Lucy’s Hunter: Newly Identified Crocodile Species Terrorized Early Human Ancestors

More than 3 million years ago, when our ancient ancestors—including the species represented by the famed Lucy fossil—roamed the landscape of Ethiopia, they faced a formidable predator: a giant crocodile with a distinctive lump on its head. Researchers have now formally described this crocodile as a modern species, Crocodylus lucivenator, meaning “Lucy hunter.”

A Predator Contemporary with ‘Lucy’

The newly named crocodile lived between 3.4 million and 3 million years ago, overlapping in both time and location with Australopithecus afarensis, the ancient human species represented by the Lucy fossil discovered in 1974 . Lucy’s skeleton is one of the oldest and most complete hominin fossils ever found, providing crucial evidence that bipedalism preceded significant brain size increases in human evolution.

Size and Dominance

Crocodylus lucivenator was a dominant predator, ranging from 12 to 15 feet in length and weighing between 600 and 1,300 pounds . Researchers believe it was the largest predator in its ecosystem, even more dominant than lions and hyenas . The crocodile inhabited a landscape of shrubland and wetlands, pocked with rivers lined with trees, where it likely employed ambush tactics, hiding in the water to attack prey coming to drink.

A Threat to Early Hominins

According to Professor Christopher Brochu, lead author of the study from the University of Iowa, the threat posed by Crocodylus lucivenator to early hominins was likely very real . “This crocodile was the biggest predator in that ecosystem… It also probably posed the biggest threat to our ancestors who lived there at that time,” Brochu stated. He suggests that Crocodylus lucivenator almost certainly preyed on Lucy’s species, and if given the opportunity, would have considered them dinner .

Classification and Discovery

The research, published March 12 in the Journal of Systematic Palaeontology, details the characteristics of the new species and its relationship to other crocodile species . Crocodylus lucivenator shares features with Pleistocene crocodile species from East Africa .