NMITA: Neogene Marine Biota of Tropical America

Strombina (Lirastrombina) costaricensis Olsson, 1922

To view genus description again click image.

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

Photograph: (Jung, 1989, Fig. 138.10) Scale bar is 1.6 mm. Image is of NMB H17217. NMB locality 17451: La Bomba, Río Banano, Limón Province, Costa Rica; Río Banano fm. Height: 15.1 mm; width: 7.1 mm.

Synonyms: Strombina costaricensis Olsson, 1922, p.128, pl. 10, figs. 8, 16, 17.

Morphologic Descriptions: Of medium size, moderately slender. Protoconch consists of about 11/4 volutions; outer lip sigmoid. Teleoconch whorls up to almost 8. The first 3 to 4 teleoconch whorls are smooth except for faint, orthocline growth lines, and their profile is somewhat convex. The succeeding whorls are sculptured axially and spirally, their profile is convex. At first the sculpture consists of axial ribs numbering 16 on the first sculptured whorl, but only 13 on late whorls. Soon after the appearance of the axial ribs incised spiral lines are introduced on the adapical part of the whorl. The spiral sculpture develops into spiral threads covering the entire height of the whorls. Body whorl circular in cross section, sculptured by axial ribs which are crossed by spiral threads. Middle part of body whorl somewhat flattened. Outer lip thickened, only slightly extended adapically; inner surface with denticles. Columellar callus well developed, smooth. Parietal callus thin. Anterior canal moderately long, only slightly recurved.

Lectotype: PRI 21054 Height: 16.8 mm, width: 8.1 mm. (Locality: Headwaters of Middle Creek, about 10 km ESE of Puerto Viejo, Limón Province, Costa Rica. Porbably early Pliocene.)

Distribution: early Pliocene(?): Middle Creek and Río Banano Formation, Costa Rica.

Return to the Species Listing of the subgenus Lirastrombina.