Be Thankful You Don't Live in the Age of 'Drop Crocs'

Australia's reputation for scary wildlife just got a prehistoric boost. Researchers have uncovered the continent's oldest known crocodile eggshells, offering a glimpse into a time when some crocodile relatives may have hunted from the trees, rather than lurking in water. The study, published in the Journal of Vertebrate Paleontology, centers on fragments of eggshell from mekosuchine crocodiles, an extinct group that lived around 55 million years ago. Some of these ancient crocs may have been at least semi-arboreal, ambushing prey from above, according to University of New South Wales paleontologist Mike Archer, who refers to them as "drop crocs," per ABC Australia.

The fossil eggs probably didn't come from a drop croc, but rather the oldest known member of the family of mekosuchines, known as Kambara, which could grow over six feet long and preyed on fish and turtles, study co-author Michael David Stein writes at the Conversation. The microstructure of the eggshells suggests the crocodiles nested on the edges of temporary lakes, perhaps only once a year, before retreating to the forests. Archer suggests they might've even nibbled on birds in trees, per ABC. But as drylands spread, mekosuchine crocs may have lost much of their habitat, forcing them into waterways before they would eventually go extinct.

The study provides new insight into the adaptability and behavior of ancient crocodiles, highlighting that they occupied a wider range of ecological niches than their modern descendants, which only arrived in Australia about 3.8 million years ago. Those modern crocs are also known to climb trees, reportedly to bask in sunlight or survey their surroundings, Smithsonian reports.