Scientists Find Possible Red Blood Cells in 115M-Year-Old Dinosaur
Fossilised Red Blood Cells Discovered in 115-Million-Year-Old Dinosaur Bone
Scientists examining the hind leg bones of a small, meat-eating dinosaur called an Aratasaurus have discovered what appear to be fossilised red blood cells alongside traces of heme, the organic molecule that enables hemoglobin to carry oxygen through the bloodstream, The Guardian reported. The specimen lived and died 115 million years ago in what is now north-eastern Brazil, providing a mineral and molecular echo of ancient biology that researchers previously assumed was impossible to preserve over deep time.
The Tech TL;DR:
- Researchers found mineralised red blood cell structures inside vascular canals of an 115-million-year-old Aratasaurus museunacionali leg bone.
- Chemical testing identified heme and collagen amino acids stabilized by a manganese compound called hausmannite.
- The discovery challenges conventional paleontological assumptions about organic molecular survival and opens new avenues for studying ancient metabolism.
Excavation History and Specimen Housing at the National Museum of Brazil
The fossilised remnants of the Aratasaurus were originally unearthed in a mine in 2008. Since their recovery, the remains have been housed and continuously studied at the National Museum of Brazil. According to New Scientist, the specific leg bone fragment was nondescript and visually uninteresting, appearing to be nothing more than a collection of standard rock-bound bone.
When Kliti Grice at Curtin University in Western Australia led a research team to analyze thin slices of the fossils, she etched out parts of the material using hydrochloric acid to dissolve the surrounding rock. Microscopic examination via electron microscope revealed small, round structures resembling red blood cells residing precisely within fine channels where blood vessels once ran. In a single slide just a fifth of a millimetre wide, researchers counted 20 distinct blood cells.
Chemical Identification of Heme and Collagen Amino Acids
To verify the biological nature of the structures, the research team conducted chemical tests that came back positive for heme and its breakdown products. Liquid chromatography-mass spectrometry analysis, as reported by New Scientist, confirmed the presence of haem B, a constituent of hemoglobin that binds to oxygen. Tests also detected traces of amino acid building blocks for collagen, a vital protein found in connective and other tissues.
Contamination checks ruled out external sediments dominated by algae. Cells found outside the bone contained chlorophyll-derived compounds, whereas those inside the vascular channels contained haem-derived molecules. To explain how these delicate structures survived 115 million years, Grice theorized that a manganese compound called hausmannite formed in and around the blood cells, stabilising them prior to fossilisation. Popular Science noted that this level of preservation likely required rapid burial in an environment rich in microbes yet low in oxygen.
Scientific Debate Over Cellular Morphology and Preservation Limits
Published in the Proceedings of the National Academy of Sciences, the findings have stoked immediate debate within the paleontological community. Mary Schweitzer at North Carolina State University, noted for her own discoveries of soft tissues and blood vessels in dinosaur fossils, expressed skepticism that the structures are genuine red blood cells. As reported by The Guardian and Futurism, Schweitzer pointed out that dinosaur red blood cells should feature a dome-like “nuclear bulge” on each side, whereas the structures found in the Aratasaurus are concave.
Despite reservations regarding the exact cellular morphology, Schweitzer acknowledged that the detection of heme and collagen amino acids remains persuasive. The study’s authors emphasize that their work does not imply that intact DNA or large proteins survive indefinitely, nor does it signal the arrival of real-world de-extinction projects akin to science fiction. Instead, Grice highlighted to The Guardian that the primary objective is determining the true limits of molecular preservation in deep time, suggesting that countless museum collections worldwide may harbor extraordinary molecular data waiting for modern analytical techniques.
Previous recoveries of blood-related remains include 75-million-year-old bone fragments from Canada in 2015 and a Tyrannosaurus rex femur from Montana in 2005, but researchers describe the Aratasaurus findings as the oldest isolation of red blood cell components to date.
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