For many, the image of a dinosaur conjures thoughts of immense size or fearsome predatory teeth. However, the ancient world harbored creatures with equally astonishing, albeit less ferocious, dental arrangements. One particular dinosaur gained notoriety for its exceptionally numerous teeth, prompting curiosity about how such a feature could exist. This animal showcased remarkable adaptations, particularly its specialized mouthparts.
Discovering the Multi-Toothed Dinosaur
The dinosaur renowned for its incredibly numerous teeth is Nigersaurus taqueti, a rebbachisaurid sauropod first identified from fossils discovered in Niger. While often referred to as having “500 teeth,” this figure represents the total number of active and replacement teeth housed within its specialized dental batteries at any given time. Its jaw contained approximately 500 slender teeth, arranged in tightly packed rows. The initial remains were discovered during expeditions in the 1960s and 1970s, with more complete specimens later found and described in 1999 by paleontologist Paul Sereno and his team.
The Remarkable Dental System
The dental system of Nigersaurus featured “dental batteries,” consisting of tightly packed rows of teeth. Multiple replacement teeth grew beneath the active ones, with each active tooth having a column of up to nine replacements stacked within the jaw. This enabled an extraordinarily rapid tooth replacement rate, with each tooth being replaced roughly every 14 days.
The structure of Nigersaurus’s jaw was broad and straight at the front, almost resembling a vacuum cleaner’s nozzle. This wide muzzle and the transverse rotation of its tooth-bearing bones meant all its teeth were located far forward in its mouth, a feature distinct from other tetrapods. The enamel on its teeth was significantly thicker on the outward-facing side, an asymmetrical design that likely contributed to their efficiency.
A Specialized Plant-Eater
The dental system of Nigersaurus was directly linked to its diet. It was a herbivore that primarily engaged in low-browsing, grazing on ground-level vegetation. Its wide, straight muzzle and constantly replaced teeth allowed it to efficiently strip soft plants such as ferns, horsetails, and early flowering plants. This feeding strategy contrasts with that of many other long-necked sauropods, which typically browsed higher in trees.
The skull’s design, including its downward-facing mouth, suggests its adaptation for grazing close to the ground. This feeding behavior earned Nigersaurus the nickname “Mesozoic cow,” reflecting its method of consuming large quantities of low-lying vegetation.
Nigersaurus in Its Ancient World
Nigersaurus lived during the middle Cretaceous period, approximately 115 to 105 million years ago. Its fossils have been primarily discovered in the Elrhaz Formation, located in what is now Niger, North Africa. This region was then a lush, riverine habitat, quite different from the modern Sahara Desert.
For a sauropod, Nigersaurus was relatively small, measuring about 30 feet (9 meters) in length and weighing around 4 tons, comparable to a modern elephant. It possessed a relatively short neck for a sauropod, with thirteen cervical vertebrae.