Nigersaurus (pronounced nye-jer-SAWR-us) is the dinosaur that had 500 teeth. This remarkable herbivorous dinosaur lived approximately 110 million years ago during the Middle Cretaceous period in what is now Niger, Africa. Its teeth were arranged in columns, creating an efficient grazing mechanism similar to a conveyor belt system.

Nigersaurus had 500 teeth arranged in dental batteries to efficiently process large quantities of plant material. As teeth wore down from constant grazing on tough vegetation, new teeth would continuously replace them every 14 days. This adaptation made Nigersaurus one of the most efficient plant-eating dinosaurs, capable of consuming vast amounts of ground-level vegetation to support its large body.

Nigersaurus was first discovered in 1976 by French palaeontologist Philippe Taquet during an expedition in the Elrhaz Formation in the Republic of Niger, Africa. However, it wasn't until 1999 that American palaeontologist Paul Sereno and his team found more complete specimens, including a nearly complete skull, which allowed scientists to fully understand this unique dinosaur's remarkable dental structure and feeding behaviour.

Nigersaurus was a specialised herbivore that primarily ate ground-level vegetation such as ferns, horsetails, and other low-growing plants. Its wide, straight-edged muzzle and downward-facing head position made it perfectly adapted for grazing close to the ground, similar to modern-day cattle. Scientists believe it spent most of its time cropping vegetation near the ground, unlike other sauropods that browsed higher vegetation.

Nigersaurus was a medium-sized sauropod, measuring approximately 9 metres (30 feet) in length from head to tail and standing about 3-4 metres tall at the hips. It weighed an estimated 4 tonnes (4,000 kilograms), making it relatively small compared to other famous sauropods like Brachiosaurus or Apatosaurus. Its lightweight construction, particularly its delicate skull, helped keep its overall weight lower.

Nigersaurus lived during the Middle Cretaceous period, approximately 115 to 105 million years ago (Aptian to Albian stages). This was a time when flowering plants were beginning to appear, and the supercontinent Gondwana was breaking apart. The region where Nigersaurus lived was a lush river delta environment, vastly different from the desert landscape of modern-day Niger.