Scientists find oldest dinosaur red blood cell traces in Brazil

Scientists from Curtin University in Perth, Australia, identified the oldest dinosaur red blood cells from 115 million years ago.

The researchers published their findings in the Proceedings of the National Academy of Sciences, a journal from the U.S. National Academy of Sciences. The team analyzed fossilized bones of an Aratasaurus museunacionali, a two-legged predator about 3.1 meters long, which were found in a gypsum mine in Ceará, Brazil, in 2008.

The specific remains included the right hind limb, featuring the femur, tibia, and parts of the foot. At the time of its death, the dinosaur was approximately four years old. The researchers found microscopic structures inside the bone's vascular channels that match the shape of fossilized red blood cells. Further tests confirmed the presence of mineralized heme, a molecule containing iron that binds with hemoglobin.

Kliti Grice, a geochemist at Curtin University and the study's lead author, explained that these findings represent a mineral and molecular echo of ancient biology rather than preserved liquid blood. The study shows that biological information can persist in fossils longer than previously thought. However, Grice clarified that the survival of these cellular shapes and chemical signals does not mean the dinosaurs' DNA survived. She noted that large biomolecules like DNA behave differently than small, chemically transformed molecular remains.

The discovery encourages paleontologists to investigate the limits of molecular survival in fossils rather than assuming biological data disappears after a certain time.