Belongs within: Palaeoheterodonta.
The Trigoniidae are a family of generally trigonal clams with an extensive fossil record, represented in the modern fauna by the single genus Neotrigonia (Beesley et al. 1998).
Characters (Beesley et al. 1998): Small to large in size (5–200 mm), triangular to subquadrate in outline, generally opisthogyrous, occasionally ortho- or prosogyrous. Posterior area and flank sculpture usually differentiated, with flanks having commarginal or oblique sculpture and posterior area, radial sculpture. Left valve with prominent strongly grooved bifid tooth, right valve with two weaker strongly grooved divergent teeth not borne on hinge plate. Anterior myophorous buttresses well developed. Pallial line entire; shells internally nacreous.
<==Trigoniidae
|--Pterotrigonia van Hoepen 1929 [Pterotrigoniinae]S98
| |--P. (Pterotrigonia)S98
| | |--*P. (P.) cristata van Hoepen 1929S98
| | `--P. (P.) pseudocaudata (Hector 1886) (see below for synonymy)S98
| `--P. (Ptilotrigonia van Hoepen 1929)S98
| |--P. (*P.) lauta (van Hoepen 1929) [=*Ptilotrigonia lauta]S98
| `--P. (P.) ultima Fleming 1987S98
`--TrigoniinaeS98
|--Pacitrigonia Marwick 1932S98
| |--*P. sylvesteri Marwick 1932S98
| `--P. hanetiana (d’Orbigny 1842) [=Trigonia hanetiana]S98
| |--P. h. hanetianaS98
| |--P. h. hectori Fleming 1987S98
| `--P. h. woodsiS98
`--Trigonia Bruguière 1789 non Aubl. 1775 (ICBN)W77
|--T. clavellataCD53
|--T. costata (see below for synonymy)CD53
|--T. lamarckiB90
|--T. margaritaceaG20
|--T. pectinataH79
|--T. semiundulataH86
|--T. signata Agassiz 1840CD53
|--T. similisCD53
|--T. (Trigonia) sulcata (Hermann 1781)SB93
`--T. uniophora Gray 1847H09
Trigoniidae incertae sedis:
AcanthotrigoniaK79
MicrotrigoniaK79
NeotrigoniaMG-H11
|--N. bednalliGW02
|--N. crebrisculpta (Odhner 1917)WBS-S15
|--N. gemmaBRW98
|--N. jacksoni Morrison 2011WBS-S15
|--N. kaiyomaruae Habe & Nomoto 1976MG-H11
|--N. lamarckii (Gray 1838)TW07
|--N. margaritaceaGO06
|--N. mediponteaBRW98
|--N. novaguineanaBRW98
|--N. strangeiBRW98
`--N. uniophora (Gray 1847)S-S90
Allorisma King 1850W77
|--A. elegansG31
|--A. elongataG31
|--A. padangenseG31
|--A. passaloides Etheridge 1917F71
|--A. subcuneata Meek & Hayden 1858W77
|--A. subelegansG31
`--A. tirolenseG31
GeratrigoniaJB12
SteinmannellaJB12
Lyroschizodus orbicularis Newell & Boyd 1975SB93
Dolabra equilateralis McCoy 1844 [=Protoschizodus equilateralis]G31
EotrigoniaBRW98
|--E. eocenicaBRW98
|--E. semiundulataQ72
`--E. subundulataBRW98
Pterotrigonia (Pterotrigonia) pseudocaudata (Hector 1886) [=Trigonia pseudocaudata, T. pseudocundata Hector 1886 (n. n.); incl. T. amuriensis Hector 1880 (n. n.)]S98
Trigonia costata [=Donacites costatus, Lyriodon costatum, Lyrodon costatum; incl. Trigonia lineolata Ag. 1840, Donacites sulcatus]CD53
*Type species of generic name indicated
References
[BRW98] Beesley, P. L., G. J. B. Ross & A. Wells (eds) 1998. Fauna of Australia vol. 5. Mollusca: The Southern Synthesis. Part A. Australian Biological Resources Study: Canberra.
