A new middle Miocene crocidosoricine shrew from the Mongolian Shargain Gobi Desert

The crocidosoricines are a relatively widespread subfamily of shrews with an early Oligocene to late Miocene temporal range, generally known from Europe, and, to a lesser extent, from Asia. A new discovery from the Mongolian middle Miocene locality Sharga 2 (the lower part of the Oshin Suite) adds new data to the understanding of Crocidosoricinae arising in Asia, and allows the description of a new genus and species: Shargainosorex angustirostris gen. et sp. nov. A large number of fossil remains (more than 200 specimens from 95-100 buried shrews) made possible the description of the morphology of the new species in detail, and even to try to reconstruct the rostrum shape and estimate the size of the skull and body. Morphologically, and apparently adaptively, the Shargain shrew was more similar to the Sorex species, including tooth pigmentation, but also carried a number of white-toothed shrew features (Crocidura, Suncus). Based on these findings, we can assume the spreading of Miosorex sensu lato from Europe to Asia during the early Miocene, when the group acquired a number of adaptive sorex-like features as a possible result of occupying new trophic niches in this part of the continent.