Wednesday, March 7, 2012
Cretaceous Eutherians and Origins of
Cenozoic and Modern Placental Mammals

John R. Wible, PhD
Curator of Mammals
Carnegie Museum of Natural History

Earth Theater, First Floor Rear
Carnegie Museum of Natural History
Noon–1 p.m.

An extinction event at the end of the Cretaceous (65 million years ago) wiped out roughly 75% of the species living at the time. The impact this extinction had upon the evolution of placental mammals, the dominant mammal group today, is unclear. Wible focuses on the Cretaceous and Cenozoic (the last 65 million years) fossil record in light of the anatomy of living placentals. His studies suggest that there are no identifiable placentals living in the Cretaceous. This undeniably couples the end Cretaceous extinction event with the long-recognized explosive burst of early Cenozoic placental fossils, making this the origination of the modern placental lineages and their subsequent diversification.

Related Publication: Wible, J.R., G.W. Rougier, M.J. Novacek, and R.J. Asher. 2009. The eutherian mammal Maelestes gobiensis from the Late Cretaceous of Mongolia and the phylogeny of Cretaceous Eutheria. Bulletin of the American Museum of Natural History, 327: 1-123.

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