Answer :
Final answer:
Tiktaalik was a significant fossil discovery because it was a tetrapod-like fish with transitional features, bridging the gap between aquatic and terrestrial animals and providing insight into the evolutionary transition from fish to amphibians.
Explanation:
The discovery of Tiktaalik was special because it was a tetrapod-like fish with transitional characteristics. This fossil discovery represents a significant find in evolutionary biology, as it helps explain the transition from aquatic life to terrestrial existence. Tiktaalik roseae, discovered in 2006, is often referred to as a "fishapod" due to its mix of features found in both sarcopterygian fishes and early tetrapods. Living approximately 375 million years ago, its structure suggests it inhabited shallow water environments. Importantly, while Tiktaalik had gills and lungs, changes in its gill structure provided it a neck – a novelty among fish – allowing greater head mobility for feeding.
The creature's eyes sat atop its head, enabling it to scan its environment much like land animals do. The real significance of Tiktaalik lies in its limbs. Its fin bones had connections to its shoulder akin to weight-bearing limbs, hinting at the evolutionary progression towards true limbs capable of supporting the animal's weight on land. The discovery of Tiktaalik fills a gap in the fossil record by showing a clear example of a transitional form. It precedes known early tetrapods, like Acanthostega and Ichthyostega, by around 10 million years, solidifying its status as a transitional clade between fish and amphibians.
