Africa yields dinosaur to rival T. rex.

Poor Tyrannosaurus rex. Once considered the largest predatory dinosaur, this North American beast from the end of the Cretaceous period now has to share the title of king carnivore with not one, but two other giants, thanks to recent fossil finds.

While working in the Moroccan Sahara last year, Paul C. Sereno, a paleontologist at the University of Chicago, and his colleagues unearthed a 5.3-foot-long skull and other bones belonging to a poorly known theropod called Carcharodontosaurus, they report in the May 17 Science. The fossils reveal that this 90-million-year-old hunter reached roughly 45 feet in total length, slightly longer than the biggest known T. rex. Last year, Argentine scientists announced the discovery of a similar-size South American theropod called Giganotosaurus (SN: 9/23/95, p. 199).

Sereno's group also found a previously unknown, smaller Moroccan theropod. They named the fleet predator Deltadromeus. The finds give new insight into how dinosaurs evolved as the once-unified continents split apart and moved toward their modern positions. Similarities between Carcharodontosaurus, Giganotosaurus, and some North American predators suggest that dinosaurs from different continents intermixed through most of the Cretaceous. By 90 million years ago, however, Africa had separated from other landmasses, leaving its dinosaurs to evolve in unique ways, says Sereno.