Ancient Eggshell Discoveries Reveal Secrets of Tree-Hunting Crocodiles

Scientists have discovered Australia’s oldest known crocodile eggshells. This find could reveal fascinating details about ancient crocodiles, particularly those that might have hunted by dropping down from trees.

The eggshells belong to mekosuchine crocodiles. These prehistoric reptiles roamed Australian waters over 55 million years ago, long before the saltwater and freshwater crocodiles appeared around 3.8 million years ago.

Paleontologist Michael Archer notes that mekosuchine crocodiles could grow to at least 16 feet (5 meters). Remarkably, they are believed to have hunted from trees. Australian researchers have cheekily nicknamed them “drop crocs,” drawing a humorous comparison to the feared “drop bear,” a mythical creature in Australian folklore.

“It’s a strange idea,” Archer said. “But some of them appear to have been terrestrial hunters in the forests.” He likened their hunting technique to that of leopards, suggesting they may have pounced on unsuspecting animals from above.

An international team, led by the Institut Català de Paleontologia Miquel Crusafont in Barcelona, uncovered these fossils from a backyard in southeast Queensland. Their findings were published in the Journal of Vertebrate Paleontology.

The ancient eggshells offer insights into the anatomy of these reptiles, as well as their breeding habits and adaptations. Xavier Panadès i Blas, the study’s lead author, explains that the eggshells carry geochemical signals which can inform researchers about nesting locations and breeding behaviors.

Mekosuchine crocodiles likely went extinct in Australia around 3,000 years ago. Their decline may have been due to habitat loss from drying landscapes, increased competition with other predators, and reduced prey availability, according to co-author Michael Stein.

The discovery takes place in Murgon, a town about three and a half hours from Brisbane. Archer recalls starting excavations in this area back in 1983, when he and a colleague simply knocked on a rancher’s door to request permission to dig in their backyard. The residents were thrilled to learn they were living on a prehistoric treasure trove.

Archer believes there are still many surprises to uncover at this site. Each excavation provides new clues about ancient life in Australia.

Identifying extinct species from an eggshell alone is challenging, according to Dean Lomax, a paleontologist and author of The Secret Lives of Dinosaurs. While he didn’t take part in this research, he acknowledges that the eggshell’s geological context offers strong evidence linking it to the mekosuchine crocodiles.

“Matching the fossil eggs to the crocs that laid them can yield invaluable information,” Lomax adds. “It enhances our understanding of their reproduction and lifestyle.”

This discovery not only excites paleontologists but also captivates the public’s imagination, reminding us of the extraordinary creatures that once roamed our planet.

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