation in extant amniotes suggests that the stiffened thorax, coupled with mobile gastralia and prepubic bones, may be most consistent with an extracostal mechanism for lung ventilation in large pterodactyloids, perhaps similar to a crocodile-like visceral displacement system Anat Rec, 297:2233-2253, 2014. (c) 2013 Wiley Periodicals, Inc.