Traces of ancient blood found in 115 million-year-old dinosaur fossil, new study claims

Scientists have discovered the first direct molecular evidence of dinosaur blood preserved within a 115-million-year-old fossil bone from Brazil. The bone contains structures resembling red blood cells, which were confirmed through chemical analysis revealing heme molecules, a key component of hemoglobin, as well as traces of collagen.

This groundbreaking discovery was reported in the Proceedings of the National Academy of Sciences on November 2, 2026. The fossilized structures were found within vascular canals inside the bone, a location where red blood cells are typically found in living vertebrates, and the surrounding sediment did not contain these structures, indicating they are not the result of external contamination.

The rapid burial of the dinosaur in a low-oxygen environment, along with protective minerals, may have contributed to the preservation of these molecules for millions of years.