Supersaurus - world's longest dinosaur

 

Life restoration of Supersaurus

It would take 4 full seconds for the fastest man in the world to run from nose to tail.  It is longer than 3 large school busses parked fender to fender.  One animal would occupy nearly half a football field!  Meet Supersaurus, the longest dinosaur yet discovered.  Dr. BC's minimum numbers place it over 128' long, but he thinks it was more likely nearly 140' long.  Though really, really long it isn't the heaviest dinosaur to ever live, that honor goes to Argentinosaurus.  The heaviest animal that ever lived?  That title belongs to the living Blue Whale.  See our neat chart comparing them, as well as the largest mammal that ever lived, Paraceratherium, and a Tyrannosaurus.

 

Supersaurus compared to the heaviest dinosaur, Argentinosaurus, and the heaviest animal to ever live, the Blue Whale.

 

Supersaurus vivianae, "Vivian's Super Lizard" was named by Jim Jensen in 1985.  He found a shoulderblade over 8' long, an impossibly long length, especially considering the next closest shoulderblade of similar shape was "just" 4' long.  The shoulderblade belonged to a kind of long-necked, long-tailed dinosaur known as a sauropod, and more specifically to one of the longest neck-and-tailed ones, the diplodocids.  

Jim continued collecting and soon found another shoulderblade over 8' long.  And a neck bone nearly 5' long, by far the longest neck bone of any animal ever discovered.  Over the ensuing nearly 3 decades, paleontologists from Brigham Young University uncovered additional bones belonging to Supersaurus, including the tallest tail bones and, until the discovery of Argentinosaurus, the tallest back bone  

Dr. BC recently studied newly prepared bones of Supersaurus at the Brigham Young University Museum of Paleontology, as well as two new specimens of Supersaurus.  One you can see on display at the Wyoming Dinosaur Center in Thermopolis.  Nicknamed 'Jimbo' it is an incredibly cool skeleton to see with the original fossils underneath it.  The other, 'Goliath', is heading to the Grandview Museum of Natural History in China but, thanks to COVID, its shipping had been delayed and he was able to study it before it heads to its new home.

All three of these supergiant sauropod dinosaurs are extremely close to one another in size.  The fact 3 dinosaurs of the same genus are so similar suggests this was the average size Supersaurus reached, hinting that much, much longer individuals are yet to be discovered!  

Supersaurus has sometimes been thought of as a giant Barosaurus.  Dr. BC suggested such a thing many years ago and others have done so in the recent past.  However, with 3 partial skeletons showing the same characters, we now know how to spot a Supersaurus, as long as we have the tail! 

 

How do we know it was so long?  Thanks to the hard work over many years at the Brigham Young University Museum of Paleontology preparing hundreds of tons of dinosaur bones, they have uncovered a number of new neck and back bones.  We now have nearly 50% of the presacral vertebrae, a huge number for sauropods.  We have 80% of the sacral vertebrae as well.  The tail consists of upwards of 80 individual bones, and though we don't have even 25% of the tail we do have important representative parts throughout the tail.  Plus we have a complete, articulated tail of Apatosaurus, a close cousin of Supersaurus as well as good tail chunks of Barosaurus and Diplodocus.  Dr. BC took the known specimens and determined how long each body segment would be, then extrapolated the lengths of Supersaurus based off of these known ratios using 3 different Supersaurus specimens.  He also measured each vertebra and then, using existing animals, determined the percentage of size change between each position.  The largest mystery in Supersaurus was where does the giant BYU 9024, the huge cervical vertebra, go?  Is it the longest bone in the neck?  Or should Dr. BC model it as if it was much farther forward as it certainly resembles that of a much smaller, further forward neck bone of Barosaurus.  After modeling it both ways, and comparing the model to 'Jimbo', Dr. BC concluded the vertebra is farther back, making the animal "only" 128 - 138' long (39-42 meters).  Part of its newfound length comes from understanding that its tail is similar to Apatosaurus yet the vertebrae are 20%+ longer!

 

 

 

 

 

The dark black is a back bone near the shoulders, the one in the middle is near the hips.  The white bone is the tallest back bone I could find of Diplodocus.  Notice how much tinier the centrum (the round part at the bottom) is.