# Oldest Dinosaur Red Blood Cells Discovered in 115-Million-Year-Old Fossil Researchers identify ancient hemoglobin structures within a Brazilian theropod dinosaur leg bone fragment. - **Source:** [New Scientist](https://www.newscientist.com/) - **Published:** 2026-11-02 - **Topic:** [Business](https://brifing.si/c/business) - **Original article:** - **On Brifing:** https://brifing.si/s/32e02037-724d-4c3b-80a6-decebb1433c8 ## Discovery of Ancient Cells Researchers have identified exceptionally preserved red blood cells within a 115-million-year-old leg bone fragment. The specimen belongs to Aratasaurus museunacionali, a theropod dinosaur discovered in Brazil in 2008. This finding represents the oldest instance of dinosaur red blood cells ever documented, significantly predating previous discoveries from Canada and Montana by millions of years. ## Unassuming Fossil Origins The Aratasaurus specimen was not a display-quality fossil, appearing as a nondescript bone fragment. At the time of death, the individual was not fully grown, measuring approximately three meters in length and weighing roughly 34 kilograms. Its unremarkable appearance previously led researchers to overlook the profound biological secrets hidden within the internal structure. ## Methodology and Extraction Kliti Grice and her team at Curtin University utilized hydrochloric acid to dissolve the surrounding rock matrix. This process revealed abundant cellular structures, with 20 blood cells visible within a single slide measuring just one-fifth of a millimeter wide. The cells were located inside fossilized blood vessels, confirming their biological origin within the dinosaur. ## Molecular Verification Process To confirm the identity of the cells, the team employed liquid chromatography–mass spectrometry. This analysis detected haem B, a key constituent of hemoglobin responsible for oxygen binding. The presence of these specific molecules provides robust molecular evidence that the structures are indeed red blood cells, rather than mineral deposits or random biological debris. ## Ruling Out Contamination Researchers rigorously addressed potential contamination from surrounding sediments, which were dominated by algae. They compared chemical signatures inside and outside the bone. Cells found outside contained chlorophyll-derived compounds, while those inside contained haem-derived molecules. This distinct chemical separation confirms that the hemoglobin structures originated from the dinosaur rather than the surrounding environmental sediment. ## Comparative Biological Analysis The team compared the Aratasaurus cells to those of modern birds and crocodiles, the closest living relatives of dinosaurs. The fossilized cells were significantly larger than those of modern counterparts. This size discrepancy suggests either that the cells swelled during the fossilization process or that the species possessed unique physiological traits compared to modern relatives. ## Unlocking Museum Collections This discovery highlights the untapped potential of nondescript fossil material currently held in museum drawers worldwide. By applying modern molecular techniques to previously ignored specimens, researchers can extract new biological data. This approach transforms how paleontologists view existing collections, turning seemingly uninteresting bone fragments into valuable sources of ancient molecular and physiological information. ## Future Scientific Implications The successful isolation of these cells marks a milestone in paleontology, demonstrating that molecular evidence can survive for over 100 million years. This methodology opens new avenues for studying dinosaur physiology and evolution. Future research will likely focus on applying these advanced chemical analysis techniques to other archived fossils to reconstruct ancient life. ## Sources covering this story - https://www.newscientist.com/article/2596881-dinosaur-red-blood-cells-recovered-from-115-million-year-old-fossil/?utm_campaign=RSS|NSNS&utm_content=home&utm_medium=RSS&utm_source=NSNS — --- _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._