MORPHOLOGY, ASTOGENY, AND ORIGIN OF TREPOSTOMID BRYOZOANS OF THE GENUS RHOMBOTRYPELLA NIKIFOROVA, 1933

Abstract

On the basis of a comprehensive analysis of the morphology of the genus Rhombotrypella, its astogeny is described for the first time. The taxonomic composition of this genus is revised to comprise 45 species. The lifespan of this genus is shown to range from the Bashkirian (Middle Carboniferous) to the terminal Kazanian (Late Permian). A proposal is made that the genus Rhombotrypella descended from the genus Nikiforopora in the Bashkirian in the Donets marine basin. The dynamics of its species diversity shows three peaks: Moscovian, Gzhelian, and (the highest) Artinskian.