My main research interest focuses on studying functional morphology and ecology of Cretaceous mammals, particularly during the Early Cretaceous. The Early Cretaceous was an important time in mammalian evolution. The introduction of flowering plants and concomitant radiation of insects provided vast new resources for early mammals. Traditionally, many Cretaceous mammals had been considered mainly insectivorous. Newer research is showing that the story is more complex. Cretaceous mammals, though relatively small, still occupied a rather diverse range of body sizes and ecological niches. Currently, I am studying better ways to quantify size, shape, and tooth microstructure of Early Cretaceous mammals, using 2-D and 3-D analysis. Tooth size is correlated with body size, and size, along with tooth shape, wear patterns, and microstructure, can provide insight into the ecology of early mammals. Other collaborative projects include studying mammal faunas from Early Cretaceous Lakota Formation in South Dakota and the Cloverly Formation in Montana and Oklahoma.

• Cifelli, R.L., Gordon, C.L. and T. Lipka. 2013. New multituberculate mammal from the Early Cretaceous of eastern North America. Canadian Journal of Earth Sciences 50(3): 315-323.

• Cifelli, Richard L. and C.L. Gordon. 2007. Re-crowning mammals. Nature 447: 918-920.