Urosphen

Urosphen is an extinct genus of prehistoric bony fish that lived from the early to middle Eocene.
Description.
"Urosphen" was slow like "Nardoechelys". Despite its slow movement, it had different ways to attack other fishes. 
If it weren't for the extinction of the other prehistoric Anguillidae, you might think that "Urosphen" would hunt other extant fish. It has a relative from Brazil and Asia called "Urosphenopsis".