Published on January 16th, 2022 | by Elsa Panciroli


Episode 134: Mammal Locomotion and Ecology

In this episode we talk to Professor Christine Janis about mammal palaeontology, and her career. Christine is one of the world’s foremost experts in mammal palaeontology and mammalogy. She has authored dozens of scientific papers, and has been co-author of the major textbook Vertebrate Life for the last 20 years.

Christine has had a long and distinguished career, and is currently a researcher at the University of Bristol in the UK. Her work is particularly focused on mammal locomotion and ecology. We’ll be talking about some of the research Christine has led, including on hoofed mammals, sabre-toothed South American ‘marsupials’, and Australia’s extinct giant kangaroos. We’ll talk about the use and limits of comparative anatomy, the importance of direct observation of specimens in the discipline of palaeontology, and how things have changed for researchers during her lifetime.

Professor Christine Janis, one of the world’s leading experts in mammology and fossil mammals. Here she is holding a cast of the skull of Thylacoleo, an extinct carnivorous marsupial from Australia. Photo by Elsa Panciroli.
Digital reconstructions of South American metatherian, Thylacosmilus (left), and North American placental mammal, Smilodon (right). Although there are superficial similarities between these sabre-toothed mammals, Christine and her co-authors show that the characteristics of the teeth, skull and rest of the skeleton, along with results of finite element analysis and microwear analysis on the teeth, suggest it lived very differently, and may not have any a modern analogue. Digital reconstruction by Stephan Lautenschlager.
Top to bottom: the foot bones of Osphranter (red kangaroo), Protemnodon (giant extinct kangaroo), and Dendrolagus (tree kangaroo). The differences in size, proportions, and how robust the modern kangaroo is compared to the extinct giant kangaroo, are clear. In NHMUK. Photo by Billie Jones.
The lower jaws of giant kangaroo Protemnodon in the collections at NHMUK. Photo by Billie Jones.
Christine’s masters student, Billie Jones, holding up the dissected leg of Dorcopsis, a small kangaroo. Christine is in the background. Photo via Billie Jones.
CT scanning the dissected leg of Dorcopsis, to be used in Billie’s masters thesis research. Photo by Billie Jones.

Further Reading/Selected papers:

Janis, C.M. and Ehrhardt, D. 1988. Correlation of relative muzzle width and relative incisor width with dietary preference in ungulates. Zoological Journal of the Linnean Society, 92(3), pp.267-284.

Garland, T. and Janis, C.M. 1993. Does metatarsal/femur ratio predict maximal running speed in cursorial mammals?. Journal of Zoology, 229(1), pp.133-151.

Janis, C.M., Figueirido, B., DeSantis, L. and Lautenschlager, S. 2020. An eye for a tooth: Thylacosmilus was not a marsupial “saber-tooth predator”. PeerJ, 8, p.e9346.

Jones, B., Martín-Serra, A., Rayfield, E.J. and Janis, C.M. 2021. Distal Humeral Morphology Indicates Locomotory Divergence in Extinct Giant Kangaroos. Journal of Mammalian Evolution, pp.1-15.

Wagstaffe, A.Y., O’Driscoll, A.M., Kunz, C.J., Rayfield, E.J. and Janis, C.M. 2022. Divergent Locomotor Evolution in “Giant” Kangaroos: evidence from foot bone bending resistances and microanatomy. Journal of Morphology.

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