Scientists discover preserved dinosaur blood cells and heme in 115-million-year-old fossils

An international research team led by Curtin University has identified fossilized red blood cells and heme molecules within the bones of an Aratasaurus museunacionali, a theropod dinosaur that lived 115 million years ago. The fossils were discovered in northeastern Brazil. The study, published in the Proceedings of the National Academy of Sciences (PNAS), utilized electron microscopy to detect small, spherical structures inside vascular pores that resemble red blood cells, alongside collagen amino acids and chemical evidence of heme, the oxygen-carrying component of hemoglobin.

While previous research has suggested the presence of structures mimicking blood cells in fossils, this study marks the first time such findings have been chemically confirmed. The discovery is significant as it challenges existing scientific assumptions regarding the preservation of biological tissues and molecules over vast geological timescales. Researchers believe this breakthrough could lead to similar molecular findings within existing museum collections worldwide, although the topic remains controversial due to the rapid decomposition typical of biological material.