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.