Article: A review and new classification of the brachiopod order Productida
The authors discuss the large and diverse Upper Palaeozoic strophomenide (sensu lato) group of brachiopods, the Productida, the problems inherent in previous classifications and present a new classification with diagnoses down to subfamily and tribe levels. In describing productides it is useful to differentiate between the main corpus (new term) cavity and peripheral cavities. Study of the ways in which the two valves grew leads to more precise identification of the visceral and trail regions of the shell. New data on early productides, from the lower to mid Devonian, has allowed the group to be studied in its complete stratigraphical range, as well as its wide morphological diversity, and has led to the recognition of numerous lineages and homeomorphic relationships. The new classification presented builds on these lineages phyletically and differs markedly from previous classifications in which some similar taxa, now recognized as having different origins, were grouped together. We diagnose two new tribes, the Krotoviini and the Kozlowskiini.