Curtin University team identifies 115-million-year-old blood cells

Aratasaurus museunacionali specimen recovered from Brazil

Workers recovered the specimen from a Brazilian mine in 2008.

The individual was not fully grown, measuring just over 3 meters in length and weighing about 34 kilograms. The team examined fossil material taken from the right leg of the dinosaur.

Chemical analysis confirms mineralized cellular structures

Researchers identified mineralized red blood cells containing intact heme-derived molecules and collagen amino acids within the Aratasaurus bones. They investigated the chemistry in situ, rather than extracting individual molecules, by combining microscopy with mineralogical and molecular geochemistry.

To rule out contamination, the team performed imaging, spectroscopic, and molecular analyses. These tests showed no evidence of filaments, spores, biofilms, or pyrite mineralization. High-performance liquid chromatography–mass spectrometry detected heme B in the bone extract, distinguishing the material from the surrounding rock.

Elemental mapping revealed that the microstructures contained iron, carbon, and nitrogen. The rest of the bone consisted of phosphorus, calcium, fluorine, and carbon.

Microbial mats may have preserved the fossilized cells

The researchers hypothesize that the fossilized cells were preserved because the dinosaur died on a microbial mat. The researchers hypothesize that the oxygen-starved environment potentially stabilized the delicate structures.

The report was supplied by Victor O. Leshyk. Leshyk supplied the report regarding these findings.

Discovery surpasses previous 80-million-year-old record

The 115-million-year-old blood cells represent the oldest known example of potential dinosaur blood cells. Previous discoveries of this type only dated back about 80 million years.

Researchers previously identified 75-million-year-old bone fragments in Canada in 2015. A Tyrannosaurus rex femur found in Montana in 2005 contained blood cells dating back 68 million years.

Experts express caution regarding biological origins

Some experts say the shapes of the structures do not match those of reptilian red blood cells. Mary Schweitzer noted that non-mammalian red blood cells retain nuclei, which creates a characteristic nuclear bulge. The observed structures lack this feature.

Schweitzer praised the team's rigor and molecular approach but remained skeptical that the structures are genuine dinosaur red blood cells. Mauricio Barbi of the University of Regina said the authors provided convincing evidence of mineralized structures consistent with red blood cells but noted that caution was still needed.

Curtin University plans further replication studies

Kliti Grice of Curtin University explained that "morphology by itself isn't enough to establish its biological origin". This necessitates the use of both microscopic and chemical evidence.

Grice stated that the "immediate priority is replication" by examining different fossils and geological settings using complementary techniques. Researchers could revisit thousands of fossils already held in museum and university collections to look for molecular, mineralogical, and microscopic information.