Conus federalis (Weisbord, 1962)
Descrizione e caratteristiche (1):
Shell moderately
large and solid,
the spire nearly straight-sided in profile, the angle of
divergence 120-130 degrees.
Post-nuclear whorls at least eight, the
nucleus decollate. Earliest
post-nuclear whorls subangularly convex, the later ones a little concave, the summit of the
last two encroaching
slightly on the
whorl preceding. The angulation of
the first whorls is medial;
with growth the angulation develops into
a subnodulous shoulder near the base of
the whorl, and with further development the shoulder
disappears. Whorls thickened at the
summit into a subsutural collar
below which are three spiral threads
or riblets rendered crenulate by
the numerous curved axial growth
lines that traverse the shell.
These growth lines on the
fascicle have a relatively small curvature
indicating that the anal notch of
the shell is not deeply indented. The
spiral riblets on the spire are confined to
the posterior half
of the whorl, the anterior
half being more or less smooth. Sutures narrowly
channeled to slightly gaping. Body whorl
subrounded and smooth at
the shoulder, slightly concave at
the base, ornamented with about 32 subequal to
unequal low revolving cords with occasional interstitial
threads; the lowest nine or ten threads above
the fasciole become successively
larger toward the base and develop
into rounded riblets with distinct
concave interspaces. The anterior fasciole
is a little
convex, fashioned of
about four fused spiral ribs crossed by
numerous fine axial incremental. Body of
shell traversed by numerous fine and
coarse axial growth markings which tend
to nodulate the basal spiral
ribs. Aperture oblique, widest anteriorly.
Outer lip broken
along the rim, the anal notch also destroyed. Lower
lip long, bayonet-Jike, a narrow sulcus
separating it from
the adjacent fasciole. Anterior canal broad, the notch
virtually absent. Around
the middle of the body whorl and above
the anterior fasciole there is
a faded white band, with clouds, suffusions, and streaks of
light tan over the rest of the surface.
Dimensions.—Holotype (nucleus
decollate), length 45.4 mm.; max. width 23.9 mm.
Type locality.—Playa Grande
formation (Maiquetia member) at W-23,
north flank of Punta Gorda anticline.
One specimen, the holotype.
Comparisons.—C. federalis, n. sp. is close
to the Recent C. juliae Clench (1942, pp.
26^27, pi. 12, fig.
4) dredged nine miles off Fort
Walton, Florida, in 15 fathoms, but one difference that is immediately noticeable is that
the spire of C. juliae is
higher and
considerably more attenuated.
In the Eastern Pacific the nearest analogue is C. purpurascens Broderip
(in Sowerby, 1833, Conch. III., p.
1 [117], pi. 25,
fig. 13) which
inhabits
the coast from Baja California to Ecuador, in
tide pools
and rocky shores; the principal difference
is that C. federalis is
more poimted anteriorly. C. purpurascens is an
extremely variable form
both in shape and coloration. The
"typical" shell
has a low
spire and strongly
shouldered whorls, but there are endless
variations to the
rounded form known as C. regalitatis Sowerby.
Krebs (1864, p. 6)
listed C. purpurascens from Guadeloupe in the
West Indies, but according to
Hanna and Strong ( 1949, p.
300) this may have been an error
of locahty or identification (1).
|
|
|
Conus federalisHolotype PRI
26321
Pliocene
– Zancleano |
Conus federalisPlate
40 – fig. 5, 6 mm.
45,4 x 23,9 |
Bibliografia Consultata
·
(1) - Weisbord, N. E., 1962. Late Cenozoic Gastropods
from Northern Venezuela. Bulletins
of American Paleontology, 42 (193 ).