Researchers have discovered an astonishing diversity of microorganisms in 1.88 billion-year-old Canadian rocks. They show that these prokaryotic organisms have established methods to survive in a harsh environment. They tend to bring some of the eukaryotes that humans are a part of. Therefore, perhaps it would be prokaryotic-eukaryotic transition forms.
The Precambrian is the geological period that covers the history of the Earth from its formation 4.5 billion years ago (Ga) to 540 million years ago (Ma). The study of this period in which life appears is crucial to our understanding of the evolution of life in its infancy. In fact, the first known forms of life (3.5 Ga) are prokaryotes, unicellular living beings whose DNA is bathed in the cell, and among which are bacteria and archaea. Other organisms, the eukaryotes, are known with certainty around 1.65 Ga. Unlike the first, its DNA is clearly individualized in a nucleus. It includes a wide variety of living things, from single-celled algae to pigeons and humans. Several paleontological sites help to understand the beginnings of life, including that of Schreiber (Canada). HASDating back to 1.88 Ga, this site has been known since the 1950s, when many microfossils, very small fossils, were discovered. But the biological nature of these microfossils has been debated over the years. In this context, a team of Japanese researchers carried out a study published on September 15, 2022 in the journal to verify the biological nature of the microfossils from the Schreiber deposit, as well as their real diversity.
Photos of recurring fossils from the Schreiber site known from the 1950s. Credits: Sasaki et al.
Two new types of microfossils have been discovered
The study allowed the identification of five new morphologies, or morphotypes, among the microfossils: colonial, ellipsoidal, spherical with inclusions, spiny, and spherical with projection. But what exactly are these microfossils? Detailed analyzes of its morphology and chemical composition, compared to what is known today, provide some answers. The researchers were initially able to observe that these structures are in fact biological in origin. In general, the[…]