How to tame a Spinosaurus easily:-

S1: To find a Spinosaurus, go to rivers (mainly the rivers near the Redwoods).

S2: Options:-

1 Clear out the area if you think anything could trouble you while taming it and if you have a quick mount, knock it out that way.

2 Or build atleast pillars which are 12-14 times higher and knock it out that way.

3 If both of them are risky, build 15-20 fence foundations and stone walls of atleast 3-4 times high and finally finish it with ramps and knock it out with that way.

S3: Knock it out with either tranquilizer darts and a long rifle or tranq arrows and a crossbow.

S4: Feed it Argentavis Kibble (Old ARK Mobile only), Exceptional Kibble, Raw prime fish meat or Raw fish meat.

S5: You have a Spinosaurus :D

Facts:-

F1: It's saddle unlocks on lvl 71.

F2: It is quite quick in water as well as land.

F3: It also has an untameable version in Extinction which is Corrupted Spinosaurus.

F4: When in water, it has a Hydrated buff which increases it's damage and resistance.

It took a long time writing this :)