- Branquias de pez.
- Escamas de pez.
- Articulaciones y huesos de extremidades medio pez, medio tetrápodo, incluyendo una articulación de muñeca funcional.
- Costillas y cuello móvil de tetrápodo.
- Una región auricular modificada.
Tiktaalik lived approximately 375 million years ago. Paleontologists suggest that it is representative of the transition between non-tetrapod vertebrates (“fish”) such as Panderichthys, known from fossils 380 million years old, and early tetrapods such as Acanthostega and Ichthyostega, known from fossils about 365 million years old. Its mixture of primitive “fish” and derived tetrapod characteristics led one of its discoverers, Neil Shubin, to characterize Tiktaalik as a “fishapod”.
Tiktaalik roseae is the only species classified under the genus. The name Tiktaalik is an Inuktitut word meaning “burbot”, a freshwater fish related to true cod. The “fishapod” genus received this name after a suggestion by Inuit elders of Canada’s Nunavut Territory, where the fossil was discovered. The specific name roseae cryptically honours an anonymous donor.
Putative tetrapod footprints found in Poland and reported in Nature in January 2010 were “securely dated” at 10 million years older than the oldest known elpistostegids. If this is a true tetrapod record,Tiktaalik was a “late-surviving relic” rather than the original transitional form. An alternative interpretation is that the Polish trackways, which do not have digital impressions, were made by walking fish