''Akmonistion'' is an
extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
genus of
holocephalian that lived in the
Early Carboniferous. The genus contains a single species, ''A. zangerli'', discovered by
Stan Wood in 1982. It is distinguished by an unusual enlarged formation of the dorsal fin, called a "spine-brush complex", of unknown function. This is also found in the better known genus ''
Stethacanthus
''Stethacanthus'' is an extinct genus of shark-like holocephaliansCoates, M., Gess, R., Finarelli, J., Criswell, K., Tietjen, K. 2016. A symmoriiform chondrichthyan braincase and the origin of chimaeroid fishes. Nature. doi: 10.1038/nature20806 ...
''. Remains have only been found near
Bearsden
Bearsden () is a town in East Dunbartonshire, Scotland, on the northwestern fringe of Greater Glasgow. Approximately from Glasgow city centre, Glasgow City Centre, the town is effectively a suburb, and its housing development coincided with t ...
in
Scotland.
The genus name is derived from the Ancient Greek “''akmon''” (“anvil”) + ''“istion''” (“sail”) referring to the appearance of its first dorsal fin.
It reached in length.
References
Carboniferous fish of Europe
Fossil taxa described in 2001
Symmoriiformes
{{paleo-cartilaginous-fish-stub