Their body structure did not vary as much as other dinosaurs, perhaps due to size constraints, but they displayed ample variety. Some, like the diplodocids, possessed tremendously long tails, which they may have been able to crack like a whip as a signal or to deter or injure predators, or to make sonic booms. "Supersaurus", at long, was the longest sauropod known from reasonably complete remains, but others, like the old record holder, "Diplodocus", were also extremely long. The holotype (and now lost) vertebra of "Amphicoelias fragillimus" (now "Maraapunisaurus") may have come from an animal long; its vertebral column would have been substantially longer than that of the blue whale. However, research published in 2015 speculated that the size estimates of "A. fragillimus" may have been highly exaggerated. The longest dinosaur known from reasonable fossils material is probably "Argentinosaurus huinculensis" with length estimates of to according to the most recent researches. However the giant "Barosaurus" specimen BYU 9024 might have been even larger reaching lengths of 45-48 meters (148-157 ft).