Supersaurus vivianae - World's Longest Dinosaur
It would take the fastest sprinter in the world 4 full seconds to run the length of the newly crowned "World's Longest Dinosaur." I studied new material of Supersaurus, a sauropod (long-necked, long-tailed) dinosaur that lived around 150 million years ago in the Late Jurassic of Colorado and Wyoming. My conclusion, published in the Society of Vertebrate Paleontology annual meetings, is that it exceeded 128 feet (39 m), and likely was 137 feet (42m) from nose to tail, claiming the “world’s longest” title from a number of titanosaurs. To put the length into perspective, Supersaurus is longer than 4 fire trucks, or 3 large school busses, or even 2 semi-trailers. Were two Supersaurus to kiss they'd cover nearly an entire football field! In addition to being the world's longest dinosaur, it is vastly longer than today's longest animal champ, the blue whale, which measured "only" 110' long.
Supersaurus (with the bones from the original specimen in white) compared to extinct, and living animals. Illustration by Daniel Barrera Guevara.
Supersaurus holds many records in the animal kingdom. It has the longest shoulder blades (>8'), neck bone (>4.5'), neck (>50'), and tail (>60'). The base of the tail is also the deepest at over 6’ tall before muscles are added. It has one of the longest legs of any dinosaur at over 12'. Everything about this animal is otherworldly in proportions. Thanks to 39 years of work we now have 3 specimens to study from 3 different locations. All demonstrate the same thing, that Supersaurus was a stunningly long animal.
Long animals have unique challenges. For instance, its brain wouldn't register a minor tail injury for up to 30 seconds and even something drastic, such as the severing of the tip of its tail, would take over a full second for it to realize something bad had happened.
Supersaurus with reflection - painting by Sean Fox.
The tail of Supersaurus ended in the animal kingdom's longest whip at over 30' long. The whip portion of the tail was made up of bones about the length of a human's middle finger, wrapped tightly in muscle, sinew, and scales. With hip muscles the size of a car, the amount of power it could generate would have turned the tail into a devastating weapon, severely crippling anything approaching it from behind. The tip of the tail may even have been able to create a sonic boom by breaking the speed of sound!
Dr. Ray Wilhite, a veterinary anatomist and sauropod expert at Auburn University, says “Supersaurus lives up to its larger than life moniker in having a super complex history, super interesting morphology, and super-sized anatomy.” Dr. Wilhite has extensively studied the Supersaurus appendicular (non-vertebral) elements. He pointed out that previous illustrations of Supersaurus have had the shoulder blades misoriented. The Supersaurus illustration for this work takes his new studies into account.
Despite being the longest dinosaur, it was built comparatively lightly with numerous air sacs in its body, similar to birds. Such weight reduction suggests Supersaurus weighed much less than the super heavy titanosaurs like Argentinosaurus, tipping the scales somewhere between 60,000 lbs - 90,000 lbs or more. Supersaurus, however, weighed more than 5 adult male elephants or 9 average cars. Argentinosaurus, the heaviest animal to ever walk the land, came close to doubling Supersaurus in weight, however with its whiptail Supersaurus takes it in overall length.
To me, a full adult Supersaurus need only fear lightning. None of the potential predators posed a threat unless it was ambushed while drinking and it was grabbed by its head. Even then, the sheer power of its neck could have lifted a predator 20' off the ground! Speaking of drinking, the neck pose of this illustration is not meant to be representative of its resting position, rather I asked for a look as if it was going to get a drink of water. The nearly horizontal vertebral column is aesthetically pleasing to me and bucks the current trend of all sauropods being illustrated with their necks at strong angles from the horizon. I call it "classic lines capturing an action pose."
Longer specimens certainly existed. The 3 we have found are all very close in size to one another, which we can take that to mean this is the *average* size adults attained. I wouldn't be surprised if we find individuals that exceed half-a-football field on their own.
Fossil Crates is working on a fantastic Supersaurus traveling exhibit for 2022 that will include casts of the longest bones ever discovered. Look for it at a museum near you!
