For every mosa there is a 17% chance for it to spawn as an alpha mosa which is tied with the tuso for the highest alpha spawn chance (note, in general all alpha creatures have a 5% chance to spawn instead of their normal variant, but this is from looking in-depth of spawns)

Swam down on my basilo and found an alpha.

He smiled at me

I smiled back

My basilo smiled too.

Then we got turned into minced meat

To find a mosa it’s very easy on the island, just search around Carno island a you will find one if you don’t see it tidy save. I also recommend using a Bary to tame ⬆️Doot so more peeps can see

Anyone think this thing is terrifying

On the center map Mosa trench is at 65 45. You're welcome. I learned the hard way.

I’ve spent like 2 days searching for this and it’s like all Mosasaurus are extinct

READ THIS FOR MAJOR MOBILE TAMING AND LOCATION TIPSWhen looking for a Mosa in ark mobile you need to run these two cave and farm the the Lava cave and the ice one these give crossbows and swimming gear then you get a dolphin (now what you have been waiting for) to find these with ease you need to kill the Plesiosaur and Leeds these actually clog up mosa spawns there mains spawns are behind herbi island and the artic ocean. The reason you farm the artifacts is they give you ascended gear so they last longer and the keep you warm ( I know this is not allowed but hit up so this goes out for mobile players because we need more help

Not sure if its just my game on ps5 but just in case, I finally found a Mosasaurus, and then a few more. All of them were trapped in underwater rocks. I could only see the tail or their smiles. Just a tip if you're having trouble finding them. Since already trapped, I just tranq'd and used cryo to take them with me. Hope it helps.

A good way of looking for these things (mobile): sweep the border of the map and the ocean floor, using an ichthy to keep everything away. Once you find one, park your ichthy somewhere, then swim up to the depth limit of the mosa (you might have to test where it is though, be careful, mosas can swim up FAST). Being off the ichthy will catch its attention. Swimming up to the depth limit will cause it to Aggro off of you, so go back and forth with going to its depth limit, attracting it, and swimming back up to fill it with tranqs. The basic idea is attract, swim up, fill with tranqs, repeat. Hope this helps!