Favocassidulina Tuberculata N. SP., A New Benthic Foraminifer from the Portuguese Continental Slope

Favocassidulina tuberculata, a new benthic foraminiferal species from Integrated Ocean Drilling Program Site U1391 drilled on the southwest Portuguese continental slope, is described. This new species has a slit-shaped apertural opening oblique to the test periphery instead of paralleling the periphery as the type species Favocassidulina favus (Brady) does. And more notably, this species possesses a test surface ornamented with tubercles, quite different from the coarse honeycomb wall structure of F. favus and the finely irregular cancellate surface ornamentation of other Favocassidulina species. This paper for the first time reports the presence of the genus Favocassidulina in the Atlantic Ocean.