Wikipedia
Tristichopterids (Tristichopteridae) were a diverse and successful group of tetrapodomorph fishes living throughout the Middle and Late Devonian. They first appeared in the Givetian stage of the Middle Devonian. Within the group sizes ranged from a few tens of centimeters ( Tristichopterus) to several meters ( Hyneria and Eusthenodon).
Some tristichopterids share some of the features of the elpistostegalians, a paraphyletic assemblage of fishes close to the origin of tetrapods. This mainly concerns the shape of the skull and a reduction in size of the posterior fins.
An old and persistent notion is that Eusthenopteron was able to crawl onto land using its fins. However, there is no evidence actually supporting this idea. All tristichopterids went extinct by the end of Late Devonian.