Scientists Identify Possible Dinosaur Blood Cells in 115-Million-Year-Old Fossil
Researchers from Curtin University report the detection of cell-like structures and heme molecules in a Brazilian theropod leg bone, suggesting preservation of dinosaur blood components for over 100 million years.
A team of scientists from Curtin University in Australia says they have identified structures resembling red blood cells and associated blood-derived molecules in a 115-million-year-old leg bone of the small theropod Aratasaurus museunacionali, recovered from a Brazilian mine in 2008. Microscopic examination revealed ellipsoidal microstructures within the bone’s vascular canals that match the size and shape of blood cells, and chemical analyses detected heme B, a molecule essential for oxygen transport in blood.
"Something that looks like a blood cell under a microscope is interesting, but morphology by itself isn't enough to establish its biological origin," said Kliti Grice, an organic geochemist at Curtin University. "Our approach brings together microscopic observations with chemical evidence associated with the structures. The convergence of independent lines of evidence is much more powerful than saying, 'this looks like a red blood cell'."
The researchers used imaging, spectroscopic and molecular techniques to rule out alternative explanations such as fungal or microbial contamination, noting the absence of filaments, spores or biofilm structures. Elemental mapping linked the cell-like features to iron, carbon and nitrogen, consistent with heme composition, while the surrounding bone matrix showed different elemental signatures.
According to the study, the preservation may be linked to the fossil’s geological context—a shallow, low-oxygen marine environment with microbial mats that facilitated manganese mineralization, potentially stabilizing delicate structures during fossilization.
"The immediate priority is replication," Grice added. "We need to examine additional fossils, different geological settings and other parts of the dinosaur family tree using complementary microscopic, chemical and molecular techniques. If similar signals can be demonstrated independently, we can begin asking much bigger questions about preservation and, cautiously, about ancient physiology."
The findings, if confirmed, would represent the oldest known example of possible dinosaur blood cells, extending the record beyond previous claims limited to about 80 million years.