Chitinozoans from the Ordovician Los Azules Formation, Central Precordillera, Argentina

摘要

Chitinozoans from the Los Azules Formation, central Precordillera of Argentina are documented. The formation is di- vided into three members. Two chitinozoan assemblages are recognized: the late Llanvirn Lower Los Azules Palynological Assemblage int eh middle member includes smooth forms, while the early Caradoc upper Los Azules Palynological Assemblage, from the upper member, is mainly composed of ornamiented specimens. Two new species are described: Eisenackitina yolei Ottone and Holfeltz and Hercochitina volkheimerii Ottone and Holfeltz. The Los Azules chitinozoan faunas have species in common with contemporaneous as- Semblages from Laurentia but also nothern Gondewana nad Baltica.