Protovirgularia Dichotoma- Protovirgularia Rugosa: an example of a compound trace fossil from the Lower Cretaceous (Agrio Formation) of the Neuquén Basin, Argentina

FERNÁNDEZ, D. E., PAZOS, P. J. AND AGUIRRE-URRETA, M .B.

ICHNOS

Taylor & Francis

Lugar: Philadelphia; Año: 2010 vol. 17 p. 40 - 47

1042-0940

This study focuses on the description of a compound trace fossil from the Cretaceous of the Neuquén Basin, Argentina. This structure comprises two discrete ichnotaxa:Protovirgularia cf. dichotoma M?Coy, 1850 and Protovirgularia rugosa (Miller and Dyer, 1878). Open nomenclature is chosen due to some differences from the ichnospecies diagnoses. The compound trace as a whole is the product of locomotion and resting behaviours (repichnia and cubichnia); this is not questioned, but discussed. The inferred producer is a deposit-feeding palaeotaxodont bivalve, which belongs to a taxonomic group almost unknown and not yet reported in the Neuquén Basin. The sample was taken from rocks interpreted as being deposited in a tide-influenced, marginal-marine setting, corresponding to the uppermost section of the Agrio Formation. This also represents one of the first cases of a compound trace fossil described for the Neuquén Basin.