Scientists find traces of red blood cells in dinosaur fossil

Scientists have identified what appear to be red blood cells in a 115-million-year-old dinosaur fossil, according to a study published in the Proceedings of the National Academy of Sciences. The fossil, a partial hind limb from the theropod Aratasaurus museunacionali, was discovered in northeastern Brazil in 2008.

The study used advanced microscopic imaging and chemical analysis to detect not only structures resembling red blood cells but also heme, a molecule found in hemoglobin. This marks the first time heme has been detected in situ in a dinosaur fossil, according to the researchers.

The team suggests that the low-oxygen conditions at the burial site may have slowed decomposition, allowing organic material to be preserved. Along with heme, the bone also contained manganese oxides, which may have contributed to the preservation of the structures.

Despite the findings, some experts remain skeptical. They argue that the structures may not be actual red blood cells but rather the result of preservation processes. The study’s authors acknowledge that further research is needed to determine whether similar preservation occurs in other fossils.

The researchers plan to expand their work to other fossils to better understand how widespread such molecular preservation might be. They hope this could eventually help scientists learn more about dinosaur physiology and how it compares to modern animals.

However, experts like Timothy Cleland and Mary Schweitzer caution that finding heme does not necessarily mean DNA or other biological molecules have survived. They emphasize the need for more studies to confirm the authenticity of the structures and their significance.