Titanosaur, diverse group of sauropod dinosaurs classified in the clade Titanosauria, which lived from the Late Jurassic Epod (163.5 million to 145 million years ago) to the end of the Cretaceous period (145 million to 66 million years ago). Titanosaur fossils have been found on all continents except Antarctica and include some 40 species. The group contains the largest terrestrial animals known, some even approaching the size of modern whales. Like other sauropods, titanosaurs were herbivorous quadrupeds with long tails, long necks, and small heads. They differed from other sauropods, however, in that the titanosaurs’ bodies were stockier and their limbs produced a wider stance than other sauropods. Titanosaurs also possessed vertebrae with a honeycomb-like internal structure and six sacral vertebrae (vertebrae adjacent to the pelvis), but they lacked the hyposphene-hypantrum joints (which connected one vertebra to another) in their dorsal vertebrae (vertebrae that articulate with the ribs). In addition, some titanosaurs, such as Rapetosaurus and Saltasaurus, have been shown to have possessed osteoderms (armoured plates).