Crichtonsaurus is a dinosaur confirmed to appear in Additional Creatures 2: Wild ARK.
Crichtonsaurus, named after Michael Crichton: the author of Jurassic Park, is a small species of ankylosaur that lived 75 million years ago in China. Not much is known about this creature, only being known from a few bones, but it is known for its small size, only being around 3 meters long.
Crinchtonsaurus is planned in Additional Creatures to be almost be completely immune to damage. The only exception will be damage over time status effects like venom and bleed. The mod developer also has his own idea of it having an on-command "crouch" move, which will essentially make the chrictonsaurus act as cover for PvP players, because bullets and explosives will do absolutely nothing to it.