Lower and Middle Famennian (Upper Devonian) conodont biostratigraphy from Compte section (Central Pyrenees, Spain)

Abstract

A detailed analysis of the conodont sequence in the Compte section, located in the Spanish Central Pyrenees, demonstrates an almost continuous biostratigraphical record for the Famennian sequence studied. Forty-seven conodont taxa have been identified allowing the identification of six lower and middle Famennian zones through the index taxa. The lower part of the section, corresponding to the Comabella Formation, begins with the Palmatolepis termini Zone, followed by the Palmatolepis glabra prima Zone. The top of the Comabella Formation comprises the Palmatolepis gl. pectinata Zone with the Palmatolepis rhomboidea Zone starting near the base of the La Mena Formation. At the middle of this formation the Palmatolepis gracilis gracilis Zone appears, and near the top, the Palmatolepis marginifera marginifera Zone marks the beginning of the middle Famennian, which continues through the base of the Barousse Formation. Comparing these new findings with the previous data from Boersma (1973) reveals significant chronostratigraphic and biostratigraphic discrepancies, which are discussed in detail. Additionally, comparisons with other sequences located worldwide show that the ranges of most conodonts appear delayed in the Compte section. Our data supports the revised global standard conodont zonation proposed by Spalletta et al. (2017) for this portion of the Famennian.