A favored theory to explain the extinction of dinosaurs, together with many other species, has been the globally catastrophic collision of a large asteroid with the Earth. Supporting the evidence is an extraterrestrial chemical element in a layer of dust found worldwide at a geological level laid down contemporaneously with the supposed event. A new competing theory contents that any asteroid impact was irrelevant, because it was massive volcanic activity that caused the extinctions by putting enough dust into the atmosphere to cool the planet. The Deccan region of India contains extensive volcanic flows that occurred within the same time period as the supposed asteroid impact and the extinctions.
Which one of the following, if true, most strongly indicates that the asteroid-impact theory is at least incomplete, if not false?
A) Large concentrations of dinosaur nests with fossil eggs found in Alberta indicate that at least some species of dinosaurs congregated in large groups during some part of their lives.
B) Dinosaur remains indicate that some species of dinosaur could have migrated in herds over wide ranges, so that they could have traveled to escape the local effects of certain catastrophes.
C) Legends from many cultures, such as the Greek legend that Cadmus raised an army by sowing dragons' teeth in the ground, show that various ancient peoples worldwide were familiar with the fossils of dinosaurs.
D) In the Gobi desert in China, where now only small animals can eke out an existence, fossil dinosaur skeletons 27 feet long were found in circumstances indicating that the climate there was as dry when the dinosaurs lived as it is now.
E) The fossil record in Montana from below the layer of extraterrestrial dust shows a diminution over time in dinosaur species from 35 to 13, and dinosaur teeth found above the dust layer show a diminution in species from 13 to 5.
Can anyone please explain why answer choice E is correct? Thank you so much for your help!