[B90] Brazier, J. 1890. Mollusca trawled off Merimbula, New South Wales. Proceedings of the Linnean Society of New South Wales, series 2, 4 (3): 747–750.
[CD53] Chapuis, F., & G. Dewalque. 1853. Description des fossiles des terrains secondaires de la province de Luxembourg. M. Hayez: Bruxelles.
[F71] Fletcher, H. O. 1971. Catalogue of type specimens of fossils in the Australian Museum, Sydney. Australian Museum Memoir 13: 1–167.
[GO06] Giribet, G., A. Okusu, A. R. Lindgren, S. W. Huff, M. Schrödl & M. K. Nishiguchi. 2006. Evidence for a clade composed of molluscs with serially repeated structures: monoplacophorans are related to chitons. Proceedings of the National Academy of Sciences of the USA 103 (20): 7723–7728.
[GW02] Giribet, G., & W. Wheeler. 2002. On bivalve phylogeny: a high-level analysis of the Bivalvia (Mollusca) based on combined morphology and DNA sequence data. Invertebrate Biology 121 (4): 271–324.
[G20] Goldfuss, G. A. 1820. Handbuch der Naturgeschichte vol. 3. Handbuch der Zoologie pt 1. Johann Leonhard Schrag: Nürnberg.
[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.
[H79] Haast, J. von. 1879. Geology of the Provinces of Canterbury and Westland, New Zealand. A report comprising the results of official explorations. “Times” Office: Christchurch.
[H09] Hedley, C. 1909. The Marine Fauna of Queensland: Address by the President of Section D. Australasian Association for the Advancement of Science: Brisbane.
[H86] Hutton, F. W. 1886. The Mollusca of the Pareora and Oamaru systems of New Zealand. Proceedings of the Linnean Society of New South Wales, series 2, 1 (1): 205–237.
[JB12] Johnson, M. E., & B. G. Baarli. 2012. Development of intertidal biotas through Phanerozoic time. In: Talent, J. A. (ed.) Earth and Life: Global biodiversity, extinction intervals and biogeographic perturbations through time pp. 63–128. Springer.
[K79] Kauffman, E. G. 1979. Cretaceous. In: Robison, R. A., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt A. Introduction. Fossilisation (Taphonomy), Biogeography and Biostratigraphy pp. A418–A487. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).
[MG-H11] McEnnulty, F. R., K. L. Gowlett-Holmes, A. Williams, F. Althaus, J. Fromont, G. C. B. Poore, T. D. O’Hara, L. Marsh, P. Kott, S. Slack-Smith, P. Alderslade & M. V. Kitahara. 2011. The deepwater megabenthic invertebrates on the western continental margin of Australia (100–1100 m depths): composition, distribution and novelty. Records of the Western Australian Museum Supplement 80: 1–191.
[Q72] Quilty, P. G. 1972. The biostratigraphy of the Tasmanian marine Tertiary. Papers and Proceedings of the Royal Society of Tasmania 106: 25–44.
[SB93] Skelton, P. W., & M. J. Benton. 1993. Mollusca: Rostroconchia, Scaphopoda and Bivalvia. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 237–263. Chapman & Hall: London.
[S-S90] Slack-Smith, S. M. 1990. The bivalves of Shark Bay, Western Australia. In: Berry, P. F., S. D. Bradshaw & B. R. Wilson (eds) Research in Shark Bay: Report of the France-Australe Bicentenary Expedition Committee pp. 129–157. Western Australian Museum.
[S98] Stilwell, J. D. 1998. Late Cretaceous Mollusca from the Chatham Islands, New Zealand. Alcheringa 22 (1): 29–85.
[TW07] Taylor, J. D., S. T. Williams, E. A. Glover & P. Dyal. 2007. A molecular phylogeny of heterodont bivalves (Mollusca: Bivalvia: Heterodonta): new analyses of 18S and 28S rRNA genes. Zoologica Scripta 36 (6): 587–606.
[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.
[WBS-S15] Willan, R. C., C. Bryce & S. M. Slack-Smith. 2015. Kimberley marine biota. Historical data: molluscs. Records of the Western Australian Museum Supplement 84: 287–343.