Tristichopterus, with a maximum length of sixty centimetres, is the smallest genus in the family of prehistoric lobe-finned fish, Tristichopteridae that was believed to have originated in the north and dispersed throughout the course of the Upper Devonian into Gondwana. Tristichopterus currently has only one named species, first described by Egerton in 1861. The Tristichopterus node is thought to have originated during the Givetian part of the Devonian. 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.

Tristichopterids (Tristichopteridae) were a diverse and successful group of fish-like tetrapodomorphs living throughout the Middle and Late Devonian. They first appeared in the Eifelian stage of the Middle Devonian. Within the group sizes ranged from a few tens of centimeters (Tristichopterus) to several meters.