Prehistoric primate skeleton. Fossilised skeleton of a Plesiadapis sp. primate. Plesiadapis were herbivorous primates that lived around 58-55 million years ago during the Late Palaeocene, in what is now North America. They are one of the oldest known primate-like mammal species. Photographed at the In the Shadow of the Dinosaurs exhibition at the National Museum of Natural History, Paris, France, in 2011.