Muridae, ILLIGER, 1811

Kimura, Yuri, Flynn, Lawrence J. & Jacobs, Louis L., 2017, Early Late Miocene Murine Rodents From The Upper Part Of The Nagri Formation, Siwalik Group, Pakistan, With A New Fossil Calibration Point For The Tribe Apodemurini (Apodemus / Tokudaia), Fossil Imprint 73 (1 - 2), pp. 197-212 : 206

Muridae gen. et sp. indet.

M a t e r i a l. Only known specimen is YGSP 34559, left M1 from locality Y 311, upper part of the Nagri Formation, 10.1 Ma, dimensions 2.05 × 1.23 mm, L/W ratio = 1.67 ( Text-fig. 9e ).

D e s c r i p t i o n. Twinned first and second chevrons, with strongly individualized labial as well as lingual anterocone, the lingual anterocone central and somewhat larger than the other two cusps. The enterostyle is about the same size as the paracone. The posterior cingulum is short, and the precingulum shelf is developed. In moderate wear the paracone is not connected to the metacone, although the enterostyle shows a weak connection forming with the hypocone. Although broken, three roots are indicated, including a single, large lingual root, no rootlet in evidence.

D i s c u s s i o n. This M1 presents features that do not match any other Siwalik murine. Its large size is comparable to that of Parapodemus badgleyae , but YGSP 34559 shows no paracone-metacone connection, which should be in evidence at this stage of wear. Although the distinctive cusp pattern without stephanodonty distinguishes YGSP 34559 from other known Siwalik species, the specimen conceivably represents a variant of Parapodemus badgleyae .

Figures

Text-fig. 9. First upper molars of Parapodemus badgleyae sp. nov. (a–d) and Muridae, gen. et sp. indet. (e). a) YGSP 33936, holotype, locality Y 259, b) 33939 from Y 259, c) 34542 from Y 311, d) 34543 from Y 311, e) 34559 from Y 311. All molars but c are left molars, all figured with buccal side upward and at the same scale.