Palaeobiology of non-avian theropod dinosaurs

在阿尔伯塔省恐龙省立公园出土的800多具骨骼中，2014年在加拿大发现了迄今为止收集到的最好的小型兽脚亚目恐龙（Saurornitholestes）标本，目前正在研究中。该项目与北美西部其他地区正在进行的类似研究相结合，形成了一幅独特的生态恐龙群落的图景，其中单个分类群正在迅速进化。在艾伯塔省，兽脚亚目恐龙的进化变化可以通过红鹿河沿岸一系列不同的恐龙动物群来追踪。然而，由于来自亚洲的新形式的移民，了解局部的进化变化是复杂的，我一直在研究几种兽脚亚目恐龙可能的起源地区。我在亚洲的主要关注点是蒙古的Nemegt组，它大致与恐龙公园组同期。在这两个地区中任何一个地区出现的恐龙家族都预示着它将在另一个地区被发现（最近在阿尔伯塔省发现的两种亚洲兽脚亚目恐龙——阿尔瓦雷兹龙和小盗龙就是证明）。***我与HQP正在进行的项目的具体例子包括北美和亚洲的驰龙类（包括龙爪龙）的描述和系统发育分析。来自阿尔伯塔省和蒙古的窃蛋龙的描述和系统发育分析在这个时期尤其富有成效，并提供了caenagnathid兽脚亚目洲际交流的细节。***我与中国同事的长期交往使我有很多机会在中国研究近亲兽脚亚目恐龙。这项工作正在继续进行，以获得一个新的中国troodontid分类群，这将使我们对Troodon有更深入的了解。2009年在阿尔伯塔省收集的一种鸟螨有羽毛印记；两篇关于这些羽毛的论文已经发表，他们与多伦多和隆德（瑞典）的实验室合作，用扫描电镜和地球化学技术分析了保存完好的黑素体。我实验室的其他项目还包括用牙釉质分析稳定同位素。虽然以前用于确定灭绝动物的营养水平，但这项技术现在可以分析更小的样本，包括小型兽脚亚目动物牙齿上的牙釉质。一个类似的合作牙齿项目使用激光消融牙釉质中的同位素来确定恐龙公园牙齿的成岩变化程度，并将同位素测年技术与已知的放射性测年技术进行比较，作为其他地区同位素研究的对照。通过我的研究开始的另一个合作项目涉及蒙古骨骼的地球化学指纹，作为一种机制，以改善非法偷猎或缺乏来源信息的标本的位置信息。近年来我的实验室的成功与我对培养hqp的信念直接相关*****

Of more than 800 skeletons excavated in Dinosaur Provincial Park in Alberta, the best specimen of a small theropod (Saurornitholestes) ever collected in Canada was found in 2014, and is presently under study. This program is integrated with similar studies in progress in other parts of western North America, and a picture is emerging of ecologically specific dinosaur communities in which individual taxa are rapidly evolving. Within Alberta, evolutionary changes in theropods can be tracked through a succession of different dinosaur faunas along the Red Deer River. Understanding evolutionary change locally is complicated, however, by the immigration of new forms from Asia, and I have been studying probable areas of origin of several theropods. My prime focus in Asia is the Nemegt Formation of Mongolia, which is roughly contemporaneous with the Dinosaur Park Formation. The presence of any dinosaur family in either of the two regions predicts it will be found in the other region (as witnessed by the recent identification in Alberta of alvarezsaurids and microraptorines -- two Asian theropod dinosaur taxa). *** Specific examples of projects that I have underway with HQP include the description and phylogenetic analysis of dromaeosaurids (including Saurornitholestes) of North America and Asia. The description and phylogenetic analysis of oviraptorosaurs from Alberta and Mongolia is especially productive at this time, and is providing details of an intercontinental interchange of caenagnathid theropods.*** My long association with colleagues in China gave me many opportunities to work on closely-related theropods in China. This work is continuing with a new taxon of Chinese troodontid, which will give us greater familiarity with Troodon. An ornithomimid collected in Alberta in 2009 has feather impressions; two papers have been published on the feathers, and their richly preserved melanosomes are now being analyzed with SEM and geochemical techniques through collaborations with labs in Toronto and Lund (Sweden). Other initiatives in my lab include the analysis of stable isotopes using tooth enamel. Although used previously to determine trophic levels of extinct animals, the technology can now analyze much smaller samples, including enamel from the teeth of small theropods. A similar collaborative tooth project uses laser-ablation of isotopes in enamel to determine the degree of diagenetic alteration in teeth from Dinosaur Park, and to compare isotopic dating techniques with known radiometric dates as a control for isotopic studies in other regions. Another collaborative project started through my research involves the geochemical fingerprinting of bones from Mongolia as a mechanism to improve locality information on specimens that were either illegally poached or lack information on provenance. The success of my lab in recent years can be correlated directly with my belief in training HQP.*****