Conus ageri (Hendricks, 2015)

Description

Shell size. Shell moderately small (largest observed specimen, PRI 67514, is 32.5 mm). Last whorl. Typically conical, sometimes ventricosely conical (RD 0.54–0.61, μ = 0.57; PMD 0.83–0.89, μ = 0.86; n = 17); outline slightly convex, except at anterior quarter, which is slightly concave. Shoulder sharply angulate, smooth. Widest part of shell just below shoulder. Aperture slightly wider at base than near shoulder. Siphonal notch absent; anterior-most end of lip sometimes extends slightly beyond columella. Incised spiral grooves on anterior half that diminish towards the shoulder; pustules sometimes present on adapical surfaces of intervening ribs (e.g., PRI 67510).

Spire whorls. Spire height moderate (RSH 0.18–0.23, μ = 0.20; n = 17); outline slightly concave. Protoconch diameter 0.7–0.8 mm (based on PRI 67510, PRI 67511, and PRI 67518), number of whorls unknown. Tubercles absent from all spire whorls. Sutural ramp flat to concave on early whorls, concave in later whorls; spiral ornamentation absent, but growth lines prominent across sutural ramp. Subsutural flexure symmetrical and square-shaped to slightly curved abaxially; depth 1.5–2.3x width⁽¹⁾.

Coloration pattern. Two noninteracting patterns present. The primary (base) pattern consists of axially-arranged, irregularly-shaped blotches of variable width. The secondary pattern typically consists of about 20–30 spiral rows of dots or dashes. The two patterns differ in the color of emitted light. Sutural ramp with blotches⁽¹⁾.

Etymology

Named in honor of paleontologist Derek V. Ager, author of “The Nature of the Stratigraphical Record”⁽¹⁾

Material examined

Holotype: PRI 67515. Paratypes: PRI 66171, PRI 67510–67514, PRI 67516–67536. All type specimens are from TU station 1354. Other specimens: PRI 67231–67232 (TU station 1422)⁽¹⁾.

Type locality and horizon

TU 1354: Cañada de Zamba, Dominican Republic; lower Pliocene Gurabo Formation⁽¹⁾.

Remarks

A specimen of cone snail (NHMUK PI BM 64050) remarkably similar to Conasprella ageri is present in collections at the NHMUK associated with Guppy’s report on fossil mollusks from Jamaica (photographs of the specimen may be viewed online through the NHMUK Palaeontology Collection Database:

http://www.nhm.ac.uk/research-curation/scientificresources/collections/palaeontological-collections/palaeontology-specimen-database/index.php).

NHMUK PI BM 64050 is labeled as “Conus solidus,” a very differently shaped species that is synonymous with Conus recognitus Guppy, 1867 (this was recognized by Maury, Pilsbry, and Woodring). It does not appear that the distinctive morphology of NHMUK PI BM 64050 was ever formally described by Guppy or other workers. It is likely a specimen of C. ageri, as its shell characteristics are consistent with the new species (it is not known at the present time, however, whether it bears a preserved coloration pattern visible under UV light)⁽¹⁾.

Two poorly preserved shells—PRI 67231 and PRI 67232—are from TU station 1422 and may be additional specimens of C. ageri. PRI 67231 has a well-preserved coloration pattern that is consistent with C. ageri, except that the primary pattern consists of two nearly continuous spiral bands that separate an unpigmented region in the middle of the last whorl (see Fig. 8 O,P)⁽¹⁾.

The specimens of Conus granozonatus Guppy, 1866 figured by Woodring (from Jamaica) and holotype of Conus trisculptus Pilsbry and Johnson, 1917 (ANSP 2567) (from the Dominican Republic) are very similar in shell form to C. ageri, but both species show evidence of tubercles on the shoulder, which are not present on C. ageri⁽¹⁾.

Among extant species, C. ageri is most similar in shell morphology and coloration pattern to the eastern Pacific species Conasprella tornata (Sowerby II, 1833) (Fig. 8Q,R). Conasprella tornata was assigned by Puillandre et al. [2] to the subgenus Ximeniconus and this assignment is also followed here for C. ageri⁽¹⁾.