Armadillo

Armadillos Temporal range:Palaeocene–Recent
Nine-banded Armadillo
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Superorder:	Xenarthra
Order:	Cingulata
Families
†Pampatheriidae †Glyptodontidae Dasypodidae

Pink Fairy Armadillo,Chlamyphorus truncatus

Aarmadillois in theCingulata,anorderofNew Worldplacentalmammals.The living ones have aleatheryarmoredshell. The wordarmadilloisSpanishfor "little armored one".

There are about 10livinggeneraand about 20speciesof armadillo. Their average length is about 75centimeters(30 in), including the tail. Thegiant armadillogrows up to 100 cm (39 in) and weigh 30 kg (66lbs). All species live in theAmericas.Most of the 20 species are found in open areas, such asgrasslands,but some also live inforests.

Armadillos species are mostly found inSouthandCentral America,especially aroundParaguay.Many species areendangered.

Embryology

The nine-banded armadillo has an unusualreproductivesystem, in whichgeneticallyidenticalquadrupletsare born in each litter.

Because they are alwaysgeneticallyidenticalclones,the group of four young is a good subject for scientific, behavioural or medical tests. They provide the same biological and genetic makeup, and then get different treatment. This is the only regular case of 'polyembryony' in the classMammalia,where one fertilised egg splits into four embryos. It only happens in the genusDasypus,and not in all armadillos. Other animals which have this reproductive method areparasitoidwasps,certainflatwormsand various aquaticinvertebrates.

Classification

Order CINGULATA

• †FamilyPampatheriidae:giant armadillos
• †FamilyGlyptodontidae:glyptodonts
• FamilyDasypodidae:armadillos
  • SubfamilyDasypodinae
  • SubfamilyTolypeutinae

† indicates extinct taxon