Where to find T-rex?

[Frostwake]

According to every monster list Ive seen, theres supposedly a T-rex monster somewhere in the mirage/lefein area, and hes the most powerful and rewarding normal monster in the game, yet Ive been searching for it like mad and I cant find it... I only seem to find "Allosaurus" which is a cut down version... since I want to have a 100% monster list its important:confused:

[Dr Unne]

http://www.ffclassic.net/worldmap.php?x=6&y=1
http://www.ffclassic.net/worldmap.php?x=6&y=2
http://www.ffclassic.net/worldmap.php?x=5&y=2
http://www.ffclassic.net/worldmap.php?x=5&y=1

He is rare, it may take you a while.

[Nekhbet]

Park your airship below the desert, then head straight up until you hit mountains. Wander around there.

That's where I found him.