550 million years ago, a worm-like creature crawled over the muddy bottom of the ocean in today's China, pausing for a while, leaving a distinct imprint of its belly, crawling a little farther, and dying. His traces were preserved over the millions of years - a stroke of luck for researchers. The fossils are one of the oldest evidences of mobility.
The ability to move oneself was a breakthrough in evolution. As the world's first living beings swirled passively through the water, mobility brought independence and the opportunity to conquer new habitats. However, when the world learned to walk is not finally clear. Proof is difficult. Although researchers always find suspicious impressions in sediments, but whether they actually come from a crawling animal, was difficult to determine clearly - until now.
The special feature of the current fossil find: He not only provides 550 million year old crawl tracks, but also the animals that had left them. The up to 27 cm long creatures are reminiscent of millipedes or worms in the shape of an ear of wheat with their elongated shape.
Twice as old as the oldest dinosaurs
The animal named Yilingia spiciformis lived in the Ediacarium - the time before the great Cambrian species explosion around 540 million years ago, when many of today's animal tribes originated. By comparison, the first dinosaurs lived about 235 million years ago and died 66 million years ago.
VIRGINIA TECH / SHUHAI XIAO / ZHE CHEN / AFP
Hidden object with worms: The fossilized ocean floor is 550 million years old
Hardly any animals were known from the Ediacarium, researchers report to Shuhai Xiao from the Chinese Academy of Sciences in Nanjing in the journal "Nature". The now discovered fossil shows that at that time the first mobile animals must have originated.
The name Yilingia comes from the district of Yiling, where the fossils were discovered. The fact that the animal was already moving purposefully at that time could point to an already developed central nervous system.
So far, the researchers do not know where to classify the unusual worm in the family tree of life. The annelids - that is annelid worms - or the arthropods - ie arthropods, which include insects, millipedes and arachnids - are possible.
