Conus roigi (Marks, 1951)

Description [based on holotype and three paratypes).

Shell of moderate size, biconical, spire about one-third of total length; nucleus of three elongate, bare whorls with apical angle of 45 degrees; spire of seven whorls, with pleural angle ranging from 65 degrees in specimen of six whorls to 90 degrees in specimen of seven whorls; spire whorls ornamented with prominent tubercles crossed on the sides by two slightly raised spiral bands; tubercles numbering 21 on penultimate whorl of holotype, bands extending only to penultimate whorl; growth lines regular, prominent, moderately recurved on body whorl ; body whorl with sharply angulated shoulder, ornamented on base by about 14 raised spirals of irregular widths; siphonal notch rather shallow; anal notch deep; anal fasciole concave ⁽¹⁾.

Dimensions of holotype [incomplete). — Length 27,6 mm., diameter 15,2 mm.

C. roigi is distinguished mainly by the banded tubercles on the spire whorls. Conus roigi is placed in Leptoconus because of the deep anal notch, shallow siphonal notch, and sharply angulated shoulder. The outer lips of the types are broken, but are presumably retractive. The most similar described species is C. tuberacola Anderson from the Tubera group, Miocene, of Colombia. C. roigi is smaller and thinner-shelled than C. tuberacola, lacks the beaded sides on the young specimen, and has sharper spirals about the base of the body whorl and stronger growth-line traces on the spire whorls ⁽¹⁾.

C roigi occurs in the Subibaja formation. Lower Miocene, of the Las Masas sector of the Progreso Basin. Associated with it, in a matrix of fine silty sandstone, are Turris albida, Tritiaria landesi, Turris uaningeni, etc. The species is named for C. A. Roig, who collected most of the type material.

Material. — Holotype no. 20497, Paleontological Research Institution, from locality LP.C. 2558, near Las Masas. Paratype no. 20498 (figured) from the locality LP.C. 1 1203. Paratype no. 7991, Stanford Univ. Paleont. type coll., from locality LP.C. 1 1203, near Las Masas ⁽¹⁾.

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Conus roigi Plate 9, figs. 7, 9	Conus roigi PRI 20498
Conus roigi PRI 79783	Conus roigi PRI 79783

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Bibliografia Consultata

· (1) - Marks, J. G., 1951. Miocene Stratigraphy and Paleontology of Southwestern Ecuador. Bulletins of American Paleontology, 33 (139 )