# Fossilised Red Blood Cells Discovered in 115-Million-Year-Old Dinosaur Bone Researchers identify heme compounds in Aratasaurus fossils, challenging conventional wisdom 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/99dd9120-e2d0-472f-8c5f-3d5c0df4e853 ## Discovery of Ancient Biology Scientists have identified structures resembling red blood cells within the hind leg bones of an Aratasaurus dinosaur. This specimen, dating back 115 million years, was discovered in a Brazilian mine in 2008. The team utilized electron microscopy to observe these small, round structures located within the dinosaur's original blood vessel channels. ## Chemical Evidence of Heme Chemical analysis confirmed the presence of heme, the organic compound responsible for oxygen transport in hemoglobin. Researchers also detected amino acid building blocks for collagen within the fossilized remains. These findings suggest that molecular traces of original biological tissues can persist far longer than previously assumed in the field of paleontology. ## The Role of Hausmannite 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 prior to the fossilization process. This mechanism potentially explains how delicate amino acids survived deep time within the bone matrix. ## Scientific Community Skepticism The findings have sparked debate among experts like Prof Mary Schweitzer. While she acknowledges the presence of heme and collagen, she questions the identification of the structures as red blood cells. Schweitzer notes that the observed concave shapes lack the characteristic nuclear bulge expected in dinosaur red blood cells, suggesting alternative interpretations. ## Challenging Conventional Wisdom The study challenges the long-held paleontological belief that all endogenous organic materials inevitably degrade within a million years. As technological approaches to specimen analysis become more sophisticated, researchers are increasingly finding evidence that contradicts these traditional timelines. This shift encourages a re-evaluation of how we interpret the preservation potential of ancient fossils. ## Museum Collections as Archives This research highlights the untapped potential of existing museum collections worldwide. Prof Grice suggests that extraordinary molecular information may already be present in specimens held in storage. By applying modern analytical techniques to these old fossils, scientists can ask new questions about dinosaur metabolism, activity levels, and their overall biological evolution. ## Caution Regarding Extraordinary Claims Despite the excitement, the research team emphasizes the need for extreme caution when interpreting these results. Prof Grice explicitly states that this discovery does not imply the survival of large biological molecules like DNA. The primary objective remains determining the extent of genuine molecular information that deep time can realistically preserve. ## Future Research Implications The study, published in the Proceedings of the National Academy of Sciences, marks a significant step in paleobiology. By focusing on mineral and molecular echoes of original biology, scientists are opening new avenues for investigation. Future efforts will likely focus on refining analytical methods to distinguish between genuine biological remnants and mineral artifacts. ## 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._