Conus
bocapanensis (Spieker, 1922)
Descrizione e caratteristiche:
Shell
small to medium-sized, unequally biconic, the spire turreted. The spire is
fairly high, including about a third of the entire height, its slopes straight
in profile. Whorls 8-9 in number, the first two of the spire smooth and
rounded, the following with a marked keel at the lower third, the surface above
the keel being concave and below straight. On the spire the sculpture is of
growth-lines, poorly defined, only. On the body whorl are sixteen or seventeen
spiral bands, separated by narrow interspaces, with growth-lines in the
interspaces. The spiral sculpture is weaker near the shoulder. The shoulder of
the body whorl is sharp, the surface below being straight. Aperture fairly narrow,
of constant width, the columella slightly reflexed at the base.
Height,
37; diameter, 17 mm.
This
species is closely related to a group of small cones from the
Antillean-Carribean region. It is perhaps closest to C. tortuosostriatus
(Toula, 1911), from Gatun; it differs only in having simple instead of
differentiated spiral sculpture, and in lacking the beaded keels characteristic
of tortuosostriatus. It is also similar to Conus multiliratus var.
gaza (Johnson and Pilsbry, 1911), from Gatun, Bowden, and Santo Domingo and
Zorritos, but it is more slender, and has broad-topped ribs on the body whorl
instead of the finer spirals of gaza.
C.
imitator (Brown and
Pilsbry, 1911), from Gatun, differs in having 16 ribs on the lower half of the
body whorl instead of 16 over the entire surface, and in having the profile of
the spire concave instead of straight. The spire of bocapanensis differs
in similar way from that of C. planiliratus (Sowerby, 1870), from Santo
Domingo; the profile is straight in lines instead of concave (1).
Lower Zorritos Fm. North of Quebrada de Boca Pan, Perù.
Upper Miocene: Panama, Perù, Ecuador
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Conus bocapanensisPlate 1 fig. 3 mm. 37 x 17 Perù |
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Conus bocapanensisPlate 1 fig. 3 mm. 37 x 17 |
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Bibliografia Consultata
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(1) - Spieker, E. M., 1922. The Paleontology of the Zorritos
Formation of the North Peruvian Oil Fields. Johns Hopkins University
Studies in Geology, 3: 1 -196
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