Published December 31, 2019 | Version v1
Taxonomic treatment Open

Plesiothyreus Cossmann 1888

Description

PLESIOTHYREUS COSSMANN, 1888

Scutella Broderip, 1834: 47 (in part; not Lamarck, 1816). Type species: Scutella crenulata Broderip, 1834: 48 (Anaa, Tuamotu Archipelago, French Polynesia; three syntypes BMNH) [a probable junior synonym of Pileopsis cytherae Lesson, 1831: 387 (Matavai Bay, Tahiti, French Polynesia; holotype or a syntype MNHN-IM-2000-32564)], by subsequent indication by synonymy under Scutellina Gray.

Scutellina Gray, 1847: 168 (not Agassiz, 1841; replacement name for Scutella Broderip, 1834). Type species: Scutella crenulata Broderip, 1834 by original designation.

Plesiothyreus Cossmann, 1888: 191. Type species: Capulus parmophoroides Cossmann, 1885: 198; pl. 8, fig. 2 (Eocene, Paris Basin, France; type unknown), by original designation.

Phenacolepas Pilsbry, 1891: 89 (replacement name for Scutellina Gray, 1847).

Scutulina Cossmann, 1912: 214 (replacement name for Scutellina Gray, 1847).

Cinnalepeta Iredale, 1929: 274. Type species: Patella cinnamomea Gould, 1846: 151 (New South Wales, Australia; holotype USNM 5837), by original designation.

Remarks: The Eocene type species Plesiothyreus parmophoroides closely resembles certain Recent shells in shape and ornamentation, including that of Plesiothyreus newtoni Sowerby III, 1894. The close phylogenetic kinship among Pl. newtoni, ‘ Pileopsiscytherae Lesson, 1831 (type of Phenacolepas Pilsbry, 1891) and ‘ Patellacinnamomea Gould, 1846 (type of Cinnalepeta Iredale, 1929) leaves no doubt as to the synonymy of the latter two genera under the oldest Plesiothyreus Cossmann, 1888 (Fig. 1). The synonymous relationship between Plesiothyreus and Phenacolepas has already been suggested from a conchological point of view by Christiaens (1989). Regardless, the family name Phenacolepadidae based on Phenacolepas remains in accordance with current classification (see ICZN Article 40.1).

This genus contains several extant species that are characterized by a large (> 8 mm), conical or capshaped shell. The ventral side of the shell has a row of denticles on a slightly raised keel along the apertural rim (Fig. 5A, B; see also Cossmann, 1885: pl. 8, fig. 2; Christiaens, 1989: 21), although this feature is lacking in Plesiothyreus cinnamomeus and its junior synonym Plesiothyreus pulchellus (Lischke, 1871). Masculine.

Notes

Published as part of Fukumori, Hiroaki, Yahagi, Takuya, Warén, Anders & Kano, Yasunori, 2019, Amended generic classification of the marine gastropod family Phenacolepadidae: transitions from snails to limpets and shallow-water to deep-sea hydrothermal vents and cold seeps, pp. 636-655 in Zoological Journal of the Linnean Society 185 on page 647

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Linked records

Additional details

Biodiversity

References

  • Cossmann MM. 1888. Catalogue illustre des coquilles fossiles de l'Eocene des environs de Paris. Annales de la Societe Royale Malacologique de Belgique 23: 3-320 + pls. 1 - 12.
  • Broderip WJ. 1834. Description of a new genus of Gastropoda. Proceedings of the Zoological Society of London 2: 47-49.
  • Lamarck J-B. 1816. Histoire naturelle des animaux sans vertebres, presentant les caracteres generaux et particuliers de ces animaux, leur distribution, leurs classes, leurs familles, leurs genres, et la citation des principales especes qui s'y rapportent; precedee d'une Introduction offrant la determination des caracteres essentiels de l'Animal, sa distinction du vegetal et des autres corps naturels, enfin, l'exposition des principes fondamentaux de la Zoologie. Tome troisieme. Paris: Verdiere.
  • Lesson A. 1831. Mollusque, Annelides et Vers recueillis. In: Duperrey MLI, ed. Voyage autour du monde execute par ordre du roi sur la corvette de S. M. La Coquille pendant les annees 1822, 1823, 1824, et 1825, ser. Zoologie (par M. Lesson), Vol. 2. Paris: Arthus Bertrand, 239-471 + pls. 1 - 16.
  • Gray JE. 1847. A list of the genera of Recent Mollusca, their synonyma and types. Proceedings of the Zoological Society of London 15: 129-219.
  • Agassiz L. 1841. Monographies d'Echinodermes vivans et fossiles. Echinites. Famille des Clypeastroides. Seconde monographie, Des Scutelles Neuchatel: L. Agassiz.
  • Cossmann MM. 1885. Description d'especes du terrain tertiaire des environs de Paris (suite). Journal de Conchyliologie 33: 197-206.
  • Pilsbry HA. 1891. On the use of the generic name Scutellina. Nautilus 5: 88-89.
  • Cossmann MM. 1912. Rectifications de nomenclature. Revue Critique de Paleozoologie 16: 213-215.
  • Iredale T. 1929. Queensland molluscan notes, no. 1. Memoirs of the Queensland Museum 9: 261-297 + pls. 30, 31.
  • Gould AA. 1846. Descriptions of new shells, collected by the United States exploring expedition, and belong to the genus Patella. Proceedings of the Boston Society of Natural History 2: 148-153.
  • Christiaens J. 1989. The Phenacolepadidae. Gastropoda: Neritoidea. Part 2. Gloria Maris 28: 17-48.