Conus
(Eugeniconus) paranobilis (Petuch, 1991)
Diagnosis (1).
–Spire low to moderate; shoulder carinate; early postnuclear whorls
tuberculate; sutural ramps with several raised spiral threads on earliest
whorls and pronounced axial growth lines; subsutural fl exure symmetrically
curved; raised spiral threads at base of last whorl (1).
Description.
–Shell dextral, moderately small to mediumsized. Last whorl conical;
outline straight to slightly convex. Shoulder carinate. Spire low to moderate;
whorls often stepped; outline fl at to concave; apex mammillate in very low-spired
individuals. Poorly preserved protoconchs on two specimens (UF 114766, PRI
54488) appear paucispiral. First two or three postnuclear whorls tuberculate.
Teleoconch sutural ramps nearly fl at in early whorls, concave to sigmoidal in
later whorls, with several raised spiral threads on earliest whorls; axial
growth lines often pronounced. Subsutural fl exure symmetrically curved; depth
approximately one and one-half to two times width. Last whorl with raised
spiral threads on anterior third, sometimes extending to shoulder in larger
specimens. Color pattern on last whorl consisting of pigmented axial fl ames
that sometimes merge to form reticulations surrounding unpigmented regions that
are blotch- or tent-shaped (1).
Morphometrics and shell shape as a function of shell size.–
Morphometric data collected from 10 specimens, including the type
specimens listed below, are summarized in Table 21. For these specimens, MD =
0.48(SL) + 0.86 (R2 = 0.99) and MD = 0.52(AH) + 1.04 (R2 = 0.99) (1).
Occurrence.
–The holotype of Conus paranobilis was collected from the Tamiami
Formation (Pinecrest Beds) exposed at the APAC Quarry, Sarasota County,
Florida. Specimens are also known from Pinecrest Beds exposed in Manatee,
Collier, and Okeechobee counties, Florida. Conus paranobilis is
restricted to the Tamiami Formation of southern Florida (1).
Remarks.
–Petuch’s holotype of Eugeniconus irisae appears indistinguishable
in shell characteristics from the holotype of Conus paranobilis. Petuch
(2004: 294) characterized the color pattern of E. irisae as “finely triangle-patterned,” thereby differentiating it from the
“coarsely triangle-patterned” C.paranobilis.
In my examination of the holotype of E. irisae, however, I could see no color pattern on the last whorl (including
under ultraviolet light), making it impossible to verify this claim. Petuch
(2004: 294) also differentiated E.irisae from C. paranobilis by noting its “more slender shell with a narrower shoulder,” its
“distinctly canaliculate spire whorls,” and its “smoother shell”; I have,
however, observed variation in more than 30 shells of C. paranobilis, and these attributes do not seem substantial enough to justify the
recognition of this additional, co-occurring species, which was described based
on two specimens (the holotype, AMNH 50681, and a paratype reportedly [Petuch,
2004: 293] located in Petuch’s personal research collection) (1).
Conus paranobilis could be confused with the
co-occurring, low-spired species C. miamiensis (1).
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Late
Pliocene Tamiami Fm. (Pinecrest Beds) of Sarasota County, Florida (UF 111423) |
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from the Tamiami Fm. (Pinecrest Beds) of Collier
County, Florida, shown under regular and ultraviolet light, which causes the original coloration pattern of the
shell to be revealed (PRI 54626) |
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F, G. Eugeniconus paranobilis (Petuch, 1991).
(2) Pinecrest Member and Golden Gate Member (lower beds,
Petuch Unit 7 equivalent), Tamiami Formation. Length 36 mm, from Petuch Unit 7 in the APAC Pit, Sarasota,
Sarasota County, Florida. Note the characteristic color pattern composed of
large white triangles and ovals on a dark background, similar to the living
Indo-Pacific Eugeniconus nobilis and Eugeniconus renatae. |
Bibliografia Consultata
· (2) - Petuch, E. J., 1991. W. H. Dall Paleontological Research Center Special Publications Number 1, 1