Scientists Say They Found Fossilized Red Blood Cells in a 115-Million-Year-Old Dinosaur Bone

PERTH, Australia, Nov. 2 (TodayViralUSA) — Scientists say they have found what appear to be fossilized red blood cells inside the leg bones of a 115-million-year-old dinosaur, along with chemical traces of the molecule that lets blood carry oxygen, a claim that is drawing both excitement and skepticism from other researchers.

The team, led by Kliti Grice of Curtin University in Western Australia, examined the hind leg bones of an Aratasaurus, a small meat-eating dinosaur that lived in what is now northeastern Brazil. The findings were published in the Proceedings of the National Academy of Sciences, The Guardian reported.

What the researchers found

Electron microscope images showed small, round structures resembling red blood cells inside fine channels where blood vessels once ran. Chemical tests detected heme, the compound that allows hemoglobin to carry oxygen, along with its breakdown products. The tests also found traces of amino acids that make up collagen, a key protein in connective tissue.

“Fossilised red blood cells with distinct chemistry related to heme have never been found in situ in any fossil, let alone a dinosaur. This is a world first,” Grice said.

The researchers suggest a manganese mineral called hausmannite, which formed in and around the cells, may have stabilized them before fossilization and helped preserve the amino acids. The Aratasaurus remains were found in a mine in 2008 and are held by the National Museum of Brazil.

Not everyone is convinced

Mary Schweitzer of North Carolina State University, known for finding remnants of blood vessels and soft tissue in dinosaur fossils, questioned whether the structures are red blood cells. She noted that dinosaur red blood cells would be expected to carry a nucleus that makes them bulge on both sides, while the structures in the study are concave. Schweitzer said she was more persuaded by the detection of heme and collagen amino acids.

If confirmed, the work could open new ways to study dinosaur blood, metabolism and activity levels. Grice cautioned that it does not mean large molecules such as proteins or DNA survive in ancient fossils. “Any extraordinary claim needs extraordinary analytical evidence,” she said. “The aim isn’t to find Jurassic Park DNA, it’s to determine how much genuine molecular information deep time can preserve.”