They said they don't know exactly what species the footprints belong to, but described the creature as a bilaterian animal, like an arthropod.
The fossils date back to the Ediacaran Period, which was between 635 to 541 million years ago.
They are often assumed to have appeared and radiated suddenly during the so-called "Cambrian Explosion" about 541 to 510 million years ago, but scientists now tend to consider that their evolutionary ancestry was rooted in the Ediacaran Period.
"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.
An worldwide team of scientists found that the fossil of an animal appendage dates back to the Ediacaran period, sometime between 541 and 635 million years ago.
However, this creature - which provides the earliest evidence of an animal with legs - would have existed around 10 million years before then. The research was published in Science Advances on June 6, 2018.
They were discovered by researchers from the Nanjing Institute of Geology and Palaeontology from the Chinese Academy of Sciences and Virginia Tech in the United States.
"The trackways are somewhat irregular, consisting of two rows of imprints that are arranged in series or repeated groups", explained notes from the Chinese Academy of Sciences. This sea-dwelling animal had paired appendages that raised its body above the ocean floor, the footprints left behind by its multiple feet suggest.
Professor Shuhai Xiao, a geobiologist at Virginia Tech University, told The Guardian: "Animals use their appendages to move around, to build their homes, to fight, to feed, and sometimes to help mate".
An global research team discovered the fossil tracks in China dating back to the Ediacaran Period, just before the Cambrian Explosion when life on Earth increased rapidly.
Mystery surrounds the one-millimetre long creatures that made the prints, since no trace of their bodies has been found.
The ancient trackways and burrows are pictured.
'At least three living groups of animals have paired appendages (represented by arthropods such as bumble bees, annelids such as bristle worms, and tetrapods such as humans)', said Dr Chen.
Near the ancient footprints, the team found fossilized burrows, which suggests that the animal might have been periodically tunneling into sediments and microbial mats, either in search of food or perhaps to mine for oxygen.