NMITA: Neogene Marine Biota of Tropical America

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To view shell in 3 orientations. To see a SEM image of the protoconch.

Photograph: (Jung, 1989, Fig. 274.10) Scale bar is 1 mm. Image is of USNM 412966. USGS locality 5882h: Río Banano, Limón Province, Costa Rica; Río Banano fm. Height: 8.3 mm; width: 3.9 mm.

Synomyms: Strombina sincola Olsson, 1922, p. 129, pl. 10, fig. 19, 21; Strombina (Sincola) sincola Olsson, Olsson & Harbison, 1953, p. 230.

Morphologic Descriptions: Shell small and slender. Protoconch consists of 3 volutions; its outer lip is sinusigerous. Teleoconch whorls up to 6; their profile is straight. Except for the body whorl the teleoconch whorls are sculptured by orthocline to somewhat prosocline axial ribs extending from suture to suture. Number of axial ribs ranging from 13 to 16 per whorl. The axial ribs are sometimes slightly thickened adapically. Body whorl with a moderately pronounced shoulder, its base sculptured by spiral cords. Dorsal hump and hump to the left of the aperture prominent. Outer lip thickened, somewhat extended adapically, its inner surface with denticles. Columellar callus well developed, usually with some denticles. Parietal callus thick, with a ridge bordering the posterior canal. Anterior canal short, slightly recurved.

Lectotype: PRI 21059 (Río Banano, Limón Province, Costa Rica, Río Banano Formation, early Pliocene).

Distribution: Early Pliocene: Río Banano Formation along the lower course of Río Banano (about 10 kilometers SW of Limon) and in the Quebrada Brazo Seco (20 kilometers W of Limón), Costa Rica.

Return to the Species Listing of the subgenus Sincola.