NMITA: Neogene Marine Biota of Tropical America

Bifurcium nuestrasenorae (Maury, 1917)

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Photograph: (Jung, 1989, Fig. 333.1) Scale is 1 mm. Image is of NMB H17084. NMB locality 15882: Río Gurabo, Dominican Republic; Gurabo fm. Height: 8.8 mm; width: 4.7 mm.

Synonyms: Columbella (Strombina) neustrasenorae [sic], Maury, 1917a, p. 98, pl. 15, fig. 11 (nuestrasenorae in explanation of plate); Not Strombina neustrasenorae Maury, Woodring, 1928, p. 284; Strombina (Bifurcium) nuestrasenorae (Maury), Jung, 1986, p. 22, pl. 11, figs. 10-12, pl. 12, figs. 1-9, text-figs. 18, 20, 21.

Morphologic Description: Of small size, rather stout. Protoconch consists of a little more than two volutions; its outer lip is sinusigerous. Teleoconch whorls up to 5. The first 2 or 3 spire whorls are sculptured by orthocline to slightly prosocline axial ribs. There are 14 to 20 axial ribs per whorl. Subsequent whorls smooth except for faint, slightly prosocline growth lines. Profile of spire whorls straight to slightly convex. Whorls somewhat shouldered. Body whorl moderately inflated, its shoulder accentuated by a spiral depression. Body whorl sculptured by a varying number of spiral cords near its base and one or two more or less well developed axial swellings on its left side. Outer lip strongly thickened, extended adapically and recurved, with prominent denticles on its inner surface. Columellar callus well developed, with a varying number of conspicuous denticles. Parietal callus prominent, with a ridge forming the left margin of the posterior canal. Anterior canal moderately long, recurved.

Holotype: PRI 28732 (Restricted by Jung (1986, p.22) to NMB locality 15882: Río Gurabo, Dominican Republic, lower part of Gurabo Formation, late Miocene).

Distribution:Late Miocene:lower part of the Gurabo Formation of the Rio Gurabo section, northern Dominican Republic; Cercado Formation of the Rio Cana section, northern Dominican Republic. Early Pliocene: Globorotalia margaritae zone of Arroyo Zalaya, northern Dominican Republic.

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