Protobranchia

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title: "Protobranchia" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["bivalve-taxonomy", "mollusc-subclasses"] description: "Subclass of bivalves" topic_path: "general/bivalve-taxonomy" source: "https://en.wikipedia.org/wiki/Protobranchia" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Subclass of bivalves ::

| image = Acila cobboldiae.jpg | image_caption = Two views of a left valve of Acila cobboldiae from the early Pleistocene of the Netherlands | taxon = Protobranchia | authority = Pelseneer, 1889 | subdivision_ranks = Orders | subdivision = Nuculanida

Nuculida

Solemyida | synonyms = Palaeotaxodonta

Protobranchia is a subclass of bivalve molluscs. It contains the extant orders Nuculanida, Nuculida, and Solemyida.

These are deep water clams of a small and primitive order with a taxodont hinge (composed of many similar, small teeth), generally with a central ligament pit, large labial palps which are used in deposit feeding and the gills used only for respiration, the anterior and posterior adductor muscles are nearly equal in size, a foot which is divided sagittally and longitudinally with papillate margins. The foot in Protobranchia clams is without a true byssus gland, although they frequently have a nonhomologous byssal gland in the heel. The byssal gland in these clams does not produce threads as in Pteriomorphia.

2010 Taxonomy

In 2010 a new proposed classification system for the Bivalvia was published by Bieler, Carter & Coan revising the classification of the Bivalvia, including the subclass Protobranchia.

Subclass: Protobranchia

Order: [[Nuculanida]]

Source:

• Superfamily: Nuculanoidea
  • Family: Bathyspinulidae
  • Family: Lametilidae accepted as Phaseolidae
  • Family: Malletiidae
  • Family: Neilonellidae
  • Family: Nuculanidae
  • Family: Siliculidae
  • Family: Tindariidae
  • Family: Yoldiidae

Order: [[Nuculida]]

Source:

• Superfamily: Nuculoidea
  • Family: Nuculidae
  • Family: Sareptidae

Order: [[Solemyida]]

Source:

• Superfamily: Manzanelloidea
  • Family: Manzanellidae
  • Family: Nucinellidae
• Superfamily: Solemyoidea
  • Family: Solemyidae

Order: † [[Praecardiida]]

• Family: † Butovicellidae
  • Genus: † Butovicella
• Family: † Praecardiidae
  • Genus: † Slava
  • Genus: † Cardiola
• Family: † Antipleuridae
  • Genus: † Dualina
  • Genus: † Hercynella

References

References

1. {{WRMS species. 106. ''Protobranchia'' Pelseneer, 1889. 8 July 2010
2. Barnes, Robert D.. (1982). "Invertebrate Zoology". Holt-Saunders International.
3. Bieler, R., Carter, J.G. & Coan, E.V. (2010) ''Classification of Bivalve families''. Pp. 113-133, in: Bouchet, P. & Rocroi, J.P. (2010), ''Nomenclator of Bivalve Families. Malacologia'' 52(2): 1-184
4. {{WRMS species. 203. ''Nuclanoida'' Carter, D.C. Campbell & M.R. Campbell, 2000. 9 October 2010
5. {{WRMS species. 382247. ''Nuculida'' Dall, 1889. 20 September 2010
6. {{WRMS species. 22629. ''Solemyoida'' Dall, 1889. 9 July 2010

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