Notice et description de deux crânes de rhinocéros (Perissodactyla, Rhinocerotidae) presents au Museum des sciences naturelles d’Angers

We report the discovery of two incomplete crania of rhinoceros in the Muséum des sciences naturelles d'Angers, France. Both crania had belonged to old collections, had no documentation attached, and had been dubiously identified. Both are lacking premaxillae and mandible, and specimen MHNAn.2010.439 is damaged (left tooth row broken) and also shows possible signs of a developmental pathology. Nasal rugosities indicate that each of the two crania had only one horn, which places both in the genus Rhinoceros Linnaeus, 1758, all other extant rhinoceros genera having two horns. The majority of characters in specimen MHNAn.2010.439, such as the wide mesopterygoid fossa, or the double premolar crochet are consistent with a placing in species Rhinoceros sondaicus Desmaret, 1822, subspecies Rhinoceros sondaicus sondaicus Desmaret, 1822. Characters in specimen UCO 001, such as a pronounced median projection on the posterior margin of the palate, the simple premolar crochet, or the absence of a crista in every tooth seem to place it in the same species but in the recently-declared extinct subspecies Rhinoceros sondaicus annamiticus Heude, 1892. The specimen UCO 001 is particularly well-preserved. The rareness of these animals makes any discovery of material such as this particularly important in the study and conservation of rhinoceros species.