Researchers have discovered a 380-million-year-old heart and other organs in the fossil of an ancient jawfish collected in the Kimberley region of Western Australia.
Experts say it’s the oldest three-dimensional preserved fossil heart ever found in a vertebrate vertebrate, shedding new light on human evolution.
The research, published in the Science Journal on Friday, finds the position of the organs in the bodies of arthropods — an extinct class of ancient armored fish — similar to modern shark anatomy.
Curtin University lead researcher and paleontologist Kate Trinajstic said the heart’s discovery was remarkable given its age and level of preservation.
‘It drove us completely crazy’
The find came as a surprise to a global team, including researchers from Australia, France and Sweden.
“We knew there was something in it. We didn’t know its size,” Professor Trinajstic told AAP.
“We were completely amazed that there was a heart. We had no preconceived notions that we could have kept that.”
Researchers used neutron beams and synchrotron X-rays to scan the samples, which were embedded in limestone.
They constructed 3D images of the soft tissues based on the different densities of minerals deposited by the bacteria and the surrounding rock.
Scans revealed that the fish looked remarkably like a modern-day shark, with a two-chambered, S-shaped heart under its gills.