There is an island full of them on ranarok in SW tropics the island is literally dimetrodons, jerboas, and pelagornis

WHY CANT MY ARGY PICK IT UP EVEN THOUGH IT SAYS IT CAN??!

These guys are quite great to have tamed, especially if your making a pack of a dinosaur. They incubate eggs, and stuff the egg under their stomach so that they get damaged instead of the egg. They also hide in the sand when submerged in water and touching the sandy floor, so that only their fin is visible. It make them practically invincible, at that state. They also deal a lot of damage; I have seen one single handedly kill a paracer. (note that the Dimetrodon got very damaged, and afterwards a carno one shot it) they also serve as air conditioning unit, so I imagine that they would be good to bring to the volcano, red woods, etc. they aren’t very fast, though, which is good if your shooting it and don’t have a cliff around. (Though, watch out for other dimetrodons around, since they will defend other dimetrodons.)

This is basically a small friendly spino that lives in swamps

The dimetrodon is not aggressive. If you do attack it, don't worry, they're very slow and quite easy to take down.

These guys are like a lizard but with a spino sail, they also keep eggs warm so they can hatch and they are also neutral, So be nice to these if your not ready to fight.

I don't mind that it can't be picked up by tapejara or pt (already makes it a pain in the ass to tame) but why can't it be picked up by argy it's literally so small

Can't be carried by an argy in mobile I lost my argy named aorus in the swamp to test that 😭

In fjordur you can find them in the jungle swamp realm

You can find these guys in the swamp area by redwoods, desert near the water and in the swamp heading to the floating islands! I incubated one wyvern egg with two of these guys. I put on my level points into melee.