The oldest fossilised traces of motility were revealed by an international multi-disciplinary team of researchers in a new research.
According to the study published in PNAS on Monday, the new evidence is 2.1bn years old, while the previous remnants were dated to 570m years ago.
The new evidence was discovered by Abderrazak El Albani and his team at the Institut de Chimie des Milieux et Matériaux de Poitiers (CNRS/Université de Poitiers), in a fossil deposit in Gabon, where the oldest multicellular organisms have already been found.
The deposits, which were located in the Franceville Basin, allowed researchers to re-date the appearance of multi-cellular life on earth to 2.1bn years-approximately 1.5bn years earlier than previously thought (600m).
Findings of the study showed that this rich biodiversity has occurred in the same time with a peak in dioxygenation of the atmosphere, and developed in a calm and shallow marine environment.
The team revealed the existence of fossilised traces of motility in this same geological deposit next to fossilised microbial biofilms, which formed carpets between the superficial sedimentary layers. This shows that certain multicellular organisms in this primitive marine ecosystem were sophisticated enough to move through its mud, rich in organic matter.
Using the 3D with X-ray computed micro-tomography, a non-destructive imaging technique, the researchers analysed and reconstructed the traces.
“The more or less sinuous structures are tubular, of a generally consistent diameter of a few millimetres, and run through fine layers of sedimentary rock. Geometrical and chemical analysis reveals that they are biological in origin, and appeared at the same time the sediment was deposited,” according to the research.
Researchers believe that the organisms behind this phenomenon moved in search of nutritive elements and the dioxygen, both produced by cyanobacteria.
