The dinosaur with the most teeth is likely the Nigersaurus.

Nigersaurus is a sauropod dinosaur that lived during the Late Cretaceous period, approximately 110 to 95 million years ago. It had an exceptionally large number of teeth compared to other dinosaurs.

Nigersaurus had a unique dental arrangement in its long, narrow jaws. It possessed numerous small, peg-like teeth that lined the front of its jaws and extended back along the sides. The total number of teeth in Nigersaurus is estimated to be around 500, which is significantly higher than most other dinosaurs.

The abundance of teeth in Nigersaurus is thought to be an adaptation for its feeding habits. It had a broad, flat muzzle and specialized jaws that enabled it to graze on low-growing vegetation, likely ferns and other soft plants. The numerous teeth allowed for efficient cropping and grinding of plant material as it fed.

While Nigersaurus is known for its impressive tooth count, it is important to note that teeth numbers can vary among individuals and species. Some other dinosaurs, such as hadrosaurs (duck-billed dinosaurs), also had a high tooth count, with hundreds of teeth arranged in dental batteries within their mouths.

Understanding the dental anatomy and tooth count of dinosaurs provides insights into their dietary preferences and feeding strategies. Nigersaurus, with its extensive dental array, represents an intriguing example of the diverse adaptations that allowed dinosaurs to exploit different ecological niches during their long reign on Earth.