Researchers from Flinders University, along with colleagues in the UK and Sweden, used the scanning to uncover the origins of a 400-million-year-old fossil fish called Ligulalepis. The technology has also revealed a 3D-model of the fish’s ancient brain and confirms it as the ancestor of all modern bony fish.

The fossil’s also linked to the bone structure of human skeletons, providing anatomical evidence about human evolution from fish which can today be found within the makeup of our own bodies.

Flinders University Research Associate, Dr Alice Clement, says the discovery of two 3D-preserved fossils in Australia allowed the team to scan hidden features inside the skull and lead to the reconstruction of an ancient brain cavity.

“Our research reveals previously unknown details about the pattern of dermal skull bones, the shape of the brain and other soft tissue features. It resolves the big question about what the ancestor of all modern bony fish looked like,” Clement says.

“Understanding the structure is important because Ligulalepis is in a crucial position on the evolutionary tree. This discovery identified this fish as being the ancestor of all bony fish right before two major groups split and evolved different bodies.”

The University’s palaeontology professor, John Long, says bony fish are an important group because land animals such as mammals, reptiles and amphibians evolved from them.

“Not many people would think humans evolved parts of their bone structure from a fish. We are all just highly advanced fishes, that’s the point of our story. Four hundred million years ago, some of these fish started to develop fins at the front with bones that would eventually become the humerus, ulna and radius that forms our arm.”

Flinders University’s research has highlighted the evolutionary relationships of the first bony fishes and demonstrated the importance of palaeontology to help accurately understand our distant origins.