Belongs within: Tannuolinidae.
Contains: Paterinida, Linguloidea, Acrotheloidea, Ephippelasmatidae, Acrotretidae.
The Linguliformea are one of the major subgroups within the brachiopods, containing the phosphatic-shelled species. They are represented in the modern fauna by the Discinacea and Linguloidea, with the remaining subgroups being extinct. The Cambrian to Silurian Acrotretida differ from other linguliforms in having shells with columnar lamination (Holmer et al. 2002), in contrast to other groups with lamellae of a uniform composition or the baculate lamellae of the Linguloidea. The shell of acrotretidans is usually ventribiconvex, with the ventral valve commonly conical to subconical. In life, the musculature was most likely reduced relative to other brachiopods (Holmer & Popov 2000).
Characters (Kaesler 2000): Brachiopods with organophosphatic stratiform shells, inarticulated or with rudimentary articulation not involving teeth and sockets, outer mantle lobe without lobate cells; posterior body wall present; pedicle emerging between valves or supra-apically with extension of coelomic cavity as core; alimentary tract with anus; lophophore initially with median tentacle, lost during growth, tentacles in double row throughout ontogeny; larvae planktotrophic with variously ornamented shell, developed without mantle reversal.
<==Linguliformea [Lingulata, Lingulatea]
|--+--PaterinidaRNP03
| `--Lingulida [Atremata, Lingulacea, Mesocaulia]WCB00
| |--LinguloideaHSW02
| `--AcrotheloideaHP00
`--Acrotretida [Acrotretacea, Acrotretidina, Acrotretoidea, Neotremata]RNP03
| i. s.: Craniotreta Termier & Monod 1978 [=Craniotrata (l. c.), Graniotreta (l. c.)]HP00
| `--*C. caltepensis Termier & Monod 1978HP00
| Dzhagdicus Sobolev 1992HP00
| `--*D. sentus Sobolev 1992HP00
| Schizotretoides Termier & Monod 1978HP00
| `--*S. tauricus Termier & Monod 1978HP00
|--Curticia Walcott 1905R65 [CurticiidaeHP00]
| |--*C. elegantula Walcott 1905R65
| `--C. minuta Bell 1941HB93
|--EoconulidaeHP00
| |--Otariconulus Holmer & Popov 2000 [=Otariella Popov & Holmer 1994 non Waterhouse 1978]HP00
| | `--*O. priscus (Popov & Holmer 1994) [=*Otariella prisca]HP00
| |--Undiferina Cooper 1956HP00
| | |--*U. rugosa Cooper 1956R65
| | `--U. nevadensisHP00
| `--Eoconulus Cooper 1956HP00
| |--*E. rectangulatus Cooper 1956R65
| |--E. clivosusHP00
| |--E. cryptomyus Gorjansky 1969HB93
| `--E. semiregularisWBM97
`--+--Scaphelasmatidae [Scaphelasmatinae]HP00
| |--Artiotreta Ireland 1961R65
| | `--*A. parva Ireland 1961R65
| |--Rhysotreta Cooper 1956R65
| | `--*R. corrugata Cooper 1956R65
| |--Eoscaphelasma Koneva, Popov & Ushatinskaya in Koneva et al. 1990HP00
| | `--*E. satpakensis Koneva, Popov & Ushatinskaya in Koneva et al. 1990HP00
| |--Batenevotreta Ushatinskaya 1992HP00
| | `--*B. formosa Ushatinskaya 1992HP00
| |--Tobejalotreta Koneva, Popov & Ushatinskaya in Koneva et al. 1990HP00
| | `--*T. aseptata Koneva, Popov & Ushatinskaya in Koneva et al. 1990HP00
| `--Scaphelasma Cooper 1956R65
| |--*S. septatum Cooper 1956R65
| `--S. micaW97
`--+--Biernatidae [Biernatinae]HP00
