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

Chitinozoans from the Los Azules Formation, central Precordillera of Argentina are documented. The formation is divided into three members. Two chitinozoan assemblages are recognized: the late Llanvirn Lower Los Azules Palynological Assemblage in the middle member includes smooth forms, while the early Caradoc Upper Los Azules Palynological Assemblage, from the upper member, is mainly composed of ornamented specimens. Two new species are described: Eisenackitina yolei Ottone and Holfeltz and Hercochitina valkheimerii Ottone and Holfeltz. The Los Azules chitinozoan faunas have species in common with contemporaneous assemblages from Laurentia but also northern Gondwana and Baltica.