A museum specimen of particular note was a fossil , the Hydrarchos or Zeuglodon , which the Complete Guide to the St. Louis Museum called " the greatest fossil in the world . " The Zeuglodon was constructed mainly from basilosaurus fossils discovered in 1848 in a field in Alabama . After they were extricated from the rock in which they were found , Dr. Koch purchased the fossils for the St. Louis Museum . The fossils were shown to Yale chemist Benjamin Silliman , likely before being rearranged by Koch . Silliman , who had recently lectured on the basilosaurus , wrote a letter to Koch about his find . A broadside promoting the exhibit took Silliman 's letter out of context and presented the hydrarchus as " Leviathan of the Antediluvian World " . Proffesor Joseph Leidy also attested to the authenticity of the fossils , though it 's not clear if he saw them before or after Koch 's rearrangement . Professor Jeffries Wyman eventually exposed the hoax , and Silliman wrote another letter to Koch asking not to be associated with the exhibit . The hydrarchos continued to be displayed and was taken by Koch to Dresden , where it was destroyed by Allied bombing of that city during WWII . A smaller model was destroyed in the Great Chicago Fire
Great Chicago Fire
Great Chicago Fire
St. Louis Museum