Like humans, chimpanzees suffer from cardiovascular diseases, and because of such diseases in the heart muscle of monkeys, connective tissue begins to grow. Sometimes this tissue gives real bone – four such heart bones are described in Scientific Reports by researchers from the University of Nottingham. In two cases, these are spongy bones (similar to ribs or bones of the wrist), in one case – hyaline cartilage, and in another case – fibrous-cartilage formation with signs of ossification. All bones are very small, only a few millimeters in size, and have arisen as a result of idiopathic myocardial fibrosis – a disease that people suffer from, and the natural question is whether bones are found in human hearts. (However, several years ago we already wrote about how the heart can turn into bone.)
In general, chimpanzees are not the only animals with bones in the heart; they are found in cows and buffaloes (whose heart bones are quite large), in sheep, otters, dogs and camels. Moreover, in some species, the bones in the heart are a common thing, and, apparently, are not associated with any pathology.