Giant land tortoises on different Galapagos islands have different shell shapes and neck lengths, apparently a response to their different diets. Where food is sparser and at a greater height, there is a competitive advantage to saddleback shells and longer necks. In contrast to the usual theme of island species getting smaller, this guy is a pretty good size.
I chose the “pond turtle” (posted earlier this week) and this land tortoise as if they went together, but after posting I began to wonder whether that was true. Some poking about suggests that they are related – fellow chelonians.