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Fossil discovery identifies ancestor of all bony fish and link to humans

(Fish + 400m years = humans)

Modern scanning techniques have been used to uncover the origins of a 400 million year old fossil fish called Ligulalepis, revealing a 3D model of its ancient brain and confirming the ancestry of all modern bony fish.

Researchers from Flinders University, along with colleagues in the UK and Sweden, have also uncovered the fossil’s link with the bone structure of human skeletons, providing anatomical evidence about human evolution from fish which can today be found within the make-up 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,” Dr 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,”

Flinders University Strategic Professor in Palaeontology, 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, ”

“400 million years ago, some of these advanced fishes were starting to develop fins at the front that had bones that would eventually become the humerus, ulna and radius that forms our arm and these fish started to develop that in their fins,” Professor Long says.

Flinders researchers prepared the tiny specimen, less than 2 centimetres in length out of the rock using weak acetic acid to expose the bone, than employed modern technology to visualize the skeletal anatomy of two fossils.

“CT scanning restored the anatomy of the two speciments and powerful X-rays were used to reveal hidden features inside the skulls,”

“The scans illustrate the changes early fish went through to achieve their current body plan. This includes fish we most like to eat like salmon, tuna and trout as well as those we keep as pets like goldfish,”

The first discovery of the fish called Ligulalepis was a tiny fossil found in limestone in Wee Jasper, New South Wales about 20 years ago, then about 2 years ago a second skull was discovered by Flinders University PHD student Benedict King at the same location.

“This fuelled debate around osteichthyan evolution ever since without any clear resolution as to where this enigmatic fish sits in the family tree,” Dr Clement says.

“But after the second skull was discovered by Flinders University, we also reconstructed the brain cavity which allowed us to digitally restore the brain shape for the first time,”

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

He was my uncle