The initial idea of PalEurAfrica (full title of the project: Origin of the European modern faunas through Paleogene Central Africa collections was born 10 years ago from a discussion between Gregg F. Gunnell and the first author (TS). They noted how little was known about the relationship between African and European Paleogene mammal faunas despite their geographical proximity. This was observed at the end of the editing process of a previous thematic volume on the dispersal of continental vertebrates during the Paleogene (Smith and Gunnell, 2013). Giant leaps in knowledge about the evolution of the earliest modern vertebrates have been made over the last three decades thanks to important studies and discoveries by researchers in North America, Europe, North Africa and Asia. Recent advances made in the study of vertebrate evolution suggest that the earliest modern mammals such as primates, perissodactyls(odd-toed ungulates) and artiodactyls (even-toed ungulates), appeared suddenly in Europe, Asia, and North America at the Paleocene-Eocene Thermal Maximum (PETM) 56 Ma ago. Modern mammals likely originated during the late Paleocene in tropical habitats farther south. The PETM is the first and most prominent in a series of hyperthermals, short-lived events of extreme global warming. The PETM is especially important as an analogue for current global warming trends. Studies of the PETM have demonstrated its effect on past mammal dispersal, evolution and ecology, and highlighted potential biotic effects of future climate change.