Striarca

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Striarca
White cockleshell (Striarca lactea)

White cockleshell ( Striarca lactea )

Systematics
Subclass : Pteriomorphia
Order : Arcida
Superfamily : Arcoidea
Family : Noetiidae
Subfamily : Striarcinae
Genre : Striarca
Scientific name
Striarca
Conrad , 1862
Striarca centenaria (Say, 1824), Miocene, New Jersey, USA, type species of the genus Striarca Conrad, 1862

Striarca is a shell - genus in the family noetiidae in order Arcida . There are currently six (recent) species belonging to the genus Striarca . It is the type genus of the subfamily Striarcinae.

features

The housings, which have the same flaps, are egg-shaped, oblong-egg-shaped, oblong-trapezoidal or rounded-triangular to approximately rectangular. The mostly small housings reach an adult size of five to 20 millimeters. The vertebra is shifted forward, it is more or less far in the front half of the housing. The vertebra can be slightly opisthogyr, orthogyr, or prosogyr. Due to the strongly curled vertebrae, the dorsal field can be quite wide when viewed from above. When the flaps are closed, the housings only have a small gap through which the byssus can escape.

The lock is taxodont with numerous. uniform teeth. The teeth are not interrupted by any gaps. The ligament in front of, between and behind the vertebrae is diamond-shaped and more or less long and also takes up more or less space on the dorsal field.

The whitish skin is thick and very robust. The ornamentation consists of fine to coarser radial ribs and / or concentric, more or less strong growth strips that can form a net-like pattern. The periostracum is hairy or shaggy. The surface line is not indented. The two sphincters are approximately the same size, or the posterior sphincter is slightly larger than the anterior sphincter. Low rims are formed around the muscle attachment points.

Geographical occurrence and habitat

The genus occurs worldwide in warm seas. One species also penetrates into moderate latitudes. The species of the genus Striarca mostly live in shallower water, from the tidal range to the continental slope.

Taxonomy

The taxon was proposed by Timothy Abbott Conrad in 1862 . The World Register of Marine Species assigns seven (recent) species to the genus Striarca , plus five fossil species according to the Paleobiology Database:

The World Register of Marine Species treats Gabinarca Iredale, 1939 and Galactella Cossmann & Peyrot, 1912 as synonyms .

literature

  • Markus Huber: Compendium of Bivalves. 901 S., Hackenheim, ConchBooks, 2010 ISBN 978-3-939767-28-2
  • Fritz Nordsieck : The European sea shells (Bivalvia). From the Arctic Ocean to Cape Verde, the Mediterranean Sea and the Black Sea. 256 p., Gustav Fischer Verlag, Stuttgart 1969 (p. 21 as Acar nodulosa )

Individual evidence

  1. ^ Robert Parr Whitfield: Mollusca and Crustacea of ​​the Miocene Formations of New Jersey. United States Geological Survey, Monographs, 24: 1-142, Washington, DC 1894 Online at www.biodiversitylibrary.org (p. 42)
  2. ↑ Timothy Abbot Conrad: Descriptions of New Genera, Subgenera and Species of Tertiary and Recent Shells. Proceedings of the Academy of Natural Sciences of Philadelphia, 1862: 284-291, Philadelphia 1862. Online at www.biodiversitylibrary.org (p. 290)
  3. ^ A b World Register of Marine Species: Striarca Conrad, 1862
  4. ^ Paleobiology Database Striarca Conrad 1862