Walking fish disclose fresh evolutionary insights
- An extraordinary fish in 375 million years ago had unique features in its head that helped pave the way for vertebrate animals to live on land. The findings showed that the migration from water to land merely having a fish's fins transform into legs. The head showed changes from more primitive fish that helped adapt to the new feeding and breathing conditions presented by a terrestrial environment, the scientists said. Like some other fish of its time, it had gills and lungs. It likely inhabited the mudflats of freshwater flood plains of a subtropical environment.
- It was a large aquatic predator, measuring up to 9 feet long,with sharp teeth and a flattened head like a crocodile and unlike primitive fish. It may have been able to exit the water for short jaunts on land. "Fish in the water, insects on land - it could feed on all of those if you look at the skull," said Neil Shubin of the University of Chicago.
- The scientists described key features in its head and braincase and the decline in size of a bone called the hyomandibula. As land animals evolved, the hyomandibula eventually became the stapes, one of the tiny bones in the middle ear. The underside of the skull remained encased in rock at the time Tiktaalik's discovery was announced. Using a needle to remove rock grain by grain under a microscope, scientists have painstakingly studied the inside of the creature's skull.
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