Full Breakdown
Rare Triassic Amphibian Fossil Identified from a Sydney Garden Wall
5/7/2026, 11:41:53 AM
Discovery of a 240-Million-Year-Old Amphibian in a Garden Wall
In May 2026, paleontologists from the University of New South Wales (UNSW) and the Australian Museum formally described a fossil amphibian dating to the Middle Triassic, about 240 million years ago. The specimen, named Arenaerpeton supinatus, was recovered from a garden retaining wall built in the 1990s with stones sourced from a quarry in the Sydney Basin. The fossil had remained hidden within the wall for decades before being donated to the museum for study.
From Quarry Stone to Museum Exhibit
A retired chicken farmer first uncovered the stone while gathering quarry rocks for the wall. Recognizing its unusual nature, he later transferred the block to the Australian Museum in Sydney. Examination revealed an almost complete skeleton together with faint outlines of skin and soft tissue—an exceptionally rare preservation state for temnospondyl amphibians.
Temnospondyls and the Triassic Sydney Basin
Temnospondyls were a diverse group of early amphibians that flourished before and during the age of dinosaurs. Arenaerpeton inhabited freshwater environments of the ancient Sydney Basin and likely preyed on fish such as *Cleithrolepis*. Its broad head, heavy build, and pair of fang-like tusks on the palate give it a superficial resemblance to the modern Chinese giant salamander, though it was considerably more robust.
Researchers and Institutions
The study was led by paleontologist Lachlan Hart, a PhD candidate at UNSW’s School of Biological, Earth and Environmental Sciences, and senior lecturer Dr Matthew McCurry, curator of palaeontology at the Australian Museum. Both institutions co-authored the paper, which appeared in the *Journal of Vertebrate Paleontology*.
Anatomy and Preservation
Arenaerpeton measured roughly 1.2 m from head to tail, large for its clade. The fossil preserves the skull, vertebral column, ribs, limb elements, and soft-tissue outlines that reveal rib size and body thickness. Robust teeth and the palate tusks indicate a predatory diet.
Significance for Paleontology and Heritage
The completeness of the skeleton, combined with soft-tissue traces, offers unprecedented data for reconstructing Triassic aquatic ecosystems. Researchers note that later temnospondyls persisted in Australia for another 120 million years, with some lineages attaining even greater sizes, suggesting that increasing body size may have aided survival across mass-extinction events. Dr McCurry called the find “one of the most important fossils found in New South Wales in the past 30 years” and a key component of Australia’s fossil heritage.
Official Statements
The research team emphasized that the specimen’s articulation and soft-tissue preservation provide rare insight into the morphology and ecology of early amphibian predators. They also highlighted the broader evolutionary implication that body-size trends could have contributed to the long-term resilience of temnospondyls in Gondwanan habitats.
Verbatim Quotes
- “This fossil is a unique example of a group of extinct animals known as temnospondyls, which lived before and during the time of the dinosaurs,” — Lachlan Hart, Paleontologist, UNSW & Australian Museum
- “We don't often find skeletons with the head and body still attached, and the soft tissue preservation is an even rarer occurrence.” — Lachlan Hart
- “Superficially, Arenaerpeton looks a lot like the modern Chinese Giant Salamander, especially in the shape of its head,” — Lachlan Hart
- “This is one of the most important fossils found in New South Wales in the past 30 years, so it is exciting to formally describe it,” — Matthew McCurry, Senior Lecturer, UNSW & Curator, Australian Museum
Future Research
The team plans micro-CT scanning to resolve internal structures and comparative analyses with other Gondwanan temnospondyls. Additional fieldwork in the Sydney Basin aims to clarify the paleoenvironmental conditions that supported large amphibian predators during the Triassic.
