Towards a uniform nomenclature for ground squirrels: the status of the Holarctic chipmunks Author Patterson, B. D. Author Norris, R. W. text Mammalia 2016 80 3 241 251 journal article 1864-1547 Tamias Illiger, 1811 Diagnosis Median dark dorsal stripe narrow and flanked by two paler stripes more than twice its width; all four of the dark stripes short, none extending onto the rump or shoulder; ears broad, rounded at the tips; tail <40% total length; antorbital foramen rounded (suborbicular); posterior border of the zygomatic notch reaches level of P4–M1; postorbital process long and broad basally; well-developed lambdoidal crest; palate long, extending well beyond the plane of the last molars; auditory bullae relatively small; upper incisors with weak or no longitudinal striations; a single upper premolar (P4), whose anterior root projects buccal to the masseteric knob; upper molar series slightly convergent posteriorly; head of the malleus elongate, the planes formed by the lamina and manubrium ca. 60°; hypohyal and ceratohyal elements of hyoid apparatus separate in adults; conjoining tendon between anterior and posterior sets of digastric muscles rounded in cross-section; baculum nearly straight, upturned at tip, with slight median ridge on ventral surface. Karyotype 2N=38; Giemsa-stained chromosomes show at least nine structural rearrangements from the pattern shown by Neotamias ( Nadler et al. 1977 ) . Type species Sciurus striatus Linnaeus, 1758 . Included species Tamias striatus ( Linnaeus, 1758 ) – Eastern chipmunk.