A tiny fossil discovered in the Scottish Highlands may be the puzzle part to find out the evolutionary origin of most animals.
The microfossil dates back to a billion years ago, and it appears that its source is an ancient organism somewhat between unicellular and multicellular animals.
The chances are that it is possible the oldest fossil of its kind ever found. The discovery may lead to precious theories of how life evolved.
Paleobiologist Charles Wellman from the University of Sheffield in the UK said:
“The origins of complex multicellularity and the origin of animals are considered two of the most important events in the history of life on Earth, our discovery sheds new light on both of these.”
They discovered a primitive spherical organism composed of an arrangement of two distinct cell types, the first stage towards achieving multicellular structures, which hasn’t been previously described in the fossil record.
The fossils measured less than 30 micrometres across and were discovered in the Diabaig Formation at Loch Torridon, a site that contains microfossils from a lacustrine setting older than 1 billion years.
The stone deposits of the ancient lake bed preserved the fossils in a decent shape, down to subcellular levels, Sciencealert reports.
The new organism is known as Bicellum brasieri. Its mature form seems to be made up of a tiny sphere of condensed, somewhat spherical cells, surrounded by a differentiated outer layer of long, thick cells that look like small sausages.
Two populations presented a mix of cell types known as stereoblasts.
The scientists analyzed the information and saw it as an early form of the organism during a differentiation process when its shape was still being defined.