Late Ordovician and earliest Silurian meristellid brachiopods in Scandinavia

Four species of late Ordovician and earliest Silurian meristellid brachiopods are known in Scandinavia. Cryptothyrella terebratulina (Wahlenberg) is the only known member of the genus from the Ordovician and is the likely ancestor of Silurian species of Cryptothyrella. The principle radiation of Cryptothyrella occurred in North America during the earliest Silurian and is interpreted as radiation into a platform sea where earlier faunas had been exterminated. Revision of the genus Hindella reveals it to be a meristellinid with deeply impressed ventral muscle scars; therefore, the Subfamily Hindellinae Schuchert, 1913, is suppressed. The new Subfamily Hyattidininae is erected to encompass genera formerly associated with Hindella in the suppressed subfamily. Hindella kiaeri n. sp. is described from the Late Ordovician and Early Silurian in the oslo area. Atrypa crassa J. de C. Sowerby and Atrypa cassidea Dalman are included in Hindella.