One of my favorite displays at the New Mexico Museum of Natural History and Science is found in the hall Age of the Super Giants. This hall covers the Jurassic period found in New Mexico. There are several displays found in this hall, but the crowning jewel is the two titans in the middle.

The photo above is the first thing one sees when walking into this Hall. The Stegosaur (right) looks on as Saurophaganax (left) is rushing in to attack the Seismosaurus (center).

Seismosaurus is one of the largest sauropods/land animals to ever live. Scientist believe that it reach a length of 33 meters, making this tied for the longest dinosaur ever discovered. It is believed to have weighed 27 metric tons. It was found in New Mexico and is the only one known from the fossil record.

There is some debate over whether Seismosaurus is actually a new genus or if it is just the largest specimen of Diplodocus ever discovered. The consensus at this point is that Seismosaurus is just the largest Diplodocus to have ever been discovered. The only way to settle this debate is if some lucky paleontologist finds another specimen that includes the anatomy that we are lacking.

The erect skeleton is a fabrication of the fossils found. Above are the actual fossils from Seismosaurus. They include most of the pelvis, part of the tail, the lower back section, and a few ribs. The rest of the anatomy on the erect skeleton was created by scaling up the bones from Diplodocus.

Seismosaurus would have had two lines of defense against predators, such as Saurophaganax. The first would have been it size. When it reached, adulthood a predator would have to be very desperate to attack one of them. The second would be the tail you see above. Sauropods, such as Seismosaurus were able to whip their tails at supersonic speeds, just like a bullwhip. It could have been used for defense, but it also could have been used for communicating with other sauropods with sound.

Saurophaganax would have been the apex predator of the late Jurassic. Saurophaganax was closely related to Allosaurus, however, Saurophaganax was ~ 12 meters long (just shy of the length of a T. rex). Saurophaganax shared many of the same attributes that made Allosaurus such a fearsome predator. Some of those include strong legs for running and a large head with teeth like steak knives.

However, the feature that I feel made Saurophaganax a terrifying predator was its clawed hands. Saurophaganax would have been able to run up to an animal and slash at its belly with one hand, while holding it with the other. The largest claw was over 15 cm long.

Again, the erect skeleton is a fabrication, but above is a photo of the actual fossils of Saurophaganax that were found in New Mexico. Some specimens of Saurophaganax have been found in other states, but none were complete. Much like with Seismosaurus, Saurophaganax was reconstructed by scaling up bones from Allosaurus.

This display is a jaw dropping experience. The size of these two animals is astonishing. The WOW! one hears from children and adults walking through this hall never ends. It is quite amazing just to sit in this hall and imagine the world that held these beasts in it. This display is just one of the extraordinary exhibits one can find at the New Mexico Museum of Natural History and Science.