Scientists find traces of red blood cells in a dinosaur fossil

Key Points:

• Researchers have found the strongest evidence yet of red blood cells in a 115 million-year-old dinosaur bone, using new microscopic imaging and chemical analyses to detect structures resembling red blood cells and chemical traces of heme within the fossil.
• The fossil, from the theropod dinosaur Aratasaurus museunacionali, was discovered in Brazil’s Romualdo Formation, where low-oxygen burial conditions and mineral deposits may have helped preserve organic material, including possible blood cell structures.
• While the study marks a significant advancement by combining multiple lines of evidence, some experts remain skeptical about definitively identifying the structures as red blood cells, noting differences from modern relatives and questioning certain chemical findings.
• The research opens new avenues for exploring molecular preservation in fossils, potentially allowing scientists to investigate dinosaur physiology and biology in unprecedented detail, though it does not imply recovery of dinosaur DNA.
• Future studies aim to examine other fossils across species and environments to determine how common such preservation is and to deepen understanding of prehistoric molecular information and its implications for evolutionary biology.