Assemblages of vertebrates of Bathonian, Callovian (Jurassic) and Neocomian (?), Late Aptian (Early Cretaceous) are studied. Main parts of Middle Jurassic-Cretaceous sediments of the region are estuarine in origin. Salinity of the waters, amount of chondrichthyan remains and content of phosphates in sediments increased in periods of the sea (transgressions into Fergana estuarine reservoirs. A hypothesis concerning the formation of estuarine Bathonian black bituminose shales and Aptian "blue beds' is proposed. Hydrologic and biocenotic conditions of reservoirs are important in the balance of deposition of red and grey colored sediments. -English summary