Tiktaalik was a prehistoric fish that was an ancestor to modern tetrapods. It shared anatomical features with tetrapods (e.g., four limbs) and fish (e.g., gills, scales). With these features, Tiktaalik could be best described as a(n)
intermediate form or transitional fossil between fish and tetrapods. It provides important evidence for the evolution of tetrapods from fish.
Tiktaalik is best described as a transitional species or a "missing link" between fish and tetrapods. It was a prehistoric fish that existed around 375 million years ago in what is now the Canadian Arctic.
To determine that Tiktaalik was a transitional species, scientists analyzed its fossilized remains and compared its anatomy to both fish and tetrapods. By identifying shared anatomical features, they were able to draw conclusions about its evolutionary position.
One of the key features of Tiktaalik is its four limbs, which are reminiscent of tetrapods (four-limbed animals, including amphibians, reptiles, birds, and mammals). These limbs had a similar bone structure to those of tetrapods, indicating a significant adaptation for movement on land.
Additionally, Tiktaalik had gills and scales, common characteristics of fish. Gills allowed it to breathe in water, and its scales provided protection and covered its body in a way similar to other fish.
By combining these characteristics, Tiktaalik displayed a combination of fish-like and tetrapod-like features, making it a critical transitional species in the evolutionary journey from fish to tetrapods.
In summary, Tiktaalik could be best described as a transitional species, exhibiting shared anatomical features of both fish and tetrapods, thereby representing a key link in the evolution from aquatic to terrestrial life.