If you are having a hard time finding spino's in their respective spawn zones (especially Ragnarok), kill all the fish in that area. They share the same spawn capacity and can be out spawned by coles! ( up vote so Rag players know!!!)
I found one across from my base. I followed one of the tamimg pen tutorials but made the pen to small and the game kept crashing. I died over 5 times and finally got it trapped then a raptor killed me, when I respawned I saw the spino running towards my base. I thought it was the end of my dinos but no, it looked at my dodo the wrong way and all my creatures (10 dodo, 1 dimorphodon, two dilos,1 Iguanadon, one petradon, and two parasaurs) all mobbed it and it started running faster than anything I've seen in ark. I ended up making a huge pen and having to chase the spino into it because of the trauma from all those dodos... Now I have it, but am over level 52 and don't have a saddle for it.
To be strictly honest the spinosaur is one of the best mounts in game if you are even wble to obtain one be sure to make it a high level one they are very squishy at first so go around killing small dinos before attacking big prey
As far as I know, only 3 wild carnivores will aggro onto the sight of your spino, other Spinos, Rexes, and Gigas. You can probably outfight other spinos, outrun rexes, or outfight lower level ones, and outrun gigas. Very useful.
TLC patch coming in March 2018 to add the ability to swap between 2 legged mode (faster attacks and ability to attack with claws) and 4 legged mode (Faster movement), as well as increased turning radius, movement speed, damage, and health regen while in water and for a short time after leaving it. Like so people can see!