Clavotrigonia spinulosa (G. Young & J. Bird, 1828) † accepted as Promyophorella spinulosa (G. Young & J. Bird, 1828) † (new combination reference)
Cornbrashella Ayoub-Hannaa, M. R. Cooper, Abdelhady & Fürsich, 2023 † (original description)
Cornbrashella distincta (Kitchin, 1903) † (basis of record)
Cornbrashella pullus (J. de C. Sowerby, 1826) † (basis of record)
Cotswoldella Ayoub-Hannaa, M. R. Cooper, Abdelhady & Fürsich, 2023 † (original description)
Cotswoldella asiatica (Douvillé, 1916) † (basis of record)
Cotswoldella culleni (Lycett, 1877) † (basis of record)
Cotswoldella densestriata (Behrendsen, 1892) † (basis of record)
Cotswoldella elegantissima (Meek, 1873) † (basis of record)
Cotswoldella gadoisi (Cossmann, 1911) † (basis of record)
Cotswoldella hemisphaerica (Lycett, 1853) † (basis of record)
Cotswoldella kidugalloensis (L. R. Cox, 1965) † (basis of record)
Cotswoldella langrunensis (Bigot, 1893) † (basis of record)
Cotswoldella parva (Kitchin, 1903) † (basis of record)
Cotswoldella ranvilliana (Bigot, 1893) † (basis of record)
Magharitrigonia Ayoub-Hannaa, M. R. Cooper, Abdelhady & Fürsich, 2023 † (original description)
Magharitrigonia asymmetrica Ayoub-Hannaa, M. R. Cooper, Abdelhady & Fürsich, 2023 † (original description)
Magharitrigonia brevicostata (Kitchin, 1903) † (new combination reference)
Magharitrigonia cristagalli (Bigot, 1893) † (new combination reference)
Magharitrigonia senex (Kobayashi & Mori, 1954) † (new combination reference)
Orthotrigonia L. R. Cox, 1952 † (taxonomy source)
Orthotrigonia exortiva (Kitchin, 1903) † accepted as Charigonia exortiva (Kitchin, 1903) † (basis of record)
Orthotrigonia gracilis (Kitchin, 1903) † accepted as Charigonia gracilis (Kitchin, 1903) † (basis of record)
Orthotrigonia kutchensis (Kitchin, 1903) † accepted as Charigonia kutchensis (Kitchin, 1903) † (basis of record)
Parorthotrigonia Ayoub-Hannaa, M. R. Cooper, Abdelhady & Fürsich, 2023 † (original description)
Parorthotrigonia lepidomorpha (A. M. Abdallah & Fahmi, 1969) † (basis of record)
Promyophorella spinulosa (G. Young & J. Bird, 1828) † (basis of record)
Promyophorella tuberculata (Agassiz, 1840) † (basis of record)
Retetrigonia Ayoub-Hannaa, M. R. Cooper, Abdelhady & Fürsich, 2023 † (original description)
Retetrigonia imbricata (J. de C. Sowerby, 1826) † (basis of record)
Retetrigonia parcinoda (Lycett, 1872) † (basis of record)
Trigonia castor A. d'Orbigny, 1850 † (basis of record)
Trigonia hemisphaerica lunulata Parnes, 1981 † accepted as Cotswoldella hemisphaerica (Lycett, 1853) † (source of synonymy)
Trigonia hemisphaerica var. gregaria Lycett, 1877 † accepted as Cotswoldella hemisphaerica (Lycett, 1853) † (source of synonymy)
Trigonia interlaevigata Quenstedt, 1857 † (additional source)
Trigonia meriani Agassiz, 1840 † accepted as Trigonia reticulata Agassiz, 1840 † (source of synonymy)
Trigonia monilifera Agassiz, 1840 † accepted as Trigonia reticulata Agassiz, 1840 † (source of synonymy)
Trigonia papillata Agassiz, 1840 † accepted as Trigonia reticulata Agassiz, 1840 † (source of synonymy)
Trigonia parvula Agassiz, 1840 † accepted as Trigonia reticulata Agassiz, 1840 † (source of synonymy)
Trigonia reticulata Agassiz, 1840 † (additional source)
Trigonia spinulosa G. Young & J. Bird, 1828 † accepted as Promyophorella spinulosa (G. Young & J. Bird, 1828) † (new combination reference)
Trigonia stelzneri Gottsche, 1878 † (additional source)
Trigonia sumiyagura T. Kobayashi & Kaseno, 1947 † (additional source)

Sinai for Magharitrigonia asymmetrica Ayoub-Hannaa, M. R. Cooper, Abdelhady & Fürsich, 2023 † 

 Nomenclature

 for Cotswoldella parva (Kitchin, 1903) †

The basionym, Trigonia parva Kitchin, 1903, is a junior homonym of Trigonia parva Forbes, 1844, and its replacement ... [details]