It is an almost complete fossil. It would be one of the first examples of a four -legged animal that evolved from living under water to live on the mainland. He is 346 million years old. It is the fossil of the first land animal.
Westlothiana Lizziaediscovered in 1984 in Scotland, looked like Salamandra. Like other similar tetrapods, they are common ancestors of current amphibians, birds, reptiles and mammals. Including humans.
Near volcanoes
The researchers had never determined the exact age of the fossil. The University of Texas in Austin did it. They are 14 million years older than it was believed. The new age reinforces the importance of the finding. The research is in PLOS One magazine.
The site in is close to old volcanoes whose lava flows had hardened a long time ago forming basaltic rock. The lava and the rubble eroded the sediments containing circums. They were dragged into a lake where limestone was formed, burying these first tetropod creatures.
The uranium-pim of the circums were performed and found the age. Before Garza's bet, scientists had calculated that fossils were as old as similar fossils around the world. About 331 million years. The maximum, more precise and old age, of 346 million years is significant. It suits the specimens in Romer's gap. This is a period of time between 360 and 345 million years ago. There, for reasons that scientists do not know with certainty, very few fossils have been discovered.
Leaving the sea
It was during this crucial point of history that aquatic fish made an evolutionary leap. They developed lungs and four legs to become land animals. This is one of the most important milestones in the history of animal evolution.
The Scottish site where fossils were found is the East Kirkton quarry. It is a treasure of early tetropod records. There have been seven fossils of trunk tetrapods. Hundreds of millions of years ago, when these first four -legged creatures wandered, this site was a tropical forest with nearby active volcanoes. There was a toxic lake and a diverse community of plants and animals. From there comes the fossil of the first terrestrial animal. Our common ancestor.
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