I was out looking for high level rexs on what I like to call the Viking map. When I couldn’t find any good levels I went to the lava island and found a level 150 female Rex. I killed the low level that was with her and started shoting traq darts when she started running I had got so scared when she ran into lava. I stopped firing and luckily she got out before she died and I knocked her out and tamed her.