Spatula clams

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Spatula clams
White bean (Thracia phaseolina)

White bean ( Thracia phaseolina )

Systematics
Subclass : Heterodonta
Euheterodonta
Superordinate : Anomalodesmata
Order :
Superfamily : Thracioidea
Family : Spatula clams
Scientific name
Thraciidae
Stoliczka , 1870

The spatula clams (Thraciidae) are a biology of the mussels . The oldest representatives of the family are known from the Jura .

features

The unevenly hinged cases are medium-sized. They are egg-shaped to oblong-egg-shaped in outline, the rear edge gapes. The rear end is often more or less pronounced, beak-like, elongated or truncated. The vertebrae are opisthogyr, orthogyr, or prosogyr. The right flap is larger and more arched than the left flap and usually towers above it. As a result, the vertebra of the left valve sits in a cavity in the vertebra of the right valve. The inner ligament sits on a spoon-shaped process (lithodesma) just below the vertebrae. Often there is also a small external ligament; it can also be absent. Lock teeth are missing. The mantle bay is usually wide and deep. The two sphincters are roughly the same size, but variable in outline. The siphons are separate and usually long. The foot is large and has no linen (any longer).

The skin is thin and aragonitic . The outer layer of the shell is granular-prismatic or columnar-prismatic, the inner layer is mostly homogeneous or dendritic-prismatic. They do not form a layer of mother-of-pearl. The ornamentation consists of lines parallel to the edge, often somewhat irregular, which can also be grainy, or the surface is almost smooth.

Geographical distribution and habitat

The family is spread around the world. The focus of diversity, however, lies in the temperate and cooler seas. The animals live deeply to shallowly buried in a tube in the sediment or lie on the sediment.

Taxonomy

The taxon was drawn up by Ferdinand Stoliczka in 1870 . MolluscaBase assigns the following genera to the family:

supporting documents

literature

  • S. Peter Dance, Rudo von Cosel (arrangement of the German edition): The great book of sea shells. 304 p., Verlag Eugen Ulmer, Stuttgart, 1977 ISBN 3-8001-7000-0 , p. 274.
  • Rudolf Kilias: Lexicon marine mussels and snails. 2nd Edition. 340 p., Verlag Eugen Ulmer, Stuttgart 1997 ISBN 3-8001-7332-8 , p. 307.
  • Raymond Cecil Moore (Ed.): Treatise on invertebrate paleontology. Mollusca, 6, Part N, Bivalvia 2. XXXVIII S., S. N491-951, New York, 1969, S. N850.
  • 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. 159.
  • Guido Poppe and Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda). 221 p., Verlag Christa Hemmen, Wiesbaden 1993, ISBN 3925919104 , p. 137 (2000 unc. Reprint)

Individual evidence

  1. ↑ Antonio Checa1, Elizabeth M. Harper, Marc Willinger: Aragonitic dendritic prismatic shell microstructure in Thracia (Bivalvia, Anomalodesmata). Invertebrate Biology, 131 (1): 19-29 doi : 10.1111 / j.1744-7410.2011.00254.x
  2. ^ Ferdinand Stoliczka: The Pelecypoda, with a review of all known genera of this class, fossil and recent. In: Paleontologia Indica, Memoirs of the Geological Survey of India. 3, SI-XXII, 1-537, Pl. 1-50, Calcutta 1870-1871 (p. 1-22, Pl. 1-12: 1870, pp. I-XXII, 223-537, Pl. 23-50 ), 1871, pp. 106, 108 ( online at www.biodiversitylibrary.org )
  3. ↑ MolluscaBase: Thraciidae Stoliczka, 1870 (1825)

Web links

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