Scientists in Australia have made an exciting discovery—a 15-million-year-old fossilized freshwater fish that not only provides clues about ancient life but also has preserved stomach contents and color patterns.
This is the first time such a discovery has been made in Australia.
A rare fossil discovery
A team of researchers led by Dr. Matthew McCurry from the Australian Museum and UNSW Sydney found the fossil at McGraths Flat, a fossil site in New South Wales near the town of Gulgong.
The site is classified as a Lagerstätte, meaning it contains fossils with exceptional detail and quality.
According to Dr. McCurry, these fossils formed between 11 and 16 million years ago and reveal that this region was once a lush, temperate rainforest filled with life.
This newly discovered fish species has been named Ferruaspis brocksi, honoring Professor Jochen J. Brocks from the Australian National University, who helped discover fossils at the site.
A window into Australia’s ancient past
- brocksi belongs to the Osmeriformes group, which includes modern fish like the Australian smelt and Australian grayling.
However, until now, scientists were unsure when and how these fish first arrived in Australia. This discovery helps fill in the missing pieces of Australia’s evolutionary history.
“Before this fossil, we didn’t have clear evidence of when this group of fish came to Australia or how they evolved over time,” said Dr. McCurry.
“Now, we have an incredible opportunity to study how these fish lived in ancient ecosystems.”
A glimpse into ancient eating habits
One of the most fascinating aspects of this fossil is its preserved stomach contents, giving scientists a direct look at what the fish ate.
The fossil reveals that F. brocksi fed on a variety of invertebrates, with its most common prey being phantom midge larvae.
Additionally, the fossil includes evidence of a parasite. A juvenile freshwater mussel, called a glochidium, was attached to the fish’s tail. These tiny mussels use fish to travel upstream by clinging onto their tails or gills.
Revealing the fish’s true colors
Another groundbreaking discovery is that scientists were able to determine the fish’s color patterns. Using a high-powered microscope, researchers found tiny color-producing structures called melanosomes. These structures allowed them to reconstruct the fish’s coloration, something rarely done for extinct fish species.
“The fish had a darker top, a lighter belly, and two stripes along its sides,” explained Dr. Michael Frese, a researcher from the University of Canberra and CSIRO.
Melanosomes have been used before to determine the color of fossilized feathers, but this is the first time they have been used to reconstruct the color of an ancient fish.
Professor Brocks, for whom the species is named, expressed his excitement about the discovery. “Splitting open the rust-red slabs of rock at McGraths Flat is like opening an ancient book,” he said. “Finding the first vertebrate among the many plant and insect fossils was an incredible surprise. Having this beautiful fossil named after me is a true joy.”
This discovery is a major breakthrough in understanding Australia’s ancient freshwater ecosystems. It provides new insights into the evolution of fish, their diet, and even their appearance.
“This fossil offers a rare snapshot of life in Australia 15 million years ago,” said Dr. McCurry. “It’s a piece of our ancient past that helps us understand how life has changed over time.”
With discoveries like this, paleontologists continue to unlock the mysteries of Earth’s history, one fossil at a time.
