They are easy first get slow level if you are start game. Preferably a lvl1 to a lvl 10. Then knock it out with a slingshot or tranqs. I run in circles and knock it out. After that let starve for 3-5 minutes then feed green kibble ,crops , or mejos. After that give either narco berries or narcotics. Then you got a trike.
First go find a triceratops.
Find a good rock it can’t climb.
Jump on the rock.
Keep shooting it with tranq arrow or darts.
When knocked out pur in carno kibble a mejos.
Wait and feed it nartics then you got a triceratops.
Don’t tranq them out when there getting ready to charge or the will be stuck for ever and the will just keep getting ready to charge I just found this bug so I don’t know if there’s a way to fix it but be careful when taming a trike
So what you do is get a lot of the purple berries and those black ish berries. Go on a higher rock that the trike cannot get to u. Use a slingshot and aim near the body. The head has too much armor on it and cannot knock it out. The body is the most Vulnerable. The black ish berries will make its Unconsciousness go up and it saves you a good amount of time to tame it. I hope this info was good enough!