Christine M. Janis
Professor
Ph.D., Harvard University

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My research focuses on the evolutionary history of large mammals, both in terms of their anatomy (and what this can reveal about past behaviors) and their community structure. My particular interest is in ungulate (hoofed mammals) evolution over the past 20 million years or so. Mammalian community structure, especially that of large herbivores, has a high correlation with local habitats and environments, and change in community structure over time can reveal patterns of climatic change. In my role as senior editor for the volumes “Evolution of Tertiary Mammals of North America” (Cambridge University Press: 1998, 2008) I have accumulated a large amount of information on North American species over the pasat 65 million years, relating to both presence in fossil localities and ecomorphological characteristics. I am currently collaborating with Mikael Fortelius and Jussi Eronen (University of Helsinki), who manage the NOW (Neogene Old World Mammals) database, to combine the North American data with that from the Old World. Preliminary work shows that mammalian communities reveal very different patterns of rainfall and encroaching aridity over the past 20 million years between the two areas. Previous work with John Damuth (University of California, Santa Barbara) has shown interesting patterns in mid Miocene (~18 – 12 million years ago) ungulate communities in North America, where the faunas appear to be “over-rich” in browsers, possibly reflecting an increase in levels of plant productivity (see Janis, Damuth and Theodor 2000, 2002, 2004). Our ongoing research suggests that this was a worldwide phenomenon, thus implying some hitherto unknown global climatic conditions during the mid Miocene, and we currently have funding to investigate these trends with the herbivorous marsupial faunas of Australia. Other current research focuses more on the functional morphology of individual fossil lineages. I originally focused on the use of dental and skull remains to determine diet, but more recently have become interested in the postcranial skeleton and evolution of locomotion, including a study of the evolution of the pacing gait in camels (see Janis, Theodor and Boisvert, 2002) and the mode of locomotion in sthenurine kangaroos (extinct giant browsing forms). Previous work on the reasons for the evolution of cursorial (so-called running) adaptations in ungulates (e.g., Janis and Wilhelm 1993), is being extended by work in progress with my former graduate students, Andrew Clifford; our hypothesis is that cursoriality is more related to energy conservation at slow gaits rather than to speed.

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