The Early Pleistocene Mimomys hordijki (Arvicolinae, Rodentia) from Europe and the origin of modern nearctic sagebrush voles (Lemmiscus)
Ancient voles with rooted cheek dentitions assigned to the subgenus Cromeromys of the genus Mimomys are known in the Early Pleistocene (Gelasian and 'Calabrian') fossil record of northeastern Siberia and in the late Early Pleistocene ('Calabrian') record of Canada and United States. The Late Pliocene to Early Pleistocene Holarctic rooted voles of the Mimomys (Cromeromys) group, including (here redescribed) European Mimomys (C.) hordijki, shows affinities with the modern Lemmiscus and provides clues for a robust hypothesis on the origin that genus. The modern Nearctic arvicolini rodents Lemmiscus (sagebrush voles) were long thought to represent a closely related sister group of Palearctic steppe lemmings of the tribe Lagurini. However, ample morphological, paleontological, and genetic evidence suggests their attribution to the tribe Arvicolini, as a sister clade of modern Microtus. Arvicolini have rootless molars and are assumed to have originated from the Pliocene rhizodont Mimomys.
KEY WORDS: Arvicolinae; Mimomys; Cromeromys; Lemmiscus; Pliocene-Pleistocene; Eurasia; North America
PE Article Number:
Copyright: Society of
Vertebrate Paleontology November 2011
Submission: 15 June 2007. Acceptance: 16 April 2011