Heme Survives Deep Time

A PNAS study reports intact heme‑derived molecules and cell‑like structures in the hind leg of a 115‑million‑year‑old Brazilian theropod (Aratasaurus museunacionali). Chemical and microscopic tests localized heme to vascular channels in the fossil bone while surrounding sediment lacked it, suggesting preservation of some blood components far longer than previously believed. — If biomolecules such as heme can survive tens of millions of years, molecular paleontology gains a new toolkit to infer physiology, metabolism and activity in extinct animals, reshaping scientific narratives and public understanding of deep‑time biology.