Scientists have reported dinosaur blood preserved inside 115-million-year-old bones, revealing that delicate biomolecules can persist far longer than once assumed and potentially reshaping how prehistoric life is studied.
An international team led by Curtin University identified fossilized red blood cells and chemical signatures of blood molecules in the remains of Aratasaurus museunacionali, a carnivorous theropod from northeastern Brazil. According to the study in the Proceedings of the National Academy of Sciences, the team also detected amino acids associated with collagen, a key structural protein in bone and connective tissues.
The research provides the first definitive chemical confirmation of hemoglobin-derived molecules inside fossilized dinosaur red blood cells. Earlier work had noted cell-like structures in ancient bones, but scientists had not conclusively verified these particular molecular remnants within them.
Ancient dinosaur blood preserved inside fossilized bones
Analysis of the dinosaur’s limb bones revealed numerous mineralized red blood cells within vascular canals, the tiny channels that once carried blood vessels. Chemical tests detected heme molecules, components of hemoglobin that enable red blood cells to transport oxygen.
The detection of these molecules offers direct chemical evidence of ancient blood within the fossil. It also shows that certain biological materials, long considered too fragile to last millions of years, can persist under exceptional conditions.
The study was led by John Curtin Distinguished Professor Kliti Grice, founding director of Curtin University’s WA-Organic and Isotope Geochemistry Centre and an Australian Research Council Laureate Fellow.
“To detect intact heme-derived molecules in 115-million-year-old red blood cells is astonishing: this really is a landmark discovery,” Professor Grice said. “It not only extends the known fossil record of blood, but also offers a direct molecular window into the physiology of long-extinct animals so we may better understand them and the world they lived in.”
How dinosaur blood survived 115 million years
The team links the extraordinary preservation to the manganese-oxide mineral hausmannite, which appears to have stabilized the fossilized blood cells and protected their molecular components, including collagen-related amino acids, across geologic time.
This mineral effectively formed a natural capsule that shielded microscopic traces of the dinosaur’s biology long after death.
Burial conditions likely played a crucial role as well. Researchers suspect the animal was rapidly covered by sediment in a low-oxygen setting with abundant microbial activity, circumstances that may have aided the survival of otherwise fragile biological material.
The collaboration involved Curtin University’s School of Earth and Planetary Sciences, the Japan Agency for Marine-Earth Science and Technology, the Brazilian National Museum, the Regional University of Cariri, and Johns Hopkins University.
A discovery that challenges fossil preservation limits
The results challenge a longstanding view in paleontology that molecules associated with blood, particularly those derived from hemoglobin, could not persist over such vast timescales.
Beyond confirming the survival of ancient blood components, the study suggests other fossils may harbor molecular information that standard examinations have missed.
“These findings challenge longstanding assumptions that certain biomolecules such as hemoglobin cannot survive deep time,” Professor Grice said. “It opens exciting new avenues for molecular-level paleontology, allowing us to investigate the evolution of blood, metabolism and even activity levels in ancient animals.”
Such molecular insights could help reconstruct aspects of extinct animals’ metabolism and physiology that are difficult to infer from bones alone.
Implications for ancient life beyond Earth
The significance may extend to the search for life in extreme environments, including beyond Earth. Understanding how fragile structures persist for millions of years could guide strategies to detect ancient biosignatures elsewhere.
Professor Martin Van Kranendonk, head of Curtin University’s School of Earth and Planetary Sciences, said the work is reshaping understanding of molecular preservation over immense timescales and under harsh conditions.
These insights carry implications for astrobiology. If biological molecules or their chemical fingerprints can endure under favorable conditions for more than 100 million years, researchers may reconsider where and how to search for traces of ancient organisms.
“This study exemplifies how coordinated efforts across institutions, continents and scientific disciplines can unlock extraordinary insights into ancient life,” Professor Van Kranendonk said.
The research received support from a 2021 Australian Research Council Laureate Fellowship awarded to Professor Grice. The paper, titled “Heme signatures in mineralized red blood cells within vascular canals of a 115-million-year-old dinosaur bone,” appears in the Proceedings of the National Academy of Sciences.
Earlier coverage of related work can be found in Ancient dinosaur blood traces reported in 115M-year fossil.