Descubren huellas de animales fosilizados de 550 millones de años, la más antiguas que se hayan encontrado

INDEPENDENT.- Scientists in China have discovered what they claim are the oldest fossilised animal footprints ever found.

The parallel tracks were formed in mud up to 551 million years ago in southern China's Yangtze Gorges.

They potentially date to 10 million years before the Cambrian Explosion, when arthropod and other animal life rapidly flourished, and when creatures with pairs of legs capable of leaving such footprints were thought to have arisen.

Scientists from the Chinese Academy of Sciences' Nanjing Institute of Geology and Palaeontology, along with colleagues from Virginia Tech in the US, studies the tracks and burrows found within part of the Denying Formation, a fossil-rich area near the Yangtze River.

Asked how the teams knew the impressions were footprints, Dr Shuhai Xiao of Virginia Tech told The Independent: "If an animal makes footprints, the footprints are depressions on the sediment surface, and the depressions are filled with sediments from the overlying layer.

"This style of preservation is distinct from other types of trace fossils, for example, tunnels or burrows, or body fossils.

"The footprints are organised in two parallel rows, as expected if they were made by animals with paired appendages. Also, they are organised in repeated groups, as expected if the animal had multiple paired appendages."

Previously, no evidence of limbed animals had been discovered that pre-date the Cambrian Explosion, the sudden surge in diversity that occurred on Earth around 510 to 540 million years ago.

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