The following is a documentary telecast in one of the children's television programmes. Read it and answer the questions. Dinosaurs are a popular topic when we discuss the prehisto... The following is a documentary telecast in one of the children's television programmes. Read it and answer the questions. Dinosaurs are a popular topic when we discuss the prehistoric era. Today, let's unearth more mysteries of this lesser known era. Have you heard of any prehistoric mammals? If not, you would surely love to see Megatherium, an elephant-sized ground sloth. Look at this life-size replica of the megatherium which greets visitors at the Sloth Sanctuary in Costa Rica. Imagine that an elephant-sized hairy animal with giant claws ambling through the landscape, looking for trees it could sit in front of and slowly chew the leaves. This extinct herbivore stood seven metres tall and weighed seven tons. There are many views in the scientific world about the disappearance of this creature. One of them is that they disappeared as a result of fast changes in the climate. Another is that these sloths had been hunted to extinction by the carnivores. Now let's look at an extinct carnivorous sea creature. Ammonites were a group of shelled sea creatures that mysteriously disappeared at the same time as the dinosaurs. Ammonites were invertebrates: creatures without a backbone. Instead, they had a very supportive shell. Ammonites grew as big as one metre in diameter. They probably lived in warm, shallow, tropical areas of the ocean. Their diet consisted of small fish. Ammonites were popular on the menus of larger carnivorous marine creatures, but they would either have had to pull them out from the shell, or have had jaws powerful enough to crush them. Read more