ORDER XENARTHRA

NATIONAL WILDLIFE (?) - Of 20 species of armadillos, only one (the nine-banded) is found in the US. Unlike any other mammal, it produces four genetically identical offspring at almost every birth. Additionally, it can delay implantation until suitable conditions exist. Armadillos are in the same order with anteaters and tree sloths (Edentata, or Xenarthra). These three all came north over the Panama isthmus 3 million years ago, with the latter two disappearing about the time Man made his impact in North America, or about 10,000 years ago. The armadillo was only known to exist in Central America until a colony made it as far north as Texas in 1850. Then, in the swiftest migration known in mammalian history, the nine-banded armadillo raced through the Gulf States toward the Atlantic, reaching Florida in the late 1970's. Now, 30 million live in the southern US. Crossing small rivers, the armadillo has the ability to either swim across, or actually walk across the bottom of the river, emerging up to five minutes later on the other side.

Armadillos dig dens in the ground and surface in late afternoons to feed. They have keen smell, but poor eyesight. Only the nine-banded and a few South American species have the trait of quadruple identical pups from the same fertilized egg. This increases the rate of pop success, since only one ovum per year occur. Delayed implantation can be as long as two years (the fertilized egg develops into a multiple-celled blastocyst and floats free in the uterus until favorable conditions exist. Numerous animals, like bear and many members of the weasel family can delay implantation for several months, but nothing like this.)

Armadillos have become an interest to scientists since it’s been discovered they, too, can contract leprosy. They are now used in leprosy research.