Scientists have recently analyzed glass spherules that were created by

we need and have concluded.
right away, only A and D remain.
to have killed - properly relates a cause-effect relation.
A

Scientists have recently analyzed glass spherules that were created by the meteor impact near the Yucatan Peninsula in Mexico and have concluded that the infamous meteor arrived 300,000 years too early to have killed the dinosaurs.

(A) and have concluded that the infamous meteor arrived 300,000 years too early to have killed the dinosaurs. - Nothing seems wrong. So we will review other options.
(B) but have concluded that the infamous meteor arrived 300,000 years too early to have killed the dinosaurs. - there is no need for "but" in the sentence since there is no contrast
(C) having concluded that the infamous meteor arrived 300,000 years too early to have killed the dinosaurs. - not parallel
(D) and have concluded that the infamous meteor arrived 300,000 years too early to kill the dinosaurs. - the meaning is changed. It seems as if the meteor came 300,000 years early especially to kill dinosaurs.
(E) and concludes that the infamous meteor arrived 300,000 years too early to have killed the dinosaurs. - and concludes is not parallel

So the answer is A

Between Option A and Option D, Option A is better because of the following reasoning.

Option A can be re-written as :

Scientists have recently analyzed glass spherules that were created by the meteor impact near the Yucatan Peninsula in Mexico and have concluded that the infamous meteor arrived 300,000 years too early to have the dinosaurs killed.

Unlike Option A, Option D implies that the meteors arrival happened to kill the dinosaurs. However, it was just an effect of the arrival that killed the dinosaurs. To make it clearer, we may refer to below two versions of a sentence:

1. The City's mayor awarded the CEO of Infrotraction, a budding EPC industry, for building the city's major highway.
2. The City's mayor awarded the CEO of Infrotraction, a budding EPC industry, for having built the city's major highway.

Here, the second sentence is better for the same reason that the CEO himself did not build the highways but got it built from others in the company.