Earliest Evolution of Multituberculate Mammals Revealed by a New Jurassic Fossil

Abstract

Early Multi: Multituberculate mammals (multis) first arose in the Jurassic and became extinct in the Oligocene, a span of over 100 million years, which makes them the longest-living order of mammals known. This highly diverse and abundant group filled many niches occupied by today's similarly diverse rodents. Multis are known for their complex dentition and unique locomotor adaptations, which facilitated their divergence into a suite of ecosystems.Yuanet al.(p.779) describe a new basal multi from a nearly complete skeleton that shows that the underpinnings of these adaptations arose early in the evolution of the order, setting the stage for the major diversification and radiation of the group that came during the Cretaceous and Paleogene.