Eothynnus

Eothynnus
Temporal range:
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Carangiformes
Suborder: Carangoidei
Family: Carangidae
Genus: Eothynnus
Woodward, 1901
Species:
E. salmoneus
Binomial name
Eothynnus salmoneus
Woodward, 1901

Eothynnus is an extinct species of prehistoric jackfish that lived during the lower Eocene of Europe and eastern North America. It contains a single species, E. salmoneus. It is known primarily from some preserved skulls from what is now the Isle of Sheppey (as a part of the London Clay Lagerstatten) in England. A single vertebra is also known from the Nanjemoy Formation of Virginia, US.

It was originally thought to be a tuna or mackerel, hence the generic name translating as "dawn" or "Eocene tuna." Later, it was reappraised to be a jackfish, related to Teratichthys and Eastmanalepes (syn. "Caranx primaevus"). It is one of the largest fish known from the London Clay.