THE FIRST FOSSIL RECORD OF THE SAWSHARK PLIOTREMA (PRISTIOPHORIDAE) FROM THE NEOGENE OF THE SOUTH-EASTERN PACIFIC (CHILE)

We present the first fossil record of the sawshark genus Pliotrema from the south-eastern Pacific Ocean. The examined material was obtained from a little-known fossil locality named “Arenas de Caldera” in the Atacama region of Chile. The fossiliferous deposits belong to the Bahia Inglesa Formation, which is most likely middle Miocene–early Pliocene in age. There are no extant species of this sawfish in the eastern Pacific, probably due to the onset of cooling conditions during the Neogene. The type of environment for the elasmobranchs reported in this study is interpreted as demersal, based on the bathymetric affinities of extant species. Our results show that future studies are needed to better understand the evolutionary history and past distributions of this sawshark genus and their implications on current biogeographic patterns.