Spinosaurus

Fossils of BSP 1912 VIII 19 specimen discovered in 1912 were destroyed during WWII.

An excerpt from the article 14 facts about Spinosaurus
During the allied bombardment of Munich in 1944, British pilots dropped bombs on a museum where the fossilized bones of Spinosaurus were kept. It was the only specimen known to humanity at the time. Until the 1990s there were only monographic descriptions of this reptile made by Stromer.