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). 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.
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.. Another species, H. willemoesii from the Late Jurassic-aged Solnhofen Formation of Germany, is now placed in Macropoma.
See also
Sarcopterygii List of sarcopterygians List of prehistoric bony fish
References