Leptoconus
petasus (Ludbrook, 1978)
Shell large,
obconic, with a gradate sharply-pointed concavely-elevated spire, flattening on
the periphery, of varying height from one-fifth to one-third height of shell; protoconch
small of 2 high smooth whorls, adult whorls 10, each almost completely
embracing the previous whorl, shoulder angulate, sutural ramp flat to concave,
surface smooth but for concave axial growth striae above the shoulder
reflecting the sinus in the outer lip and about 12 weak lirae on the base of
the last whorl; last whorl large, narrow and straight in profile in young
shells but becoming broader and convex in profile in older specimens. Aperture
fairly narrow, oblique, outer lip parallel to the columella, margin convex
below and sinuate above the shoulder, columella gently convex, with a strong
tooth-like callus anteriorly bordering the siphonal canal. Two specimens show a
colour pattern of spiral rows of fine dots on the last whorl (1).
Dimensions: height
height of spire diameter
WAM 69.523 109
21 57
69.385
64 10 41
69.525
50 16 21
70.38
66 12 33
Remarks: This
species is very close to C. (L.) monile Hwass in Bruguière (1792). The
lack of spiral sculpture on the spire whorls which have only axial growth
striae reflecting the apertural sinus is the same in both species. The spire
tends to be larger in C. (L.) petasus. The colour pattern of C. (L.)
monile (“necklace”) is that of a number of spiral rows of dots like a
series of necklaces of different-sized beads whereas in C. (L.) petasus
it may be likened to bands of fine seed-pearl necklaces. In this the pattern is
more like that of C. (L.) nielsenae Marsh as figured by Wilson &
Gillett (1971, pl. 101, fig. 5). The strong tooth-like callus at the base of
the columella is not present in C. (L.) monile. The specific name is
given because of the faint resemblance of the spire to a conical sun-hat.
Paratype WAM 69.525 is an immature shell with an unusually high gradate spire;
the anterior tooth-like callus is well developed.
Distribution: Roe Calcarenite; Early Pleistocene.
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Conus petasus(1)
Plate 21 – figg. 1-5 1, 2. WAM 69.523, holotype. 3. WAM 69.525, paratype. 4. WAM 69.385, paratype. ( ? ) 5. WAM 70.38, paratype. |
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Conus petasus(1)
WAM 69.523, holotype Plate 21 – figg. 1-2 mm. 109 x 57 |
Conus petasus(1)
WAM 70.38, paratype Plate 21 – fig. 5 mm. 66 x 33 |
Conus petasus(1)
WAM 69.385, paratype Plate 21 – fig. 4 mm. 64 x 41 |
Conus petasus(1)
WAM 69.525, paratype Plate 21 – fig. 3 mm. 50 x 21 |
Bibliografia Consultata