Potamides janeae, DeVries, 2019

DeVries, Thomas J., 2019, Early Paleogene brackish-water molluscs from the Caballas Formation of the East Pisco Basin (Southern Peru), Journal of Natural History 53 (25), pp. 1533-1584 : 1558

Potamides janeae sp. nov.

( Figure 4 (r – t))

Diagnosis

Shell with broadly conical spire. Whorls with three beaded spiral cords. Varices and ventrolateral varix absent. Columella with single fold.

Description

Estimated shell length 15 mm; conical, spire angle about 25°. Protoconch unknown. Spire with at least eight whorls. Whorls flat-sided, sutures thinly incised, recessed. All preserved whorls with three beaded spiral cords. Medial spiral cord narrow, with smallest beads, and close to anterior cord. Beads nodular, spherical, aligned axially in nearly orthocline rectilinear ribs. Base of whorl demarcated by weakly beaded strong spiral cord, with adaxially adjacent, smooth, strong, quadrate spiral cord and weak third spiral cord close to axis. Remainder of base with convex axial threads. Columella with single fold anterior to midpoint. Anterior and posterior canal, if present, and outer lip not preserved.

Etymology

Named in honour of Jane Cody DeVries, mother of the author.

Material

All material from B8771 (type locality). UWBM 107579 , holotype, L (9.0), W (5.1) ; remainder are paratypes: UWBM 107580 , L (9.5), W (5.0) ; UWBM 107581 , L (4.1), W (5.0) ; UWBM 107634 , L (4.9), W (4.6) ; MUSM INV 248 , L (8.0), W (5.0) ; MUSM INV 249 , L (8.8), W (4.1)

.

Remarks

Specimens of Potamides janeae sp. nov. differ from those of P. henryi sp. nov. by having only three spiral cords, instead of four, and by having unbeaded spiral cords on the base.

Occurrence

Lower Paleogene, Cuenca Member, Caballas Formation, East Pisco Basin, southern Peru.

Figures

Figure 4. Gastropods from the Caballas Formation. (a–e) Nerita squatina sp. nov., B8771. (a) UWBM 107577, holotype, W 5.7 mm, spire. (b) UWBM 107648, paratype, W 8.5 mm, shoulder of last whorl. (c) UWBM 107649,paratype, W 10.1 mm, anterior of outer lip.(d) UWBM 107647,paratype,W 7.8 mm,inner surface of outer lip. (e) UWBM 107646, paratype, W 6.2 mm, columnar teeth. (f) Calyptraea cf. C. aperta Solander, 1766, UWBM 107578, B8772,W (diameter) 9.9 mm, external mould. (g) Ampullina ortoni Gabb, 1870, UWBM 107,627, B8772, L 36.8 mm, abapertural view, last whorl mostly missing; left margin annotated. (h–l) Melanella indicaformis sp. nov. (h) UWBM 107620, paratype, B8772, L 8.2 mm, apertural view. (i) UWBM 107619, paratype, B8769, L 9.4 mm, apertural/lateral view. (j) UWBM 107623, paratype, B8769,L 8.2 mm, apertural view. (k) UWBM 107618, paratype, B8772, L 10.6, abapertural view. (l) UWBM 107617, holotype, B8769, L 11.1 mm, abapertural view. (m–q) Potamides henryi sp. nov. (m) UWBM 107582, holotype, B8772, L 17.8 mm, lateral view. (n) UWBM 107582, W 6.9 mm, basal view. (o) UWBM 107586, paratype, B8771, L 11.2 mm, lateral view. (p) UWBM 107587, paratype, B8769, L 9.5 mm, abapertural view. (q) UWBM 107650, paratype, B8770, L 15.4 mm, lateral view, shell compressed. (r–t) Potamides janeae sp. nov., B8771.(r) UWBM 107579, holotype, L 9.0 mm, lateral view. (s) MUSM INV 249, L 8.8 mm, lateral and columellar view. (t) UWBM 107580, L 9.5 mm, layeral and columellar view. (u, v, x) Papposilenus utriculus gen.nov., sp. nov. (u) UWBM 107592,paratype, B8772, L 18.7 mm, oblique view of base. (v) UWBM 107589, holotype, B8772, L 25.5 mm, lateral view. (x) UWBM 107590, B8770, L 17.6 mm, lateral view.(w, y,z,jj) Rhinotamides everriculum sp.nov. (w) UWBM 107598,paratype, B8772,L 23.5 mm, abapertural view, juvenile. (y) UWBM 107593, holotype, B8769, L 21.1 mm, abapertural view. (z) UWBM 107594, paratype, B8772, L 19.4 mm, apertural view, posterior and anterior missing. (jj) UWBM 107593, apertural view.(aa,bb) Terebralia pauli gen. nov.sp.nov., UWBM 107599,holotype,B8771, L 9.2 mm.(aa) Abapertural view. (bb) Apertural view, outer lip missing. (cc) Terebralia marki gen. nov. sp. nov., UWBM 107600, holotype, B8771, L 9.8, lateral view. (dd–ii). Nodifaunus gainesi sp. nov. (dd) UWBM 107609, holotype, B8769, L 42.4 mm, apertural view. (ee) MUSM INV 264, paratype, B8772, L 31.0 mm, apertural view, anterior missing. (ff) UWBM 107609, abapertural view. (gg) UWBM 107612, paratype, B8770, L 14.2 mm, abapertural view, juvenile. (hh) UWBM 107612, apertural view. (ii) UWBM 107610, paratype, B8769, L 25.9 mm, apertural view, anterior missing.