Easiest way to take down one of these: get a cross bow or a bow if ur not a high level 2, I recommend using tranq arrows to knock out one of these and use a melee weapon to not waste ammo and also look for a cliff that the bronto can't reach and get top of it now shoot it with tranq arrows and kill it while it's KOd might be cruel but hey, you just got yourself free prime meat or just tame it if u want
Tip : Don't put wooden / metal spike walls near your base if you live in an area with a lot of sauropods.
this is why : since they like to wander around, There's a chance that they will get stabbed by the spikes when they wander near your base. And they will get mad at you, kill your tames, and wreck your base.
so please be careful and think twice before setting up spikes near your base.
I was wandering around with my trike gathering berries and a mf called bronto that i hit by accident his level was high and my trike was decent he damage 126 or something i tried to fight back but his knockback can send you to another island i tried to escape but i was lagging and the bronto was faster then my trike sadly my trike died because he was gathering berries pray for my trike:(