Spektrum der Wissenschaft (in German) reports on a study in PNAS by a team led by Kliti Grice of Curtin University. In a 115-million-year-old leg bone of the Brazilian dinosaur Aratasaurus, they found tiny oval structures that they identify as red blood cells. Two lines of evidence support this: the structures contain breakdown products of haemoglobin, including traces of the heme ring, and they appear only inside the bone's blood vessel canals. Iron and high manganese levels from the oxygen-poor sediment may have helped preserve them.

The article is careful not to oversell. Fungal spores or mineral spheres formed after death have not been fully ruled out. That is how extraordinary claims should be handled: several independent lines of evidence, and honest room for doubt.

Source: Lars Fischer, Spektrum der Wissenschaft (German) (2026-11-02)

Summarised by the FTI newsdesk.