Scientists unearthed a skull of the most primitive four-legged creature in Earth's history, which should help them better understand the evolution of fish to advanced animals that walk on land.
The 365 million-year-old fossil skull, shoulders and part of the pelvis of the water-dweller, Ventastega curonica, were found in Latvia, researchers report in a study published in today's issue of the journal Nature. Even though Ventastega is likely an evolutionary dead-end, the finding sheds new details on the evolutionary transition from fish to tetrapods. Tetrapods are animals with four limbs and include such descendants as amphibians, birds and mammals.
While an earlier discovery found a slightly older animal that was more fish than tetrapod, Ventastega is more tetrapod than fish. The fierce-looking creature probably measured about 3 or 4 feet long and ate other fish. It likely had stubby limbs, scientists said.
This all happened more than 100 million years before the first dinosaurs roamed.
Scientists don't think four-legged creatures are directly evolved from Ventastega. It's more likely that in the family tree of tetrapods, Ventastega is an offshoot branch that eventually died off, not leading to the animals we now know, said lead author Per Ahlberg, a professor of evolutionary biology at Uppsala University in Sweden.