Fossils of fish up to 16 million years old, perfectly preserved in central New South Wales, have provided an extraordinary glimpse into the past. These fossils, discovered at the McGraths Flat site, feature small freshwater fish embedded in an iron-rich mineral called goethite. Remarkably, the fossils have retained microscopic details, including the fish’s stomach contents and the outlines of cells that determine colour, allowing scientists to reconstruct their final days with unprecedented clarity.
++ Musk claims ‘massive cyber attack’ after X outages
Lead author Dr Matthew McCurry, curator of palaeontology at the Australian Museum, explained that palaeontology often leaves many gaps, with isolated bones being the typical findings. “To see an almost complete animal with preserved soft tissues is incredibly rare,” he said. This discovery marks the first detailed evidence in Australia of the fish group Osmeriformes, which today includes species like graylings and smelts. The fossils even retained remnants of melanophores, the cells responsible for pigmentation, providing insight into the fish’s colour patterns.
The fish, which were counter-shaded with darker backs and lighter bellies, were also found to have been filled with the antennae of phantom midge larvae and other half-digested remains. This information sheds light on the fish’s diet just before their demise, offering a rare snapshot of their life in the final moments. The researchers suggest that the fish died in a lake-like environment, possibly after a nearby river overflowed, allowing the fish to feast on the abundant larvae before they met their end with full stomachs.
++ Protester climbs Big Ben in London and calls for freedom for Palestine
This discovery is not only a major advancement in the study of fossil fish but also provides an invaluable opportunity to understand Australia’s ancient ecosystems during the Miocene. Dr Alice Clement, an evolutionary biologist and palaeontologist not involved in the study, noted that the analysis of melanophores in fossils represents a significant breakthrough. The study of colour and patterns in ancient animals is still in its infancy but promises to offer further insights into evolutionary biology. This find helps to unravel how Australia’s unique fauna adapted to the changing climatic conditions of the time, offering a “geological lesson” in how species evolve in response to environmental shifts.
