Conasprelloides
planiliratus (Sowerby I, 1851)
Conasprelloides
planiliratus bocasensis (Olsson,
1922)
Description:
Coloration
pattern (1)
Two noninteracting patterns present. The
primary (base) pattern consists of two solid bands: one on the anterior half of
the last whorl, the other on the posterior half, but below the shoulder. The
secondary pattern consists of about 17–20 spiral rows of dots (which are often
square-shaped) or dashes; these sometimes coalesce just below the shoulder to
form short axial streaks. The two patterns differ in the color of emitted
light. Sutural ramp with radial blotches; some of these appear to be extensions
of the secondary pattern (axial streaks) over the shoulder.
Remarks (1)
Conus planiliratus can be distinguished from co-occurring
fossil species by the presence of spiral ribs over much of its last whorl, the
presence of spiral threads on its sutural ramp, and its distinctive coloration
pattern. Among extant western Atlantic species, C. planiliratus bears strong similarity in shell
morphology to C. cancellatus Hwass
in Bruguière, 1792 and C.stimpsoni Dall,
1902, both of which were recently characterized and compared by Kohn [8].Conus planiliratus differs
from both of these species in its coloration pattern, which features a heavily
pigmented secondary pattern (spiral rows of dots and dashes); this is not
present in either of the extant species. Tucker and Tenorio [34] placed C. planiliratus in
the genusConasprelloides Tucker and Tenorio, 2009, which
Puillandre et al. [2] considered synonymous with the subgenus Dauciconus. Puillandre et al. [2] placed both C. cancellatus and C.stimpsoni in
the subgenus Dauciconus and this assignment is followed here
for C. planiliratus
Distribution:
Costa Rica (4)
Jamaica
Panama
Santo Domingo (1)
Conus planiliratus bocasensis
Shell
of medium size, solid with a broad, stubby outline; spire low, conic with
nearly straight sides and composed of seven or
more whorls; the 1st 4 or 5 post-nuclear whorls are coronated; spire-whorls
with 3 faint spirals and curved growth-lines; body-whorl large and wide, with
25 strong but somewhat irregular simple
spiral cords; their interspaces are wide and with crowded, raised lines of growth and sometim.es
intercalated spirals; anterior canal nearly straight.
Length 32, breadth 17 mm.
Conus planiliratus can be distinguished from co-occurring
fossil species by the presence of spiral ribs over much of its last whorl, the
presence of spiral threads on its sutural ramp, and its distinctive coloration
pattern. Among extant western Atlantic species, C. planiliratus bears strong similarity in shell
morphology to C. cancellatus Hwass
in Bruguière, 1792 and C.stimpsoni Dall,
1902, both of which were recently characterized and compared by Kohn [8].Conus planiliratus differs
from both of these species in its coloration pattern, which features a heavily
pigmented secondary pattern (spiral rows of dots and dashes); this is not
present in either of the extant species. Tucker and Tenorio [34] placed C. planiliratus in
the genusConasprelloides Tucker and Tenorio, 2009, which
Puillandre et al. [2] considered synonymous with the subgenus Dauciconus. Puillandre et al. [2] placed both C. cancellatus and C.stimpsoni in
the subgenus Dauciconus and this assignment is followed here
for C. planiliratus
Length 32, breadth 17 mm.
This Cone, which should probably be considered as
distinct, is fairly common
in the shale beds, belonging to the Gatun Stage on Bocas
Island. From typical planiliratus it differs in its broad stubby form and coarse
sculpturing.
Gatun Stage: Bocas del Toro, Panama.
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Conus planiliratus bocasensis (4)
Plate 3, fig. 14, 16 |
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Conus planiliratus (4) |
Middle Miocene Panama – Bocas del Toro |
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GG 20131 Miocene – Yaque River – Santo Domingo |
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OR 64057 Miocene – Jamaica |
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Conus planiliratus (1) PRI 67502, TU 1354 SL 24.0 mm Reversed images photographed under
UV light |
Conus planiliratus (1) PRI 66179, TU 1354, SL 23.4 mm Reversed images photographed under
UV light |
Conus planiliratus (1) PRI 67504, TU 1354, SL 23.2 mm Reversed images photographed under
UV light |
Conus planiliratus (1) PRI 67508, TU 1354 SL 18.9 mm Reversed images photographed under
UV light |
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Comparison of lecithotrophic and
planktotrophic gastropod protoconchs (outlined) in two Pliocene fossils from
the Dominican Republic; position of protoconch-teleoconch boundary indicated
by arrow.
Left: Conus symmetricus has a protoconch with
about 2 whorls and a diameter of about 0.7 mm, indicative of lecithotrophic
development.
Right: Conus planiliratus has a protoconch with
over three whorls and a diameter of about 0.7 mm, indicative of
planktotrophic development (the earliest protoconch whorl(s) are missing in
the specimen shown).
Specimens are from the collection
of the Paleontological Research Institution. Image by Jonathan R. Hendricks
for the Digital
Atlas of Ancient Life project.
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Conus planiliratusmm. 17,5 x 9,0 Upper Miocene – Gatun Formation Panama [AZFC 548-01] |
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Conus planiliratus (1) PRI 67502, TU 1354 SL 24,0 mm Reversed images photographed under
UV light |
Conus planiliratus (1) PRI 66179, TU 1354, SL 23,4 mm Reversed images photographed under
UV light |
Conus planiliratus (1) PRI 67504, TU 1354, SL 23,2 mm Reversed images photographed under
UV light |
Conus planiliratus (1) PRI 67508, TU 1354 SL 18,9 mm Reversed images photographed under
UV light |
Conus planiliratusmm. 17,5 x 9,0 Miocene – Gatun Formation Panama [AZFC 548-01] |
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Conus planiliratus (1) PRI 67503, TU 1354 SL 21,3 mm |
Conus aquitanicus (2) MNHN F.A30831 Miocene |
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E’ davvero strabiliante la
somiglianza tra il Conus planiliratus ed il Conus aquitanicus
sia con riferimento alla forma sia per quanto riguarda la colorazione. |
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Bibliografia Consultata
·
(1)
- Hendricks (2015) “Glowing Seashells: Diversity of Fossilized Coloration Patterns on
Coral Reef-Associated Cone Snail (Gastropoda: Conidae) Shells from the Neogene
of the Dominican Republic”
·
(3)
- Sowerby (i), G. B. Sr., 1849. Description
of new species of fossil shells found by J. S. Heniken, Esq.. The
Quarterly Journal of the Geological Society of London, 6: 44 -53
·
(4) -
Olsson, A. A., 1922. The Miocene of Northern Costa Rica with Notes on its
General Stratigraphic Relations. Bulletins of American Paleontology, 6
(39)