Guzhangian and Paibian (Cambrian) trilobites from allochthonous blocks in the Quebrada Oblicua, Precordillera of Mendoza, Argentina

ABSTRACT Cambrian trilobites from two separate allochthonous limestone blocks of La Cruz olistoliths at the Quebrada Oblicua (Precordillera of Mendoza, Argentina), originally described by the naturalist Carlos Rusconi in the 1950s, are revised herein. One of the olistoliths is dominated by the late Guzhangian cedariid Cedaria puelchana Rusconi, whereas the other block contains Pseudagnostus cf. P. idalis Öpik, Dunderbergia punctata (Rusconi) new combination, Sigmocheilus cf. S . sigmoidalis (Palmer), Litocephalus obliquoanus (Rusconi) new combination, and Onchonotopsidae? gen. et sp. indet., which indicate a late Paibian age ( Dunderbergia Zone). The genera Dunderbergia Walcott (= Tabalqueia Rusconi), Sigmocheilus Palmer, and Litocephalus Resser (= Cayupania Rusconi) are reported from South America for the first time. In line with previous studies on Cambrian faunas from the Precordillera, the assemblages revised here show North American (Laurentian) affinities.