Virgiconus miamiensis

Conus (virgiconus) miamiensis (Petuch, 1986)

Diagnosis.

Shell with very low spire; protoconch mammillate; sutural ramps sigmoidal in profile, with spiral grooves on first several early postnuclear whorls and fine, raised spiral threads on later whorls; subsutural flexure diagonal; last whorl with raised spiral threads extending from base of shell to shoulder⁽¹⁾.

Description.

Shell dextral, moderately small to mediumsized. Last whorl conical to ventricosely conical; outline straight to slightly convex; maximum diameter reached beneath shoulder. Shoulder angulate to subangulate. Spire height low; outline flat to concave. When preserved, larval shell protruding above later teleoconch whorls, maximum diameter ca. 0.7 mm. Teleoconch sutural ramps sigmoidal in profile; spiral grooves present on fi rst several early postnuclear whorls and fine, raised spiral treads on later whorls. Subsutural flexure diagonal; depth approximately one and one-half times width. Last whorl with raised spiral threads often extending from anterior end to shoulder (although becoming nearly obsolete toward the shoulder in some specimens). Color pattern on last whorl consisting of ca. 30 rows of spiral dots or dashes, with pigmentation occurring on top of the spiral threads⁽¹⁾.

Occurrence.

Petuch’s types are from the Tamiami Formation (Pinecrest Beds) exposed at the Bird Road locality, Miami-Dade County, Florida (UF locality DA001). Observed specimen lots also come from Pinecrest Beds exposed in Collier, Charlotte, Manatee, and Sarasota counties, Florida. A single specimen (UF 114799), however, was observed that is apparently from a locality (UF Locality HN004) in Hendry County, Florida, that predominantly contains material from the Caloosahatchee Formation. Aside from this single record, C. miamiensis is restricted to the Tamiami Formation of southern Florida⁽¹⁾.

Tamiami formation:

Buckingham Limestone Member
Ochopee Limestone Member
Bonita Springs Marl Member
Golden Gate Reef Member
Pinecrest Sand Member

Remarks.

A species very closely resembling Conus miamiensis was described and figured by Kamp (1967: 59-61, pl. 5, figs 5-7) in her thesis, but was never published; this name is consequently unavailable. Kamp’s “types” are present in the FLMNH as UF 112310, 115828 (Pl. 18, Fig. 3), 115829 (Pl. 18, Fig. 4), and 115830 (Pl. 18, Figs 7-8). I consider these to be specimens of C. miamiensis, because they fully agree with Petuch’s types ⁽¹⁾.

Petuch (1986) correctly noted the general similarity of Conus miamiensis to some members of the extant IndoPacific clade (Duda & Kohn, 2005) containing the species C. virgo Linnaeus, 1758, C. emaciatus Reeve, 1849, C. flavidus Lamarck, 1810, C. frigidus Reeve, 1848, and C. terebra Born, 1778 ⁽¹⁾.

Among co-occurring species, C. miamiensis can be confused with the low-spired taxon C. paranobilis Petuch, 1991, but lacks the distinctive color pattern (a pigmented netting surrounding white blotches or tents), stepped spire whorls, and tubercles on the early postnuclear whorls that characterize C. paranobilis ⁽¹⁾.