Tiny, Rare Bone Found in the Hearts of Chimpanzees

We may refer to some humans as “hard-hearted,” but some animals, such as oxen and sheep, actually have a tiny bone in their heart tissue. Now, scientists detected the same kind of bone, called an os cortis, in some of humans’ closest relatives, chimpanzees—raising questions about the possibility of such a bone in some human hearts, they say.

Researchers from the United Kingdom published their findings in the journal Scientific Reports last week. The team, led by Catrin Rutland of the University of Nottingham, studied the chests of 16 chimpanzees with micro-computed tomography, an advanced kind of 3-D X-ray imaging, Brooks Hays reports for United Press International.

The beautiful chimpanzee os cordis imaged by the fantastic @stu_rock in the @UoNHounsfield for our latest research 'Discovery of os cordis in the cardiac skeleton of chimpanzees' https://t.co/VpPrKRKHw4 pic.twitter.com/NRLB5nhvYB

— Dr Catrin Rutland (@catrinrutland) June 10, 2020

The longest bone measured by researchers was 7.6 millimeters, or about the size of a pencil eraser. All the bones were hollow, with fine interlocking bone structures inside, she tells Aristos Georgiou of Newsweek.

“The discovery of a new bone in a new species is a rare event, especially in chimps which have such similar anatomy to people. It raises the question as to whether some people could have an os cordis too,” Rutland says in a statement.

However, researchers have yet to fully understand how the os cordis functions in hearts, or whether its presence is linked to heart disease in some way. Scientists in this study learned that the millimeters-long bone was more likely to be found in the hearts of chimpanzees suffering from a kind of heart disease called idiopathic myocardial fibrosis (IMF). The team had set out to research signs of heart disease in chimpanzees, a condition that affects 70 percent of adult captive chimps, reports Carly Cassella for Science Alert. Wild chimpanzees, or Pan troglodytes, are listed as endangered on the IUCN Red List, so understanding heart disease in chimps is key to protecting the species, according to the statement.

As Cassella notes, the relatively small scope of this study means that more work needs to be done to determine how widespread the os cordis is in chimpanzee populations. But researchers are hopeful that future study could clarify the link between the os cordis bone and heart disease, in chimps and humans.

“Chimpanzees are endangered in the wild, thus the study of causes and mechanisms of cardiac disease is paramount in order to protect this species and maintain healthy captive populations,” Rutland tells Newsweek. “The possibility of os cordis occurring in humans suffering from similar cardiovascular disorders should be considered. People also suffer from fibrosis and may also have an os cordis.”

Nora McGreevy | | READ MORE

Nora McGreevy is a former daily correspondent for Smithsonian. She is also a freelance journalist based in Chicago whose work has appeared in Wired, Washingtonian, the Boston Globe, South Bend Tribune, the New York Times and more.