Palaeobiology of non-avian theropod dinosaurs

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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.*****