A systematic revision of the late Furongian trilobites from Cerro Pelado, Mendoza, Argentina

Abstract

Late Furongian (late Cambrian) trilobites are described from the black, deep water limestones of the El Relincho Formation in Cerro Pelado, Precordillera of Mendoza, western Argentina. In addition, selected type specimens of the Carlos Rusconi collections at the Museo de Ciencias Naturales y Antropológicas J.C. Moyano, Mendoza, are revised. The assemblages are largely dominated by the agnostoid Lotagnostus peladensis (Rusconi), which proved to be a species with variably effaced dorsal furrows. Polymeroids include Mendoparabolina pirquinensis Rusconi, Hungaia peladensis Rusconi, and Loganellus cf. macropleurus Rasetti, as well as some fragmentary remains of uncertain affinities. Generic occurrences strongly support connections with Laurentia. Although the species identified are endemic to the southern Precordillera, they mostly resemble faunas from the lower Saukia Zone of western North America, and the Onchonotus richardsoni and Keithia subclavata faunas of eastern Canada and US.