DISSERTATION RESEARCH: The early evolution and adaptive radiation of saurian reptiles

论文研究：蜥蜴类爬行动物的早期进化和适应性辐射

• 批准号: 1501851
• 负责人: Alan Turner
• 金额: $ 1.03万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2017-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501851&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; early; evolution; adaptive

Reptiles form a critical component of the modern ecosystem, with over 20,000 known species. Fossil and molecular evidence shows that all of these living species belong to a single group, Sauria, which originated over 260 million years ago, during the Permian Period. Although saurians are rare in the Permian fossil record, they become common and diverse following a massive extinction event at the end of the Permian, 252 million years ago. This end-Permian extinction occurred at the same time as massive volcanic eruptions and acidification in oceans, wiping out an estimated 95% of species living at the time. The saurians that appear after the extinction very quickly evolve an incredible diversity of body sizes, body shapes, and diets, suggesting that they took advantage of the many gaps in the ecosystem caused by the extinction. However, the family tree of the oldest Sauria is poorly understood, and critical questions about the ancestors of all modern reptiles remain unanswered: How does the diversity of Sauria change over the period of environmental change at the end of the Permian? How rapidly did the early saurian groups change anatomically? What did the ancestor of all living reptiles look like, and how have the lineages we see today changed from that ancestor? Answering these questions will allow scientists to understand the impact that similar environmental changes occurring today, could have on living animal species. It will also provide a baseline for the changes we might expect following more serious environmental crises. Fossils from the Permian and Triassic periods are far too ancient to preserve DNA, and reconstructing their evolutionary history must rely on detailed anatomical study. Unfortunately, the anatomy of most early saurians have not been well described. This dissertation project has required restudy of dozens of museum collections worldwide, funded largely by grants from private foundations. These allowed development of the largest anatomical dataset analyzing this critical problemThese museums preserve fossils from the Karoo Formation of South Africa, a critical region that preserves a huge diversity of early diapsids from both the latest Permian and earliest Triassic,, providing an unprecedented opportunity to sample fossils at this critical moment. The dataset constructed and the photo records developed for this project will be made available to the public via NSF-funded databases (e.g., Morphobank).

爬行动物构成了现代生态系统的关键组成部分，拥有20,000多种已知物种。化石和分子证据表明，所有这些生物属于二叠纪时期以上超过2.6亿年前的单一群体Sauria。尽管在二叠纪化石记录中很少见，但在2.52亿年前的二叠纪结束时，它们在大规模的灭绝事件中变得普遍和多样。这种终结者的灭绝是与大规模火山喷发和海洋中的酸化同时发生的，估计当时有95％的物种。在灭绝之后出现的Saurians很快就会发展出令人难以置信的身体大小，体形和饮食的多样性，这表明他们利用了由于灭绝而造成的生态系统中的许多差距。但是，最古老的Sauria的家谱对所有现代爬行动物的祖先的关键问题都没有得到解答：Sauria的多样性在二叠纪结束时的环境变化时期如何变化？早期的Saurian群体在解剖学上改变了多快？所有活着的爬行动物的祖先是什么样的，我们今天看到的血统与那个祖先有何变化？回答这些问题将使科学家能够了解当今发生类似的环境变化可能对活物种产生的影响。它还将为我们可能期望发生的更严重的环境危机的变化提供基准。二叠纪和三叠纪时期的化石太古老，无法保留DNA，重建其进化史必须依靠详细的解剖学研究。不幸的是，大多数早期的索里人的解剖结构尚未得到很好的描述。该论文项目需要重新研究全世界的数十个博物馆收藏，主要由私人基金会的赠款资助。这些允许开发最大的解剖数据集，分析了这一关键问题，这些博物馆将化石保留在南非的卡鲁形成中，这是一个关键的地区，一个关键的地区，它保留了最新的二叠纪和最早的三叠纪早期二叠纪的巨大多样性，从而提供了这一至关重要的机会，可以在这一关键的时刻品尝过塑料。为该项目构建的数据集和为该项目开发的照片记录将通过NSF资助的数据库（例如Morphobank）提供给公众。