Belongs within: Linguloidea.
The Discinoidea are a lineage of brachiopods exhibiting holoperipheral growth on the ventral valve, known from the Ordovician to the present (Holmer & Popov 2000).
Characters (Holmer & Popov 2000): Growth of ventral valve holoperipheral; larval shell smooth, large (about 0.5 mm across), lacking pedicle notch; pedicle opening in young, postlarval stages forming triangular notch in posterior margin of ventral valve; adult pedicle opening may be closed posteriorly or extend to margin of shell; anterior end of track of pedicle opening usually closed by listrium; ventral valve lacking well-defined pseudointerarea; muscle system with paired posterior and anterior adductors and three pairs of oblique muscles; posterolateral muscle fields in ventral valve situated posterior to umbo; mantle canal system bifurcate in recent stocks; vascula media well developed.
<==Discinoidea [Discinacea, Discinida]
| i. s.: Heliomedusa Sun & Hou 1987C12, PH00
| `--*H. orienta Sun & Hou 1987PH00
|--Trematidae [Ptychopeltidae]HP00
| |--Drabodiscina Havlíček 1972HP00
| | `--*D. grandis (Barrande 1879) [=Discina grandis]HP00
| |--Tethyrete Havlíček 1994HP00
| | `--*T. frigerum Havlíček 1994HP00
| |--Schizobolus Ulrich 1886 [incl. Ljaschenkovia Batrukova 1969]HP00
| | |--S. concentricus (Vanuxem 1842) (see below for synonymy)R65
| | `--‘*Ljaschenkovia’ udmurtica Batrukova 1969HP00
| |--Trematis Sharpe 1848R65
| | |--*T. terminalis (Emmons 1842) [=Orbicula terminalis]R65
| | |--T. millipunctataR65
| | |--T. punctataW77
| | `--T. silurianaW77
| `--Schizocrania Hall & Whitfield 1875 (see below for synonymy)HP00
| |--*S. filosa (Hall 1847) [=Orbicula filosa]R65
| |--‘*Orbiculothyris’ costellata Wolfart in Wolfart, Bender & Stein 1968HP00
| |--S. helderbergensis (Hall 1892)HB93
| |--‘*Ptychopeltis’ incola Perner 1903R65
| `--S. salopiensis Williams 1974HB93
`--Discinidae [Acrosaccidae, Discininae, Disciniscinae, Orbiculidae, Orbiculoideinae]HP00
|--Oehlertella Hall & Clarke 1890R65
| `--*O. pleurites (Meek 1875) [=Discina pleurites]R65
|--Pelagodiscus Dall 1908R65
| `--*P. atlanticus (King 1868) [=Discina atlantica]R65
|--Lindstroemella Hall & Clarke 1890 [=Lindstoemelia Dunbar & Condra 1932, Lindstromella Hall & Clarke 1889 (n. n.)]HP00
| `--*L. aspidium Hall & Clarke 1890R65
|--Roemerella Hall & Clarke 1890R65
| `--*R. grandis (Vanuxem 1842) [=Orbicula grandis]R65
|--Chrustenotreta Havlíček 1994HP00
| `--*C. chrustenica Havlíček 1994HP00
|--Kosoidea Havlíček & Mergl 1988HP00
| `--*K. fissurella Havlíček & Mergl 1988HP00
|--Lochkothele Havlíček & Mergl 1988HP00
| `--*L. intermedia (Barrande 1879) [=Discina intermedia]HP00
|--Schizotretinia Havlíček 1994HP00
| `--*S. euxina Havlíček 1994HP00
|--Lingulodiscina Whitfield 1890R65
| |--*L. exilis (Hall 1860) [=Lingula exilis]R65
| `--L. marginalisMB12
|--Schizotreta Kutorga 1848R65
| |--*S. ‘elliptica’ Kutorga 1846 [=Orbicula elliptica non d’Archiac 1843]R65
| `--S. corrugataR65
|--Acrosaccus Willard 1928HP00
| |--*A. shuleri Willard 1928R65
| `--A. willardiHP00
|--Discradisca Stenzel 1964HP00
| |--*D. antillarum (d’Orbigny 1845) [=Orbicula antillarum]HP00
| |--D. laevisE97
| `--D. strigataE97
|--Discina Lamarck 1819R65
| |--D. striata (Schumacher 1817) [=Crania striata; incl. *D. ostreoides Lamarck 1819]R65
| |--D. cumingiiC64
| `--D. humilisBF86
|--Discinisca Dall 1871R65
| |--*D. lamellosa (Broderip 1833) [=Orbicula lamellosa]R65
| |--D. laevisWR65
| |--D. strigataPR97
| `--D. tenuisCG97
`--Orbiculoidea d’Orbigny 1847R65
|--*O. forbesii (Davidson 1848) [=Orbicula forbesii]HP00
|--O. donetzensisG31
|--O. koninckiiG31
|--O. mediorhenanaWJ97
|--O. missouriensisG31
|--O. nitidaW97
|--O. papulaG31
|--O. spitzbergensisG31
`--O. subovalis Biernat 1973HB93
Schizobolus concentricus (Vanuxem 1842) [=Lingula concentrica; incl. Discina truncata Hall 1863, *Schizobolus truncatus]R65
Schizocrania Hall & Whitfield 1875 [incl. Orbiculothyris Wolfart in Wolfart, Bender & Stein 1968, Ptychopeltis Perner 1903]HP00
*Type species of generic name indicated
References
[BF86] Babcock, L. E., & R. M. Feldmann. 1986. Devonian and Mississippian conulariids of North America. Part A. General description and Conularia. Annals of Carnegie Museum 55 (15): 349–410.
