Conus vergrandis (Hoerle, 1976)

 

 

Diagnosis (1):

 

Shell small; slender; spire moderately high, flat-sided to slightly concave in outline. Adult specimens consisting of seven teleoconch whorls plus two rounded nuclear whorls. Sutures distinct, lightly adpressed. First three post-nuclear whorls elevated, exposing axially costate ornamentation in front of carinate shoulders. Early spire whorls flat on summits, later whorls barely convex. Growth lines faint, close-set, shallowly opisthocyrt. Microscopic spiral threading present. Shoulder of final whorl outlined by small cord. There is a scarcely perceptible widening of the last whorl at the ad apical third. Anal notch shallow; lip nearly straight ; aperture narrow posteriorly, widening anteriorly and crenated in harmony with basal sculpture. Abapical third of last whorl ornamented with ten, heavy, rounded cords, separated by narrower, unequal interspaces.

 

Dimensions of holotype: height 15.1 mm, diameter 8.5 mm.

Holotype: USNM 220117.

Type locality: TU 546, Ten Mile Creek, about 1/2 miles west of Chipola River (NW Y4 Sec. 12, T1N, R10W), Calhoun County, Florida (?=USGS 2212, "one mile west of Bailey's Ferry").

Occurrence: Chipola Formation, Florida ; late lower Miocene.

Figured specimens: Fig. 2, USNM 220 117 (holotype). Fig. 3, USNM 220118; height 9.1 mm, diameter 4.8 mm; locality TU 546.

Other occurrences: TU locality nos. 196, 457, 458, 459, 554, 655, 710, 830, 950, 951, 998, 1050, 1098.

 

Discussion:

 

C. vegrandis bears a resemblance to C. tricoratus n. sp. in the similar outline, adpressed sutures and axially costate early whorls. Both species have seven teleoconch whorls in the adult stage, however, C. vegrandis is consistently slightly larger. The dissimilarities are the two nuclear whorls and convex anal fasciole of C. vegrandis as opposed to three nuclear whorls and flat anal fasciole of C. tricoratus. The latterspecies has a narrow smooth band in front of the suture. This band is absent on C. vegrandis. Of the over 350 specimens of this small ( vegrandis, Latin for "little") species collected by the writer 75% were taken from Ten Mile Creek, 25% from Chipola River localities and none were found along Farley Creek

 

 

 

 

 

Conus vergrandis

 

2. USNM 220117 (holotype ): mm. 15.1 x 8.5

Locality: TU 546, Ten Mile Creek

3. USNM 220118: mm. 9.1 x 4.8 mm.

Locality: TU 546, Ten Mile Creek.

 

Conus vergrandis

mm. 20,2

Alum Bluff Group, Chipola Formation, Calhoun County, Florida.

 

 

 

 


 

 

Conus vergrandis (Hoerle,1976)

mm. 17,9 x 10,1

Miocene - Collected in the Ten Mile Creek Spoil Banks at low water level in 1999. Chipola Formation, Calhoun County, Florida

[AZFC 442-01]

 

 


 

Conus vergrandis

mm. 20,2

Conus vergrandis mm. 17,9 x 10,1

Miocene

[AZFC 442-01]

Conus vergrandis

USNM 220117

mm. 15,1 x 8,5

 

Conus tricoratus

USNM 220120 (holotype)

mm. 13.3 x 6.7

 

 


Bibliografia Consultata

 

         (1) - Hoerle, S. E., 1976. The Genus Conus (Mollusca: Gastropoda) from the Alum Bluff Group of Northwestern Florida. Tulane Studies in Geology and Paleontology, 12 (1 )