Subgenus Stenocranius, the only included species (Gromov and Polyakov, 1977; Pavlinov and Rossolimo, 1987, 1998; Pavlinov et al., 1995a; Zagorodnyuk, 1990). Corbet (1978c) claimed that M. abbreviatus on Hall and St Matthews Isls in the Bering Sea and M. miurus in Alaska are closely related vicariant species; based on morphological and zoogeographic criteria, Rausch (1964) considered North American miurus to be conspecific with Asian gregalis. Ample studies and an array of data convincingly refute this connection and reveal the morphological similarities between M. gregalis and M. miurus as convergent (Conroy and Cook, 2000a; Fedyk, 1970; Vorontsov and Lyapunova, 1976; Zagorodnyuk, 1990; also see M. miurus). Allozymic analysis by Mezhzherin et al. (1993) placed M. gregalis in a clade with M. oeconomus, M. middendorfii, M. fortis, and Lasiopodomys brandtii, but their taxon sampling was limited.

Intraspecific chromosomal variation among Mongolian samples documented by Kovalskaya (1989) and earlier chromosomal data presented by Zima and Kral (1984a). Occurrence on the Svjatoj Nos peninsula and isthmus in Lake Baikal documented by Reiter et al. (1995). Dupal (1998) reported chronoclinal changes in m1s from ancestral M. hintoni of the early Pleistocene, through the middle Pleistocene M. gregaloides, to living M. gregalis in Russia; transformations in crown length can be correlated with three trends associated with geographical and physical environmental gradients. An early origin of M. gregalis is consistent with its phylogenetic position basal to both Eurasian and North American species, as suggested by analysis of cytochrome b sequences (Conroy and Cook, 2000a). The taxa egorovi and kriogenicus, based on late Pleistocene fossils, were described as subspecies of M. gregalis (Dupal, 1998). Although not part of the modern fauna on the British Isles, M. gregalis occurred there during Late Glacial times in the Pleistocene (Kowalski, 1967; Yalden, 1999).