Dinosaur Bones Preserve 115-Million-Year-Old Blood
Heme and blood cells in a Brazilian theropod suggest molecular traces can survive deep time, based on a single research specimen.
Updated on Nov. 2, 2026 in Geology
Researchers report fossilized red blood cells and hemoglobin-derived molecules preserved in the bones of a theropod dinosaur, Aratasaurus museunacionali, that lived about 115 million years ago in Brazil. The findings, published in Proceedings of the National Academy of Sciences and led by Curtin University in Australia, are research-stage and rest on the analysis of a single specimen.
Why it matters
The work pushes the known limits of molecular preservation in deep-time fossils, which has been debated for decades. If blood-derived molecules can survive over 100 million years, paleontologists gain a new kind of chemical evidence about extinct animals' physiology.
The analysis identified preserved red blood cells within the bones' vascular canals, heme inside those cells, and amino acids associated with collagen protein. The evidence rests on one specimen, and the source does not provide a quantitative comparison with other fossils.
The players
Curtin University
An Australian research university that led the study, known for its work in geoscience and paleontology.
Proceedings of the National Academy of Sciences
A peer-reviewed multidisciplinary journal published by the U.S. National Academy of Sciences, which carried the study.
The details
The dinosaur's carcass was buried quickly after death in a low-oxygen environment rich in microorganisms, which slowed decay. Hausmannite, a manganese mineral, then mineralized the red blood cells, stabilizing their structures over geologic time. Heme, the iron-containing component of hemoglobin that carries oxygen in blood, was detected within those preserved cells. Collagen, the structural protein that makes up much of bone, was represented by associated amino acids.
Timeline
The dinosaur lived approximately 115 million years ago in what is now northwestern Brazil.
The study was published in PNAS on Monday, November 2, 2026.
The Tech Race
Molecular paleontology, the chemical analysis of ancient remains, is a growing sub-field that uses mass spectrometry and mineralogy to test whether organic compounds survive deep time. This study adds a specific chemical identification to that effort, though it remains a single-specimen result that other labs must reproduce.
This is a research finding with no consumer product or service attached, so it does not change anything for the general public directly. Its near-term effect is on paleontology labs, which may adopt similar mineralogical and molecular methods to test other fossil specimens.
The takeaway
Watch whether other laboratories can detect heme or similar blood-derived molecules in independent dinosaur specimens, which would test whether this preservation is common or unusual. The published PNAS paper is the primary record to check for the full methods and data.
Further reading
For more on how rocks and minerals record ancient life, explore our Geology coverage.
