Chalicomys Kaup, 1832

Casanovas-Vilar, Isaac & Alba, David M., 2011, The Never-Ending Problem of Miocene Beaver Taxonomy, Acta Palaeontologica Polonica 56 (1), pp. 217-220 : 219

Genus Chalicomys Kaup, 1832

Chalicomys jaegeri Kaup, 1832 (type species) Palaeomys castoroides Kaup, 1832 (original description) Chelodus typus Kaup, 1832 (original description) Steneofiber jaegeri ( Kaup, 1832) : Stehlin and Helbing (1925) Castor vidali Crusafont,Villalta, and Bataller, 1948 Palaeomys plassi Franzen and Storch, 1975

Chalicomys subpyrenaicus ( Lartet, 1851) Castor subpyrenaicus Lartet, 1851 (original description) Steneofiber jaegeri ( Kaup, 1832) : Stehlin and Helbing (1925) Steneofiber depereti carnutense Ginsburg, 1971 Steneofiber subpyrenaicus ( Lartet, 1851) : Mörs and Stefen (2009)

Chalicomys catalaunicus (Bataller, 1838)

Steneofiber jaegeri ( Kaup, 1832) : Bataller (1924)

Steneofiber minutus var. c atalaunica ( Bataller, 1938)

(original description)

Steneofiber depereti Mayet, 1908 : Crusafont et al. (1948)

Steneofiber hesperus Douglass, 1901 : Xu (1994)

? Eucastor (Schreuderia) catalaunicus ( Bataller, 1938) : Hugueney (1999)

Chalicomys adroveri ( Aldana Carrasco, 1992) Chalicomys jaegeri Kaup, 1832 : Agustí et al. (1984) Schreuderia adroveri Aldana Carrasco, 1992 (original description)? Eucastor (Schreuderia) adroveri ( Aldana Carrasco, 1992) : Hugueney (1999)

many). This species stands out because of its small size as compared to the other known Chalicomys and Steneofiber species ( Fig. 2 ). Mörs and Stefen (2010) did not mention this material, but Stefen (2009) considered that it could be probably assigned to Chalicomys , because the hypostriid extends until the crown base. Rekovets et al. (2009) consider the specimens of Dorn−Dürkheim to be juveniles of Chalicomys jaegeri (= Palaeomys castoroides in Rekovets et al. 2009) and in accordance synonymise Chalicomys plassi with this species. Nevertheless, these authors do not discuss this issue further. Interestingly, the p4 of C. plassi overlaps in size with the dp4 of C. jaegeri , which is also present in Dorn−Dürkheim ( Fig. 2 ). Franzen and Storch (1975) argued that this specimen could be clearly distinguished from the dp4 of C. jaegeri by the presence of three well−defined roots. Nevertheless, the dp4 of C. jaegeri does indeed show three roots exactly in the same position (see Van de Weerd 1976: pls. 15, 4a). Accordingly, we consider that this tooth is most likely a dp4 of C. jaegeri , and that C. plassi is a junior subjective synonym of the latter. Regarding the supposed m3 of C. plassi , it corresponds in size ( Fig. 2 ) and morphology to the m3 of Euroxenomys minutus rhenanus comb. nov. from Dorn−Dürkheim. Furthermore, as in E. minutus rhenanus , the “m3” of C. plassi is devoid of cement. We therefore agree with Rekovets et al. (2009) and conclude that C. plassi is not a valid species, resulting from unfortunate misidentification of the cheek teeth of other beaver species present at Dorn−Dürkheim.

Figures

Fig. 2. Scatterplot for the lower cheek teeth of all the Chalicomys species as compared to Steneofiber depereti. Schreuderia adroveri and Euroxenomys minutus rhenanus comb. nov. are also included for discussion (see text for details). A. m 1/2. B. m3 C. p4. The measurements for S. depereti from Hambach were taken from Mörs and Stefen (2010); for Chalicomys jaegeri from Eppelsheim from Stefen (2009) and from MB2B from Van de Weerd (1976); for Chalicomys plassi and E. minutus rhenanus from Dorn−Dürkheim from Franzen and Storch (1975); for S. adroveri from Torrent de Febulines from Aldana Carrasco (1992); for Chalicomys batalleri from ACM/C4–C2 and Chalicomys subpyrenaicus from Simorre from Casanovas−Vilar et al. (2008); and for Chalicomys catalaunicus from Sant Quirze from Crusafont Pairó et al. (1948) and Casanovas−Vilar et al. (2008). Acronyms for locality names are as follows: ACM/C4–C2, Abocador de Can Mata locality C4–C2; MB2B, Masía del Barbo 2B. All the measurements are in millimetres.