Late Miocene/Pliocene divergence of zokors (Myospalacidae, Rodentia) of North Asia: phylogeny and paleobiogeography

Recent studies of zokor evolution in Chinese territory have shown that the main divergence of lineages of this family occurred at the boundary of the Late Miocene and Early Pliocene. However, the question of how the divergence of this family occurred in the territory of North Asia has persisted. In this study, the evolutionary history of Myospalacidae in the region is presented on the basis of zokor remains from 12 localities dated to the Late Miocene and Early Pliocene. From the Upper Miocene of Western Siberia, the species Prosiphneus murinus was identified. At the end of the Early Pliocene, an endemic form, which we described as a new species, Sibirosiphneus ingenuus sp. nov., appeared in Western Siberia. On the basis of this species, we define the origin of the genus Sibirosiphneus. We describe the more hypsodont Late Pliocene form of this genus as Sibirosiphneus seletiensis sp. nov. Two species are identified from North Mongolian localities dated to the first half of the Early Pliocene: Prosiphneus eriksoni and Pliosiphneus antiquus. During the second half of the Early Pliocene, Pr. eriksoni disappears from the corresponding faunal associations of Northern Mongolia, but Pl. antiquus remains, which is mostly uncommon for synchronous localities from the territory of China. Thus, in the Late Miocene, there was a single ancestral range of zokors in North Asia, which split during the Early Pliocene. We consider such a shift as evidence of fragmentation of one large ecological zone.https://zoobank.org/urn:lsid:zoobank.org:pub:52DBF1BA-3448-4D62-AA03-39E6145C4ACF