News release

From: Flinders University

New pieces have been added to the puzzle of the evolution of some of the oldest fish that lived on Earth more than 400 million years ago.

In two separate studies, experts in Australia and China have found new clues about primitive lungfishes, the closest living relatives of land vertebrates.

The new research builds on long-running work by Flinders University and other palaeontologists in the fossil-rich Gogo site in Western Australia's far north, and with the Chinese Academy of Sciences.

The study of living and fossil lungfish provides anatomical clues into the evolutionary development of tetrapods, backboned animals with limbs including humans, that first left the water to live on land.

The mysterious fossil from the Late Devonian Gogo Formation in WA has been further analysed using the latest technologies including CT scanning and computed tomography, with the results published in the Canadian Journal of Zoology.

Lead author Dr Alice Clement, from Flinders University's Palaeontology Lab, says new research is slowly adding to the story of the key Australian fossil site's rich diversity of lungfishes – including re-examining poorly preserved specimens.

One such damaged specimen has yielded valuable new clues. It comes from Australia's first 'Great Barrier Reef,' the Devonian-age reef in the Kimberley region of northern WA.

"The unusual specimen was so enigmatic, the authors who first described ii in 2010 considered it could be a whole new type of fish never before seen in science," explains Dr Clement, from the College of Science and Engineering.

"Using high-tech scanning, this time we were able to create comprehensive new digital images of the external and internal cranium, showcasing the complexity of the brain cavity of this fascinating lungfish," she says.

"In fact, we were also able to confirm that previous impressions were probably viewed upside down and back to front."

Coauthor Hannah Thiele, with support from multiple museums and facilities such as Australian Nuclear Science and Technology Organisation (ANSTO), was able to use the advanced technologies to put a new lens on this most enigmatic specimen.

"We were able to compare its most preserved inner ear area with other Gogo lungfish.  This is an extra data point in the amazing collection of lungfish and early vertebrate species," she says.

"It adds to the wider understanding of the evolution of these earliest lobe-finned fishes, both in Gondwana and across the world."

Meanwhile in the journal Current Biology, another reconstruction of an early fish skull has described a species called Paleolopus - a lungfish that swam in the South Chinese seas 410 million years ago.

Flinders researcher Dr Brian Choo and colleagues at the Chinese Academy of Sciences, led by the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, have called the new fossil, Paleolophus yunnanensis ('Old crest from Yunnan').

"Paleolophus gives us an unprecedented look at a lungfish from a time between their earliest appearance and their great diversification a few million years later,” says Dr Choo, from the College of Science and Engineering at Flinders University.

"It was a time when the group was just starting to develop the distinctive feeding adaptations that would serve them for the remainder of the Devonian and onwards to the present day."

Lungfish are an incredibly ancient lineage, he says, “including the still living Australian lungfish from Queenland, that have long fascinated researchers due to their close relationship to the tetrapods, or backboned animals with limbs, including humans".

"The exceptional lungfish skull unearthed in 410 million-year-old rocks in Yunnan gives us major insights into the rapid evolutionary diversification between the early-, mid- and late Devonian.”

Dr Choo adds that the new specimen had similar and divergent features compared to the earliest and most primitive Diabolepis fossil in southern China, and species such as Uranolophus from Wyoming in the US and other forms like Australia's Dipnorhynchus.

The new article, ‘A new fossil fish sheds light on the rapid evolution of early lungfishes’ (2025), by Tuo Qiao, Xindong Cui, Wenjin Zhao, Chengxi Lu, Maokun Li, Jing Lu, Brian Choo and Min Zhu has been published in Current Biology (CellPress) DOI: 10.1016/j.cub.2025.11.032.

The article, 'Deciphering Cainocara enigma from the Late Devonian Gogo Formation, Australia' (2025) by Hannah S Thiele, John A Long, Joseph J Bevitt (Australian Centre for Neutron Scattering, ANSTO) and Alice M Clement has been published in the Canadian Journal of Zoology (Canadian Science Publishing) DOI: 10.1139/cjz-2025-0109.

Acknowledgements: 

The China study was supported by the National Natural Science Foundation of China (92255301 and 42302005) and the Australian Research Council Discovery Project (DP 220100825).

The Gogo study was supported by funding from the Australian Research Council (ARC DP 220100825). Researchers acknowledge the Gooniyandi community and country for access to their land, fossils and knowledge.