A few species of animals naturally have a bone in their hearts, including cows, sheep, and dogs. This os cordis has not been seen in primates, until recently discovered in chimpanzees in a study by the University of Nottingham’s School of Veterinary Medicine and Science. Not all chimpanzees, but some chimps who have heart problems, specifically idiopathic myocardial fibrosis (IMF). This is the first time a heart bone has been found in great apes.
For the new study, 16 chimpanzees, some with IMF and some without, had their hearts scanned with x-ray microcomputed tomography. No animal needed to be killed, as all chimps died of natural causes in European zoos. The scans generated clear, high-resolution images showing the tiny os cordis, which measures just a few millimeters across.
For anatomy nerds out there, this “hyperdense” bone structure was found inside the right fibrous trigone. Simply described, this meaty part of the heart forms a link between the aortic, mitral, and tricuspid valves.
Some chimp hearts also exhibited cartilago cordis, that is, cartilage formation. This is an important discovery, because the cartilage might have something to do with the growth of the rare bone structure, as cartilage has the potential to turn into bone.
This discovery might open up research into possible ossification of human hearts with IMF. Read more about the discovery at Gizmodo.
(Image credit: Bjørn Erik Pedersen)