Recently, Associate Professor WANG Yaqiong from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), together with collaborators from several domestic and international institutions, reported for the first time the occurrence of two marine ostracod fossils, Bicornucythere bisanensis s.l. and Pistocythereis bradyformis (Fig. 1), from Pleistocene lacustrine deposits of the Qaidam Basin.
The relevant research findings have been published in the international geoscience journal Palaeoentomology.
Long-distance dispersal (LDD) refers to the process by which organisms or their dispersal units spread, over a given time scale, to regions that are difficult or impossible to reach under their normal dispersal capabilities. Previous studies on the long-distance dispersal of marine ostracods at intercontinental, intra-oceanic, and interoceanic scales have generally considered migratory birds to be an unlikely dispersal vector.
These fossil specimens had previously been misidentified as the non-marine ostracod Cytherissa qaidamensis. Both fossil and extant records indicate that B. bisanensis s.l. and P. bradyformis are largely restricted to coastal areas of the western Pacific, including China, Korea, Japan, and the Russian Far East, within a latitudinal range of approximately 20°-43° N (Fig. 2).
The discovery of these marine ostracods in Pleistocene terrestrial deposits of the Qaidam Basin, far from any modern coastline, strongly suggests that they may have undergone long-distance dispersal via migratory water birds during the Pleistocene, crossing more than 2,000 km and traversing vast continental interiors. This finding not only provides new fossil evidence for the potential role of migratory birds in the long-distance dispersal of marine ostracods, but also implies that the East Asian Flyway or East Asia/Australasia Flyway, one of the world’s three major modern migratory bird flyways, may have already been established during the Pleistocene. In addition, the palaeo-Qaidam Lake may have served as an important stopover site within this migratory network.
This study was supported by the National Key Research and Development Program of China and the National Natural Science Foundation of China.
Reference: Yaqiong Wang*, Ping Yang, David J. Horne, Yanhong Pan, 2025. Marine ostracods found in lacustrine deposits of the Qaidam Basin suggest long-distance dispersal during the Pleistocene. Palaeoentomology, 8(6): 609-617. https://doi.org/10.11646/palaeoentomology.8.6.2.
Fig.1 Bicornucythere bisanensis s.l. (A) and Pistocythereis bradyformis (B–I).
Fig.2 Long-distance dispersal of marine ostracods via water birds from the coastal areas of the West Pacific Ocean to the Qaidam palaeo-lake.
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