|Final Fantasy X-2 Enemy|
- Normal: "A fiend that that sometimes attacks with Poison Fang and won't hesitate to use Stone Fang in a pinch. Watch out!"
Oversoul: "Now sporting a Darkness attack in its oversouled state. As an added bonus, it remembers how much damage it has taken when counterattacking."
The Archaeothyris is an enemy from Final Fantasy X-2. Its low Magic Defense and weakness to Ice make it an easy foe to deal with. However, be on guard with Softs as it can inflict Petrify, and carry lots of Antidotes as well to counteract Poison Fang.
Archaeothyris was an amniote which lived 320 million years ago, in the Middle Carboniferous period. It is the oldest undisputed synapsid known. It was found in Nova Scotia, the same locality as Hylonomus, and Petrolacosaurus, all of which resemble Archaeothyris.