Christine Marie Janis, PHDEdit My Page
My research focuses on the patterns of fossil mammal evolution over the past 25 million years, specifically the large herbivores (hoofed mammals), examining both change in anatomy through time, indicative of past behavior, and at changes in fossil community structure, indicative of past environments. Of special interest is the evolution of the North American Miocene savanna faunas, and how the mammalian communities can illuminate the transition from woodland to grassland habitats at that time.
I've wanted to be a paleontologist from an early age, triggered by being taken to see "Fantasia" at age 7. That was the year that I also started riding horses, so I attribute my career (as an ungulate [hoofed mammals] paleobiologist) to having outgrown neither the horse phase or the dinosaur phase.
As great as is the diversity of life on earth today, the fossil record increases out knowledge of life's diversity by many orders of magnitude. The fossil record also adds something that is lacking from the study of the living world alone: the dimension of time, and the documentation of what actually happened during the history of organisms.
Although one cannot study the biology of extinct animals directly, there are ways by which once can make sound inferences about what they were like as living beings, such as qualitative or quantitative comparison with living animals of known biology and/or the use of principles of biomechanics. (The use of isotope geochemistry is a new development in this area, but as I am primarily a biologist this is not a technique that I use myself.)
Mammals are especially good subjects for paleobiological investigations, as their bony remains provide much information about diet and mode of locomotion, and there is a large diversity of living mammals with which to compare the fossil ones. The structure of the communities of fossil mammals, in terms of diversity of body sizes, and dietary and locomotor types, can also provide excellent information about their habitat (in an entirely different fashion from evidence from fossil plants), and tracking changes in communities through time can provide information as to the tempo and mode of climatic and environmental changes.
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 past 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 Eurasia. Work in submission 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 (~17 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. John Damuth and I have recently published a large review on hypsodonty (high-crowned teeth) in mammals.
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) (Work in progress).
Current research with Borja Figueirido (formerly my postdoctoral student, now a lecturer at the University of Malaga, Spain), relates to large scale patterns in mammalian diversity over the past 65 million years, plus landmark morphometric studies on craniodental morphology of ungulate mammals (extending my work of several years ago with new types of statistical analysis). We have also recently published a paper on the elbow anatomy of the thylacine (the so-called "marsupial wolf"), showing that it was not as cursorially-adapted as assumed, and so unlikely to have had wolf-like hunting behavior, and are currently expanding our research to include other features of forelimb anatomy.
In addition to my research on mammalian paleobiology, I also have an interest in the paleophysiology of early tetrapods. I have published several papers on this issue, the most recent (2012) on the use of dermal bone as a potential buffer for terrestrial acidosis.
In addition to academic research I also write around 40% of the textbook "Vertebrate Life" (Pough, Janis & Heiser). I was involved in the 5th edition (1998), 6th ed. (2001), 7th ed.(2004), 8th ed. (2008), and recently finished work on the 9th edition.
1985: George Gaylord Simpson Prize for Paleontology (Yale University, USA)
2007: Elected Fellow of the Paleontological Society
Society of Vertebrate Paleontology (USA)
The Paleontological Society (USA)
The Palaeontological Association (UK)
GRIPS (Greater Rhode Island Paleontological Society) charter member.
Society for the Study of Mammalian Evolution (president)
Society for Integrative and Comparative Biology
National Center for Science Education
National Science Foundation (Sedimentary Geology and Paleobiology Program).
Collaborative Research (with John Damuth, University of California Santa
Barbara) (4/15/2101): Were there "too many" browser species in local faunas of the early Miocene? Testing a global hypothesis using the Australian mammal fossil record.
Comparative Biology of the Vertebrates (Biol 1880): An evolutionary approach to vertebrate anatomy and diversity, including dissection labs and comparative osteology.
Vertebrate Evolution and Diversity (Biol 0390): a lower level course aimed at modes of thought and understanding in science, as well as vertebrate evolution.
I have also taught courses or seminars (graduate and otherwise on the following topics); Mammalian diversity and design, mammalian paleobiology, vertebrate paleontology, human evolution, dinosaurs in society and culture, macroecology, history of evolutionary ideas.
- Comparative Biology of Vertebrates (BIOL 1880)
- Vertebrate Evolution and Diversity (BIOL 0390)
- Janis, C.M., B. Shoshsitaishvili , R. Kambic, and B. Figuerido (2012). On their knees: distal femur asymmetry in ungulates and its relationship to body size and locomotion. Journal of Vertebrate Paleontology 32:433-445.(2012)
- Janis, C. M., K. Devlin, D. E. Warren, and F. Witzmann. (2012) Dermal bone in basal tetrapods: a palaeophysiological hypothesis of adaptation for terrestrial acidosis. Proceedings of the Royal Society, B. (published online April 25th doi: 10.1098/rspb.2012.0558)(2012)
- Figueirido, B., C. M. Janis, J. A. Pérez-Claros, M. de Renzi, and P. Palmqvist (2012). Cenozoic climate change influences mammalian evolutionary dynamics. Proceedings of the National Academy of Sciences 109:722-727.(2012)