Muridae, Illiger, 1811

Aplin, K. P. & Helgen, K. M., 2010, Quaternary Murid Rodents Of Timor Part I: New Material Of Coryphomys Buehleri Schaub, 1937, And Description Of A Second Species Of The Genus, Bulletin of the American Museum of Natural History 2010 (341), pp. 1-80 : 11-12

Family Muridae Subfamily Murinae Coryphomys Schaub, 1937

TYPE SPECIES: Coryphomys buehleri Schaub, 1937 .

CONTENT: Coryphomys buehleri Schaub, 1937 , Coryphomys musseri , sp. nov.

REVISED DIAGNOSIS: A genus of largebodied, complex-toothed murines distinguished from all others by the combination of the following morphological features: molar crowns moderately hypsodont and weakly inclined; anterocentral cuspid prominent on m1; principal lingual cusps of upper molars (t1, t4) isolated from central cusps until molars attain advanced state of wear; a discrete cusp t7 united to cusp t8 on each of M1–2; posterior cingulum forming an elevated, transverse occlusal ridge behind cusps t8–t9 on each of M1–3, and barring contact between central row cusps on successive molars; upper and lower third molars almost equal in area to the corresponding second molars; upper and lowers incisors large and with simple, D-shaped cross-sections; incisive foramen very short and narrow, penetrating only a short distance into palatal lamina of maxilla; zygomatic plate tall and narrow, with a straight anterior margin and shallow zygomatic notch; stem of stapedial artery extremely reduced such that promontorium lacks a conspicuous stapedial sulcus; rostrum shortened; and maxillary sinus complex enlarged and elaborate, causing a marked constriction of both the posterior nasopharynx and the infraorbital sulcus.

Presence of a large cusp t7 on each upper molar distinguishes Coryphomys from the majority of previously described murine genera. Among genera with large cusps t7, Coryphomys is distinguished from all except Carpomys and Spelaeomys ( Hooijer, 1957; Musser, 1981b) by the presence of a substantial posterior cingulum on all three upper molars. It is distinguished from Carpomys by its highly cuspidate molar form (cusps are largely fused into transverse laminae in Carpomys spp. ) and the absence of labial cusplets on m2–3. It differs from Spelaeomys in numerous details of molar morphology including the greater size of the posterior cinguli on all upper molars, the absence of cusp t3 on M2–3, and the absence of accessory labial cuspids and cusplets on all lower molars.

REMARKS: Under Article 32.5.2.1 of the Fourth Edition of the International Code of Zoological Nomenclature ( International Commission on Zoological Nomenclature, 2000: 40) the original specific epithet bühleri is adjusted to buehleri .