“The Horned Serpent panel ... lives or has ever lived nearby sub-saharan African coasts.” Other tusked animal drawings have been found, including tusked lions, snakes, antelopes and people ...

Horns can help distinguish age and sex ... rinderpest—a virus that’s nearly always fatal to hoofed animals—to Africa, and it caused buffalo numbers to crash across the continent.

Under the hot African sun ... by following the trail of scent each enormous animal leaves behind it on the landscape. Black rhinos boast two horns, the foremost more prominent than the other.