Sofasaurus Rex: King of the Prehistoric Jungle

When I hear the word dinosaur, the movie Jurassic Park instantly pops up in my head. I think of that giant bloodthirsty T-Rex assaulting that helpless Jeep in the pouring rain, tossing it around like it was a Hot Wheels car. The infamous muddy dino-track was stamped on my impressionable 7-year old mind. Just the ripple across the water from vibrations of those looming footsteps was enough to send me running behind the couch in terror. Needless to say, I loved it! Yeah, they were big, scary, and could snap me in half like that poor and unsuspecting goat, yet still I was Dino-Crazy. But I didn't like those velociraptors--they were just plain mean.

Dinosaurs were the kings of an unknown world that I could only daydream about. They stomped around, fiercely dominating like the T-Rex, or serenely wandering like the gentler leaf-eating Brontosaurus. As large as they were in my young mind, they were just as massive to their real pre-human world. To this day, they are still the largest beasts to have ever walked the earth. Some reached masses that were roughly 8 times larger than than of their modern counterparts¹. But were they really commanding tyrants of the primordial jungles?

According to Dr. Brian McNab of the University of Florida, they were more like giant "couch potatoes." While the common image of dinosaurs is the vicious and carnivorous "sharp-tooth" of Land Before Time cartoon film series fame, the vast majority were herbivores. Fossils show that many of the plants that existed alongside the dinosaurs were edible. So the dinosaurs had a royal banquet of mosses, ferns, evergreen conifers, and for the late-comers, even flowering plants.

Dinosaurs were "like couch potatoes sitting within easy reach of high calorie foods" says McNab². So it is no wonder that they were so huge! McNab goes on to say that "the factors most responsible for setting the maximal body size of vertebrates are resource quality and quantity, as modified by the mobility of the consumer, and the vertebrate's rate of energy expenditure." McNab was able to conclude this after the application of a model based on the energy expenditures, body mass, and eating habits of varanid lizards, These lizards include animals like the Komodo Dragon, Goannas, and other species of monitor lizard, and the closest living metabolic ancestors of the dinosaurs³.

¹ McNab, Brian K. Resources and energetics determined dinosaur maximal size. Proceedings of the National Academy of Science. Published online before print July 6, 2009. doi: 10.1073/pnas.0904000106

² Irvine, Chris. "Dinosaurs the 'couch potatoes' of prehistoric world." The Telegraph. July 7, 2009.

³ Greene, Harry W.Diet and Arboreality in the Emerald Monitor, Varanus Prasinus, With Comments on the Study of Adaptation. Field Museum of Natural History. 1986.

Image Credit: http://shop.neatorama.com/product-info.php?thesaurus-dinosaur-extinction-pid265.html