A Massive Pliocene Crocodile May Have Hunted Lucy and Other Early Hominins, 3 Million Years Ago

More than three million years ago, Lucy – the famous complete fossil of an early human ancestor discovered in Ethiopia in 1974 – moved across a landscape of wetlands, rivers, forests and grasslands. These waterways supported life throughout the region, attracting animals large and small to drink. But they could also have hidden one of the most fearsome predators in the ecosystem.

In a new study published in the Journal of Systematic Paleontologyresearchers describe a previously unknown species of crocodile that lived in the same region and time period as Lucy. The reptile, named Crocodylus lucivenator – meaning “Lucy’s Hunter” – lived around 3.4 to 3 million years ago in the Hadar region of Ethiopia. Adults probably reached 12 to 15 feet long (3.6 to 4.5 meters) and weighed between 600 and 1,300 pounds (270 and 590 kilograms), making them the largest predators in the environment.

“This highlights that the threats did not only come from predatory mammals. We are used to thinking that big cats, hyenas and wild dogs are their main threats. This crocodile was the biggest threat faced by Lucy and her species,” said lead author Christopher Brochu. Discover.

Crocodile fossils from Lucy’s landscape

The fossils that revealed Lucy’s hunter were excavated from the Hadar Formation, the same region where Lucy’s skeleton was discovered.

During the Pliocene Epoch, Hadar contained a network of lakes and rivers surrounded by a mix of habitats that changed over time. These waterways would have created the ideal conditions for ambush predators.

Researchers analyzed 121 fossil remains, including skulls, teeth and jaw fragments representing dozens of crocodiles. Although many of the fossils were fragmentary, together they provided enough information to reconstruct the animal’s anatomy.

For Brochu, the discovery began with a visit to the Addis Ababa museum in 2016. “Excitement! I always feel that when I see something that could be a new species! It’s like I opened a box that had been closed for centuries,” Brochu shared with Discover.

At the time, however, the fossils did not immediately match a known group of crocodiles, prompting a closer look at other specimens collected from the same region.

Learn more: A 25-inch crocodile relative walked on two legs in the forests of the Late Triassic 225 million years ago

A crocodile with an unusual mix of features

Part of what made Crocodylus lucivenator The unusual combination of features preserved in its skull was difficult to classify.

“On the one hand, some of the cranial sutures of the Hadar crocodile resemble those of the extinct group (Paleoafrican Crocodylus), and the naris (nose hole) opens slightly forward and not just upward. But it had a hump on the snout normally associated with crocodiles currently living in the Western Hemisphere,” Brochu explained to Discover.

This hump – which rises from the middle of the crocodile’s snout – is unusual for fossil African crocodiles. In modern species, similar structures are often used as visual signals during courtship, when males lower their heads to show this feature to potential mates.

The skull also extended further in front of the nostrils than in PaleoAfrican crocodiles, another trait that more closely resembles living species including the Nile crocodile.

Crocodile Fighting Signs

Fossils also preserve insights into their behavior. One specimen has partially healed wounds along the jaw, evidence that the animal survived a violent encounter with another crocodile. Similar bite marks frequently appear in modern crocodiles, which often clash in territorial conflicts or competitions for mates.

Thanks to the wounds healing, the crocodile lived long enough to recover from the encounter, showing that fights between these reptiles were not uncommon.

For Lucy and her loved ones, however, perhaps the most immediate concern was the presence of a powerful ambush predator in the waterways on which they depended. The same rivers and lakes that supported life in the Hadar region may also have been the hunting grounds of Lucy’s hunter.

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