Evolution and classification of the Productellidae (Productida), upper Paleozoic brachiopods

Abstract

In the Lower Devonian the first productellids evolved from their chonetidine ancestors as the Productellinae. This subfamily was the stem group from which all the later Productidina evolved, yet three of its five subfamilies persisted to the end of the Permian. The main characters used in the new classification, here presented, for the Productellidae are described and reviewed, and the main changes seen during its evolution are discussed. Within this new classification five new genera are described: in the Overtoniinae are Barunkhuraya Lazarev from the latest Famennian, Onavia Lazarev from the Tournaisian, both from Mongolia, and Echinariella Lazarev (type species Krotovia jisuensiformis Sarycheva) from the late Permian of Transcaucasia; in the Marginiferinae there is Breileenia Brunton from the Visean of western Europe and in the Plicatiferinae is Maemia Lazarev from the mid and Upper Carboniferous on the coast of the Barents Sea. New species described in these genera are Barunkhuraya indrengynensis Lazarev, Onavia barunkhurensis Lazarev, Breileenia radiata Brunton, Maemia chaykensis Lazarev, and M. nana Lazarev.