Anatomical Features Linked To Ventilation and Metabolic Rates Of Fossil Birds and Dinosaurs

[04:20 . 29]威廉J.希勒纽斯恒温动物，或称“温血动物”是动物进化中的一项重大创新。因为大多数与恒温动物相关的生理适应都发生在软组织中，不会变成化石，所以恒温动物的早期进化，包括它在恐龙中的可能存在，在很大程度上仍然是推测性的。新的证据表明，哺乳动物与恒温动物相关的高代谢率和肺通气率需要鼻子（呼吸鼻甲）中复杂的骨骼结构来加湿吸入的空气并减少呼吸水分的流失。这项研究将测试是否同样的联系适用于现存的鸟类，并检查鸟类化石和它们的祖先恐龙，以寻找呼吸涡轮存在的证据。它将使用非侵入性、高分辨率的计算机x射线断层扫描来检查鸟类化石和各种恐龙群的代表的鼻腔内部解剖结构。研究结果将表明，在鸟类进化过程中，恒温动物何时出现，以及恐龙是否以及何时进化为恒温动物。这项研究将使人们更好地了解恐龙的生理机能，并可能弄清它们灭绝的原因。

9420290 William J. Hillenius Endmthermy, or "warm-bloodedness" was a significant innovation in animal evolution. Because most physiological adaptations associated with endothermy occur in soft tissue and do not fossilize, the early evolution of endothermy, including its possible presence among dinosaurs, remains largely speculative. New evidence suggests that the high metabolic rates and lung ventilation rates associated with endothermy in mammals require complex bony structures in the nose (respiratory turbinals) that humidify inhaled air and decrease respiratory water loss. This research will test to see whether the same association holds for living birds, and examine fossil birds and their ancestors, the dinosaurs, for evidence of the presence of respiratory turbinals. It will use non-invasive, high-resolution computed X-ray tomography scans to examine the nasal internal anatomy of fossils of birds and representatives of a variety of dinosaur groups. The results will show when endothermy arose during the evolution of birds, and whether and when endothermy evolved in dinosaurs. The research will lead to a greater understanding of the physiology of the dinosaurs, and possibly of the reasons for their extinction.