The Devonian brachiopods Karbous and Trigonatrypa and their taxonomic placement

Abstract

Glassiids are a group of smooth-shelled, rather unattractive Silurian and Devonian brachiopods that have barrel-shaped inner spiralia that lie across the valves. Few genera in the family have known spiralia. This contribution tries to amend that by looking at the internals of two of the five genera attributed to the family. One, the genus Trigonatrypa, has spiralia like the rest of the family. The other, Karbous, has spiralia directed down into the dorsal valve. This new obser- vation based on similar internal characteristics of the type species Karbous aperinus relocates the genus to the family Karpinskiidae.