Huh... in Japanese, a fossil is a "stone" (化石) – "kaseki" is kinda like "transformed stone," as in the organic thing became stone. I suppose it does fit Ariya's power – causing something to stop changing is essentially transforming that something into stone.
Wait a f#cking minute... 🤨 Turning you into stone... Ugly af.... Has snakes...
THAT'S MEDUSA!