Tristichopterus

Tristichopterus is an extinct genus of Devonian eotetrapodiform fish in the family Tristichopteridae. The type species, T. elatus, was first described by Philip Grey Egerton in 1861 from remains of Givetian age found in Scotland. In 2013, a second species, Eusthenopteron kurshi was attributed to the genus based on remains from Latvia, originally assigned to Eusthenopteron, but this has not been universally recognised, With a maximum length of sixty centimetres, is the smallest genus in the family. Tristichopterus was thought by Egerton to be unique for its time period as a fish with ossified vertebral centers, breaking the persistent notochord rule of most Devonian fish. but this was later reinspected and shown to be only partial ossification by Dr. R. H. Traquair.  Tristichopterus alatus closely resembles Eusthenopteron and this sparked some debate after its discovery as to whether it was a separate taxon.