Critical Reasoning

15. The southern half of a certain region of the earth was covered entirely by water during the Cretaceous period, the last 75 million years of the Mesozoic era, the era when dinosaurs roamed the earth. Dinosaurs lived only on land. Thus, Plesiosaurs—swimming reptile that lived during the Cretaceous period exclusively—were not dinosaurs. No single species of dinosaur lived throughout the entire Mesozoic era.
If the statements in the passage are true, each of the following could be true EXCEPT:
(A) Dinosaurs inhabited the northern half of the region throughout the entire Mesozoic era.
(B) Plesiosaurs did not inhabit the southern half of the region during the Cretaceous periods.
(C) Plesiosaurs did not inhabit the southern half of the region before the Cretaceous period.
(D) Dinosaurs did not inhabit the northern half of the region during the Cretaceous period.
(E) Dinosaurs inhabited the southern half of the region throughout the entire Mesozoic era.


Oa is e.

E

because dinos only lived on land and southern half was under water for last 75 years of mesozoic era

is it the OA?

statement says "No single species of dinosaur lived throughout the entire Mesozoic era"

Hence E cannot be true

IMO C

This is given - "Plesiosaurs—swimming reptile that lived during the Cretaceous period exclusively". Hence we can infer that they did not live before the Cretaceous period.

The other options dont seem to be valid. Any thoughts?

Sorry guys, did not notice 'EXCEPT' in the question -

E should be the correct answer.

s_kaks wrote:statement says "No single species of dinosaur lived throughout the entire Mesozoic era"

Hence E cannot be true

E doesnt talk about one single species of dinosaur..It talks about Dinosaurs as a whole...

there might be many species of dinosaurs...for eg: Species1 might have been present during the first 100 years of Mesozoic era..species 2 might have been present during the next 500 yrs and species 3 over the last 75 yrs...

since E talks in Dinosaur as a whole, there is atleast one species of dinosaur which would have existed in the last 75 yrs of the Mesozoic era...

Hope this clarifies.

I would go with option E as the correct option