This is just outside Zahhab Region, where it can't be focused on, so you get it's info and trivia when you first see it.
As one of the three super-legendary and long-extinct creatures (the other two being the Anomalocaris and the Sea Serpent), this does not appear in your encyclopedia as a silhouette, and only appears after you have found it.
Some players have been able to lure Cameroceras into the map with food, allowing the player to focus on it.
It has appeared in three documentaries:Sea Monsters - A Walking with Dinosaurs trilogy, Walking with Monsters (But it only had a brief cameo), and Animal Armageddon (It played a major role in this documentary, but was identified as a Straight-Shelled Nautiloid).