Scientists crowned the world's longest dinosaur — a Supersaurus longer than 3 school buses from nose to tail

• Supersaurus was likely the world's longest dinosaur — around 137 feet from nose to tail.
• Paleontologist Brian Curtice awarded the title after analyzing Supersaurus bones in Colorado.

With a head the size of a horse and hip muscles as big as a car, Supersaurus was among the world's largest dinosaurs. Now, new research suggests it was also the world's longest dinosaur, spanning 137 feet, on average, from nose to tail — the equivalent of three large school buses lined up end to end.

Another group of dinosaurs, titanosaurs, were previously contenders for the longest dino title — that is, until Brian Curtice, a paleontologist at the Arizona Museum of Natural History, discovered evidence that seemed to settle the debate.

Curtice analyzed a collection of giant bones from the Dry Mesa Dinosaur Quarry, a 55-acre site in Colorado, and determined that the fossils must have belonged to a Supersaurus, since they matched the size and structure of other Supersaurus skeletons.

Prior to Curtice's analysis, a field worker named Jim Jensen had categorized the bones as belonging to three different sauropods (dinosaurs with long necks and tails): Supersaurus, Ultrasauros, and Dystylosaurus.

"Traditionally everyone looked at Dry Mesa as this bone salad," Curtice told Insider.

Mapping the bones helped him realize that the pit contained one large animal — not several. The biggest bones were all located in the same pocket of the quarry, he said, which made sense: Most Supersaurus bones would have been too heavy to be lifted or blown away by the wind.

"Once we started plotting it on the map, the puzzle pieces fell into place," Curtice said.

After measuring the bones, he determined that Supersaurus had shoulder blades at least 8 feet long, legs more than 12 feet long, a neck at least 50 feet long, and a tail at least 60 feet long. Though his research is still awaiting peer review, Curtice presented his findings at the annual Society of Vertebrate Paleontology meeting earlier this month.

The bones resembled two other Supersaurus skeletons, Goliath and Jimbo

Curtice said Jensen's theory that the bones belonged to three different dinosaurs never checked out.

"He was caught up in the moment," Curtice said. "He wasn't classically trained."

Paleontologists now question whether Ultrasauros and Dystylosaurus were distinct dinosaur types, or if the names merely misclassify other dino remains. But they're confident that Supersaurus roamed modern-day Colorado and Wyoming around 150 million years ago.

Paleontologists have identified two partial Supersaurus skeletons in addition to the one at Dry Mesa. A 2008 paper described a Supersaurus named "Jimbo" found in Wyoming about a decade earlier. Researchers have also identified a brand-new Supersaurus skeleton named "Goliath," although their results haven't been published in a peer-reviewed journal.

Curtice said Jimbo and Goliath's skeletons helped him recognize the Supersaurus bones in Colorado.

"Jimbo allowed us to inform our understanding of Supersaurus, so when we went back to the Dry Mesa Dinosaur Quarry we were able to go, 'Oh, that looks like that. And that looks like that,'" Curtice said. "Now Goliath validates Jimbo."

But calculating the length of the bones was still tricky without a full skeleton.

"It should have 15 or 16 neck bones and we have six of them," Curtice said. "So the big challenge is 'Wait, which six do we have?' They don't come with numbers on them."

Curtice understood, at least, that the bones followed a pattern: They got smaller by a certain percentage as you moved away from the longest bone, which allowed him to estimate the length of the missing bones.

If two of the dinosaurs were to touch noses, Curtice found, they might span nearly an entire football field — a conservative estimate, he added.

"What's shocking to me is how close in length Goliath and Jimbo are," Curtice said. "If you get three animals that are within a few feet of one another, now we know, 'OK, that's the average.'"

The dinosaur likely used its long, powerful tail as a weapon

There's a reason the tail and neck make up the bulk of Supersaurus' length.

Curtice suspects that the Supersaurus used its tail — a long chain of thick bone wrapped in muscles and heavy scales — to club predators. The tail might also have been useful as a kickstand, allowing the animal to rise up on its hind legs and reach food in tall trees.

Curtice compared its neck to a giant vacuum cleaner: "If you stand in one spot and then you sweep your neck side to side, you have a tremendous amount of ground you can cover to grab food."

Ultimately, he added, few dinosaurs were a match for Supersaurus' brute strength and expansive mass. Its neck alone could have lifted a predator 20 feet off the ground.

"It had a large range," Curtice said, "so if it moved its hip and slammed its tail around, it could hit multiple predators."