The Sardinian Mammoth’s Evolutionary History: Lights and Shadows

The dwarf Sardinian mammoth, Mammuthus lamarmorai, is a well-known species frequently cited in the literature; however, the fossil record of the Pleistocene Sardinian mammoths mainly consists of isolated remains (an incomplete skeleton from Guardia Pisano Hill, isolated teeth and a largely incomplete tibia from different localities, and some footprints from Funtana Morimenta), which have been found in sites presumably ranging in age from the late Middle to the Late Pleistocene. All of the remains have been ascribed to a single species of an endemic mammoth, Mammuthus lamarmorai, which is moderately reduced in size. The paucity of remains increases uncertainties about the chronological range of Sardinian mammoth remains, some of which are currently missing, while others lack sound information about their exact provenance or were removed and collected without contextual information. As a result, the different sizes of molariform teeth from different localities, the lack of chewing tooth remains at Guardia Pisano Hill, and the doubtful chronology of some remains hamper any attempt to infer whether one or more species that originated from an anagenetic or radiative evolutionary process or through multiple arrivals from the mainland inhabited the island. Therefore, the continental ancestor or ancestors of Sardinian mammoth populations and the time and number of dispersals of the ancestral taxon or taxa have long been debated, and the persistence through time of mammoth endemic populations still remains an unsolved matter. This research summarizes and critically reviews our knowledge about the Sardinian endemic mammoth, provides new evidence about the Sardinian mammoth’s ancestor and the possible time of its dispersal from the mainland to the island, gives new information about the Sardinian mammoth’s histology and physical characteristics, and highlights some focal, unsolved questions (e.g., morphological and dimensional differences in dentition, number of Sardinian mammoth species, population dynamics, decline, and disappearance). Further research and increasing data, which will enable taphonomic, spectrometric, and dating studies, will provide better results to solve the remaining questions.