A new fossil from an ancient group of mammals is providing scientists with new information about how mammals survived a mass extinction and flourished in the aftermath.

New Fossil Tells Of Survival And Rapid Evolution For Ancient Group Of Mammals

How mammals survived mass extinction

The fossil is from a group of mammals – known as multituberculates – that lived along with the dinosaurs for 100 million years. They were mostly small and resembled today’s rodents, with enlarged incisors and molars with many cusps. Some may have fed on plants and leaves.

They were among the few land-animals that survived the extinction that killed the dinosaurs. After the extinction, they thrived for a brief time, but then dwindled to extinction about 35 million years ago. They may have been outcompeted by rodents.

New Fossil Tells Of Survival And Rapid Evolution For Ancient Group Of Mammals

The new species, Kimbetopsalis simmonsae, was found in the San Juan Basin of northwestern New Mexico last summer. It has helped scientists reconstruct the family tree of this particular group of multituberculates which includes the biggest species of multituberculate, Taeniolabis, that weighed as much as 100 kg – about the size of a large beaver. Kimbetopsalis simmonsae lived only about 500 thousand years after the dinosaur extinction. It may have been a forebear to Taeniolabis – it was a bit smaller and occurred about 200 thousand years earlier.

The study, carried out by the New Mexico Museum of Natural History and Science, the University of Edinburgh, and the University of Nebraska, was published in the Zoological Journal of the Linnean Society. It was supported by the Marie Curie Foundation, the Natural Environment Research Council, the US Bureau of Land Management, and the National Science Foundation.

Dr Thomas Williamson of the New Mexico Museum of Natural History and Science, who led the research, said: “New Mexico is especially famous for its record of Paleocene mammals. Fossils such as these are critical for telling us how animals survived truly catastrophic environmental change. Multituberculates were among the first mammals to thrive in the post-apocalyptic world following the mass extinction that killed the dinosaurs.”

For further information, please contact: Dr. Tom Williamson (USA), tel 505 841 2835 email thomas.williamson@state.nm.us

Dr Steve Brusatte (UK), tel 07858 129629, email Stephen.Brusatte@ed.ac.uk