Scientists have identified Australia’s oldest crocodile eggshells — Wakkaoolithus godthelpi — from a clay pit in Murgon, Queensland, dated to about 55 million years ago. The eggs belong to extinct mekosuchines, some of which grew up to 5 m and may have been terrestrial or semi‑arboreal ambush predators. The study highlights how eggshell microstructure and geochemistry reveal nesting and breeding behaviour and promises further insights into Australia’s early forest ecosystems.
55‑Million‑Year‑Old ‘Tree‑Hunting’ Crocodiles: Australia’s Oldest Crocodile Eggshells Discovered
Scientists have identified Australia’s oldest crocodile eggshells — Wakkaoolithus godthelpi — from a clay pit in Murgon, Queensland, dated to about 55 million years ago. The eggs belong to extinct mekosuchines, some of which grew up to 5 m and may have been terrestrial or semi‑arboreal ambush predators. The study highlights how eggshell microstructure and geochemistry reveal nesting and breeding behaviour and promises further insights into Australia’s early forest ecosystems.
12:50 PM, 11/12/2025Science
Ancient 'drop crocs' uncovered in Queensland
Researchers have recovered what are now recognised as Australia’s oldest crocodilian eggshells, revealing a strange group of reptiles that may have hunted from trees about 55 million years ago. The material was excavated from a long-running dig in a clay pit on a grazier’s property in Murgon, Queensland — a site that preserves a rare snapshot of Australia when it was still connected to Antarctica and South America.
The newly identified eggshells have been assigned to an extinct group of crocodiles called the mekosuchines, and the egg type has been named Wakkaoolithus godthelpi in honour of the Wakka Wakka First Nations people on whose land the fossils were found. The research is published in the Journal of Vertebrate Paleontology.
Some mekosuchines reached lengths of up to five metres. Based on anatomical evidence and the eggshells’ context, the authors suggest several species were at least partly terrestrial and some may have been semi‑arboreal ambush predators — so‑called “drop crocs” that could have leapt from trees onto unsuspecting prey.
“It’s a bizarre idea. But some of them appear to have been terrestrial hunters in the forests,” said palaeontologist Michael Archer (University of New South Wales). “Some were apparently at least partly semi‑arboreal — perhaps hunting like leopards, dropping out of trees on any unsuspecting thing they fancied for dinner.”
The team infers these crocodiles nested on lake margins and adjusted their reproductive strategies to cope with fluctuating environmental conditions. Eggshell fragments preserve microstructural and geochemical signals that reveal not only which animals laid them but also likely nesting locations and breeding behaviours.
Lead author Xavier Panadès i Blas urged that eggshells be treated as a routine part of palaeontological collections: collected, curated and analysed alongside bones and teeth. Co‑author Michael Stein noted the Murgon forest harboured other early animals, including the world’s oldest known songbirds, Australia’s earliest frogs and snakes, a range of small mammals with South American links, and one of the oldest known bats.
Further excavations at Murgon are expected to refine our understanding of Australia’s prehistoric ecosystems before the continent became fully isolated and modern crocodilian lineages arrived.