Though its historical importance has long been overshadowed by Egypt, its neighbor to the north, Sudan’s archaeological record is pivotal to understanding the history of Africa itself, experts say, and a wave of new discoveries may be adding crucial new information.

“The history of Sudan can play a role for Africa that Greece played for the history of Europe,” Mr. Rilly said enthusiastically. “People have been living here for 5,000 years” along the Nile, he added. “It is difficult not to find something.”

One overlooked fact is that Sudan has more pyramids than Egypt, in places like Nuri and Bijrawiyah, though they are smaller and not as old. In the town of Sedeinga in northern Sudan, for instance, Mr. Rilly and others excavated 35 small pyramids in the past few years, a discovery that points to what he called an ancient “democratization of pyramids.”

“Anyone who could afford it built one,” he said. “It was for social distinction.”

The pyramids at Sedeinga are built close together. Made of mud brick, they range in height from under three feet for children to as high as 32 feet for nobles.

Not far from Sedeinga is the town of Dukki Gel, where a Swiss archaeologist, Charles Bonnet, has been working in the area for 44 years. He focuses on the ancient civilization of Kerma — so much so that his friends call him Charles “Kerma” Bonnet — which flourished around 1500 B.C. Mr. Bonnet’s colleagues say that his research has greatly added to the understanding of 1,000 years of Sudan’s ancient history.