Dinosaur World: Iguanodon

By Craig: A couple of weeks ago my soon to be 10 year old son and I drove from Tampa Florida in a blinding rain to Plant City. It was only about a 25 mile drive and considering that I drove nearly 600 the day before it seemed like a hop, skip and a jump. My son was excited as I had not seen him in over a month. We had been to Dinosaur World before. In fact, we celebrated my sons 5th birthday there back in 08. As if the Gods knew we had arrived, the rain suddenly stopped and we made our way into the newly constructed visitor center. There, we found, much to my sons interest fossils of every kind. There were trilobites that were hundreds of millions of years old along with other plant and sea life from those ancient times. Although there was plenty to see at the visitors center and gift shop, we bought our tickets and walked out into the overcast morning to be greeted by a bunch of towering Sauropods. We made our way along one of the many paths that looped around the park and were greeted by numerous other Mesozoic beasts. On one of the paths I was intrigued to see what seemed to be a herd of grazing dinosaurs. I was, however, confused by the name on the plate in front of the display "Iguanodon." This brought me back to my childhood where I can remember one of my favorite dinosaur models from the Marx play set that I shared with my brother. These grazing Iguanodon's appeared totally different than the Iguanodon of that time period. I was well familiar with the story of Iguanodon.

Iguanodon by Zdenek Burian (mid 20th century)

 

Hawkins Crystal Palace Iguanodon (1854)

 

    In the early 1820s an English doctor named Gideon Mantell found some interesting fossil teeth which he later compared to the much smaller teeth of an iguana. He quickly noticed the similarities and so the creature was named Iguanodon meaning "iguana tooth." Other fossils were found until Mantell could make a rough sketch of what he believed the creature to look like. Mantell's Iguanodon was a quadruped with a length of about 60 feet. It was a herbivore that lived in antediluvian times which learned men of the day believed occurred before the flood of Noah.

                                             Mantell's early 1830s sketch of Iguanodon

    In 1841 Richard Owen first coined the name "Dinosaur" meaning "terrible lizard." Iguanodon was one of the first three species classified in Owens Dinosauria. Owens, however, took issue with the size of Mantell's Iguanodon and cut the length of the beast in half to a more modest number of 30 feet. Owen became the most respected authority of dinosaurs in Europe by the mid 19th century. In 1853 an artist named Benjamin W. Hawkins was approached to see if he could create life size models of the Iguanodon and Megalosaurus for the Crystal Palace building which was going to reopen in London in 1854. Hawkins' Iguanodon was based on Owen and Mantell's interpretation of what the creature looked like. Today it is a ludicrous looking creature, a squat quadruped with a horn above its nose looking more like an overgrown Rhinoceros than anything else. To bring in the new year of 1854 a dinner was held inside of the Iguanodon model with Richard Owen seated at the head of the table.

Richard Owens proposes a toast inside the Iguanodon model

    In the years that followed the Crystal Palace exhibition Iguanodon went through a series of changes. In 1878 a coal mine in Bernissart Belgium yielded one of the greatest dinosaur finds of the 19th century. Dozens of Iguanodon skeletons were found, some of them almost complete.  Louis Dollo, a young curator of the Natural history Museum in Brussels took charge of cataloging the find. He found that not only was Iguanodon not prone and lizard like, but possessed a more bird-like structure with large hind legs and shorter front ones. Dollo also correctly asserted that the horn-like bone which Owen and Mantell had placed above Iguanodon's nose was in reality a massive thumb claw that probably would have given Iguanodon a highly effective weapon of defense against predators. Dollo's bipedal, giraffe like Iguanodon that grazed on the high branches of trees stood as the model for nearly a century before it was found that he had erred slightly with the position of its tail. A modern model of Iguanodon shows that it probably grazed on all fours and ran on its longer and much stronger hind legs. It's head looking almost nothing like a modern iguana!

      As I stood there with my son staring at the new Iguanodon models on display I could almost imagine the two of us traveling back to the Cretaceous. However, the Iguanodon that greets us as we exit our time machine is not the one modeled on the modern interpretation. In fact, it is indeed the Iguanodon of my play set. It is Dollo's beast! It greets us with a nod of his head and laughs at us as it masticates a large fern.

"I am here to say goodbye to you Craig." It says after swallowing its fare.

"What do you mean?" I respond.

"Well, I am a mere interpretation of somebody else's fancy you see. The creature that you behold ceases to exist after today. From now on you will only know me in my modern form."

I was thunderstruck by what I was hearing. It couldn't be...When I think of Iguanodon I think of my Marx's white toy Iguanodon that I got from Santa Clause for Christmas when I was five! Dollo's beast!

"You mustn't say that!" I screamed. I looked at my son who could not understand what all the commotion was about.

"You must accept reality my friend. I am an antiquated reject only fit to be discarded to the backroom of a dusty library shelf. Goodbye my friend. You were my last believer!"

Suddenly without another word the massive beast solidifies into a plastic model. I edge closer and look on it's tail. It reads "Iguanodon" and then "Taiwan." My illusion is destroyed and I am suddenly transported back to my own time. Our visit to the Cretaceous being of a very short duration.

                                 Modern interpretation of the Iguanodon (Dinosaur World)

                                                              Marx's toy Iguanodon
Yes indeed, Iguanodon has perhaps been the one dinosaur that has undergone the most changes since Mantell first identified it nearly two centuries ago. There are, to be sure, similar tales when attempts were made to piece together whole bodies from fragmentary fossil evidence. The late 19th century paleontologist Edward Drinker Cope most famously is known for placing the head of the aquatic Elasmosaurus on the wrong end of its body. When the mistake was first brought to his attention by his rival Othniel Charles Marsh he vehemently fought the accusations! Even today pieces are still being put together so that we can get a more accurate and better understanding of our planets ancient past.