Unrelated animals on different continents that look alike because they do the same job. Aardvarks are African, hairy, and have no shell. Armadillos are American and covered in bony armour plates. Both dig, both eat ants and termites, and neither is closely related to the other.
The core difference
- aardvark — sub-Saharan Africa. Pig-like, sparse hair, long snout, no armour. Sole surviving species of its entire order.
- armadillo — the Americas. Covered in bony plates under the skin, around twenty species.
Convergent evolution
The resemblance is the classic case of unrelated animals arriving at the same design because they solve the same problem. Eating ants and termites rewards a long sticky tongue, powerful digging claws, poor eyesight and a good sense of smell. Aardvarks, armadillos, pangolins, echidnas and anteaters all have that toolkit and are only distantly related — pangolins are closer to cats than to any of the others.
The armour is real bone
An armadillo's shell is not a shell in the tortoise sense but plates of bone covered in horn, embedded in the skin. Only the three-banded armadillo can actually roll into a complete ball; most species run or dig instead.
The aardvark is a lone survivor
It is the only living member of the order Tubulidentata, named for its unusual teeth — no enamel, and made of thin tubes of dentine that wear down and grow continuously. It has no close living relatives at all, which is unusual for a mammal of its size.
Where the names come from
Aardvark is Afrikaans for earth pig — aarde (earth) plus varken (pig). It is not a pig, but the resemblance is obvious enough that the name stuck. It also gives the word its dictionary fame: with two initial As it is the first entry in many English dictionaries.
Armadillo is Spanish for little armoured one, from armado. The Aztec name meant turtle-rabbit, which is arguably the better description.
Frequently asked questions
Are aardvarks and armadillos related?
No. They live on different continents and are only distantly related. They resemble each other through convergent evolution, because both dig for ants and termites.
Can all armadillos roll into a ball?
No. Only the three-banded armadillo can form a complete ball. Most species escape by running or digging.
What does aardvark mean?
Earth pig, from Afrikaans aarde and varken. It is not a pig, and it is the only surviving member of its entire order.