Dhaka, Nov. 3 -- Scientists have discovered what they consider the strongest evidence yet of blood cells in a dinosaur fossil inside bone from the right leg of a medium-sized meat-eater that prowled Brazil some 115 million years ago during the Cretaceous Period.

The researchers identified numerous microscopic structures in bone from the species Aratasaurus museunacionali that appear to be fossilised red blood cells.

They also detected chemical evidence related to a key component of these cells - an iron-containing biomolecule called heme that is associated with hemoglobin, the protein that gives blood its red color.

The evidence for blood cells and heme was found in vascular canals inside bones of an Aratasaurus individual, thought to ...