Armadillos are small mammals that originated in South America. Their closest relatives are the sloth and anteater.
As with most mammals it is believed that the ancestors of our nine-banded armadillo came to the North American continent via the short-lived Panamanian land bridge three (3) million years ago; many of which went extinct.
A relatively new resident to North America, the modern day armadillo did not take up residency in the United States until about 150 years ago. Prior to 1850 this backyard visitor was not seen north of the Rio Grande River. They have been very successful in the southern United States. So much so that, according to Michigan State University, their northward "march" and continued colonization has puzzled many biologists. Scientists have determined that the degree of range expansion per year is nearly ten times faster than the average rate expected for any mammal!