A primitive nimravine skull from the Quercy fissures, France: implicationsfor the origin and evolution of Nimravidae (Carnivora)

A carnivore skull from the Phosphorites of Quercy, France, is described her ein. Its well-preserved basicranial structure, cat-like morphology, and den tal reduction support the assignment of this specimen to the Nimravidae. Th is is the most primitive nimravid described and its overall morphology is t he closest yet to the hypothetical ancestor of the Nimravinae as previously conceived. In addition, the monophyly of the Nimravinae is reinforced by t he similar basicranium of the specimen described here compared to other nim ravid genera. It suggests that this typical basicranial structure appeared well ahead the sabretooth features in this group. The early evolution and d iversification of the Nimravinae occurred during the Late Eocene in the nor thern hemisphere but the precise geographic area is still unknown. A rapid evolution during the initial radiation of the group or an incomplete fossil record in Eurasia could both equally explain the rapid and worldwide distr ibution of the Nimravinae. (C) 2001 The Linnean Society of London.