a difficult grammar question

[curious]

Hi,

which one is the best choice here? I'm perplexed. Thanks for your help.

Dinosaurs may have terrorized other creatures during their time on Earth, ---------- now it has emerged that some species had a taste for the flesh of their own kind.


A) unless
B) whether
C) because
D) even if
E) so that

[Tdol]

Hmm- I don't like the choices. I'd go for 'but' or something similar.

[curious]

does but introduce/express a concesion? If yes, what would the concession be when but was inserted in the sentence?

- Does that the dinosaurs may have terrorized other creatures have anything to do with the fact that whether some creatures had the trait of eating their own kind or not?
- Does the first sentence bear any logical relation to the second one?

All the dinosaurs may have terrorized other creatures, but it has emerged that some dinosaur species ate their own kind. ????????

[Tdol]

That's the concession- we knew they scared others, but we have only recently learned of their cannibal tendencies.