Ecological structure and stage of ecogenesis of Paleozoic ammonoids in the Uralian paleobasin

The ecological structure of Paleozoic ammonoid assemblages of the Uralian paleobasin is discussed. Life forms (nektobenthic, planktonic, and benthopelagic) are used as ecological units. Four stages in evolution of the communities, with distinct structure and evolutionary pathways, are recognized.