# Fossilised Red Blood Cells Discovered in 115-Million-Year-Old Dinosaur Bone Researchers identify heme compounds in Aratasaurus fossils, challenging traditional views on organic preservation. - **Source:** [Science | The Guardian](https://www.theguardian.com/science) - **Published:** 2026-11-02 - **Topic:** [Business](https://brifing.si/c/business) - **Original article:** - **On Brifing:** https://brifing.si/s/0ab097a9-ec35-4aa2-9c5c-d588a4ad3323 ## Ancient Biological Discovery Scientists have identified structures resembling red blood cells within the hind leg bones of an Aratasaurus dinosaur. This creature lived 115 million years ago in what is now north-eastern Brazil. The discovery, published in the Proceedings of the National Academy of Sciences, marks a potential breakthrough in understanding ancient biological preservation. ## Chemical Evidence of Heme Researchers utilized electron microscopy to observe small, round structures within fossilized blood vessel channels. Chemical testing confirmed the presence of heme, the organic compound enabling hemoglobin to transport oxygen. These tests also revealed amino acid building blocks for collagen, providing further evidence of original biological material surviving within the ancient fossilized remains. ## Role of Mineral Stabilization Prof Kliti Grice suggests that a manganese compound known as hausmannite may have facilitated this rare preservation. By forming in and around the blood cells, this mineral likely stabilized the biological structures before the fossilization process completed. This mechanism potentially protected both the heme and collagen amino acids from rapid environmental degradation. ## Scientific Community Debate The findings have sparked significant debate among paleontologists regarding the nature of these structures. Prof Mary Schweitzer notes that the observed concave shapes differ from the expected dome-like appearance of dinosaur red blood cells, which typically feature a nuclear bulge. This skepticism highlights the difficulty of interpreting microscopic remnants in ancient specimens. ## Challenging Conventional Wisdom The research directly challenges the long-standing paleontological consensus that endogenous organic materials disappear within a million years. As technological approaches to analyzing specimens become more sophisticated, scientists are increasingly finding evidence that contradicts earlier assumptions. This shift suggests that many fossils may contain more molecular information than previously believed by experts. ## Museum Collection Potential The study encourages a re-examination of existing fossil collections held in museums worldwide. Prof Grice suggests that extraordinary molecular data might already be present in these archives, waiting for new analytical questions. This perspective shifts the focus from finding new field sites to extracting deeper insights from specimens already available to researchers. ## Cautious Scientific Interpretation Despite the excitement, researchers emphasize extreme caution regarding the implications of this discovery. Prof Grice clarifies that this work does not imply the survival of large biological molecules like DNA or intact proteins. The primary goal remains determining the extent of genuine molecular information that deep time can realistically preserve in fossils. ## Future Research Directions This discovery opens new avenues for investigating dinosaur metabolism, activity levels, and internal biology. By moving beyond simple morphological analysis, scientists can now apply advanced chemical testing to ancient bones. Future studies will likely focus on verifying these molecular echoes to better understand the physiological capabilities of extinct species throughout history. ## Sources covering this story - https://www.theguardian.com/science/2026/nov/02/fossilised-red-blood-cells-aratasaurus-dinosaurs-bone — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._