Linguloidean brachiopods from the Lower Ordovician (Tremadocian) of northwestern Argentina

The new obolid Torobolus subplanus gem et sp. nov. from the lower Tremadocian Devendeus Formation, and the the new species Libecoviella tilcarensis and Leptembolon argentinurn from the upper Tremadocian Santa Rosita Formation are described and illustrated. Libecoviella is typical of the upper Tremadocian Trenice Formation and Floian Klabava Formation of the Prague Basin and has been reported recently from Australia. Leptetnbolon has been recorded in the same Bohemian formations, but together with other taxa it forms the Thysanotos-Leptembolon Association present in northern Estonia and a series of high-latitude terranes. The record of Leptembolon and Libecoviella in the high- to temperate-latitude Central Andean region points to a peri-Gondwanan distribution of these genera. The presence of Bohemian-like obolids in northwestern Argentina suggests a migratory route linking the Central Andean Basin with north Gondwana and Perunica along the elastic platforms fringing the North African and Brazilian shields.