Armadillo

Armadillos Fossil range: Upper Palaeocene to Recent
Nine-banded Armadillo
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Superorder: Xenarthra Order: Cingulata Illiger, 1811
Families
†Pampatheriidae †Glyptodontidae Dasypodidae

Pink Fairy Armadillo, Chlamyphorus truncatus

Armadillos are small placental mammals, known for having a bony armor shell. The Dasypodidae are the only surviving family in the order Cingulata, part of the superorder Xenarthra together with the anteaters and sloths. The word armadillo is Spanish for "little armored one".

There are approximately 10 living genera and about 20 species of armadillo. Their average length is about 75 centimeters (30 in), including tail. The Giant Armadillo grows up to 100 cm (39 in) and weigh 30 kg (66lbs). All species live in the Americas.

Armadillos species are primarily found in South and Central America, particularly in Paraguay and surrounding areas. Many species are endangered. Some species groups, such as the long-nosed armadillos, are widely distributed over the Americas, whereas others, such as the fairy armadillos, are concentrated in smaller ranges in South America.

One species, the nine-banded armadillo, (Dasypus novemcinctus), is found in the United States, primarily in the south central states (notably Texas), but with a range that extends as far east as South Carolina and Florida and as far north as Nebraska; they have been consistently expanding their range in North America over the last century due to a lack of natural predators, and have been found as far north as southern Illinois.

Embryology

The nine-banded armadillo has an unusual reproductive system, in which genetically identical quadruplets are born in each litter.

Because they are always genetically identical clones, 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 class Mammalia, where one fertilised egg splits into four embryos. It only happens in the genus Dasypus, and not in all armadillos. Other animals which have this reproductive method are parasitoid wasps, certain flatworms and various aquatic invertebrates.

Classification

Order CINGULATA

• †Family Pampatheriidae: giant armadillos
• †Family Glyptodontidae: glyptodonts
• Family Dasypodidae: armadillos
  • Subfamily Dasypodinae
  • Subfamily Tolypeutinae

† indicates extinct taxon

References

Look up Dasypodidae in Wikispecies, a directory of species