Toxodon Skeleton, Natural History Museum, London, UK

In the fossil halls of London’s Natural History Museum, the Toxodon skeleton stands as a window into a vanished world. This massive South American mammal, discovered in the 19th century, baffled Charles Darwin when he first examined its bones during the voyage of the *Beagle*. With the bulk of a hippo, the teeth of a rodent, and the stance of a rhinoceros, Toxodon seemed like nature’s puzzle. Today, its reconstructed form looms under the vaulted arches, a reminder of both the strangeness of evolution and the breakthroughs in paleontology that helped Darwin shape his theory of natural selection.