Critical analysis of the carnivoran mammal success in Europe during the Paleogene

Why are we surrounded by only one group of placental carnivorous mammals (Carnivora: the presentday lions, dogs, bears, and seals among others) today, while at least three other groups of placental mammals (Hyaenodonta, Mesonychia, Oxyaenidae) were in competition with carnivorans 50 million years ago? Since the 1990s, palaeontologists have investigated the success of carnivoraform mammals (including Carnivora) and their crucial adaptations in detail. Analysis of the taxonomic and morphological diversification of these groups in the North American fossil record clearly demonstrated that carnivoraforms outcompeted hyaenodonts and oxyaenids during the Eocene, specifically from around 50 Ma onwards. We document the evolutionary history of the taxonomic diversity as well as the evolution of the body mass of carnivorous mammals that lived in Europe during the Paleogene (66–23 Ma). The results suggest that this competition was diametrically opposed in North America and Europe. Carnivoraforms actually did not become diversified in Europe during the Eocene and thus were not as taxonomically successful in Europe as in North America during that period. Moreover, during the Eocene, European hyaenodonts varied more in body mass than carnivoraforms. The situation dramatically changed during the 'Grande Coupure' (around Eocene–Oligocene boundary; ca. 33.9 Ma). This transition corresponds to a major faunal turnover in Europe: during the earliest Oligocene global cooling event (Oi-1), the Eocene endemic carnivorous fauna was replaced by immigrant taxa (hyaenodonts and carnivorans), mainly from Asia. This abstract is a contribution to the Belspo Brain Pioneer project BR/175/PI/CARNAGES funded by the Belgian Science Policy Office.

Proceedings, Abstract of an Oral Presentation or a Poster

Paleontology