Below are some fun images with additional Supersaurus information. Please don't hesitate to email Brian@FossilCrates.com if you'd like to discuss more about this marvelous dinosaur! Or join PaleoPortals for access to unique videos and twice a month live Zoom calls with actual paleontologists.
The Dry Mesa Dinosaur Quarry map from 1972. All giant diplodocid elements were found in the "Supersaurus pocket" of the quarry. There has been no large diplodocid element found anywhere else in the giant quarry, in fact all of the remaining diplodocids are small, much smaller than at other quarries, despite having fully fused neurocentral sutures.
There is no duplication of large elements either. The scapulae, ischia, and pubes are all paired, one left and one right, each of the right size to be the mate of the other. A number of cervical vertebrae have been discovered that sit anterior to the largest cervical vertebra, BYU 9024. Dorsal vertebrae, such as the proximal dorsal #4 (and what was named as the holotype of Dystylosaurus) and distal (the holotype of Ultrasauros) dorsal vertebra, around #8 have no duplications either. All of the recently prepared dorsal vertebrae were found from the "Supersaurus pocket" and are of the correct size and morphology to go to the same individual. 'Goliath', the newest Supersaurus discovered (heading to the Grandview Museum of Natural History), has preserved the ~#3 and 4 and ~#8 dorsal vertebrae. The proximal dorsals have bifurcated neural spines! Looking at Dystylosaurus in light of the new material shows how the Dystylosaurus vertebra also had a bifurcate spine. 'Goliath' also has a complete hindlimb and we are now looking through the BYU collection to see if we can find hind limb elements as we have the most of the sacral elements and vertebrae surrounding it. However, the flow of rivers carries appendicular elements differently than axial elements, it may be the limb material was carried away during preservation. Or by hungry theropods wanting 'sauropod wings' :-).
There was a suggestion that BYU 9024, the giant cervical vertebra, belongs to Barosaurus. I believe that BYU 9024 belongs with Supersaurus, based on parsimony at the very least. It was found in the Supersaurus pocket, it is diplodocid and is the right size to belong to the remaining large diplodocid elements. It does resemble Barosaurus but the mid-caudals of Barosaurus resemble those of Diplodocus, it isn't the first time diplodocid axial elements have looked like other diplodocids. Knowing now that the Dystylosaurus dorsal slightly has bifurcate spines (image below, dark are is mirror of existing spine) based on a second specimen of Supersaurus ('Goliath') has brought the skeleton of this animal into a much clearer picture.
Supersaurus proximal dorsal vertebra with dark portion of neural spine apex modeled based on new 'Goliath' specimen.
A taxonomic issue revolves around the holotype specimen. Jim Jensen made it BYU 12962, a right scapulocoracoid. I am working on coming up with diagnostic characters but can't hang my hat on any yet. Had he added other specimens to as the holotype, instead of referring them, it would be a much easier situation to address. The fact we have numerous elements that belong to a single supergiant sauropod individual with established diagnostic characters present in the caudal vertebrae but can't append them to the holotype is an interesting situation to be in. I am reminded me of the Diplodocus holotype, YPM 1920, and how undiagnostic those are, yet they survived an ICZN challenge to have the holotype moved. Carpenter and McIntosh did provide some characters but, to me, it isn't diagnostic enough to keep as the name-bearer of the diplodocids. I suppose I could name a new taxon for the remaining elements, then either have that taxon subsumed under Supersaurus or have Supersaurus become a nomen dubium? For now I will continue using Supersaurus as the name.
How do we know what is a Supersaurus? It is in the tail! This illustration shows some of the differences.
Supersaurus has been excavated in Colorado (the holotype) and Wyoming.
Dr. Wilhite says, "The subvertical scapula-coracoid doesn't make sense from an anatomical point of view. The glenoid cavity faces backwards when the scapula-coracoid is oriented near vertical. In that orientation, you either have the humerus angled far backwards or trapped in the cranial part of the glenoid cavity. Jacqueline Richard's Masters thesis found marks on the ribs of Camarasaurus that support a more horizontal scapular position. One of the big questions is how far could the scaps move during locomotion. I have always thought they were more like the scaps of birds than mammals, but that is something I need to figure out. Mammal scaps, except for those with large clavicles, are highly mobile and sit subvertical."