Mammalian evolution: A beast of the southern wild.

Abstract

A newly discovered skull from the Cretaceous period belongs to a mammal that was big, strange and fast-moving. The fossil solves a long-standing mystery, and helps to resolve a controversy about mammalian evolution. See Article p.512 The gondwanatheres were mammals that lived the southern continents alongside the dinosaurs during the Late Cretaceous and early Paleocene. Known only from a few teeth and some jaw fragments, their appearance and evolutionary relationships remained obscure. The entire skull of a bizarre and badger-sized fossil mammal from the Cretaceous of Madagascar changes all that. Although almost certainly highly derived — as one would expect from a member of the unique endemic island fauna of Madagascar at that time — Vintana is clearly a gondwanathere. The anatomy of the herbivorous, large-eyed and agile creature shows that gondwanatheres were related to the better-known multituberculates, a long-lived and successful group of (now also extinct) rodent-like mammals.