Dapediidae
| Dapediidae Temporal range:
| |
|---|---|
| Fossil specimen of Dapedium politum | |
| Artist's reconstruction of Dapedium politum | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Infraclass: | Holostei |
| Family: | †Dapediidae Lehman, 1966 |
| Genera | |
| |
Dapediidae is an extinct family of holostean ray-finned fish, that lived from the Middle Triassic to the Late Jurassic (Ladinian to Tithonian).[2] They are noted for their relatively deep bodies and are thought to have been primarily durophagous.[3]
Description and ecology
Dapediids had deep, laterally flattened circular bodies covered in thick ganoid scales, which gave them a resemblance to the pycnodontiforms, a group they may or may not be related to.[3] Their teeth were adapted towards a durophagous diet; some dapediids fed on hard-shelled invertebrates[4] such as ammonites and bivalves, though they may have also engaged in generalist scavenging.[1] At least one genus and possibly some other genera (Hemicalypterus and possibly Dandya) may have been herbivorous.[1][5]
Classification
While universally agreed to be members of Neopterygii, their classification within this group has been subject to dispute, historically either being considered stem-teleosteomorphs or having affinities with Holostei (bowfins, gars and their extinct relatives).[3] Studies from the end of the 2010s onwards have tended to support holostean affinities for the group.[3][1][6][7] Their precise position within the group is disputed.[3] Dapediids are often considered to be early diverging ginglymodians or more closely related to Ginglymodi (which contains the gars and their extinct relatives) than to Halecomorphi (which contains the bowfins and their extinct relatives).[8][5] Some studies have resolved dapediids stem group representatives of the wider clade Holostei (making gars and bowfins more closely related to each other than to dapediids).[3][9] A 2016 study suggested that Dapediidae should be placed in its own order, Dapediiformes.[8] In 2025 the Ladinian Guizhoubrachysomus was identified as an early-diverging dapediid, and Dapediidae was recovered within the ginglymodian order Semionotiformes as the sister group of Macrosemiidae.[6]
References
- ^ a b c d Gouiric-Cavalli, S.; Iglesias, A.; Cariglino, B.; Reguero, M. A. (2024). "A Late Jurassic deep-bodied actinopterygian fish from Antarctica". Acta Palaeontologica Polonica. 69 (3): 467–483. doi:10.4202/app.01158.2024.
- ^ Cawley, John J.; Marramà, Giuseppe; Carnevale, Giorgio; Villafaña, Jaime A.; López‐Romero, Faviel A.; Kriwet, Jürgen (February 2021). "Rise and fall of †Pycnodontiformes: Diversity, competition and extinction of a successful fish clade". Ecology and Evolution. 11 (4): 1769–1796. doi:10.1002/ece3.7168. ISSN 2045-7758. PMC 7882952. PMID 33614003.
- ^ a b c d e f Latimer, A. E.; Giles, S. (2018). "A giant dapediid from the Late Triassic of Switzerland and insights into neopterygian phylogeny". Royal Society Open Science. 5 (8) 180497. Bibcode:2018RSOS....580497L. doi:10.1098/rsos.180497. PMC 6124034. PMID 30225040.
- ^ Smithwick, F. M. (2015). "Feeding ecology of the deep-bodied fish Dapedium (Actinopterygii, Neopterygii) from the Sinemurian of Dorset, England". Palaeontology. 58 (2): 293–311. Bibcode:2015Palgy..58..293S. doi:10.1111/pala.12145. S2CID 86168055.
- ^ a b Gibson, S. Z. (2016). "Redescription and Phylogenetic Placement of †Hemicalypterus weiri Schaeffer, 1967 (Actinopterygii, Neopterygii) from the Triassic Chinle Formation, Southwestern United States: New Insights into Morphology, Ecological Niche, and Phylogeny". PLOS ONE. 11 (9) e0163657. Bibcode:2016PLoSO..1163657G. doi:10.1371/journal.pone.0163657. PMC 5033578. PMID 27657923.
- ^ a b Xu, G.; Ma, X.; Liu, L.; Liao, J.; Tan, F.; Sun, C. (2025). "Taxonomic Revision of †Guizhoubrachysomus minor (†Semionotiformes, Ginglymodi) From the Middle Triassic (Ladinian) Xingyi Biota in Guizhou and Yunnan, China". Contributions from the Museum of Paleontology, University of Michigan. 37 (4): 79–92. doi:10.7302/27712.
- ^ Near, Thomas J.; Thacker, Christine E. (2024-04-18). "Phylogenetic Classification of Living and Fossil Ray-Finned Fishes (Actinopterygii)". Bulletin of the Peabody Museum of Natural History. 65 (1). doi:10.3374/014.065.0101. ISSN 0079-032X.
- ^ a b Thies, D.; Waschkewitz, J. (2016). "Redescription of Dapedium pholidotum (Agassiz, 1832) (Actinopterygii, Neopterygii) from the Lower Jurassic Posidonia Shale, with comments on the phylogenetic position of Dapedium Leach, 1822". Journal of Systematic Palaeontology. 14 (4): 339–364. doi:10.1080/14772019.2015.1043361. S2CID 130282395.
- ^ López-Arbarello, A.; Sferco, E. (2018). "Neopterygian phylogeny: the merger assay". Royal Society Open Science. 5 (3) 172337. Bibcode:2018RSOS....572337L. doi:10.1098/rsos.172337. PMC 5882744. PMID 29657820.