虽然梁龙是岛上最大的生物之一，但它却是岛上较小型的蜥脚类动物。除了体型和智商，梁龙有更快的最高速度和更多的耐力。当梁龙完全成年后，它大概只有雷龙的一半大小。 让我感到困惑的是梁龙居然能在岛上生存。梁龙是一种非常笨又容易轻信的动物，这常常会对它造成致命的损伤。它通常不会逃离捕食者除非它们不断被攻击，它们甚至倾向于尝试大量没有结果的示好。 由于某些特殊的原因，梁龙非常信任人类，它们似乎从来不会对人类的攻击还手！
Common name: Diplodocus
Species: Diplodocus insulaprincep
Time: Late Jurassic
Despite being one of the Island's largest creatures, Diplodocus insulaprincep is among the Island's smaller sauropods. Instead of size and intelligence, Diplodocus developed faster maximum speed and greater endurance. When fully matured, it generally only reaches about half the size of the rather enormous Brontosaurus. Diplodocus is another creature whose continued survival on the Island confuses me. It's a very thick-headed and trusting animal, often to its fatal detriment. It never flees from predators until after they've attacked it repeatedly, preferring instead to make numerous fruitless attempts at friendship. For some strange reason, Diplodocus trusts humans so much that it doesn't seem to fight back against them…ever!
Due to Diplodocus' smaller frame, it cannot support the type of "platform" saddle that other large creatures can. To make up for this, many tribes instead use an eleven-seater passenger saddle which enables Diplodocus to safely transport ten additional riders. These passengers often use ranged weapons to protect the creature, or to attack nearby enemies while on the move!