Amazing for starting out if you wanna go in the ocean and you don't have scuba gear unlocked, they are extremely fast and can outrun pretty much anything in the water like the dolphin, I still use mine even now
They are skittish but not anywhere near faster than humans. They have low torpor and health, so tranq darts are recommended. Tamed like any carnivore, kibble is Archeopteryx. Can be found anywhere in and around the swamps.
The Diplocaulus is a swamp amphibian with one major use once tamed; becoming a living oxygen bag. When swimming to the depths of the ocean, some disgusting survivors will suck on the bladders of a tamed diplocaulus' head as an effective oxygen source.