"Animals use their appendages to move around, to build their homes, to fight, to feed, and sometimes to help mate", he said, adding that the movement of sediments by the first legged creatures could have had a major impact on the Earth's geochemical cycles and climate.
For comparison, non-bilateral animals include sponges, corals, jellyfish, and anemones.
Life during the Ediacaran was characterized by algae, lichens, giant protozoans, worms, and various bacteria, but there's still a lot that paleontologists don't know about it. "This style of preservation is distinct from other types of trace fossils, for example, tunnels or burrows, or body fossils".
The body fossils of the animals that made these traces, however, have not yet been found.
Still, this discovery means that paleontologists will have to revise their vision of how life developed in Earth's primordial oceans.
Argentina's Lanzini ruled out of Russian Federation 2018
Argentina are in Group D at Russian Federation 2018, beginning their campaign against Iceland on June 16. West Ham ace Lanzini has pulled out of Argentina's World Cup squad due to injury.
Researchers aren't exactly sure how many legs the creature had - it could be two, or it could be many more.
"Previously identified footprints are between 540 and 530 million years old", Dr Zhe Chen from the Nanjing Institute of Geology and Palaeontology told MailOnline. "Also, they are organized in repeated groups, as expected if the animal had multiple paired appendages".
While bilaterian animals - including arthropods and annelids - were suspected to have first stretched their innovative legs prior to the Cambrian explosion, in what's called the Ediacaran Period, before now there was no evidence for it in the fossil record. The fossils date back to almost 3.5 billion years ago and are strong evidence of the earliest life that existed on Earth.
Prior to this, animal life on Earth consisted of simpler, single-celled or multicellular organisms, but the Cambrian Period gave rise to more complex creatures of a kind we recognise today, including bilaterian animals, who exhibited the first bilateral symmetry.
'Arthropods and annelids, or their ancestors, are possibilities.
The animal appears to have paused from time to time, since the trackways appear to be connected to burrows that may have been dug into the sediment, "perhaps to mine oxygen and food", said the report. Maybe they were never preserved, the researchers said.