Elpistostegalia

Tiktaalik (; ) is a monospecific genus of extinct sarcopterygian (lobe-finned fish) from the late Devonian Period, about 375 Mya (million years ago), having many features similar to those of tetrapods (four-legged animals). Tiktaalik is estimated to have had a total length of on the basis of various specimens.

Panderichthys is a genus of extinct sarcopterygian (lobe-finned fish) from the late Devonian period, about 380 Mya. Panderichthys, which was recovered from Frasnian (early Late Devonian) deposits in Latvia, is represented by two species. P. stolbovi is known only from some snout fragments and an incomplete lower jaw. P. rhombolepis is known from several more complete specimens. Although it probably belongs to a sister group of the earliest tetrapods, Panderichthys exhibits a range of features transitional between tristichopterid lobe-fin fishes (e.g., Eusthenopteron) and early tetrapods. It is

Elpistostegalia is a clade containing Panderichthys and all more derived tetrapodomorph taxa. The earliest elpistostegalians, combining fishlike and tetrapod-like characters, such as Tiktaalik, are sometimes called fishapods. Although historically Elpistostegalia (referred to as Panderichthyida) was considered an order of prehistoric lobe-finned fishes, it was cladistically redefined to include tetrapods.

Elpistostege is an extinct genus of finned tetrapodomorphs that lived during the Frasnian age of the Late Devonian epoch. Its only known species, E. watsoni, was first described in 1938 by the British palaeontologist Thomas Stanley Westoll, based on a single partial skull roof discovered at the Escuminac Formation in Quebec, Canada.

Qikiqtania ( ) is an extinct genus of elpistostegalian tetrapodomorph from the Late Devonian (early Frasnian stage) Fram Formation of Nunavut, Canada. The genus contains a single species, Q. wakei, known from a partial skeleton. Analysis of the fin bones suggests that Qikiqtania was well-suited to swimming, and likely incapable of walking or supporting itself out of the water, as has been suggested for the closely related Tiktaalik.

Livoniana is a genus of prehistoric tetrapodomorphs which lived during the Devonian period (Givetian - Frasnian stages, about 374 to 391 million years ago).