(d'Orbigny, 1839)
Non-spinose, high trochospiral on the umbilical side, with slit-like aperture along base of last chamber provided with broad lip. Spiral side flat, showing total spire (if not encrusted by pustules). Pustule growth in clear gradient from older to younger chambers. Umbilicus fairly open and keeled around periphery from neanic stage onward. In deeper water (>800 m) with rather thick calcite crust. Last chamber wall, however, may be very thin from secretion in deeper water.
Ref.: Bé and Ericson (1963), Glaçon and Sigal (1969), Rögl (1974), Kennett (1976), Healy-Williams (1983), Lohmann (1983, 1992), Lohmann and Malmgren (1983), Healy-Williams et al. (1985), Hemleben et al. (1985), Pharr and Williams (1987), Lazarus et al. (1995), Ravelo and Fairbanks (1995).
Distribution: Its distribution is similar to that of Globorotalia scitula, but it is more common. The right coiling form spreads farther equatorward than the left coiling one. Deep-living, reproduces in early austral spring in surface waters and migrates during the summer and fall to deeper layers. In the western North Atlantic (Bermuda) it has been observed living below 1000 m (Hemleben et al., 1985).