MATERIAL

The dental material of four Pleistocene rhinoceros species, Stephanorhinus kirchbergensis, S. hemitoechus, S. hundsheimensis, and Coelodonta antiquitatis, were studied and compared to the dental material of the five Recent rhinoceros species, Diceros bicornis, Ceratotherium simum, Dicerorhinus sumatrensis, Rhinoceros sondaicus, and R. unicornis. All the studied dental fossils come from the fossil localities of Britain and are housed in BMNH. The early middle and middle Pleistocene species S. hundsheimensis from the British Isles has traditionally been assigned to S. etruscus (Falconer, 1868). The morphological differences between S. hundsheimensis and S. etruscus are rather small, and their separation based only on isolated teeth or dentitions, which are used in this study, is difficult or even impossible (see Fortelius et al. 1993; Lacombat 2006a, 2006b). However, here we follow Fortelius et al. (1993) who suggested that all the European "etruscoid" rhinoceroses from the early middle Pleistocene can be referred to S. hundsheimensis (see also Mazza 1988 for description of S. etruscus).

The Recent rhinoceros specimens studied are housed in BMNH, FMNH, NHMD, RMCA, and UUZM. Only specimens belonging to wild-shot animals were used in this study. The Recent Ceratotherium (Gray, 1868) was treated as one species, instead of dividing it to C. simum and C. cottoni as suggested by Groves et al. (2010). Both the second and the first upper and lower molars were used in this study. Unworn teeth as well as teeth in very early or in very late wear stage were excluded. All the adequately worn upper and lower molars (M2, M1, m2, and m1) from each individual were used in all analyses except for the angle measurement analysis, in which only one lower molar of each individual animal was included. From each species upper and lower molars of ten or more individuals were studied, except for D. sumatrensis, from which lower molars were studied only from seven individuals. The dental material used in this study is shown in Appendix.