Tiktaalik

Tiktaalik (English pronunciation: /tɪkˈtɑːlɪk/; Inuktitut pronunciation: /tik.ta˩˥ːˈlik/ ; syllabics  ᑎᒃᑖᓕᒃ) is a monospecific genus of sarcopterygian (lobe-finned fish) from the Late Devonian Period, about 375 Ma (million years ago), having many features akin to those of tetrapods (four-legged animals).[1]

Unearthed in Arctic Canada, Tiktaalik is technically a fish, complete with scales and gills - but it has the flattened head of a crocodile and unusual fins. Its fins have thin ray bones for paddling like most fishes', but they also have sturdy interior bones that would have allowed Tiktaalik to prop itself up in shallow water and use its limbs for support as most four-legged animals do. Those fins and a suite of other characteristics set Tiktaalik apart as something special; it has a combination of features that show the evolutionary transition between swimming fish and their descendants, the four-legged vertebrates - a clade which includes amphibians, reptiles, birds and mammals.[2]

It and similar animals may possibly be the common ancestors of the broad swath of all vertebrate terrestrial fauna: amphibians, reptiles, birds, and mammals.[3]

The first well-preserved Tiktaalik fossils were found in 2004 on Ellesmere Island in Nunavut, Canada.