Iowa Team Identifies 15-Foot Crocodile That Hunted Lucy's Species 3 Million Years Ago

Q: Why did an ancient African crocodile resemble one from the Americas more than its modern African relatives?

It likely resembled an American crocodile because *Crocodylus lucivenator* belonged to a different, now-extinct branch of crocodile evolution in Africa, not to the lineage that led to today’s Nile crocodile. The key evidence is anatomical. Researchers found that *C. lucivenator* had a pronounced hump in the middle of its snout and a snout that projected farther beyond the nostrils than in other African crocodiles of its time. That hump is a feature seen in some living American crocodiles, but not in modern African Nile crocodiles. Scientists think it may have been used in display, possibly during courtship. That does not mean the Ethiopian species was closely related to modern American crocodiles in a simple sense, or that it was an ancestor of modern African crocodiles. The researchers’ point is that its skull combined traits that looked unfamiliar in East Africa but more recognizable in crocodilians elsewhere. In other words, Africa once had crocodile diversity that is no longer represented by the species living there today. So the resemblance reflects evolutionary history and morphology, not geography. *C. lucivenator* preserved features from an extinct lineage that happened to look more like traits seen in American crocodiles than in its surviving African relatives. The find shows that the crocodile fauna around Lucy’s habitat was more varied than scientists had realized.

3 articles · Updated · BBC Discover Wildlife · Jun 18

121 fossil remains from Ethiopia's Hadar Formation have been formally classified as Crocodylus lucivenator, a newly identified crocodile species that researchers say likely preyed on Australopithecus afarensis.
The predator lived about 3.4 million to 3 million years ago alongside 'Lucy' and, at 12 to 15 feet long and 600 to 1,300 pounds, was the largest hunter in that ecosystem.
Researchers say it was Hadar's only known crocodile and probably hunted by ambush in rivers, wetlands and waterways, targeting animals that came to drink.
A prominent snout hump and unusually extended snout set the species apart from African Nile crocodiles, while linking some features to modern crocodiles; the findings appear in the Journal of Systematic Paleontology.