Since nobody talked about it

The underwater caves on the "TheIsland" map are THE best way to obtain quality rex saddles, if you don't have that option I have a few recommendations:

Valguero: There a easy cave with no dinos where you can get 2 Yellow Loot Drops, 2 Blue Loot Drops and 2 Red Loot Drops, just make sure you have a flyer, a perfect one would be the Pteranodon

Ragnarok: Do runs in the ice cave, but make sure to grab the Loot Drops in the area before you grt into the actual caves, just lure the bears down the cliff if they agro on you

Abb: Well, basically just the Loot Drops sadly.

Extinction: Yellow, Red or Purple OSD, I recommend the Red one though

Gen/Gen2: Honestly, Pay2Win, just do the missions

Scorched Earth: Desert drops

Crystal Isles: Land drops located in the snow biome

Hope that this helped a few people, and it will take some time to get the saddles, just do not give up, it'll be worth it.

Rex saddle is L.V 74. And it's pretty easy to make.

taming rexex is easy but the only problem here are saddles. from few other comments I can tell that you can get rex saddle blueprint from ice cave and underwater caves.

(hope that helps)

For fiber best is sickle

For hide and animal or an axe

And for metal ankylosaurus or an pick

I think something good to get fiber is a therazinosaurus with his wiggly fingers

Tame a Rex closer to level 74 because it is easy to get a satle

It will be easy for me to get the metal cuz I’m only lvl 53 and I have 7597 ingots I will give you a tip go to east zone 1 you will see a small herbivore island and tame a sarco and get to that island I recommend to get a good weight sarco and then just farm and you will get a lot of ingots just from that island I got 2000 METAL ingots

Swamp cave in the redwoods on the Island map seems to have a high chance of having really good rex saddles/BP in the red drops in there

On multiple different servers I always seemed to get a BP

If you want hide for this killa just a carno and just farm alot