Conus johntuckeri

Conus (Gradiconus) johntuckeri (Bernard M. Landau, Carlos Marques da Silva, and Antoine Heitz, 2016)

Diagnosis.

Gradiconus of medium size, with shallow, symmetrically curved subsutural flexure; spire strongly scalate, of moderate height, with angular spire whorls; carina on last whorl very strong, elevated, with narrow concave portion of

whorl profile below; basal spiral sculpture very weak.

Description.

Shell medium-sized, relatively elongate; spire of medium height, strongly scalate, slightly coeloconoid. Proto-conch unknown (not preserved in available material). Spire whorls concave, smooth, carinate just below midwhorl. Subsutural flexure shallowly symmetrically curved. Last whorl sharply angled at shoulder by sharp carina, concave just below shoulder, straight-sided below, very slightly constricted at base, bearing very weak spiral threads over base. Aperture straight, narrow; outer lip weakly arcuate; siphonal canal of medium length, slightly recurved; siphonal fasciole weakly developed. Color pattern under ultraviolet light of rows of irregular rectangular blotches and axial flammules.

Differentiation.

Gradiconus johntuckeri n. sp. is characterized by its strongly scalate spire, of moderate height, with the spire whorls strongly angular, its very strong elevated carina on the last whorl with a narrow concave portion of whorl rofile below, and its very weak basal spiral sculpture.

Jung (1965) compared this shell to Conus imitator Brown & Pilsbry, 1911, from the middle and upper Miocene lower–upper Gatun Formation of Panama. However, the resemblance is superficial, because C. imitator has finely tuberculate early teleoconch whorls and an asymmetrically curved subsutural flexure. J. K. Tucker and Tenorio (2009) placed C. imitator in the genus Gradiconus. However, it probably does not belong in this genus, which is characterized by having smooth and not tuberculate early teleoconch whorls, and a paucispiral protoconch. Conus imitator has a multispiral protoconch (Woodring, 1970: 355). Unfortunately, the protoconch is not preserved in any of our Cantaure material.

Gradiconus johntuckeri n. sp. is closely similar to the holotype of Conus floridanus Gabb, 1869, illustrated by Hendricks (2008: pl. 13, figs 1–2) and the group of Plio/Pleistocene shells from Florida illustrated by the author (Hendricks, 2008: pl. 13, figs 3–28) under the name C. cf. largillierti Kiener, 1845. The Cantaure specimens differ from all the Plio/Pleistocene forms in having a far more prominent carina on the last whorl. Gradiconus is still represented on both sides on the Isthmus of Panama by moderately similar species such as G. flavescens (G. B. Sowerby I, 1834) in the Caribbean and G. scalaris (Valenciennes, 1832) in the Panamic Pacific. However, the very prominent carina on the last whorl distinguishes G. johntuckeri n. sp. from all of its congeners.

Etymology.

Named after John Tucker of Rantoul, Illinois, in recognition of his enormous contribution to the systematics of cone snails. Gradiconus gender masculine.

Distribution.

Lower–middle Miocene: Cantaure Formation, Venezuela (this paper).

The enlargement of the shell at the shoulder, as well as the greater development in height, allow us to distinguish this species from Conus talis.

Conus cf. imitator

Jung, 1965: 579, pl. 78, fig. 12.


Conus johntuckeri 3. Holotype, NHMW 2013/0556/0256 43,9 x 21,9 mm.

Conus johntuckeri 4. Paratype 1, NHMW 2013/0556/0432 mm. 38,1 x 21,2 apertural (a) and dorsal (b) views.

Conus johntuckeri 5. Paratype 2, NHMW 2013/0556/0433 mm. 32,5 x 16,4

Conus johntuckeri holotype, NHMW 2013/0556/0256, height 43.9 mm.	Conus johntuckeri holotype, NHMW 2013/0556/0256, height 43.9 mm.