Type of wall: Spinose, spines are supported by spine collars, which coalesce to form ridges. Pore concentrations average 80 pores/50 μm2 test surface area and pore diameters average 1.5 μm.

Test morphology: Test low trochospiral consisting of 2 whorls, slightly tending to planispiral, lobulate in outline, chambers globular 4-5 in the last whorl, increasing rapidly in size, if present the last chamber may be either slightly radially elongated or smaller that the last chamber. Sutures are depressed, straight on both sides; the umbilicus is moderately small, open, enclosed by surrounding chambers, aperture an umbilical-extraumbilical high arch sometimes tending to move to completely extraumbilical, bordered by an imperforate and very thick rim.

DISTINGUISHING FEATURES.— The distinctive characters of G. roeglina are the thick rim bordering the aperture and the presence of a last slightly radially elongated chamber. It differs from G. obesa by the higher arched aperture bordered by the thick rim and from G. clavaticamerata by its less developed elongated last chamber and by the thick rim bordering the aperture instead of a small lip typical of G. clavaticamerata.

DISCUSSION.— Globigerinella roeglina is here established as a new species because its typical morphology is recurrent in the investigated samples and, although generally small, it does not seem to be a juvenile form. Rather it looks like the “base” morphology from which the extreme clavate species of Quiltyella (Q. nazcaensis, and Q. clavacella) evolve. This species shows a moderate intraspecific variability, with specimens characterized by a slightly radially elongated or smaller last chamber. The species was previously identified by Spezzaferri (1994) and informally called “Protentella sp.”. It is here attributed to the genus Globigerinella because of the typical wall texture and because of its tendency to a planispiral coiling mode, even if rarely reached.

PHYLOGENETIC RELATIONSHIPS.— Probably evolved from Globigerinella obesa in the upper lower Oligocene Zone O4.

STRATIGRAPHIC RANGE.— Sporadic occurrence from lower Oligocene Zone O4 to possibly lower/mid -Miocene Zone M5 (Spezzaferri, 1994).

GEOGRAPHIC DISTRIBUTION.— Found at low latitudes in the Gulf of Mexico, tropical Indian Ocean and Paratethys sequences of Transylvania.

STABLE ISOTOPE PALEOBIOLOGY.— Unpublished data of S. Spezzaferri indicate a deep water habitat for this species.

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