An easy tame a nd easy to make saddle these are probably the best early to mid game utility dino you can get. They have good carry weight and decent attack damage and if you put levels in health you can use it to easily transport items across dangerous areas
Iguanodon is a very useful dino. Its strong, fast, have a lot of stamina, can jump really high, can collect a ton of berries, can turn it to seeds, when u need, and poop for u big eggs. :D A must-have creature in the game.