This image courtesy of Zhe Chen and Shuhai Xiao and released by Virginia Tech University on June 6, 2018, shows, the earliest known footprints left by an animal on Earth uncovered in China, and date back some 541 million years ago, a study said June 6.
Bilaterian animals used to be believed to have appeared in the Cambrian Period - the oldest footprints found used to be just 540 and 530 million years old - but now the fossils suggest that they've existed long before that in the Ediacaran Period.
The Cambrian Period marks the time in the fossil record when most major groups of animals first appeared. Researchers say that these prints were made by creatures with appendages and this discovery is proof that there were indeed animals with limbs in the Ediacaran period.
The remarkable discovery reveals how creatures with paired legs were scuttling around over 100million years earlier than previously thought.
This remarkable discovery is hailed in a study, published yesterday in the journal Science Advances by a research team from Virginia Tech University in the US and the Nanjing Institute of Geology and Palaeontology (NIGP) of the Chinese Academy of Sciences. The footprints are organized in two parallel rows, as expected if animals made them with paired appendages.
The researchers don't yet know exactly what animal left these tracks, and unfortunately we may never know.
What the team actually reported to have discovered were fossil footprints for animal appendages.
"Although the exact identity of the trace maker of the Shibantan trackways is hard to determine in the absence of body remains at the end of the trackways, we suggest that the trace maker was probably a bilaterian animal with paired appendages", the authors reported.
"These trace fossils include burrows and possible trackways that are preserved in close proximity and are apparently connected", the scientists noted in an introduction to the report.