A peculiar fusuline assemblage from the Tanes locality, Campo de Caso section (Pennsylvanian, Upper Moscovian; Cantabrian Zone, Spain)

The Campo de Caso section (eastern part of the Cantabrian Zone, NW Spain) exposes a middle to upper Moscovian (Middle Pennsylvanian) succession, up to 3500-m thick, consisting of marine shelfal and deltaic siliciclastic and shale deposits with numerous intercalated fossiliferous limestones. A limestone outcropping in the upper part of this section, close to the village of Tanes, has yielded a fusuline assemblage composed of species of the genera  Eostaffella, Pseudonovella, Ozawainella, Pseudostaffella, Neostaffella, Schubertella, Fusiella, Taitzehoella, Fusulinella, Beedeina and  Putrella . The specific composition of these genera, considered as a whole, indicates an early to mid- Myachkovian age; however, some of the taxa exhibit rare aspects, among which are the occurrence of pseudostaffellids having a “primitive” appearance recalling that of the Bashkirian  Pseudostaffella , and a  Putrella  species exhibiting a wall that, at first glance, resembles the schwagerinid wall. Data gathered during this study question the validity of the genus  Quasistaffella  Solovieva 1986 and point to consider it as a junior synonymous of  Pseudostaffella  Thompson 1942.