Bone Phosphate Isotopic Patterns of Modern and Extinct Terrestrial Vertebrates

现代和灭绝陆生脊椎动物的骨磷酸同位素模式

• 批准号: 9507992
• 负责人: Reese Barrick
• 金额: $ 16.95万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-15 至 1998-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9507992&HistoricalAwards=false
• 关键词: Bone; Phosphate; Isotopic; Patterns; Modern

Barrick 9507992 The question of whether dinosaurs lacked effective temperature control and were heterotherms or were endothermic homeotherms has important implications for their life histories, evolution, rise to dominance in terrestrial ecosystems, and eventual extinction. A great deal of evidence has been amassed regarding dinosaur endothermy which includes brain size, feeding mechanics, paleobiogeography, posture and gait, behaviors, bone histology and predator/prey relationships (Carroll, 1988; Weishample et al., 1990). These studies have changed the general perception of dinosaurs and they are now thought of as active animals, though considered to be ectothermic or mass homeotherms (Ostrom, 1980). During the initial phase of funding (EAR91-06660), we investigated the application of a new high precision 18O isotopic technique for the analysis of bone phosphate. By using the isotopic difference between core body and extremities and the phosphate paleotemperature equation, realtive body temperature differences can be calculated to determine if an fossil animal was a heterotherm or homeotherm. Of the 13 species of dinosaurs analyzed, all appear to be homeotherms with one Jurassic species exhibiting regional heterothermy. These homeothermic bone isotope patterns cannot be ascribed to diagenetic alteration, because none of the specimens have isotopic equilibrium between the co-existing phases of bone phosphate with structural carbonate or calcite cements (co-existing phase test). This proposal seeks funds to expand our modern bone isotope data base by working with the NCSU School of Veterinary Medicine on 5 modern target species. The species will also propose to expand our fossil data base to complete our survey of different dinosaur clades, and also to search for the origins of homeothermy in therapsids and in a Triassic assemblage from Argentina.

巴里克9507992 恐龙是否缺乏有效的温度控制，是异温动物还是吸热恒温动物的问题，对它们的生活史、进化、在陆地生态系统中占主导地位以及最终灭绝都有重要意义。 已经积累了大量关于恐龙内温性的证据，包括大脑大小、进食机制、古生物地理学、姿势和步态、行为、骨组织学和捕食者/猎物关系（卡罗尔，1988; Weishample等人，1990年）。 这些研究改变了人们对恐龙的普遍看法，它们现在被认为是活跃的动物，尽管它们被认为是变温动物或恒温动物（奥斯特罗姆，1980）。 在资助的初始阶段（EAR 91 -06660），我们研究了一种新的高精度 骨磷酸盐的~（18）O同位素分析 利用岩心与肢端的同位素差异和磷酸盐古温度方程，可以计算相对体温差，从而判断化石动物是异温动物还是恒温动物。 在分析的13种恐龙中，所有恐龙似乎都是恒温动物，其中一种侏罗纪恐龙表现出区域性的异温性。 这些恒温骨同位素模式不能归因于成岩蚀变，因为没有标本骨磷酸盐与结构碳酸盐或方解石胶结物（共存相测试）的共存相之间的同位素平衡。 该提案寻求资金，通过与NCSU兽医学院合作，扩大我们的现代骨同位素数据库，研究5种现代目标物种。 该物种还将提议扩大我们的化石数据库，以完成我们对不同恐龙分支的调查，并在兽孔目和阿根廷三叠纪组合中寻找恒温动物的起源。