The reading passage argues that R robustus was unlikely to be a predator However the lecturer provides the evidence in favour of the idea that the stated mammal could have been a successful hunter

In the reading passage, the author argues that R.robustus – a mammal that lived 150 million years ago, is unlikely to be a predator that hunted dinosaurs. However, the lecturer cast doubts on the claims made in article and provides the evidence in favour of the idea that the stated mammal could have been a successful hunter.
The first contradicting point is the size of the mammal as a direct indication to his possibility to hunt certain types of dinosaurs. According to the reading, R.robustus was a modern cat’s size, whereas the psittacosaurs was almost 2 meter tall. This point is challenged by the lecturer who says that the mammal could have successfully hunted baby psittacosaurs which were twice smaller than an adult species of the mammal. And that is exactly the proportion needed for a predator to successfully hunt for his prey.
Another controversial issue is the physical built of R.robustus. The author contends that its build was more suited for scavenging than hunting with its short legs positioned on the side of the body. The lecturer rebuts his argument, suggesting the example of a modern mammal, Tasmanian devil, with a similar built. It can successfully hunt at a speed of 15 km per hour therefore quite probably the ancient mammal could do the same.
The third aspect of the debate is the issue of the tooth marks on the prey’s bones, usually used as an evidence to support the idea that the prey was actively hunted and eaten. This fact brings the author of the reading passage to a conclusion that R.robustus simply found the unguarded nest with eggs, and no actual hunting took place. The lecturer, on the other hand, asserts that the mammal in discussion had powerful jaws, moreover the examination of the fossil proved that it didn’t use the back teeth to chew. This evidence lead us to the conclusion that R.robustus swallowed the whole prey or ate it in big pieces, that is why no teeth marks could be found on the skeleton of the dinosaur found in the stomach.