Plesiosminthus (Zapodidae, Mammalia) from China and Mongolia: migrations to Europe

Plesiosminthus VIRET 1926 was recorded from China and Mongolia for the first time: P. asiaticus n.sp. from the Late Oligocene of China (Tieersihabahe), and P. cf. asiaticus and P. promyarion from the Late Oligocene (biozone C1) of Mongolia (RHN-A/7 and RHN-A/9). P. barsboldi n.sp. was recovered from the Oligocene-Miocene transition (biozone D) of Mongolia (UNCH-A/3, LOG-A/2 and RHN-A/12). There are some more undetermined occurrences: Plesiosminthus sp. A and Plesiosminthus sp. B from two Late Oligocene (biozones C and C1) deposits of Mongolia (TAR-A/2 and LOH-C/1), and Plesiosminthus sp.1 (large) and Plesiosminthus sp. 2 (small) from the Oligocene-Miocene transition of China (Locality 99005). P. asiaticus is so far the most primitive Plesiosminthus-species by having upper incisors with a shallow longitudinal groove. P. promyarion, the first zapodid to immigrate and disperse in Europe in the Late Oligocene (MP26-29), was identified from the Late Oligocene of Mongolia (biozone C1).