Early Cretaceous Dinosaurs from Africa
Until the 1990s, Africa remained largely unexplored territory for dinosaurs. A few dinosaur-bearing localities were found by German expeditions to Egypt and Tanzania; French expeditions to Morocco, the Niger Republic, and Madagascar; and South African expeditions within their own country. The 1990s saw the first expeditions organized by American paleontologists to some of the localities previously visited by other countries. American paleontologists returned with more material of previously known dinosaurs and also fossils of dinosaurs not known before. Most of the fossils were from the Early Cretaceous age.
The first Carcharodontosaurus remains (teeth) were found by the French in the 19th century, and teeth and jaw fragments continued to turn up in French and German dinosaur digs everywhere across the Sahara Desert during the 20th century. Not until the 1990s did an American expedition, organized by Paul C. Sereno, turn up a good partial skeleton and skull, giving us our first good look at this mysterious giant meat-eater. Closely related to South America's Giganotosaurus, Carcharodontosaurus was about as large as Tyrannosaurus (40 to 45 feet). The American expeditions also found a new, smaller meat-eater about 30 feet long that they called Afrovenator and another new meat-eater, Deltadromeus, which was similar in size to Afrovenator but more slender.
The spectacular Late Cretaceous Spinosaurus aegyptiacus, first found by German expeditions to Egypt before World War I, has so far proved elusive; no more Spinosaurus aegyptiacus fossils have ever turned up. But a few of its Early Cretaceous relatives, which were smaller (about 35 feet) and evidently had much shorter spines along the back, have been found by French and American expeditions to Morocco. Known from fragmentary fossils are Sigilmassasaurus, Cristatusaurus, and Spinosaurus maroccanus. Known from a fairly complete skeleton is Suchomimus. The spinosaurs are currently being restudied, and Suchiomimus may prove to belong to the same species as one of the previously named spinosaurs. A spinosaur hallmark is the elongated, narrow snout with slender teeth, strongly resembling the snouts and teeth of modern fish-eating crocodiles of India. It is the reason we believe spinosaurs were mainly fish-eaters.
New African sauropods found by American expeditions included Malawisaurus, a primitive titanosaur from Malawi; Jobaria, a large but primitive sauropod similar to Cetiosaurus from the Jurassic of Great Britain; and Nigersaurus, a peculiar medium-size sauropod perhaps related to the rebbachisaurids. Nigersaurus had rows of hundreds of teeth, packed in its jaws like the dental batteries of duckbilled dinosaurs. Malawisaurus material had been discovered as early as 1928, but only after better fossils were found in the early 1990s was it possible to identify it as a new kind of dinosaur.
When the French expedition to the Niger Republic in 1972 found the sail-backed ornithopod Ouranosaurus, they also found a large, heavily built but otherwise standard iguanodontid in the same general area. This dinosaur was described and named Lurdusaurus in 1999.