The Mesozoic Acipenseriformes in northeast China and adjacent areas

Abstract

The distribution of modern Acipenseriformes was restricted at the river and estuary system of the northern hemisphere, and their Mesozoic ancestor fossils had been discovered in east Asia. The northeast Asia is the key region for the early diversification and evolution of Acipenseriformes, because the extinct family †Peipiaosteidae should have appeared in western Liaoning of China since the Middle Jurassic, then occurred in the Middle-Late Jurassic of western Asia, and flourished in the northeast Asia during the Early Cretaceous. There were at least six species of Peipiaosteidae and an early form of Polyodontidae distributed in the Lower Cretaceous volcano-sedimentary strata in northeast China and adjacent areas including the Mongolia and Transbaikalia of Russia.