Heptanema
| Heptanema Temporal range:
| |
|---|---|
| Fossil of H. paradoxum | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinistia |
| Order: | Coelacanthiformes |
| Suborder: | Latimerioidei |
| Family: | †Mawsoniidae |
| Subfamily: | †Diplurinae |
| Genus: | †Heptanema Bellotti, 1857 |
| Species: | †H. paradoxum
|
| Binomial name | |
| †Heptanema paradoxum Bellotti, 1857
| |
Heptanema is an extinct genus of prehistoric marine coelacanth from the Triassic of Europe. It contains a single species, H. paradoxa from the Middle Triassic (Ladinian)-aged deposits of Monte San Giorgio, in both northern Italy (Perledo-Varenna Formation) and southern Switzerland (Meride Formation).[1][2][3] Its placement has been long uncertain, leading to it being excluded from many fossil phylogenies, but a 2025 study found strong evidence for it being a mawsoniid closely related to the freshwater Diplurus of North America.[4]
Woodward (1891) suggested that "Coelacanthus" minor Agassiz, 1843, a nomen nudum based on a specimen from the Muschelkalk of France, could be a species of Heptanema.[5][6][7] Another species, H. willemoesii from the Late Jurassic-aged Solnhofen Formation of Germany, is now placed in Macropoma.[4][6]
See also
References
- ^ "Fossilworks: Heptanema". fossilworks.org. Retrieved 17 December 2021.
- ^ Renesto, Silvio; Stockar, Rudolf (2018). "First record of a coelacanth fish from the Middle Triassic Meride limestone of Monte San Giorgio (Canton Ticino, Switzerland)". Rivista Italiana di Paleontologia e Stratigrafia. 124 (3). doi:10.13130/2039-4942/10771. ISSN 2039-4942.
- ^ Clapham, M. (2013-12-13). "Heptanema paradoxum". Paleobiology Database.
- ^ a b Ferrante, Christophe; Cavin, Lionel (2025-06-06). "A deep dive into the coelacanth phylogeny". PLOS ONE. 20 (6) e0320214. Bibcode:2025PLoSO..2020214F. doi:10.1371/journal.pone.0320214. ISSN 1932-6203. PMC 12143573. PMID 40478838.
- ^ Bellotti, Cristoforo (1857). "Descrizione di alcune nuove specie di pesci fossili di Perledo e di altre località Lombarde.". In Stoppani A. (ed.). Studii Geologici e Paleontologici sulla Lombardia (in Italian). Milano: Carlo Turati Tipografo Editore. pp. 419–438.
- ^ a b Woodward, Arthur S. (1891). Catalogue of the Fossil Fishes in the British Museum (Natural History). Part II. London: British Museum (Natural History). Department of Geology. doi:10.5962/bhl.title.61854..
- ^ Forey, Peter L. (1998). History of the Coelacanth Fishes. London: Chapman and Hall. p. 419. ISBN 978-0-412-78480-4.