How to do barrel roll on mobile: Go to settings and then go to controls then either go to left multi tap or right multi tap. Then select Reload/Alt attack2. When you are done, go and press on your screen twice on either left or ritght side. And you pteranodon can now do a barrel roll! Disclaimer:wastes stamina alot so be careful. Like so newbies see this!
If you play on mobile and want to do the roll then go to settings left or right multi tap and chose alt attack 2 !!!
NOW FOR THE MAIN PART--- THESE THINGS CAN KILL GIGAS the normal roll does decent damage but if you roll and attack a dino while watching the dino through spyglass you can deal tons of damage (this works in mobile idk about other platforms) i killed tons of rexes,brontos,allos..etc. using this trick