Since we didn’t know they existed until 1954, there is some mystery surrounding the full knowledge of them. They were originally thought to be a turtle-like reptile, but that has changed over the years and they have been classified as a herbivore due to their long neck and short forearms. They are now assumed to be a therapod which is a carnivore. The truth is that we have no clue exactly what they were nor how they survived. At the time they were discovered, they were believed to be over 70 million years old and we only discovered them about 68 years ago