New Mexico Geological Society Annual Spring Meeting — Abstracts

UNM (university of New Mexico) -P-1 is a right ramus bearing M₃ of Mammuthus imperator. This specimen was collected from Quaternary alluvium along Salt Creek on tbe Marley Ranch northwest of Roswell. The following features justify assignment of UNM-P-1 to M. imperator: (1) M₃ has 11+ plates. (2) M₃ length = 218 mm and maximum width = 95 mm, making it a relatively broad tooth. (3) M₃ lamellar frequency = 5, an upper limit considering how highly worn this tooth is. (4) Enamel thickness: n = 20, x = 2.7 mm. (5) Enamel to enamel thickness of a plate: n = 18, x = 14.9 mm. (6) Thickness of dentin between enamel walls: n = 18, x = 9.2 mm. (7) Thickness of cementum separating enamel plates: n = 18, x = 6.0 mm. (8) Length of one complete loph and cementum separator: n = 17, x = 21. 5 mm. (9) Lack of a well developed anterior symphyseal process.

M. imperator is a relatively primitive Pleistocene mammoth typical of middle Pleistocene (late Irvingtonian) localities. This is the first report of M. imperator from New Mexico.