Scientists say a fossil of a four-legged fish sheds new light on the process of evolution.
The creature had a fish-like body but the head of an animal more suited to land than water.
The researchers' study, published in the journal Nature, says Ventastega curonica would have looked similar to a small alligator. Scientists say the 365-million-year-old species eventually became an evolutionary dead end.
... "From a distance, it would have looked like an alligator. But closer up, you would have noticed a real tail fin at the back end, a gill flap at the side of the head; also lines of pores snaking across head and body.
... Experts believe that Ventastega was an important staging post in the evolutionary journey that led creatures from the sea to the land. Scientists once believed that these early amphibious animals descended in a linear fashion, but this discovery instead confirms these creatures diversified into different branches along the way. ...
"Ventastega fills the gap between Tiktaalik and the earliest land based mammals. All these changes in these creatures are not going in lockstep; it's a mosaic with different parts of animal evolving at different rates. Ventastega has acquired some of land-animal characteristics, but has not yet got some of the other ones."
For instance, the creature had primitive feet - but with a high number of digits. ... You would have seven, eight, maybe even nine toes per foot... - bbc
Evolution takes forward and backward steps along the way. Too many toes was not as useful so that didn't last.
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