Sauropods were the true giants of the dinosaur family, some species attaining lengths of over 100 feet and weights of over 100 tons. Most sauropods were characterized by their extremely long necks and tails and thick, squat bodies; they were the dominant herbivores of the Jurassic period, though an armored branch (known as the titanosaurs) flourished during the Cretaceous. Among the most well-known sauropods were Brachiosaurus, Apatosaurus and Argentinosaurus.