There's some dinosaur erotica on Amazon. Several sites commented on it, and that seemed to feed their 'ironic' popularity. Eg: Cracked, NYMag, Buzzfeed

Imo the dino and other weird erotica is just a continuation of the several years old trend of replacing normal characters in books with popular weird characters, like Pride and Prejudice and Zombies.

The dino erotica seemed to be visible on the internet again after Jurassic World came out.