Scientists identify evidence of red blood cells in 115-million-year-old dinosaur fossil

Researchers have identified evidence of red blood cells within the fossilized remains of an Aratasaurus museunacionali, a predatory dinosaur that lived approximately 115 million years ago. The discovery, extracted from a right leg bone found in Brazil, includes microscopic structures that mirror the appearance of red blood cells, supported by chemical evidence of heme—the molecule responsible for the red pigment in hemoglobin.

Kliti Grice, a geochemist at Curtin University who led the study, noted that the findings represent mineralized echoes of ancient biological processes rather than preserved blood. Grice explicitly stated that the research did not recover any dinosaur DNA, cautioning that the presence of structural remnants and chemical signals does not imply the survival of complex genetic material.

Published in the Proceedings of the National Academy of Sciences, the research suggests that molecular signatures can persist longer than previously assumed. While researchers also detected amino acids associated with collagen, they emphasize that this does not constitute the retrieval of complete proteins or genetic codes, but rather offers a new perspective on the limits of molecular preservation.