Microfossils in Mongolia suggest earlier animal origins

A study published in Science Advances suggests that the first animals may have emerged on Earth up to 200 million years earlier than previous scientific estimates indicated. Researchers reached this conclusion after analyzing more than 140 microfossils found in the Kheseen Biota in Mongolia.

Using scanning electron microscopy, the team examined microscopic structures, including some that resemble embryos with preserved internal cells. While the high state of preservation allowed for the observation of details rarely seen in ancient organisms, researchers noted that none of the specimens can be definitively identified as animals yet.

The findings provide new temporal references for the molecular clock technique, which uses genetic differences between modern species to estimate when common ancestors lived.