Researchers supported in part by the Exobiology & Evolutionary Biology element of the NASA Astrobiology Program have discovered new and unusual fossils in Mongolia. The structures, known as macroscopic organic warty sheets (MOWS), could be the remains of fungal biofilms, or even previously unknown organisms that are now extinct. However, the team believes that multiple lines of evidence indicate that the MOWS are the remnants of ancient marine algae.

Regardless of the organisms responsible for their production, the discovery of MOWS increases our understanding of biological diversity during a period of Earth’s history known as the Cryogenian glacial interlude (662–635 million years ago). The discovery also shows that macroscopic and morphologically complex multicellular organisms were present in the Cryogenian.

The study, “Fossils of putative marine algae from the cryogenian glacial interlude of Mongolia,” was published in the journal Palaios.