Early Cretaceous crustacean microcoprolites from Sierra de la Cara Cura, Neuquén Basin, Argentina: Taphonomy, environmental distribution, and stratigraphic correlation

A new Early Cretaceous association of crustacean microcoprolites from the southern Mendoza sector of the Neuquén Basin, includes Palaxius salataensis Brönnimann, Cros and Zaninetti, 1972; Palaxius caucaensis Blau, Moreno and Senff, 1995; and Favreina cf. F. belandoi Fels, 1997. This microcoprolite association occurs in the Vaca Muerta and Chachao Formations (upper Berriasian-lower Valanginian), but Palaxius caucaensis is the first record of crustacean microcoprolites in the Mulichinco Formation and its first occurrence in Lower Cretaceous deposits. Preservation of these microcoprolites is probably a consequence of the low mud-availability in the environment together with a reduced compaction and neomorphism during diagenesis. Crustacean microcoprolites occur in outer to middle ramp deposits, suggesting that they were transported as sand-size particles.