Community structure of Eocene terrestrial vertebrates from Antarctic peninsula

The record of Paleogene terrestrial vertebrates from Antarctica is restricted to the shallow marine water sediments of the La Meseta Formation (Eocene) of Seymour Island (56 degrees 43'W 64 degrees 14'S). Mammals are represented by marsupials, edentates and ungulates. Among birds, a falconid and two ground dwellers (a ratite and a ?phorusrhacoid) were recorded. Estimates of body mass and dietary specializations are proposed for these species. Medium- to large-sized carnivorous mammals (greater than 1 kg body mass), such as South American borhyaenid marsupials, are not yet recorded, although their presence is expected. Their absence is interpreted as a consequence of the low proportion of homeothermic carnivorous in all modem vertebrate communities and the relatively small sample recovered to date. The carnivorous role could have been partially fulfilled by some of the birds (falconid and ?phorusrhacoid).