Scientists found things living inside modern mammal tissue that look and act exactly like 1.8-billion-year-old fossils.
March 25, 2026
Original Paper
Morphological comparison between cell-like entities from mammalian tissues and Precambrian microfossils
bioRxiv · 10.64898/2026.03.22.713352
The Takeaway
This study identifies active, RNA-rich microscopic particles in modern animals that are morphologically identical to some of Earth's earliest life forms from the Precambrian era. The discovery suggests that 'primordial' biological systems thought to be extinct for a billion years might still be present and functional within complex modern life.
From the abstract
The fossil record of the Precambrian era preserves some of the earliest evidence of life, yet these ancient microfossils primarily reveal morphology rather than function, leaving unresolved questions about how early cells lived, replicated and evolved. The RNA world hypothesis proposes that primordial organisms relied on RNA for both information storage and catalysis, but direct living systems reflecting such biology remain poorly characterized. Here we describe cell-like entities isolated from