NEW UPPER PERMIAN SUPERFAMILY COMPOSITELASMATOIDEA (BRACHIOPODA, TEREBRATULIDA) FROM THE EAST OF THE RUSSIAN PLATFORM: THE SPECIFICITY OF ONTOGENETIC TRANSFORMATIONS

Abstract

A previously unknown type of ontogeny is discussed that unites features of two different types of loop development: the ancient dielasmoid type, which is typical of Upper Paleozoic terebratulids, and the angustothyridid type, which is typical of the Lower Mesozoic terebratulids. A new superfamily, Compositelasmatoidea, and a new family, Compositelasmatidae, with its type genus Compositelasma gen. nov., are established based on their unique ontogenetic changes. © Pleiades Publishing, Inc. 2006.