Researchers find heme and cell-like structures in 115-million-year-old dinosaur bone

Researchers studying a 115-million-year-old dinosaur bone have reported finding microscopic structures resembling red blood cells and chemical evidence of heme, according to a study published in the journal Proceedings of the National Academy of Sciences.

The Discovery in Brazil

The fossil is a partial hind limb of Aratasaurus museunacionali, a theropod dinosaur from the Early Cretaceous. The bone was recovered in 2008 at the Mina Pedra Branca site in the Romualdo Formation in northeastern Brazil. Scientists believe the region's stagnant, low-oxygen waters may have slowed decomposition, aiding preservation.

Within the bone's vascular canals, researchers found oval-shaped microstructures. Using high-performance liquid chromatography coupled with mass spectrometry, the team identified heme B and an altered relative of the molecule. They also detected traces of hydroxyproline, an amino acid associated with collagen.

Evidence and Preservation

The study authors suggest that the presence of hausmannite, a manganese oxide, may have helped stabilize and preserve the cellular structures and their molecular components during fossilization.

To determine if the heme originated from the dinosaur or the surrounding environment, researchers compared the bone chemistry to the sedimentary matrix. While the matrix contained porphyrin signatures associated with chlorophyll and bacteriochlorophyll, the bone extracts were dominated by heme-related compounds. This contrast supports an endogenous origin, according to the study authors.

Scientific Debate

While the findings are described by lead author Kliti Grice, an organic geochemist at Curtin University, as a "landmark discovery," some experts urge caution:

• Morphology: Mary Schweitzer, a professor emeritus at North Carolina State University, noted that the structures are concave, whereas red blood cells in living relatives like birds and crocodilians typically have a "nuclear bulge" making them appear dome-like.
• Mineralization: Schweitzer also pointed out that hausmannite is not found in the red blood cells of living animals.
• Contamination: Researchers have noted that in 2019, studies of Centrosaurus bones showed that fossil bone can become a habitat for recent organic material and microbes, which can complicate interpretations of ancient chemistry.
• DNA vs. Heme: Timothy Cleland, a physical scientist at the Smithsonian Institution’s Museum Conservation Institute, noted that finding heme does not mean DNA has survived, as the two molecules fossilize differently.

Why it matters

If these findings are confirmed in more specimens, they could allow scientists to investigate dinosaur metabolism, oxygen transport, and how their biology compares to modern animals. The research suggests that extraordinary molecular information may be preserved in museum collections worldwide, waiting for new analytical techniques to be applied.

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Sources

• cnn.com: Scientists find traces of red blood cells in a dinosaur fossil | CNN
• thebrighterside.news: Scientists find first-ever evidence of fossilized blood cells in 115-million-year-old dinosaur bones - The Brighter Side of News
• theanimalrescuesite.com: Dinosaur Red Blood Cells Detected: Heme Found in 115-Million-Year Bone | The Animal Rescue Site
• theguardian.com: Fossilised red blood cells found in 115m-year-old dinosaur’s bone, say scientists | Palaeontology | The Guardian
• discoverwildlife.com: Scientists find red blood cells in dinosaur bone in "landmark discovery" | Discover Wildlife
• newatlas.com: Incredible discovery of fossilized blood cells inside a dinosaur leg bone

This article was drafted with AI assistance and checked against the sources above. Company claims are reported as claims. Cover image is AI-generated.