DISSERTATION RESEARCH: Morphometric study of crocodylian cranial ecomorphology through phylogeny and ontogeny

论文研究：通过系统发育和个体发育对鳄鱼颅骨生态形态进行形态测量研究

• 批准号: 0709771
• 负责人: Peter Makovicky
• 金额: $ 1.13万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0709771&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Morphometric; study; crocodylian

Crocodylians exhibit a high degree of cranial variation and convergence throughout their 80 million-year fossil record. Despite extensive investigation, discrepancies between morphological and molecular phylogenies persist and relate to taxa that share a slender cranial morphology believed to reflect ecological or functional specialization. Using geometric morphometrics to summarize morphological shape in crocodilian skulls, this project creates the first 3-D crocodylian skull morphology database of all 23 extant crocodylian post-hatchling ontogenies and fossil taxa from national and international collections. Analyses of this database will: 1) test the validity of current crocodylian cranial morphology and their relationship to phylogeny, 2) determine how skull shape distributions are ontogenetically and phylogenetically related, 3) determine relationships between morphological plasticity and ontogenetic environment by testing for skull shape differences between wild and farmed alligator specimens through their ontogeny. This research will provide insights into patterns and processes underlying morphological evolution and help to understand the discrepancy between molecular and morphological phylogenetic hypotheses for crocodylians. The database generated through this project will serve as a benchmark for testing hypotheses beyond the objectives of this proposal.

鳄鱼在其8000万年的化石记录中表现出高度的颅骨变异和趋同。尽管进行了广泛的研究，但形态和分子系统发育之间的差异仍然存在，并与具有细长头骨形态的分类群有关，这些分类群被认为反映了生态或功能的特化。利用几何形态计量学总结鳄鱼头骨的形态形态，该项目创建了首个三维鳄鱼头骨形态数据库，其中包括所有23个现存的鳄鱼幼体个体发育和来自国内外收藏的化石分类群。对这个数据库的分析将：1)测试当前鳄鱼头骨形态的有效性及其与系统发育的关系，2)确定头骨形状分布如何在个体发育和系统发育上相关，3)通过个体发育测试野生和养殖扬子鳄标本的头骨形状差异，确定形态可塑性与个体发育环境之间的关系。这项研究将提供对形态进化模式和过程的洞察，并有助于理解鳄鱼的分子和形态系统发育假说之间的差异。通过该项目生成的数据库将作为检验超出本提案目标的假设的基准。