Palaeobiology of non-avian theropod dinosaurs

在艾伯塔省恐龙省公园出土的800多具骨骼中，加拿大收集到的最好的小型兽脚类(蜥鸟盗龙)标本于2014年被发现，目前正在进行研究。该计划与北美西部其他地区正在进行的类似研究相结合，正在形成一幅特定于生态的恐龙群落的图景，在这些群落中，个别类群正在迅速进化。在艾伯塔省，兽脚类动物的进化变化可以通过沿着红鹿河的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，理解当地的进化变化是复杂的，我一直在研究几个兽脚亚目动物的可能起源地区。我在亚洲的主要关注点是蒙古的奈米格特组，它大致与恐龙公园组同时代。在这两个地区中的任何一个地区出现任何恐龙家族，都预示着它将在另一个地区找到(正如最近在艾伯塔省发现的阿尔瓦雷萨龙和小恐龙--两个亚洲兽脚类恐龙类群)。*我与HQP正在进行的项目的具体例子包括北美和亚洲的恐龙(包括蜥鸟盗龙)的描述和系统发育分析。来自艾伯塔省和蒙古国的卵猛龙的描述和系统发育分析在这个时候尤其富有成效，并提供了鱼尾蛇类兽脚亚目洲际互换的细节。*我与中国的同事们的长期合作给了我很多机会在中国研究关系密切的兽脚亚目动物。这项工作正在继续中国斑齿目的一个新的分类单元，这将使我们对伤齿龙更加熟悉。2009年在艾伯塔省收集到的一只鸟有羽毛印记；关于羽毛的两篇论文已经发表，它们保存完好的黑素体现在正在通过与多伦多和隆德(瑞典)的实验室合作，用扫描电子显微镜和地球化学技术进行分析。我实验室的其他举措包括使用牙釉质分析稳定同位素。虽然这项技术以前是用来确定灭绝动物的营养水平，但现在可以分析更小的样本，包括小型兽脚亚目动物牙齿的釉质。一个类似的合作牙齿项目使用激光烧蚀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辐射测量数据进行比较，作为其他地区同位素研究的对照。通过我的研究启动的另一个合作项目涉及对蒙古骨骼进行地球化学指纹识别，以此作为一种机制，改善被非法偷猎或缺乏来源信息的标本的位置信息。我实验室近年来的成功与我对培训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.*****