These things are gold mines. On ragnarok go to Viking bay and tame a megaladon then massacre these things. They are everywhere. Just don’t try and fight them without a tame. They give ez black pearls and tons of silica and chitin.
If you need black pearls on valguero, there is a cave hidden in the jungle on a hill near green ob that you can enter and drop down a big hole into a water pool. There are 4 or 5 pools in the cave, each with up to 15 eurypterids in them, you just have to kill the eels before you get the eurypterids. And the beauty of this cave is that if you leave it (make sure to bring grapples to get out if you don’t want to go the long way) the eurypterids will be back and you can farm another few hundred black pearls. It’s even easier in single player where you can exit to main menu to refresh the spawns.
Why aren’t these labeled as aerial? I think the glitch Is they think land is water and that’s the swimming animation, but it shows as flying as they should be underwater doing it. I think, not sure. I know these aren’t SUPPOSED to fly.
These devil water scorpions turn whale poop into black pearls. They cant leave the ocean floor so Get you a pike and stimulant. Stab these from a distance. Put the stim in the hot bar so if you get pinched you wont wall asleep on the ocean floor
These aren't limited to under the water, and can float over rocks. If they manage to melee you, you're probably going to be knocked out by their tranq and slowly killed. They're easy to kill at range if you're smart, and very much worth it for the chitin and silica, so just be careful to either have a tamed Dino nearby or to stay at range