Modern Concepts on the Origin and Distribution of Acipenserids (Acipenseridae)

The current data on the place and time of origin of Acipenseriformes and the family Acipenseridae, as well as on their distribution in connection with the history of the development of sea and river basins, are summarized. The supposed areas of the initial radiation of Acipenseriformes and their long-term habitation were in eastern Laurasia on a part of the modern Chita Region, Eastern and Central Mongolia, and northern and northeastern China. The eastern part of Asia should also be considered the place of origin of the family Acipenseridae. The widespread distribution of Acipenseriformes was facilitated mainly by the formation of diadromous forms from primarily freshwater species, the origin of which is associated with multiple transgressions and regressions of the ocean. Modern potamodromous acipenserids were probably formed as a result of the return of anadromous forms to living in fresh water; i.e., they are secondarily freshwater species