[C64] Carpenter, P. P. 1864. Supplementary report on the present state of our knowledge with regard to the Mollusca of the west coast of North America. Report of the British Association for the Advancement of Science 33: 517–686.
[C12] Chen, J.-Y. 2012. Evolutionary scenario of the early history of the animal kingdom: evidence from Precambrian (Ediacaran) Weng’an and Early Cambrian Maotianshan biotas, China. In: Talent, J. A. (ed.) Earth and Life: Global biodiversity, extinction intervals and biogeographic perturbations through time pp. 239–379. Springer.
[CG97] Cohen, B. L., & A. B. Gawthrop. 1997. The brachiopod genome. In: Kaesler, R. L. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda, Revised vol. 1. Introduction pp. 189–211. The Geological Society of America: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).
[E97] Emig, C. C. 1997. Ecology of inarticulated brachiopods. In: Kaesler, R. L. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda, Revised vol. 1. Introduction pp. 473–495. The Geological Society of America: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).
[G31] Grabau, A. W. 1931. The Permian of Mongolia: A report on the Permian fauna of the Jisu Honguer limestone of Mongolia and its relations to the Permian of other parts of the world. American Museum of Natural History: New York.
[HB93] Harper, D. A. T., C. H. C. Brunton, L. R. M. Cocks, P. Copper, E. N. Doyle, A. L. Jeffrey, E. F. Owen, M. A. Parkes, L. E. Popov & C. D. Prosser. 1993. Brachiopoda. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 427–462. Chapman & Hall: London.
[HP00] Holmer, L. E., & L. E. Popov. 2000. Lingulata. In: Kaesler, R. L. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda, Revised vol. 2. Linguliformea, Craniiformea, and Rhynchonelliformea (part) pp. 30–146. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).
[MB12] Mistiaen, B., D. Brice, M. K. Zapalski & C. Loones. 2012. Brachiopods and their auloporid epibionts in the Devonian of Boulonnais (France): comparison with other associations globally. In: Talent, J. A. (ed.) Earth and Life: Global biodiversity, extinction intervals and biogeographic perturbations through time pp. 159–188. Springer.
[PR97] Peck, L. S., M. C. Rhodes, G. B. Curry & A. D. Ansell. 1997. Physiology. In: Kaesler, R. L. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda, Revised vol. 1. Introduction pp. 213–242. The Geological Society of America: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).
[PH00] Popov, L. E., & L. E. Holmer. 2000. Craniopsida. In: Kaesler, R. L. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda, Revised vol. 2. Linguliformea, Craniiformea, and Rhynchonelliformea (part) pp. 164–168. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).
[R65] Rowell, A. J. 1965. Inarticulata. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda vol. 1 pp. H260–H296. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas Press: Lawrence (Kansas).
[W77] White, C. A. 1877. Report upon the invertebrate fossils collected in portions of Nevada, Utah, Colorado, New Mexico, and Arizona, by parties of the expeditions of 1871, 1872, 1873, and 1874. U.S. Geographical Surveys West of the One Hundredth Meridian 4 (1): 1–219, pls 1–21.
[W97] Williams, A. 1997. Shell structure. In: Kaesler, R. L. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda, Revised vol. 1. Introduction pp. 267–320. The Geological Society of America: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).
[WJ97] Williams, A., M. A. James, C. C. Emig, S. Mackay & M. C. Rhodes. 1997. Anatomy. In: Kaesler, R. L. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda, Revised vol. 1. Introduction pp. 7–188. The Geological Society of America: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).
[WR65] Williams, A., & A. J. Rowell. 1965. Brachiopod anatomy. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda vol. 1 pp. H6–H57. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas Press: Lawrence (Kansas).