DISSERTATION RESEARCH: The Evolution of Breathing Mechanisms in the Archosauria

论文研究：主龙类呼吸机制的进化

• 批准号: 0206169
• 负责人: Farish Jenkins
• 金额: $ 1万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2004-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0206169&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Evolution; Breathing; Mechanisms

Dissertation Research: Evolutions of Breathing Mechanisms in the Archosauria Dr. Farish Jenkins & Leon ClaessensAn understanding of the origin of vertebrate respiratory systems- how very different lung structures and breathing mechanisms evolved- has been constrained by the rarity of soft-tissue preservation in the fossil record. The problem may be circumvented by taking an integrative approach that employs both observations on living animals and a survey of hard tissue structures preserved in extinct forms. The project will focus on the evolution of lung ventilation in the Archosauria, a group of animals that includes dinosaurs, crocodilians and birds. The two living archosaurian groups, birds and crocodilians, exhibit distinct and seemingly unique respiratory mechanisms. Bird lungs are interconnected with non-respiratory air sacs, and air 'circulates' unidirectionally through lungs of fixed size; crocodilians have two-way flow and an accessory muscle that moves the lungs. The skeletal movements of the respiratory cycle (inhalation and exhalation) in birds and crocodilians have not been studied in detail. This work will represent the first attempt to correlate the mechanics of respiration with a detailed analysis of bony features, especially those that are indicators of specific movements and those that constrain movement. This combined approach represents the most promising basis on which to trace the evolution of diverse respiratory systems that is represented with the Archosauria. Specifically, this investigation will: 1. Analyze the respiratory kinematics of the trunk skeleton of birds and crocodilians through cineradiography (x-ray recording of living animals); 2. Identify and trace osteological (bony) characters and their functional implications within the archosaurian fossil record; 3. Assess the functional and structural data in a phylogenetic context (that is, in terms of evolutionary relationships inferred from other evidence) to understand evolutionary patterns.

论文研究：始祖龙中呼吸机制的进化法里什·詹金斯博士和莱昂·克莱森博士对脊椎动物呼吸系统起源的理解-如何进化出截然不同的肺结构和呼吸机制-受到化石记录中罕见的软组织保存的限制。这个问题可以通过采取一种综合的方法来规避，这种方法既包括对活动物的观察，也包括对以灭绝形式保存的硬组织结构的调查。该项目将重点研究始祖龙的肺通风进化。始祖龙是一群包括恐龙、鳄鱼和鸟类在内的动物。鸟类和鳄鱼这两个现存的始祖龙群体，表现出截然不同的、看似独特的呼吸机制。鸟的肺与非呼吸性气囊相互连接，空气通过固定大小的肺进行单向循环；鳄鱼有双向流动和推动肺部运动的附属肌肉。鸟类和鳄鱼呼吸周期(吸气和呼气)的骨骼运动尚未得到详细研究。这项工作将是首次尝试将呼吸机制与骨骼特征的详细分析联系起来，特别是那些指示特定运动的特征和那些限制运动的特征。这种结合的方法代表了追踪以始祖龙为代表的不同呼吸系统进化的最有希望的基础。具体地说，这项调查将：1.通过放射摄影术(活动物的X射线记录)分析鸟类和鳄鱼躯干骨骼的呼吸运动学；2.在始龙化石记录中识别和追踪骨学(骨)特征及其功能含义；3.在系统发育的背景下(即根据其他证据推断的进化关系)评估功能和结构数据，以了解进化模式。