Polycopidae

Unidentified Polycopidae, copyright Agnieszka Mackiewicz.

Belongs within: Halocyprida.

The Polycopidae are a group of small ostracods with the first and second antennae modified for swimming, and the thoracic limbs reduced in number (Benson et al. 1961). Though fossils have been assigned to this family going back to the earliest Carboniferous, the record is discontinuous with no known representatives for most of the intervening period (Whatley et al. 1993).

Characters (from Benson et al. 1961): Mostly rather small, less than 0.8 mm (except some doubtful Palaeozoic taxa). Carapace subcircular in lateral outline, without gape of any kind; muscle scar pattern composed of three closely juxtaposed scars. Eyes absent. First antennae (antennules) natatory, not geniculate, terminated by small bundle of long setae. Second antennae biramous, both rami fully evolute, mobile and natatory. Mandibles bearing short, very small, pediform palp that serves as a branchial appendage. Two pairs of thoracic limbs present; anterior pair large, bifid, natatory; posterior pair membranous and branchial. Postabdomen divided into two furcal rami pointed posteriorly.

<==Polycopidae [Polycopoidea]
    |  i. s.: ‘Discoidella’ spaerula (Gründel 1961) WSB93
    |--Parapolycope Klie 1936 DH86
    |    |--*P. germanica Klie 1936 BB61
    |    |--P. kunashiri Chavtur 1977 DH86
    |    `--P. rossica Chavtur 1977 DH86
    |--Polycopsis Müller 1894 DH86
    |    |--*P. compressa (Brady & Robertson 1869) [=Polycope compressa] BB61
    |    |--P. pacifica Chavtur 1977 DH86
    |    `--P. serrata Müller 1894 DH86
    `--Polycope Sars 1866 ZL87 [incl. Cypridinopsis Armstrong 1871 BB61]
         |--*P. orbicularis Sars 1866 BB61
         |--P. aidae Hartmann 1959 DH86
         |--P. angulata Chavtur 1977 DH86
         |--P. antarctica Müller 1908 DH86
         |--P. arenicola Hartmann 1954 DH86
         |--P. areolata Sars 1923 DH86
         |--P. bahamensis Kornicker 1959 DH86
         |--P. brevis Müller 1908 DH86
         |--P. cancellea Hartmann 1954 DH86
         |--P. corallicola Hartmann 1974 DH86
         |--P. coralligena Bonaduce, Ciliberto et al. 1982 DH86
         |--P. crassidenta Chavtur 1977 DH86
         |--P. demulderi Sissingh 1972 DH86
         |--P. dentata Brady 1868 DH86
         |--P. denticulata Bonaduce, Masoli et al. 1980 DH86
         |--P. difficilis Klie 1936 DH86
         |--P. dimorpha Hartmann 1954 DH86
         |--P. dispar Müller 1894 DH86
         |--P. duplidentata Hartmann 1959 DH86
         |--P. elongata Hartmann 1954 DH86
         |--P. essybaiensis Hartmann 1974 DH86
         |--P. fragilis Müller 1894 DH86
         |--P. frequens Müller 1894 DH86
         |--P. gongxianensis Zhang in Zhang & Liang 1987 ZL87
         |--P. helgolandica Klie 1936 DH86
         |--P. krylatcki Chavtur 1977 DH86
         |--P. kurilensis Chavtur 1977 DH86
         |--P. levis Hartmann 1954 DH86
         |--P. limbata Hartmann 1954 DH86
         |--P. longipes Hartmann 1954 DH86
         |--P. loscobanosi Hartmann 1959 DH86
         |--P. maculata Müller 1894 DH86
         |--P. marci Hartmann 1954 DH86
         |--P. microdispar Hartmann 1954 DH86
         |--P. minuta Hartmann 1974 DH86
         |--P. minutissima Hartmann 1974 DH86
         |--P. noodti Hartmann 1959 DH86
         |--P. obtusa Hartmann 1954 DH86
         |--P. onkophora Hartmann 1954 DH86
         |--P. ornata Bonaduce, Masoli et al. 1980 DH86
         |--P. paramushiri Chavtur 1977 DH86
         |--P. parareticulata Bonaduce, Ciampo & Masoli 1975 DH86
         |--P. pseudoorbicularis Chavtur 1977 DH86
         |--P. pseudoputjatini Chavtur 1977 DH86
         |--P. putjatini Chavtur 1977 DH86
         |--P. quasisymmetrica Hartmann 1974 DH86
         |--P. ramosa Hartmann 1954 DH86
         |--P. ramunchensis Hartmann 1962 DH86
         |--P. reticulata Müller 1894 DH86
         |--P. rostrata Müller 1894 DH86
         |--P. schulzi Klie 1950 DH86
         |--P. seridentata Hartmann 1959 DH86
         |--P. siewingi Hartmann 1958 DH86
         |--P. striata Müller 1894 DH86
         |--P. sublaevis BB61
         |--P. teneriffae Hartmann 1959 DH86
         `--P. tuberosa Müller 1894 DH86

*Type species of generic name indicated

REFERENCES

[BB61] Benson, R. H., J. M. Berdan, W. A. van den Bold, T. Hanai, I. Hessland, H. V. Howe, R. V. Kesling, S. A. Levinson, R. A. Reyment, R. C. Moore, H. W. Scott, R. H. Shaver, I. G. Sohn, L. E. Stover, F. M. Swain & P. C. Sylvester-Bradley. 1961. Systematic descriptions. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt Q. Arthropoda 3: Crustacea: Ostracoda pp. Q99–Q421. Geological Society of America and University of Kansas Press.

[DH86] Danielopol, D. L., & G. Hartmann. 1986. Ostracoda. In: Botosaneanu, L. (ed.) Stygofauna Mundi: A Faunistic, Distributional, and Ecological Synthesis of the World Fauna inhabiting Subterranean Waters (including the Marine Interstitial) pp. 265–294. E. J. Brill/Dr W. Backhuys: Leiden.

[WSB93] Whatley, R. C., D. J. Siveter & I. D. Boomer. 1993. Arthropoda (Crustacea: Ostracoda). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 343–356. Chapman & Hall: London.

[ZL87] Zhang X.-J. & Liang X.-Y. 1987. Ostracoda from the Taiyuan Formation of Xingyang and Gong Xian districts, Henan. Acta Micropalaeontologica Sinica 4 (3): 293–312.

Last updated: 19 October 2020.