Scientists have discovered a new species of dinosaur -- and it's a big deal.

The dino, Mansourasaurus shahinae, was the length of a school bus and about as heavy as an elephant, weighting in at around five tons, CNN says.

That makes it a part of a group of dinosaurs known as the Titanosauria, which includes the largest land animals known to science.

But what's even more remarkable about this discovery is what it says about the evolution of dinosaurs.

This species was found in Egypt. For more than 250 years, most dinosaur bones have been found in Europe, North America and Asia. Scientists haven't had much luck digging up and documenting fossils in Africa. And that means the course of dinosaur evolution there isn't well understood.

"When I first saw pics of the fossils, my jaw hit the floor," dinosaur paleontologist Matt Lamanna said in a statement from the Carnegie Museum of Natural History.

He's one of the coauthors of a paper published Monday in the journal Nature Ecology and Evolution that names the new species.

"This was the Holy Grail -- a well-preserved dinosaur from the end of the Age of Dinosaurs in Africa -- that we paleontologists had been searching for for a long, long time."