Eusthenopteron

Eusthenopteron was a lobe-finned fish that lived during the Late Devonian. It is well known for its relationships to the earliest tetrapods.

Description
As a sarcopterygian fish, Eusthenopteron shares some features with early tetrapodomorphs, including similar skull bones, internal nostrils, and labyrinthodont teeth. Most notable is its fin structure, which is almost identical to that of the first land-dwelling amphibians. The largest examples of Eusthenopteron grew up to almost two meters in length.

Interestingly, based on fossil evidence Eusthenopteron does not seem to have gone through a distinct larval stage and metamorphosis. This suggests that hatchling individuals were miniature versions of adults.

Discovery
Eusthenopteron was first discovered in Miguasha, Quebec, and was described by J. F. Whiteaves in 1881. Over 2000 specimens have since been recovered from the same locality.

In popular culture
Eusthenopteron is well known for its evolutionary association to the earliest tetrapods, and is often cited in older textbooks and television shows as the "missing link" between fish and amphibians. More recent fossil discoveries have shown that it was just one of many similar animals in the sarcopterygian group of fishes.