THE FIRST FINDS OF LARVAL SHELLS IN ORDOVICIAN ORTHIDS

Abstract

The paper considers the first discovered larval shells of Rhynchonelliformea brachiopods from the Lower Ordovician of the Leningrad region Casts of larval shells on the pedicle and brachial valves are characterized by a different relief, probably representing the cast of a soft larva body. Early Paleozoic Rhynchonelliformea presumably had planktotrophic long-floating larvae. The following three subtypes are recognized in the recent brachiopod classification: Linguliformea, Craniformea, and Rhynchonelliformea.