Often confusingly called the "Irish elk," this creature — found across Europe — is technically a deer. Its huge antlers were once thought to have been its downfall; the thinking was that they could have grown so large that either the animal could no longer lift its head or they'd become entangled between trees. Now, though, Megaloceros is thought to have been the victim of sudden climatic changes.

PRONUNCIATION: MEG-AH-LOSS-ER-OS
LIVED: 400,000 – 9,500 years ago
SIZE: 7 feet tall at the shoulder
FACT: Herbivorous, feeding on grass and vegetation
MEANING: Giant antler
CLOSEST LIVING RELATIVE: Fallow deer
RANGE: Europe, North Africa and Asia