More of the Mantells' Discovery and the Scientific Method...

The Mantells Observe a Phenomenon

(Step One of the Scientific Method)

And now back to Dr. Mantell and his use of the scientific method. First he and his wife found something strange, something out of the ordinary; a phenomenon. The large bones and teeth seemed out of place in their surrounding Cretacious soil (they were found in a level of soil that we associate with the Cretacious period, a time we consider today to be the last age of the dinosaurs). Dr. Mantell knew that the teeth looked like they belonged to a large herbivore, but didn't know what kind. He knew that some mammals are herbivores, but he hesitated to say his tooth belonged to a mammal because nobody had found mammal fossils from the Cretacious period yet. He also doubted that the tooth belonged to a reptile because he didn't know of any that chewed their food like an herbivore.

Dr. Mantell Forms a Hypothesis

(Step Two of the Scientific Method)

After examining the strange teeth and small bones, Dr. Mantell came up with a hypothesis. His hypothesis was that the teeth and bones were from an extinct, prehistoric animal. If this was true, it would be different from teeth and bones of extant animals.

Dr. Mantell Designs an Experiment

(Step Three of the Scientific Method)

Dr. Mantell's hypothesis was difficult to test, or at least very time consuming, because it meant that he would have to go through thousands and thousands of similar teeth at museums in order to rule out their belonging to living animals! He was able to limit the number of teeth he needed to look at though, by finding out what kind of animals' teeth were the most similar to it. Because of their size, other paleontologists like Sir Charles Lyell and Baron Georges Cuvier suggested that the teeth might belong to a hippopotamus or rhinoceros. To be more sure of his hypothesis that the teeth belonged to an extinct animal, Dr. Mantell decided to look through large teeth and bone specimens at the Hunterian Museum of the Royal College of Surgeons in England (where he lived).

Dr. Mantell Carries out his Experiment

The Hunterian Museum claimed Dr. Mantell for many days as he searched and searched through bone and teeth specimens there for something similar to his findings. The task was so large and was proving so difficult that he was about to give up when a nearby researcher happened to talk to him. This man turned out to be Samuel Strutchbury, who was currently studying Central American iguana lizards. When Dr. Mantell showed Mr. Strutchbury the teeth he had found, Mr. Strutchbury recognized them as being extremely similar to iguana teeth, although larger.

Dr. Mantell Forms a Conclusion and Alters his Hypothesis

(Step Five of the Scientific Method)

Thanks to his work in the museum and his luck in finding Mr. Strutchbury, Dr. Mantell was able to learn more about his mysterious teeth and make his hypothesis more focused. He found iguana tooth samples and noted their similarity to his teeth and while also keeping in mind the size differences in the teeth he had found with those of living reptiles. He concluded that his teeth were too similar to iguana teeth to belong to any other taxa of animal, and since there was no larger iguana-like creature roaming the earth during his time, he decided that his hypothesis that the teeth belonged to an extinct animal was valid. His new hypothesis was that the teeth belonged to an extinct reptile. He named the animal Iguanodon ("iguan" meaning iguana, and "odon" meaning tooth). Dr. Mantell wrote up his findings and published a paper on them in 1825 so that the rest of the scientific community would know about the extinct iguana creature he had found. His work sparked interest in other "giant lizards" and led people like James Parkinson and William Buckland to describe other reptilian creatures that eventually became known as the dinosaurs.

Back to Lesson Plan Map or On to Your Dino Discoveries!