Hedgehogs and moonrats: Order Erinaceomorpha

Overview 

The family Erinaceidae includes 10 genera and 23 species of hedgehogs native to the continents of Africa, Europe, and Asia.  They are considered to be the most primitive placental mammals. The word hedgehog comes from the Middle English ‘heyghoge’- ‘heyg’ meaning hedge, because in Europe, they frequent hedgerows, and ‘hogge’, from the piglike snout. Hedgehogs are terrestrial, nocturnal insectivores that all share a common trait- spiny armor.  They are ancestors of a very ancient group of mammals, and the evolution of their spiny armor is likely the key to their success in survival. 

All Spines are NOT Created Equal

All mammal spines are derived from modified hairs made of keratin, and although they are all used as a form of protection, they were each independently evolved in their respective taxonomic groups and vary in form and function.  Porcupines, echidnas, tenrecs, and spiny rats all have different types of spines. Unlike the quills of a porcupine, the spines of a hedgehog are not easily released from the skin and are only shed when the animal molts from its juvenile pelage to adult pelage, or if the animal is significantly stressed or ill.