Conus franklinae
(Hendricks, 2015)
Description
Shell size. Shell moderately small
(largest observed specimen, PRI 66142, is 32.7 mm). Last whorl. Ventricosely
conical (RD 0.58–0.59, μ = 0.58; PMD 0.79–0.83, μ = 0.81; n = 3); outline convex, except at anterior quarter, which is
slightly concave. Shoulder subangulate, smooth. Widest part of shell below
shoulder. Aperture uniform in width from base to shoulder. Siphonal notch
present. Fine spiral threads on anterior half of juvenile specimens, extending
to shoulder in mature specimens.
Spire whorls. Spire height
moderate (RSH 0.13–0.19, μ = 0.16; n = 3); outline
sigmoidal. Protoconch multispiral, diameter 0.8 mm (based on partial remains on
PRI 67230). Tubercles present on first 2 postnuclear whorls. Sutural ramp
slightly concave to flat on early whorls, convex on later whorls, with several
spiral threads. Subsutural flexure asymmetrical, depth approximately 0.5–0.9x
width (1).
Coloration pattern.
Two noninteracting patterns
present. The primary (base) pattern consists of a solid to blotchy ground
pattern that is interrupted by 2–4 spiral rows of inconsistently arranged,
unpigmented dots. The secondary pattern consists—at least in juvenile
specimens— of at least 10 spiral rows of dots. The two patterns differ slightly
in the color of emitted light. Sutural ramp with blotches that appear to be
extensions of the primary last whorl pattern.
Etymology
Named in honor of Rosalind
Franklin (1920–1958) for the important role that she played in discovering the
structure of DNA. (1).
Material examined
Holotype: PRI 66142 (TU station 1215). Paratypes: PRI 67226, PRI 67227, and
PRI 67230 (TU station 1422) (1).
Type locality and horizon
TU 1215: Río Gurabo, Dominican
Republic; lower Pliocene Gurabo Formation. (1).
Other locality
and horizon
TU 1422: Arroyo
Bellaco, Dominican Republic; upper Miocene Cercado Formation.
Remarks
The shell morphology and
coloration pattern of Conus franklinae is somewhat similar to that of C.
zambaensis. The two species do not overlap, ever, in their Fossilized Coloration Patterns on Dominican Cone Snail Shells positions of maximum diameter (PMD 0.79–0.83 in C.
franklinae, 0.84–0.88 in C. zambaensis) or relative spire heights
(RSH 0.13–0.19 in C. franklinae, 0.06–0.09 in C. zambaensis). Additionally, the
subsutural flexure in C. franklinae is asymmetrical, while that of C.
zambaensis is nearly symmetrical and deeper.
Conus franklinae bears strong similarity to the extant western
Atlantic species Conus ritae Petuch, 1995, which is only known from a
few specimens. Besides having an overall shape that is similar to C. ritae,
the coloration patterning of both species closely match. Specimens of C.
franklinae, however, have narrower last whorls than specimens of C. ritae
(Kohn reported RD values for C. ritae that range from 0.61–0.68).
Puillandre et al.
assigned C. ritae to the subgenus Atlanticonus, along with three other
species: C. cuna Petuch, 1998, C. granulatus Linnaeus, 1758, and C.
glenni Petuch, 1993 (none of these four extant species of Atlanticonus have
yet been placed in an explicit phylogenetic context). This subgeneric
assignment is tentatively also followed here for C. franklinae (1).
|
|
Conus franklinae
(A-E) PRI 66142 (holotype), TU 1215, SL 32.7 mm;
Lower Pliocene (F) PRI 67227 (paratype), TU 1422, SL 18.8 mm; Upper
Miocene (G-H) PRI 67226 (paratype), TU 1422, SL 14.7 mm; Upper
Miocene (I-M)
PRI 67230 (paratype), TU 1422, SL 10.5 mm. Upper Miocene |
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”