Go for a Stego. They’re not too difficult to tame and can gather wood and thatch as well as berries. They also provide extra defensive and offensive capabilities by means of their different plate modes, which is handy for harvesting in more dangerous areas. Your biggest problem taming them is going to be other Stegos aggro-ing when you attack one.
To the guy who said that you can’t harvest veggies, I beg to differ. On ragnarok near the dragon trench, you can find savaroot and rockarrot plants on the hills close to the beach. Easy no trouble food source.
While Iguanadons are much better in almost any way, Parasaurs still have their uses, and are definitely great for early berries. The reason being a parasaur is much easier to get saddle up and ready go, being 20 some levels before Iquanadons’s saddle. They also don’t attack you while caught in a bola making them easy to tame fast with a club. This is all not to mention the turret mode which can be very helpful throughout all game.