World's oldest heart, ‘beautifully preserved' and dating back 380 million years, found in Australia

Researchers have found the heart fossil in fish specimens discovered in West Australia's Kimberley region. (Image credit: Curtin University)

The world's oldest heart, dating back to 380 million years, has been discovered in an ancient fish species in Australia. The research, led by Perth-based Curtin University, explains the evolution of human bodies themselves, scientists said.

Researchers found the fish fossil in West Australia's Kimberley region, at a location known as the Gogo Formation.

Professor Kate Trinajstic, the head of the research, and her colleagues and collaborators, used x-rays and neutron beams to scan the fish specimens, preserved in limestone concretions, a statement released by Curtin University said.  Then, they created 3D images of the soft tissues inside them.

It is for the first time that a research as has brought forth a 3D model of a complex s-shaped heart in an arthrodire -- an extinct species of jawed fish. The study has been in the Science journal.

Lead researcher Professor Trinajstic described the discovery as astounding.

“As a palaeontologist who has studied fossils for more than 20 years, I was truly amazed to find a 3D and beautifully preserved heart in a 380-million-year-old ancestor,” she added.

The findings have significant implications for evolutionary studies.

“Evolution is often thought of as a series of small steps, but these ancient fossils suggest there was a larger leap between jawless and jawed vertebrates,"  Trinajstic said. "These fish literally have their hearts in their mouths and under their gills -- just like sharks today."

She added that the study offered important clues about how the anatomy of vertebrates evolved.

"These features were advanced in such early vertebrates, offering a unique window into how the head and neck region began to change to accommodate jaws, a critical stage in the evolution of our own bodies," the statement about the study said.