Scientists have found what they think is the oldest animal footprint in the fossil record, uncovering incredibly ancient track marks imprinted in the dirt as far back as 550 million years ago. They are often assumed to have appeared and radiated suddenly during the "Cambrian Explosion" about 541-510 million years ago, although it has always been suspected that their evolutionary ancestry was rooted in the Ediacaran Period.
Chinese team researched about it and it appeared in Science Advances Journal.
Animals use their appendages or outgrowths to move around, make their homes, feed, and find mates. However, Xiao said they are uncertain if the creature belonged to the arthropod family or whether it has many or two legs.
The trackways were reportedly leading to burrows, where researchers say it's possible the animal may have dug for food or oxygen.
While the footprints were well-preserved, scientists don't know exactly what animal made the tracks since there were no body fossils found in the site.
The paleontological team found two rows of footprints that represent not only the earliest footprints ever found but also the earliest known record of an animal with legs. That's hundreds of millions of years before dinosaurs started roaming Earth, about 245 million years ago.
These legs raised the animal's body above the sediment it was moving across.
The researchers speculate that the same creature left both the tracks and the burrows, suggesting an animal that scurried and tunneled its way across the ground.
While the researchers are unable to identify the animal behind the footprints, there are three types of living animals with paired appendages: arthropods such as bumble bees, annelids such as bristle worms, and tetrapods which include humans.
Trackways and burrows excavated in situ from the Ediacaran Dengying Formation. They observed the trackways, which were not regular, and after analyzing their characteristics, they reached the conclusion that these were formed by bilaterian animals with paired appendages.
"Arthropods and annelids, or their ancestors, are possibilities". Maybe they were never preserved.