Sauropods.

This article begins as many others on sauropods before it: "Sauropod dinosaurs were the largest animals to ever walk the Earth, by far". The largest sauropods were easily four times heavier than the largest land mammals (and the largest other dinosaur species, for that matter). The iconic body plan of sauropods is dominated by their very long neck, in some species exceeding 14 meters in length, provided with a relatively small head (Figure 1). The neck was mostly held horizontally or at a low angle. The massive but relatively short trunk was supported by four columnar legs, much like in an elephant. The bones in the fore foot of sauropods are oriented vertically, and some late forms even lost their finger bones, walking on their metacarpals (middle bones of the hand). The hind leg, which bore most of the weight, has a half-upright foot. The femur (thigh bone) was the largest bone in the skeleton, like in most other true land vertebrates (amniotes). The long neck was counterbalanced by the long tail, the base of which also functioned as the anchoring region of the giant muscles that pulled back the hind leg during walking.