My research focuses on the anatomy, life history, and evolution of vertebrates, with an emphasis on dinosaurs and mammals. One of my long-term aims is to understand how life history evolved in these groups, and how it has in turn shaped their evolution. Ultimately, I’d like to use these insights to help guide conservation biology, helping to preserve the biodiversity we have today.
I’m interested in what extinct animals looked like, and how their bodies functioned. At the heart of all my work is detailed anatomical study: deciphering the features of the fossils. I use these data to understand which bones belong to which species, and in turn this helps me reconstruct their evolutionary relationships. I use many tools in the study of anatomy, but especially 3-dimensional modelling using photogrammetry or x-ray scan data. I also use statistical approaches to quantify changes in anatomy across evolutionary timescales.
The life history of an organism is the pace at which they progress through the phases of their life, from conception through birth and childhood, to a reproductive adult form. One of the key ways that we can study this phenomenon in fossils is through the analysis of thin sections–called palaeohistology. Bones and teeth preserve growth marks and information about growth rate, allowing us to piece together the chronology of an extinct animal’s life. My research now shows that certain chemical traces are left behind, too, revealing evidence of changing diet and physiology.
Palaeontology has unique access to experiments in deep time, which allows us to test how different characters evolved through time and what forces drove these changes. I use evolutionary trees, called phylogenies, to understand how dinosaurs and mammals have evolved. I integrate both anatomical and life history data into evolutionary analyses, to determine the patterns and rates of change in these features. This reveals the correspondence between major biological transitions with evolutionary events, like radiations and extinctions.
My current research at the Royal Ontario Museum is about the mammals that lived before and after the dinosaur extinction. I’m looking inside their bones and teeth to learn how they grew over their lifetimes. By learning about their physiology and growth, we can start to understand how and why they took over global ecosystems.
After my PhD, I moved to Scotland and switched from toothless dinosaurs to mammal teeth–a big change in tooth complexity! By analyzing thin sections of the bones and teeth of fossil mammals from the early Palaeocene, I reconstructed the life histories of these pioneering species, which took over after the dinosaurs. I partnered with a team of geochemists at the University of St Andrews to analyze the teeth using cutting edge laser technology. By sequentially vaporizing the entire tooth, we produced chemical heat maps that show when ancient mammals were born, and how long they suckled for. This was a major advance that filled in a piece of the puzzle about how our ancestors got big and took over the Earth after the dinosaurs went extinct. Now, I’m using this technique to look further back in time and understand how reproduction evolved in mammals.
In addition to ongoing work on oviraptorosaurs, I have branched out to work on tyrannosaurs, the group that includes the famous T. rex. One of the long-standing mysteries about tyrannosaurs has been what they looked like as babies–fossils of baby tyrannosaurs have eluded us for centuries. In 2017, I found a baby claw that sparked a bigger project describing some enigmatic bones that we suspected might be the first baby tyrannosaurs. We took these specimens to a synchrotron particle accelerator to make incredibly detailed 3-dimensional reconstructions that showed that they were indeed embryonic tyrannosaurs. These give us our first look into the childhood of a T. rex, and I’m now working with an all-Canadian team of palaeontologists to analyze some other baby tyrannosaurs that have turned up.
Much of my PhD research focused on Caenagnathidae, a mostly North American group of oviraptorosaurs that are very poorly known. By reexamining old specimens and looking at newly discovered material, I’m slowly unravelling their diversity in North America. Recently, I’ve also been in Mongolia working on oviraptorids from the Nemegt Basin. Most species here are represented by complete skeletons, some of which are preserved brooding like modern birds. Because their anatomy is so well known, we can start asking questions about their behaviour, ecology, and evolution. You can check out some of my research in the publications section. Most of my work is also hosted on ResearchGate.
Caenagnathids were mostly North American, but their fossils have recently become increasingly common in Asia. They range in size from small, 5 kg animals like Microvenator and Caenagnathasia, to the enormous Gigantoraptor— estimated at more than 2000 kg.
My work on caenagnathids focuses on our foundational knowledge of the group: what they looked like, how many species there were, and how they were related to each other. Their delicate skeletons mean that they are mostly known from fragmentary, fossils which makes it a nightmare to determine which bones belong to the same species. In addition to describing more material and skeletons (see publications), I’ve been examining their growth using histology, and the way they dispersed back and forth between Asia and North America.
Oviraptorids are, as a group, among the best known theropods. They are exclusively Asian, and specifically are incredibly common in Mongolia and China. Dozens of species are known, their relationships are relatively well established, and most are represented by fairly complete skeletons. This lets us ask some exciting questions. What roles did they play in their ecosystems? Why were they so diverse, and how did all these forms coexist? What can we learn about their behaviour and sociality?
I tackled some of these problems during my PhD program, and we now understand how oviraptorids fit into their ecosystems and shared resources. I’ve also been able to work on some incredible oviraptorid specimens that tell us about both their behaviours and their evolution.
My research is funded by a number of agencies and small grants. These include: