Overview
- A team led by Curtin University published a paper in the Proceedings of the National Academy of Sciences on Monday, Nov. 2 reporting heme‑derived chemical signals inside ellipsoidal microstructures in vascular canals of a 115‑million‑year‑old Aratasaurus limb bone.
- Researchers used electron microscopy, elemental mapping, Raman spectroscopy and molecular separation with mass spectrometry to identify iron, carbon and nitrogen, porphyrin/hemelike signatures and amino acids consistent with collagen in bone extracts.
- The authors propose a preservation pathway in which rapid burial in low‑oxygen sediment and mineralization by hausmannite (a manganese oxide) chemically stabilized cellular shapes and fragile molecules over deep time.
- Several paleontologists note unresolved issues: the chemical signals were not shown with fine spatial mapping to be confined to the cell‑like bodies, the microstructures differ from modern reptile and bird red blood cells, and contamination and localization controls need independent verification.
- Next steps include independent replication, more spatially resolved chemical mapping and targeted reanalysis of museum specimens, and the authors stress the finding is about heme and collagen traces and does not imply DNA survival or de‑extinction is possible.