An association of benthonic foraminifera, Late Oligocene to Early Miocene in age, characteristic of the Monagas area, Eastern Venezuelan Basin, is presented in this paper.

The identified assemblage could indicate a sequence boundary between a lowstand wedge and a transgressive system tract; this assemblage overlies the Naricual Formation oil sand reservoirs; therefore it is very important to have it well described.

The studied assemblage has been picked out of samples analyzed from ten wells in the El Carito - El Furrial area. A total of one hundred species were identified, including twenty species turned out to be unidentifiable. Four new taxa have been described in this age interval.

The fauna exhibits strong dominance, being the main species: Nonionella opima, Nonion atlanticus, Textularia cf. T. grenadana, Textularia sp., Textularia panamensis, Valvulineria sp., Ammonia beccarii, Nonionella sp., and Trochammina sp. All these species correspond to a transitional to inner neritic environment.

The detailed identification of this fauna assemblage will contribute to a better understanding of the stratigraphy in the area, and in consequence to optimize hydrocarbon exploration.