ORIGIN AND DEVELOPMENT OF THE CAMBRIAN BRACHIOPOD BIOCHORES

Abstract

Analysis of the origin and dispersal of Cambrian brachiopods shows that the initial differentiation of brachiopods into the Equatorial and Notai biochores took place in the second half of the Atdabanian. In the Botomian time, the vast Equatorial biochore was broken up into a number of areas that existed till the middle mid-Cambrian. Afterward, differences between the areas diminished, and new differentiation occurred in the second half of the Late Cambrian.