Ostracod

Ostracod; Temporal range:
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Superclass:	Oligostraca
Class:	Ostracoda; Latreille, 1802
Subclasses and orders
	Myodocopa Sars, 1866 Myodocopida Sars, 1866; Halocyprida Dana, 1853; ; Podocopa Sars, 1866 Palaeocopida Henningsmoen, 1953; Platycopida Sars, 1866; Podocopida Sars, 1866; ;

Ostracods, or ostracodes, are a class of the Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 33,000 species (only 13,000 of which are extant) have been identified,^[2] grouped into 7 valid orders.^[2] They are small crustaceans, typically around 1 mm (0.04 in) in size, but varying from 0.2 to 30 mm (0.008 to 1 in) in the case of the marine Gigantocypris. The largest known freshwater species is Megalocypris princeps, which reach 8mm in length.^[3]^[4] In most cases, their bodies are flattened from side to side and protected by a bivalve-like valve or "shell" made of chitin, and often calcium carbonate. The family Entocytheridae and many planktonic forms do not have calcium carbonate.^[5]^[6] The hinge of the two valves is in the upper (dorsal) region of the body. Ostracods are grouped together based on shell and soft part morphology, and molecular studies have not unequivocally supported the group's monophyly.^[7] They have a wide range of diets, and the class includes carnivores, herbivores, scavengers and filter feeders, but most ostracods are deposit feeders.

^ Williams, Mark; Siveter, David J.; Salas, María José; Vannier, Jean; Popov, Leonid E.; Ghobadi Pour, Mansoureh (2008). "The earliest ostracods: the geological evidence". Senckenbergiana Lethaea. 88: 11–21. doi:10.1007/BF03043974. S2CID 128542158.
^ ^a ^b Brandão, S.N.; Antonietto, L.S; Nery, D.G.; Santos, S.G.; Karanovic, I. (2023). World Ostracoda Database. Accessed at https://www.marinespecies.org/ostracoda on 2023-09-12. doi:10.14284/364
^ Freshwater Life: A field guide to the plants and animals of southern Africa
^ The Triassic-Jurassic Terrestrial Transition: 37
^ Jöst, Anna B. (January 2012). Ecological Evaluation of Ostracode (Crustacea) Occurrence in the City of Munich & Phylogenetic Relationships between Ostracode Species and Populations from Bavaria (master thesis). Ludwig Maximilian University of Munich.
^ Schram, Frederick R.; Koenemann, Stefan (2022). "Ostracoda". Evolution and Phylogeny of Pancrustacea. pp. 119–140. doi:10.1093/oso/9780195365764.003.0010. ISBN 978-0-19-536576-4.
^ Oakley, Todd H.; Wolfe, Joanna M.; Lindgren, Annie R.; Zaharoff, Alexander K. (January 2013). "Phylotranscriptomics to Bring the Understudied into the Fold: Monophyletic Ostracoda, Fossil Placement, and Pancrustacean Phylogeny". Molecular Biology and Evolution. 30 (1): 215–233. doi:10.1093/molbev/mss216. PMID 22977117.

[1] Williams, Mark; Siveter, David J.; Salas, María José; Vannier, Jean; Popov, Leonid E.; Ghobadi Pour, Mansoureh (2008). "The earliest ostracods: the geological evidence". Senckenbergiana Lethaea. 88: 11–21. doi:10.1007/BF03043974. S2CID 128542158.

[:0-2] Brandão, S.N.; Antonietto, L.S; Nery, D.G.; Santos, S.G.; Karanovic, I. (2023). World Ostracoda Database. Accessed at https://www.marinespecies.org/ostracoda on 2023-09-12. doi:10.14284/364

[3] Freshwater Life: A field guide to the plants and animals of southern Africa

[4] The Triassic-Jurassic Terrestrial Transition: 37

[5] Jöst, Anna B. (January 2012). Ecological Evaluation of Ostracode (Crustacea) Occurrence in the City of Munich & Phylogenetic Relationships between Ostracode Species and Populations from Bavaria (master thesis). Ludwig Maximilian University of Munich.

[6] Schram, Frederick R.; Koenemann, Stefan (2022). "Ostracoda". Evolution and Phylogeny of Pancrustacea. pp. 119–140. doi:10.1093/oso/9780195365764.003.0010. ISBN 978-0-19-536576-4.

[oakley2013-7] Oakley, Todd H.; Wolfe, Joanna M.; Lindgren, Annie R.; Zaharoff, Alexander K. (January 2013). "Phylotranscriptomics to Bring the Understudied into the Fold: Monophyletic Ostracoda, Fossil Placement, and Pancrustacean Phylogeny". Molecular Biology and Evolution. 30 (1): 215–233. doi:10.1093/molbev/mss216. PMID 22977117.

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