Fossilized red blood cells found in 115-million-year-old Brazilian dinosaur bone

Scientists have found the first chemical proof of red blood cells in a dinosaur fossil, a 115-million-year-old bone from Brazil containing heme, a blood molecule. This landmark discovery provides direct evidence of blood components in a dinosaur for the first time. An international team led by Curtin University identified mineralised red blood cells and heme B in the theropod Aratasaurus museunacionali. The study, published in PNAS, used mass spectrometry to confirm the molecules, while testing surrounding rock showed no blood traces, verifying the find's origin. Researchers attribute the preservation to rapid burial in a low-oxygen environment, where the mineral hausmannite helped fossilise the cells. The discovery challenges assumptions about biomolecule survival and opens new avenues for studying dinosaur metabolism, though DNA remains unrecoverable.