When dinosaurs populated our planet over 66 million years ago, their species and sizes ranged dramatically. Fossil remains reveal that most giant dinosaurs were identical to the weight of 12 African elephants or the length of a Boeing 737. Meanwhile, the smallest was the size of a chicken. The infographic below from Giulia De Amicis shows dinosaurs' sizes to understand their sizes and variety. Towering as high as 39 meters (128 ft), the Argentinosaurus , or 'Argentina lizard,' is considered to be the most giant dinosaur ever discovered. These dinosaurs' height was equal to that of a 13-story house. He belonged to a subgroup of dinosaurs called sauropods. They had very extended necks and long tails, four broad legs for support, and comparatively little heads. In 1987, its bones were excavated in the Argentinian Patagonia region, a destination well-known for prehistoric skeletons. Other sauropods were also tremendous, including the Brachiosaurus , or 'arm lizard'