Media release

From: Queensland Museum

Queensland Museum scientists have described a 400-million-year-old fossil, which is possibly the smallest vertebrate fossil animal known from Queensland - Palaeospondylus australis. The findings were recently published in National Science Review (https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr/nwae444/7915995) with details about this ancient fish, found in the Georgina Basin (west of Boulia and close to the Northern Territory border), This is a remarkable addition to Queensland’s fossil record, at the other end of the size scale to prehistoric giants like dinosaurs Rhoetosaurus and Australotitan cooperensis.

What makes P. australis even more intriguing is its connection to a similar species from northern Scotland, P. gunni. First described in 1890, Palaeospondylus has puzzled palaeontologists for over a century due to its unique skeletal features and uncertain classification. The Scottish fossils, though abundant, are typically compressed, making detailed analysis challenging. However, Queensland’s fossils, while disarticulated, are exceptionally preserved in 3D, offering new insight into this enigmatic species.

The discovery of a braincase in Queensland in 2010 confirmed the presence of P. australis, marking the first time this genus has been found outside Scotland. The fossils’ honeycomb-like structure and intricate internal features hint at the fish’s early evolutionary significance. While the exact relationships of P. australis remain unclear, with features indicating it retained many larval characters, it is likely a distant relative of sharks.

This breakthrough in fossil research not only enriches our understanding of ancient Australian ecosystems but also highlights the global connections of early vertebrate life across continents. The study of Palaeospondylus australis promises to unravel more mysteries about the evolution of jawed vertebrates.