How-to videos on building six-pack abs weren't around 380 million years ago, but that didn't stop a certain species of fish from developing them.
A team of international scientists discovered a scary-looking, shark-like fossilized fish with abdominal muscles, uncovering the rare find in the photo above in the remote region of Kimberley in Western Australia, the Australian Broadcasting Corporation reported.
They are the oldest preserved muscles ever found, according to the NewScientist, which is calling them the world’s first abs.
Paleontologists from Australia, France, and Sweden made the discovery in rocks on the Gogo Formation, where more than 50 species of fish fossils have been found.
"We didn't expect these fish to have abdominal muscles; they're the abs that people have," Finders University paleontologist John Long told ABC. "Sharks don't have them, nor do any other living fish, but all living four-legged animals do have them, such as reptiles, mammals, and birds."
Kate Trinajstic of Curtin University in Perth, Australia, told New Scientist, "We were stunned to find that our ancient fossil fishes had abs."
The paleontologists told ABC that it was rare for the soft tissue in the placoderm fossils to be so well-preserved, and it allowed them to map the muscular structure of the fish.
Placoderms were jawed fish featuring armor covering their heads and parts of their bodies, and most were carnivores.
"Some were quite scary, big-time predators," Per Ahlberg of Uppsala University in Sweden told New Scientist. One was known as Dunkleosteus and grew to 33 feet long.
The one you see at the top lived 380 million years ago, or long before the invention of Bowflex.
Hat tip to Outside.