NMITA: Neogene Marine Biota of Tropical America

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

Photograph: (Jung, 1989, Fig. 291.1) Scale bar is 1.3 mm. Image is of holotype. Height: 11.7 mm; width: 5.4 mm.

Synonyms: Strombina matima Olsson, 1922, p. 127, pl. 10, fig. 7.

Morphologic Description: Of small size, moderately slender. Protoconch consists of a little more than 3 volutions; its outer lip is sinusigerous. Teleoconch whorls up to 6 1/2. Profile of teleoconch whorls straight to slightly convex. Early teleoconch whorls sculptured by orthocline axial ribs, which become somewhat prosocline on later whorls. There are 16 to 18 axial ribs per whorl. The axial ribs of later spire whorls usually are slightly thickened adapically giving a shouldered appearance to the whorls. Last part of body whorl without axial ribs and dorsal hump, but with somewhat prosocline growth lines and a spiral thickening adjoining the suture. Base of body whorl with prominent spiral cord. Outer lip thickened, not or only slightly extended adapically; its inner surface with a few moderately prominent denticles. Columellar callus moderately well developed, with or without denticles. Parietal callus well developed, with a small ridge bordering the posterior canal. Anterior canal short, slightly recurved.

Holotype: PRI 21045 (Río Banano, Limón Province, Costa Rica; Río Banano Formation, early Pliocene).

Distribution: Early Pliocene: Río Banano Formation, Limón Province, Costa Rica; Dept. of Atlantico, northern Colombia.

Return to the Species Listing of the subgenus Sinaxila.