Video has surfaced from the time a scientist found a way to make a shark's heart beat outside its body as part of an effort to learn more about one of the world's most mysterious underwater creatures.
James Ducker posted the video recently on his Twitter page, noting that it was one part of extensive research from Dr. Holly Shiels.
She traveled to Greenland to collect research on Greenland sharks, who have incredibly long lifespans.
They're not sure how old the shark heart in the video is, but research suggests it could have been from one that lived to the age of 200.
While that certainly seems like a ripe old number, it's only about midlife-crisis age for a Greenland shark. Some scientists estimate that the animals can live as long as 400 years, only reaching sexual maturity when they hit about 150.
Aside from their incredible lifespan, though, we don't know too much about Greenland sharks.
As part of an effort to collect more info on them and better learn how to protect them, Shiels and her colleagues set off to Greenland to gather research on the animals.
And part of that research meant, in a sense, bringing a heart back to life. The video of the shark heart beating isn't the cutest shark footage you've ever seen — the raw, beating heart is incredibly graphic and a bit jarring to watch.
But it's certainly interesting. The heart actually beats very slowly, an adaptation that researchers believe could help contribute to its lifespan.
The more they learn about the other adaptations that help it live for centuries, the more they could be able to help scientists looking to combat diseases and conditions that come with human aging. Perhaps one of the oldest beating hearts on the planet could hold clues about new life.