Nigersaurus, a sauropod dinosaur, roamed Africa during the middle Cretaceous period, approximately 115 to 105 million years ago. Named after the country of Niger where its fossils were found, it was a relatively small sauropod, measuring about 9 meters (30 feet) long and weighing between 1.9 and 4 tons, comparable to a modern elephant. While many long-necked dinosaurs are known for their towering heights, Nigersaurus possessed a short neck and an unusually broad, straight muzzle, hinting at an adaptation related to its diet.
The Astonishing Number of Teeth
One remarkable feature of Nigersaurus was its dental arrangement. This dinosaur possessed over 500 teeth in total. At any given time, it had more than 100 teeth actively in use across its jaws, with around 68 in the upper jaw and 60 in the lower jaw. To put this into perspective, humans typically have 32 adult teeth. These numerous, slender teeth were precisely arranged in a broad, straight muzzle, giving its face an almost vacuum-cleaner-like appearance.
A Specialized Feeding Machine
Nigersaurus’s dental array suited its feeding strategy as a low-browsing herbivore. Unlike many long-necked sauropods that fed on tall trees, Nigersaurus grazed on ground-level vegetation like ferns, horsetails, and early flowering plants, as grass had not yet evolved. Its wide, straight muzzle acted like a natural comb or rake, efficiently stripping large quantities of plant material close to the ground. This feeding behavior led some paleontologists to refer to Nigersaurus as the “Mesozoic cow” or “vacuum cleaner” of its era. The structure of its skull and neck vertebrae also suggests that Nigersaurus held its head low for grazing.
Dental Battery: A Tooth Factory
The mechanism behind Nigersaurus’s continuous supply of teeth was a system known as a “dental battery.” Its teeth were arranged in vertical columns, with up to nine replacement teeth stacked beneath each functional tooth. This continuous renewal process allowed for a rapid tooth replacement rate, with each tooth being replaced approximately every 14 days. Such a high turnover ensured that Nigersaurus always maintained a sharp and efficient grinding surface, despite the abrasive nature of its tough plant diet. The constant replacement also compensated for the wear and tear on its delicate skull bones, which were thin, some even transparent.
Unearthing the Dental Wonder
Scientists understood Nigersaurus’s dental features through fossil discoveries in the Elrhaz Formation of Niger, Africa. The first remains were reported in 1976 by French paleontologist Philippe Taquet, though the dinosaur was not formally named until 1999. American paleontologist Paul Sereno and his team conducted further expeditions in 1997 and 2000, unearthing more complete fossil material. Analysis of its delicate skull and jaw fragments provided insights into its specialized dental anatomy and feeding habits, allowing paleontologists to reconstruct the life of this ancient grazer.