Orthidae

Orthidae is a family of brachiopods in the order Orthida and class Rhynchonellata, named for its type genus Orthis. Members typically have ventribiconvex shells marked by radial ridges called costae with finer costellae between them, a strophic hinge, and a simple ridgelike cardinal process. The family ranges from the Early Ordovician to the Early Devonian, holds roughly 20 genera, and is known from North America, Russia, China, Europe, Australia and South America; it was abundant early on, dropped sharply in diversity in the Early Silurian, recovered, and finally died out at the end of the Lochkovian stage of the Early Devonian.