You will hear a recording. Select the paragraph that best relates to the recording.
(1) Researchers have found that dinosaurs had the same kinds of diet-related issues with their dentition as modern-day animals. Meat-eaters in particular had tooth cavities due to bacteria in their food. However, herbivores also had problems due to their teeth being ground down as they chewed on tough plant fibers.
(2) Tigers have sharp, curved teeth for slicing meat, while horses’ teeth are flat for grinding plants. Similarly, amongst dinosaurs, allosaurs have sharp, straight, conical teeth that were well adapted for crushing the bones of other dinosaurs, while hadrosaurs had flat teeth for eating grass and similar materials.
(3) We can tell what kind of food an extinct animal such as a dinosaur ate by examining its teeth and jaw and comparing them with present-day animals. Sharp, serrated teeth imply that it was a carnivore, whereas flat surfaces for grinding tough fibers suggest a herbivorous diet.
(4) Hadrosaurs, like horses, were adapted to a vegetarian diet. Their teeth were flat and designed for grinding tough material such as plants, though they were sometimes ground down to a flat surface. This led to problems with dentition. Allosaurs, on the other hand, like tigers, had sharp teeth for eating meat.