Paskentana globosa, Kiel & Campbell & Elder & Little, 2008
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publication ID |
https://doi.org/ 10.4202/app.2008.0412 |
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persistent identifier |
https://treatment.plazi.org/id/03DC9B54-FFEF-3374-FCD0-43477FF8C87C |
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treatment provided by |
Felipe |
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scientific name |
Paskentana globosa |
| status |
sp. nov. |
Paskentana globosa sp. nov.
Fig. 7D–G View Fig .
Etymology: The species is named for its globose shell shape.
Type material: Holotype: CAS 70394 About CAS , large specimen with last whorl and most of the aperture preserved; paratype: UCMP 555101 View Materials from Little Indian Valley (site 6), California, USA.
Type locality: Knoxville , Napa County, California, USA .
Type horizon: Specific horizon in Great Valley Group unknown .
Material.— Type material and four specimens from Knoxville (site 9).
Diagnosis.—Delicate shell with inflated last whorl; whorls convex, numerous spiral cords on periphery and base; growth lines with slight opisthocyrt sinus on apical part of whorl and straight to slightly prosocline below; aperture roundish, slightly pointed apically, columella smooth and concave with respect to aperture.
Description.—Medium sized littoriniform shell, suture shallow but distinct; sculpture of numerous (45–50 on last whorl) spiral cords that are slightly more widely spaced on periphery than near suture, this sculpture continues uninterrupted across well−rounded basal margin onto base; base of aperture and possible siphonal feature unknown. Height of holotype 40 mm.
Discussion.— Paskentana globosa sp. nov. differs from P. paskentaensis by its more globose shell, the less incised suture, and by the more regular ornament of numerous thin spiral cords. Paskentana berryessaensis sp. nov. has coarser sculpture and a larger whorl expansion rate.
Stratigraphic and geographic range.—Early Cretaceous (?), in seep carbonates in the Great Valley Group (Knoxville, site 9) and Franciscan Group (Valanginian, Little Indian Valley , site 6), California, USA.
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