| |--Opsiconidion Ludvigsen 1974 [incl. Caenotreta Cocks 1979]HP00
| | |--*O. arcticon Ludvigsen 1974HP00
| | `--O. aldridgei (Cocks 1979)W97, HP00 [=*Caenotreta aldridgeiHP00]
| `--Biernatia Holmer 1989HP00
| |--*B. rossica (Gorjansky 1969) [=Torynelasma minor rossicum]HP00
| `--B. holmiWBM97
`--+--EphippelasmatidaeHP00
`--+--+--AcrotretidaeHP00
| `--Ceratretidae [Ceratretinae]HP00
| |--Ceratreta Bell 1941R65
| | `--*C. hebes Bell 1941R65
| |--Kleithriatreta Roberts in Roberts & Jell 1990HP00
| | `--*K. lamellosa Roberts in Roberts & Jell 1990HP00
| |--Bozshakolia Ushatinskaya in Ushatinskaya, Gidaspov & Riazantsev 1986HP00
| | `--*B. coniformis Ushatinskaya in Ushatinskaya, Gidaspov & Riazantsev 1986HP00
| |--Erbotreta Holmer & Ushatinskaya 1994HP00
| | `--*E. singularis Holmer & Ushatinskaya 1994HP00
| `--Keyserlingia Pander in von Helmersen 1861 (see below for synonymy)HP00
| |--*K. reversa (de Verneuil 1845) [=Orbicula reversa]R65
| `--K. buchii (de Verneuil 1845) [=Orbicula buchii, *Clistotrema buchii, *Orbicella buchii]HP00
`--Torynelasmatidae [Torynelasmatinae]HP00
| i. s.: Cristicoma Popov in Nazarov & Popov 1980HP00
| `--*C. sincera Popov in Nazarov & Popov 1980HP00
| Acrotretella Ireland 1961R65
| `--*A. siluriana Ireland 1961R65
| Mylloconotreta Williams & Curry 1985HP00
| `--*M. elimata Williams & Curry 1985HP00
| Paratreta Biernat 1973HP00
| `--*P. similis Biernat 1973HP00
| Sasyksoria Popov & Holmer 1994HP00
| `--*S. rugosa Popov & Holmer 1994HP00
|--Torynelasma Cooper 1965HP00, R65
| `--*T. toryniferum Cooper 1965R65
`--+--Issedonia Popov in Nazarov & Popov 1980HP00
| `--*I. spinosa Popov in Nazarov & Popov 1980HP00
`--Polylasma Popov in Nazarov & Popov 1980HP00
`--*P. subsciduum Popov in Nazarov & Popov 1980HP00
Keyserlingia Pander in von Helmersen 1861 [=Kayserlingia Beecker 1891; incl. Clistotrema Rowell 1963, Orbicella d’Orbigny 1847 non Dana 1846]HP00
*Type species of generic name indicated
References
[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).
[HSW02] Holmer, L. E., C. B. Skovsted & A. Williams. 2002. A stem group brachiopod from the Lower Cambrian: support for a Micrina (halkieriid) ancestry. Palaeontology 45 (5): 875–882.
[RNP03] Robson, S. P., G. S. Nowlan & B. R. Pratt. 2003. Middle to Upper Cambrian linguliformean brachiopods from the Deadwood Formation of subsurface Alberta and Saskatchewan, Canada. Journal of Paleontology 77 (2): 201–211.
[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).
[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).
[WBM97] Williams, A., C. H. C. Brunton & D. I. MacKinnon. 1997. Morphology. In: Kaesler, R. L. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda, Revised vol. 1. Introduction pp. 321–422. The Geological Society of America: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).
[WCB00] Williams, A., S. J. Carlson & C. H. C. Brunton. 2000. Brachiopod classification. In: Kaesler, R. L. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda, Revised vol. 2. Linguliformea, Craniiformea, and Rhynchonelliformea (part) pp. 1–27. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).