A fossilized temnospondyl, a relative of modern amphibians, was discovered in a sandstone block acquired by retired chicken farmer Mihail Mihailidis in Kincumber, Australia, intended for a retaining wall. The block was later donated to the Australian Museum.
Discovery
A nearly complete fossil of a 240-million-year-old amphibian relative has been identified as one of the most significant finds in New South Wales in three decades. The specimen was originally unearthed in a sandstone block destined for use as a retaining wall.
Specimen Description
The fossil, named Arenaerpeton supinatus, dates from the Triassic period. It is articulated and nearly complete, with preserved soft tissue outlines—a rare occurrence in sandstone. While the specimen lacks a tail, its estimated total length is 1.2 meters. It features a robust body, a head shape similar to the modern Chinese Giant Salamander, and contains sharp teeth including palatal tusks.
Analysis
Paleontologists from the University of New South Wales and the Australian Museum conducted the formal description, published in the Journal of Vertebrate Paleontology. The fossil provides key insights into temnospondyl morphology and evolution. The exceptional preservation suggests the animal died in a calm, anoxic or cold aquatic environment that effectively hindered scavenging and decay.
Significance
Arenaerpeton is the only known specimen of its species. It is considered one of the most important fossil finds in New South Wales in the past 30 years. Representing an early temnospondyl in Australia, it predates later larger species and helps document the group's persistence through two mass extinctions.
"The specimen's heavyset build and formidable teeth are remarkable features."
— Lachlan Hart, paleontologist (UNSW/Australian Museum)
"This fossil is a key part of Australia's fossil heritage."
— Matthew McCurry, paleontologist (UNSW/Australian Museum)