Paul Sereno of the University of Chicago and his colleagues recovered the dinosaur remains from Niger during two trips in 1997 and 2000. The 95-million-year-old skull is from a species the scientists named Rugops primus, which translates to "first wrinkle face." The 30-foot-long creature had a short, round snout, small teeth and a tough covering of scales. "It was hard to see which end was the front, but we quickly realized we were looking at a brain case, and that it was probably an abelisaur--a huge find," Sereno recalls. In addition, the Rugops skull has a row of seven holes on either side of its snout, which the scientists posit could have anchored an ornamental feature. The researchers also recovered the 135-million-year-old spine of another dinosaur, Spinostropheus gautieri, which is an ancient relative of Rugops and other abelisaurids.
Until now, abelisauroid remains had been found only in South America, India and Madagascar. The latest finds are definitive evidence that abelisaurids and their direct ancestors were present in Africa as well, suggesting that the southern continents drifted apart over a narrow time interval around 100 million years ago. "Until the continents fully separated, dinosaurs like Rugops and other animals used narrow land bridges to colonize adjacent continents and roam within a few degrees of the South Pole," explains study co-author Jeffrey Wilson of the University of Michigan. The team describes the two fossils in a report published online today by the Proceedings of the Royal Society of London.