- Copyright © 2016, The Paleontological Society
Middle Ordovician lingulacean, trematid, and craniid brachiopods are described and illustrated for the first time from the uppermost part of San Juan Formation limestones of the Precordillera Basin, west-central Argentina. Sampled beds fall within the Ahtiella argentina brachiopod Zone, which, according to associated conodonts, is of early-mid Darriwilian age. The fauna consists of the linguloideans Glossella cuyanica n. sp. and Lingulasma? sp., the discinoidean Trematis sp., the siphonotretid Chilcatreta tubulata n. gen. n. sp., and a conical shell that is referred provisionally to the order Craniida. The linguliforms from the Cuyania (Precordillera) terrane, although still poorly known, display close similarities to those inhabiting low-to-intermediate latitude palaeocontinents, particularly Laurentia and Baltica, in accordance with evidence from rhynchonelliform brachiopods.