Acta Palaeontologica Polonica

Maximizing diductor adhension: An unusual cardinal process in Late Ordovician brachiopods from Estonia

Linda Hints

Acta Palaeontologica Polonica 49 (4), 2004: 635-638

Cardinal process is a structure on dorsal valve of brachiopods serving for separation or attachment of diductor muscles. A cardinal process with a peculiar folded myophore is described from Late Ordovician “Orthis” kukersiana−group brachiopods assigned to the genus Cyrtonotella (order Orthida). This structure differs from those of other rhynchonelliformean brachiopods and can be considered as a separate type among about twenty varieties of processes described up to now.

Linda Hints [], Institute of Geology at Tallinn University of Technology, 7 Estonia Boulevard, 10143 Tallinn, Estonia.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (for details please see, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.