''Dasypus bellus'', the beautiful armadillo,
/ref> is an extinct

armadillo Armadillos () are New World placental mammals in the order (biology), order Cingulata. They form part of the superorder Xenarthra, along with the anteaters and sloths. 21 extant species of armadillo have been described, some of which are dis ...

species

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

from the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

, living from 1.8 mya—11,000 years ago, existing for approximately . Slightly larger than its living relative, the

nine-banded armadillo The nine-banded armadillo (''Dasypus novemcinctus''), also called the nine-banded long-nosed armadillo or common long-nosed armadillo, is a species of armadillo native to North America, North, Central America, Central, and South America, making ...

, its fossils are known from

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

and records extend west to

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

and north to

Iowa Iowa ( ) is a U.S. state, state in the upper Midwestern United States, Midwestern region of the United States. It borders the Mississippi River to the east and the Missouri River and Big Sioux River to the west; Wisconsin to the northeast, Ill ...

and

Indiana Indiana ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Michigan to the northwest, Michigan to the north and northeast, Ohio to the east, the Ohio River and Kentucky to the s ...

Description

''D. bellus'' had small, simple, peg-like teeth similar to ''D. novemcinctus.'' Its maximum length was approximately long, twice the size of the nine-banded armadillo. The osteoderms of the shell and the limb bones of ''D. bellus'' are about two to two and a half times the extent of those of the living modern nine-banded armadillo ''D. novemcinctus''. The small ''D. bellus'' overlapped in size with the ''D. novemcinctus''. The body size of ''D. bellus'' decreased during the late Pleistocene, suggesting that its body size was variable.

Relations

DNA

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

testing of two ''D. bellus'' fossils and modern

s has proved the species are not genetically the same. However, one of the ''D. bellus'' fossils proved to be a specimen of ''D. novemcinctus''. The mistake was due to the high morphological similarities between the two species. It also proved that ''D. novemcinctus'' was in Florida much earlier than previously thought.

Fossils

The earliest fossils are found in early Pleistocene South America, and would emigrate into southern North America. They have been found at many sites in

, including caves,

sinkhole A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are also known as shakeholes, and to openings where surface water ...

s, river sites, coastal, and lake deposits. By the late Pleistocene, ''D. bellus'' spread into the American Southwest. The living animals apparently preferred dry scrub environments. The most frequent type of fossil found are isolated

osteoderm Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amph ...

s. The most common types of osteoderms that have been found are the hexagonal elements, which include most of osteoderms covering the shoulder or pectoral regions. Other types of osteoderms include those covering the pelvic region of the

carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...

or the so-called buckler or immovable osteoderms and the elongate rectangular elements from the movable bands, the imbricating or movable osteoderms.

Modern descendants

The beautiful armadillo likely shares a common lineage with numerous species of large armadillos from the Pleistocene of South America. This includes ''Propraopus sulcatus'' and ''Propraopus grandis.'' '' D. kappleri'', the great long-nosed armadillo, which is the largest living species of ''Dasypus'' from tropical South America, has the same features of osteoderms as ''D. bellus''. They also share a large, unreduced fifth digit on the manus. The range of ''D. novemcinctus'', the smaller nine-banded armadillo, has expanded out of Mexico and into much of the former range of ''Dasypus bellus.'' The two species are morphologically similar to each other. This had led many to believe that they might be a single, highly adaptable species that has gone through a course of phenotypical changes along with geographical range fluctuations causing from environmental changes. However, as previously stated, DNA research has proved ''D. bellus'' and ''D. novemcinctus'' to be separate species.

References

External links

The beautiful armadillo

Dasypus bellus: Florida Museum of Natural History

{{Taxonbar, from=Q902492 Armadillos Prehistoric cingulates Pliocene xenarthrans Pleistocene xenarthrans Piacenzian first appearances Pleistocene species extinctions Prehistoric mammals of North America Irvingtonian Rancholabrean Fossils of the United States Fossil taxa described in 1930 Taxa named by George Gaylord Simpson