Dinosaur blood cells found in 115-million-year-old Brazilian fossils

Paleontologists have confirmed the first-ever discovery of intact biomolecules and mineralized red blood cells inside 115-million-year-old dinosaur fossils, challenging long-held assumptions about cellular preservation. The findings were published today in PNAS. The international team chemically identified heme, an oxygen-carrying blood compound, within fossilized limb bones of a juvenile Aratasaurus museunacionali from Brazil. A manganese oxide called hausmannite helped preserve the structures, likely due to rapid burial in a microbe-rich, low-oxygen environment. Researchers say the discovery could advance understanding of blood evolution and dinosaur metabolism. It also raises the possibility that similar delicate biomolecules might survive in harsh environments elsewhere in the universe.