Fossilised Red Blood Cells Found in 115-Million-Year-Old Dinosaur

Scientists examining the remains of a small, carnivorous dinosaur have identified structures resembling fossilised red blood cells inside its hind leg bones. The creature, known as Aratasaurus, inhabited north-eastern Brazil approximately 115 million years ago. Researchers utilized electron microscope imaging to observe tiny, rounded shapes within the fine channels where blood vessels once traversed, while subsequent chemical analyses confirmed the presence of heme, the organic compound responsible for carrying oxygen through hemoglobin.

The discovery has generated considerable discussion within the scientific community due to the rapid rate at which biological molecules typically degrade. Prof Kliti Grice of Curtin University, who spearheaded the research team, described the findings as a world first, noting that crimson-related chemical signatures have never previously been identified in situ within any dinosaur fossil. Researchers suggest that a manganese compound called hausmannite may have stabilized the cells prior to fossilization, aiding in their preservation.

Extraordinary molecular preservation in ancient fossils could unlock new insights into dinosaur biology.

Despite the findings, debate remains among experts. Prof Mary Schweitzer of North Carolina State University expressed skepticism regarding whether the structures are indeed red blood cells, citing their concave appearance rather than the expected nuclear bulge. However, Schweitzer found the detection of heme and collagen amino acids more convincing. Grice emphasized that the work does not imply the survival of large biological molecules like DNA, but rather demonstrates that valuable molecular information can endure in museum collections worldwide.

Why it matters

This research challenges long-held assumptions regarding the degradation of organic materials in paleontology. By demonstrating that molecular traces can survive over deep time, the findings encourage scientists to apply advanced analytical techniques to existing museum specimens, potentially opening entirely new avenues for investigating ancient metabolism and biology.