University of Bristol logo and link Fossil Groups banner and link

Fossil Record

Multituberculate fossils have been found mainly in the Northern hemishpere, although a few isolated teeth have been found in Argentina, Morocco and Madagascar.

The oldest multituberculates are known from isolated teeth dating back to the Middle Jurassic, around 165 million years ago (Butler and Hooker, 2005).
Of the Jurassic and Cretaceous forms, only teeth, upper and lower jaws, and fragments of skull material are known. All of these multituberculates belong to the Plagiaulacida suborder, which includes the ancestors of the late Cretaceous and early Tertiary Cimolodonta. The early Cretaceous forms begin to show the modifications in teeth structure which are characteristic of their descendants, for example the third row of cusps on the upper molars.

The best record of Cretaceous multituberculates comes from late Cretaceous deposits in Mongolia; hundreds of skulls, often associated to skeletons, have been found in the Gobi Desert. The North American Late Cretaceous multituberculate forms are less complete. The European record for this time consists of a skull and isolated teeth.

Fossils of North American and Chinese Tertiary multituberculates are much more complete; many of the skulls are intact and the skeletons are preserved. In Europe, only isolated teeth are known. The multituberculates went extinct in the mid-Tertiary, possibly outcompeted by rodents.

The lower jaw of a Sinobaatar (Plagiaulacid line) has been found preserved in the abdomen of a feathered dinosaur, Sinosauropteryx, which shows that these small mammals were eaten by larger carnivores (Hurum et al., 2006).

Multituberculate hair was found in the fossilised faeces of other carnivorous mammals.

Although no exceptionally preserved soft tissues have been found, much can be deduced from the bones. The brain has been visualised by X-ray/CT scanning of complete skulls, and muscles and blood vessels have been reconstructed from the clues they have left on the bones, like ridges for muscle attachment.

Homepage  |  Characters and Anatomy  |  Palaeobiology  |  Major Subgroups  |  Fossil Record  |  Modern Forms  |  Literature and web pages

Author: Aude Caromel
Last updated: 20/11/06
Return to Fossil groups home page

Websites produced by students on the MSc Palaeobiology programme in the Department of Earth Sciences at the University of Bristol for academic year 2006-7