Tiktaalik roseae is a species of sarcopterygia, found from the Late Devonian of the Canadian Arctic Archipelago that exhibit an intermediate form between fishes and tetrapods ¹⁾, and its body length is about 80 cm (measured on Fig. 5 of the reference 5), or there is an estimation from 1.25 to 2.75 m ⁶⁾Note).

As the shoulder and elbow of the pectoral fin are flexible, Tiktaalik can raise up and support the body by the pectoral fin, using like the forelimb ^{4), 6)}. The head mobility is also improved, and these features is considered to influence its locomotion and feeding in shallow water and at the water's edge ²⁾.

Although the pelvic girdle and pelvic fin are about the same size as the pectoral girdle and pectoral fin, the pelvic fins were unable to hold the body up and would not have played a role in propulsion for walking on land ⁷⁾. However, the pelvic fins were capable of various movements in the water, which would have eventually led to the ability of terrestrial walking ⁷⁾.

Presumably, Tiktaalik livde in shallow freshwater such as channels, waterfronts, and tidal ftats around deltas and estuaries ^{1), 2), 3), 5), 6)}.