Are dinosaur bones a random find? Or is it possible to discover them by looking out for something else? I've been roaming the countryside but never seen any. Any hints or tips would be appreciated - but no spoilers! I don't want to know where they actually are, just if there is a way to find them without walking accidentally on top of them.
Dinosaur bones are found in specific locations that are static and independent of what play through you play on.
Unfortunately, there is no hint, map, or tip that can easily be used to track down each of the 30 locations found in game; you will have to "[walk] accidentally on top of them."
To get started finding Dinosaur Bones, you need to track down a Stranger.
Southeast of Horseshoe Overlook you will find a woman in the middle of a pile of mud. Speak to her and you will find that she asks you to find Dinosaur Bone Locations, there are 30 of them scattered throughout the world of Red Dead Redemption 2.