Orthotetida

Triplesia insularis, copyright Mare Isakar.

Belongs within: Rhynchonelliformea.
Contains: Davidsoniacea.

The Orthotetida were a Palaeozoic lineage of strophomenate brachiopods that are first recorded from the Ordovician. The basal genus Tetraphalerella possesses uncored pseudopunctae composed of concentric shell folds and arranged in radial rows; such structures are absent in the Davidsoniacea and Triplesiidae (Dewing 2004).

Characters (from Dewing 2004): Shell microstructure laminar, pseudopuncta present or absent, taleolae and muscle attachment pits absent. Cardinal process bilobed. Socket plates thin, upwardly concave sheets, forming long, high-socket ridges extending beyond posterior platform.

<==Orthotetida
    |--Tetraphalerella Wang 1949 D04, M-WW65
    |    |--*T. cooperi Wang 1949 M-WW65
    |    `--T. hecuba (Billings 1860) D04
    `--+--Davidsoniacea D04
       `--Triplesiidae WW65 [Tripleciinae, Triplesiacea, Triplesiida, Triplesiidina D04, Triplesiinae, Triplesioidea]
            |--Brachymimulus Cockerell 1929 [=Mimulus Barrande 1879 nec Linnaeys 1753 (ICBN) nec Stimpson 1860] WW65
            |    `--*B. perversus (Barrande 1879) [=*Mimulus perversus] WW65
            |--Epacroplecia Williams 1962 WW65
            |    `--*E. grayiae (Davidson 1870) [=Triplesia grayiae] WW65
            |--Onychoplecia Cooper 1956 WW65
            |    `--*O. brevirostris Cooper 1956 WW65
            |--Onychotreta Ulrich & Cooper 1936 WW65
            |    `--*O. mesleri Ulrich & Cooper 1936 WW65
            |--Oxoplecia Wilson 1913 [incl. California Bassler 1915 (n. n.)] WW65
            |    `--*O. calhouni Wilson 1913 WW65
            |--Plectotreta Ulrich & Cooper 1936 WW65
            |    `--*P. lindstroemi Ulrich & Cooper 1936 WW65
            |--Streptis Davidson 1881 WW65
            |    `--*S. grayi (Davidson 1848) [=Terebratula grayi] WW65
            |--Bicuspina Havlíček 1950 WW65
            |    |--*B. cava (Barrande 1848) [=Orthis cava] WW65
            |    `--B. spiriferoides WW65
            |--Cliftonia Foerste 1909 non Harvey 1859 (ICBN) WW65
            |    |--*C. striata Foerste 1909 WW65
            |    `--C. bellula WW65
            `--Triplesia Hall 1859 [=Triplecia Hall & Clarke 1892; incl. Dicraniscus Meek 1872] WW65
                 |--*T. extans (Emmons 1842) [=Atrypa extans] WW65
                 |--T. anticostiensis Twenhofel 1928 D04
                 |--T. insularis WW65
                 `--‘*Dicraniscus’ ortoni Meek 1872 WW65

*Type species of generic name indicated

REFERENCES

[D04] Dewing, K. 2004. Shell structure and its bearing on the phylogeny of Late Ordovician–Early Silurian strophomenoid brachiopods from Anticosti Island, Québec. Journal of Paleontology 78: 275–286.

[M-WW65] Muir-Wood, H., & A. Williams. 1965. Strophomenida. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda vol. 1 pp. H361–H521. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas Press: Lawrence (Kansas).

[WW65] Williams, A., & A. D. Wright. 1965. Orthida. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt H. Brachiopoda vol. 1 pp. H299–H359. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas Press: Lawrence (Kansas).