Scientists Find Heme and Collagen Traces Inside 115-Million-Year-Old Dinosaur Fossils
“This really is a landmark discovery,” Kliti Grice, a study co-author and chemist at Curtin University in Australia, said in a statement, describing the identification of organic blood compounds inside a dinosaur bone. Researchers analyzing the hind leg bones of a small, meat-eating Aratasaurus that lived in northeastern Brazil 115 million years ago have found what appear to be fossilized red blood cells and traces of heme. Electron microscope images revealed small, round structures resembling red blood cells in fine channels where blood vessels once ran. Chemical tests also identified heme, the organic compound that allows hemoglobin to carry oxygen, alongside amino acid building blocks for collagen.
Contrasting Views on Cell Structures and Organic Preservation
The interpretation of the microstructures has drawn skepticism from other researchers in the field. Prof. Mary Schweitzer at North Carolina State University in the US, who has previously discovered remnants of blood vessels and soft tissues in dinosaur fossils, is not convinced the structures are red blood cells, noting that dinosaur red blood cells should have a “nuclear bulge” making them appear dome-like rather than concave. However, Schweitzer expressed more confidence in the chemical detection of heme and collagen amino acids, telling that conventional wisdom regarding the rapid breakdown of endogenous organics is routinely challenged by modern analytical techniques.
Mineral Stabilization and the Hunt for Ancient Biomolecules
To explain how such delicate biological material survived deep time, researchers point to a specific manganese compound. According to Grice, a manganese mineral called hausmannite formed in and around the blood cells, potentially stabilizing them and the associated amino acids prior to fossilization. The study’s authors theorize this exceptional preservation required a rapid burial in a microbe-rich yet oxygen-poor environment. While the findings open new avenues for investigating dinosaur metabolism and activity levels, Grice urged caution, emphasizing that the work does not imply that large proteins or DNA survive in ancient fossils.
Frequently Asked Questions About the Aratasaurus Fossil Discovery
What is the Aratasaurus and when was it found?
Aratasaurus museunacionali was an Early Cretaceous theropod that measured over 10 feet long and weighed about 75 pounds as a juvenile. Its fossilized remains were discovered in a mine in 2008 and have since been housed in the National Museum of Brazil.
What specific chemical tests were performed on the bones?
Researchers used electron microscopes to examine thin slices of the hind limb bones and conducted chemical tests that came back positive for heme, its breakdown products, and amino acid building blocks for collagen.
Where was the research published?
The findings were published in the journal Proceedings of the National Academy of Sciences.
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