It is the oldest animal footprint on Earth. This is shown in the study published in the journal Science Advances and developed by the Institute of Geology and Paleontology of Nanking (China) and the Polytechnic Institute and State University of Virginia (United States) who studied some marks found in a formation of the Ediacarian Period, located in the South of China, in the region of the Three Gorges of the Yangtze River.
According to the survey, the traces, which were left by the appendages of an unknown animal, are between 541 and 551 million years old, which makes them the oldest animal footprint in the fossil record.
These traces, preserved near burrows, were discovered in the Dengying Formation, a rich fossil reserve in southern China, and constitute the first evidence to confirm that the presence of an ancient group of so-called bilateral animals predates the explosion of the Cambrian
This “explosion” -which began about 541 million years ago- meant the rapid appearance of a diversified variety of animals in a period of about 25 million years.
Prior to this, animal life on Earth consisted of simpler, unicellular, or multicellular organisms, but the Cambrian period gave rise to more complex creatures of the type we know today, including bilateral animals, which exhibited the first bilateral symmetry.
Bilateral animals, such as arthropods and annelids, have paired appendices and are among the most diverse animals currently and in the geological past. It is assumed that they appeared and spread suddenly during the Cambrian Explosion some 541 to 510 million years ago, although it has long been suspected that their evolutionary ancestry was rooted in the Edichar Period. Until the current discovery, however, no fossil record of animal appendages of this period had been found.
This ingenious piece of evolution gave these animals heads, tails, bellies and backs, and something incredibly useful: the legs.
The truth is that it is important to know when the first appendices appeared and in which animals, since this data will tell us when and how the animals began to change the Earth in such a particular way.
That is why these traces are so relevant to our understanding of evolutionary history, a small step for a bilateral animal, but a giant leap for the animal species.
The traces of 550 million years ago measure only a few millimeters in width, and consist of two rows of impressions arranged in parallel and made up of small repeated marks, which could be due to variations in the way of walking, rhythm, or interactions with the surface of what was once the bed of an ancient river.
In other words, this prehistoric creature was not bipedal, but something like a centipede or a spider, with multiple paired legs. The point is that “we do not know exactly which animals made these tracks, other than that these animals were bilaterally symmetrical because they had paired appendages.As long as the animal died and [was] preserved next to its tracks, it is difficult to say with certainty who He made the prints, “explains geographer Shuhai Xiao, leader of the work.
Still, due to the proximity of the traces of the pits to the burrows discovered nearby, the researchers hypothesize that the creature exhibited a “complex behavior“, like digging periodically in the sediments to extract oxygen and food in the habitat of their bed,
but beyond this, it is difficult to say if this small soft-bodied animal has left us some trace that we can find to trace the evolution and revolution animal.