Life of a dwarf giant: preliminary results on dental analysis of the Sicilian dwarf hippo Hippopotamus pentlandi

Pleistocene mammal fossils of Sicily are some of the most known Quaternary faunas in Italy, especially famous because of the phenomenon of “insular dwarfism”, which led to the occurrence of dwarf mammals, such as elephants and hippos, which thrived within the island. The Sicilian dwarf hippo Hippopotamus pentlandi is one of the most emblematic dwarf mammals that inhabited the island during Late Pleistocene, represented by several fossil specimens currently stored in many museums in Italy and abroad. However, despite being known and studied for almost a century, very little is known about its paleobiology. In this study, we present a comparative dental micro- and macro-wear analysis that has been going on between the dwarf hippo specimens stored in the Museo di Storia Naturale di Milano originating from western Sicily and the specimens stored in the Museo Paleontologico of the Università degli Studi di Catania coming from eastern Sicily. In fact, through the observations of the traces left on the occlusal surface of the dwarf hippo molars, and their related wearing, allowed us to establish what kind of food item was especially exploited by the animal. This in order to refer hippo to one of the three main dietary classes: grazers, who feed mostly on silica-filled grass, browsers, who feed mostly on leaves and fruits, and mixed-feeders, who feed on both. The aim of this work is to investigate the paleodietary preferences of the Sicilian dwarf hippo in both eastern and western Sicily and, indirectly, reconstruct the environment these animals inhabited, trying also to assess any potential paleobiological and paleoenvironmental differences between eastern and western populations.