Question

select the word or phrase that is redundant and can be removed without changing the meaning of the text. if you can imagine a mental picture of a reptile encased in bone, then youll have an idea of what the parahupehsuchus longus, an aquatic reptile of the triassic period, looked like.

Explanation:

"imagine" and "a mental picture" convey the same idea. Removing "a mental picture" doesn't change the meaning.

Answer:

a mental picture