▶ Your Answer :
In
the reading passage, there is ample support for the author’s claim
that R. robustus did not hunt psittacosaur dinosaurs actively.
However, the professor in the lecture gives several reasons as a
rebuttal to the author’s point.
First,
the professor contends that R. robustus could hunt babies of
psittacosaurs successfully. It could have been arduous for it to
catch full-grown psittacosaurs due to its relative size, but its body
was bigger than that of baby ones. According to the lecture,
predators’ mass should be at least twice of that of animals they
prey on, and this is true in case of dinosaurs discovered in the
stomach of R. robustus. Thus, it is plausible that this active hunter
was able to consume neonatal psittacosaurs and dinosaurs with a
similar size. This casts doubt on the reading passage’s claim that
they were unable to hunt psittacosaurs, whose height is almost two
meters, due to the obvious disparity of a size.
Next,
the professor argues that the length and positions of R. robustus’
legs were not a problem for hunting. One sort of modern animals has
short legs which are attached a little to the side as those of R.
robustus. However, it can reach speed up to 15 kilometers per hour,
and is a thriving predator. Hence, it would have been possible for R.
robustus to catch its prey successfully. This refutes the reading
passage’s assertion that the characteristics of R. robustus’ legs
impeded it to hunt psittacosaurs, which could move rapidly, but let
it scavenge them.
Finally,
the professor insists that an opinion with regard to teeth marks
which must remain in bones inside the stomach of R. robustus
overlooks some facts. To put it concretely, R. robustus had a
powerful jaw which was used in grabbing and holding on its prey. This
means that it did not capitalize on its back teeth to chew the food,
which is demonstrated in specimens. Therefore, it could have
swallowed its prey wholly or in big pieces. This counters the reading
passage’s suggestion that the absence of teeth marks in the bones
of pissatosaurs inside R. robustus’ stomach proves that it ate
their eggs which were not protected. For the aforementioned grounds, the professor in the lecture maintains that R. robustus could have hunted psittacosaurs well. |