Scientists discover 15 million-year-old Australian fish fossil

18 Mar 2025

A that lived in Australian freshwater lakes and rivers about 15 million years ago has been named after the researcher from The Australian 精东传媒app University (ANU) who played a key role in its discovery. 

 

Professor Jochen Brocks discovered several fossils of the ancient fish, named Ferruaspisbrocksi, at the McGraths Flat fossil site near Gulgong in New South Wales (NSW).  

 

鈥淚 am very proud to have this world-first discovery named after me and I thank my colleagues at the Australian Museum and the University of Canberra for bestowing this upon me. This discovery opens new avenues for understanding the evolutionary history of Australia鈥檚 freshwater fish species and ancient ecosystems,鈥 Professor Brocks said. 

 

Study lead author Dr Matthew McCurry, from the Australian Museum and UNSW Sydney, said that before this fossil discovery, scientists lacked concrete evidence to pinpoint when this group of fish arrived in Australia and how they evolved over time. 

 

Ferruaspisbrocksi is the first fossil freshwater Australian Smelt to be found in Australia,鈥 Dr McCurry said. 

 

鈥淭he discovery of the 15 million-year-old freshwater fish fossil offers us an unprecedented opportunity to understand Australia鈥檚 ancient ecosystems and the evolution of its fish species. 

 

鈥淭his fossil is part of the Osmeriforms fish family 鈥 a diverse group of fish species within Australia that includes species like the Australian Grayling and the Australian Smelt. But, without fossils it has been hard for us to tell exactly when the group arrived in Australia and whether they changed at all through time.鈥 

 

The researchers said the stomach contents of the fossilised fish is 鈥渟o well preserved鈥, scientists now have a glimpse into the behaviour of these ancient species.   

 

鈥淲e now know that Ferruaspisbrocksi fed on a range of invertebrates, but the most common prey was small phantom midge larvae. One of the fossils even shows a parasite attached to the tail of the fish. It鈥檚 a juvenile freshwater musselcalled a glochidium. These juvenile musselsattach themselves to the gills or tails of fish to hitch rides up and down streams,鈥 Dr McCurry said. 

 

Professor Brocks added: 鈥淭his little fish is one of the most beautiful fossils I鈥檝e found at McGrath Flat, and finding the first vertebrate among the abundant plant and insect fossils was a real surprise.鈥 

 

The species was named Ferruaspisbrocksi because it was found encased in iron-rich rock. 鈥Ferru鈥, from ferrum (Latin) meaning iron, and 鈥brocksi鈥 after Professor Brocks. 

 

Dr Michael Frese, from the University of Canberra and CSIRO, Australia鈥檚 national science agency, said that one of the most exciting aspects of the work was that they could tell the colour of the fish. 

鈥淭he fish was darker on its dorsal surface, lighter in colour on its belly and had two lateral stripes running along its side,鈥 Dr Frese said. 

 

鈥淯sing a powerful microscope, we were able to see tiny colour-producing structures known as melanosomes. Fossilised melanosomes have previously enabled palaeontologists to reconstruct the colour of feathers, but melanosomes have never been used to reconstruct the colour pattern of a long extinct fish species.鈥 

 

The new fossil site, named McGraths Flat, is one of only a handful of fossil sites in Australia that can be classified as a 鈥尝补驳别谤蝉迟盲迟迟别鈥欌 a site that contains fossils of exceptional quality with remarkable detail. 

 

鈥淭he fossils found at this site formed between 11 and 16 million years ago and provide a window into the past. They prove that the area was once a temperate, wet rainforest and that life was rich and abundant in the Central Tablelands,鈥 McCurry said. 

 

The research is published in .