Studying the fossil remains of the flesh-eating dinosaurs could help researchers learn more about how dinosaurs evolved as the African and South American continents split from each other 100 million years ago.
A team of paleontologists lead by Paul Sereno of the University of Chicago published a paper announcing the discovery of predator Eocarcharia inops, or "fierce-eyed dawn shark," and Kryptops palaios, a hard-nosed scavenger, the Chicago Tribune reported.
Both dinosaurs were about the size of an elephant and shared the same African habitat in what is now the country of Niger in the Saharan desert.
The finds are significant because they allow scientists to look at how dinosaurs evolved differently after Africa drifted apart from modern-day South America, India and Antarctica.
"This is an important slice in geological time, and we don't yet fully comprehend how dinosaurs on the southern continents were evolving then," Peter Makovicky, curator of dinosaurs at the Chicago Field Museum, told the Tribune.
The new discoveries appear to be the ancestors of other species of dinosaurs discovered on other continents that used to neighbor Africa.
"What we've found are primitive members of the two groups of megacarnivorous dinosaurs that ruled the southern continents for 50 million years," co-author Stephen Brusatte told National Geographic.
Eocarcharia was a fearsome ancestor of larger meat-eating dinosaurs, equipped with blade-like teeth and a swollen brow that gave it an intimidating look, according to National Geographic.
"This guy would have been slicing and ripping off limbs," Sereno told the Tribune.
Kryptops, while similar in size, possessed smaller teeth and arms and its face was covered in horns, which could have helped it scavenge for carcasses, National Geographic reported.
The dinosaur is an early version of the abelisaurids, which have also been found in South America and India.
Sereno and his team are trying to reconstruct the ecosystem that hosted both predators. Their work suggests that the newly discovered dinosaurs -- and the other predators they competed with -- filled roles of predator and scavenger similar to today's lions and hyenas, respectively, in Africa.The discovery of Eocarcharia also sheds light on the evolutionary path that produced giant predators like Carcharodontosaurus and Tyrannosaurus Rex, revealing a steady increase in size of these meat-eaters, the Tribune reported.