Pampatheriidae (" Pampas beasts") is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

family of large

plantigrade 151px, Portion of a human skeleton, showing plantigrade habit In terrestrial animals, plantigrade locomotion means walking with the toes and metatarsals flat on the ground. It is one of three forms of locomotion adopted by terrestrial mammals. T ...

armored Armour (British English) or armor (American English; see spelling differences) is a covering used to protect an object, individual, or vehicle from physical injury or damage, especially direct contact weapons or projectiles during combat, or ...

armadillo Armadillos (meaning "little armored ones" in Spanish) are New World placental mammals in the order Cingulata. The Chlamyphoridae and Dasypodidae are the only surviving families in the order, which is part of the superorder Xenarthra, alo ...

s related to extant

s in the order

Cingulata Cingulata, part of the superorder Xenarthra, is an order of armored New World placental mammals. Dasypodids and chlamyphorids, the armadillos, are the only surviving families in the order. Two groups of cingulates much larger than extant armad ...

. However, pampatheriids have existed as a separate lineage since at least the middle

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "da ...

Mustersan The Mustersan age is a period of geologic time (48.0–42.0 Ma) within the Eocene epoch of the Paleogene, used more specifically within the South American land mammal age (SALMA) classification. It follows the Casamayoran and precedes the Divisad ...

age, . Pampatheres evolved in South America during its long period of

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configurat ...

isolation. Although widespread, they were less diverse and abundant than the armadillos. ''

Holmesina ''Holmesina'' is a genus of pampathere, an extinct group of armadillo-like creatures that were distantly related to extant armadillos. Like armadillos, and unlike the other extinct branch of megafaunal cingulates, the glyptodonts, the shell ...

'' spread to

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the C ...

after the formation of the

Isthmus of Panama The Isthmus of Panama ( es, Istmo de Panamá), also historically known as the Isthmus of Darien (), is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North and South America. It contains the countr ...

as part of the

Great American Interchange The Great American Biotic Interchange (commonly abbreviated as GABI), also known as the Great American Interchange and the Great American Faunal Interchange, was an important late Cenozoic paleozoogeographic biotic interchange event in which la ...

. They finally disappeared on both continents in the end-Pleistocene extinctions, about 12,000 years ago.

Description

Pampatheres are believed to have attained a weight of up to . Like three-banded armadillos, and unlike

glyptodont Glyptodonts are an extinct subfamily of large, heavily armoured armadillos. They arose in South America around 48 million years ago and spread to southern North America after the continents became connected several million years ago. The best-kn ...

s, their armored shell was given some flexibility by three movable lateral bands of

scute A scute or scutum ( Latin: ''scutum''; plural: ''scuta'' "shield") is a bony external plate or scale overlaid with horn, as on the shell of a turtle, the skin of crocodilians, and the feet of birds. The term is also used to describe the anterior ...

s. The

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 amp ...

s (bony plates in the skin comprising the armor) of pampatheres were each covered by a single

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, hor ...

ized scute, unlike osteoderms of armadillos, which have more than one scute. Holmesina 3 Clean

A study of pampathere jaw biomechanics showed that their masticatory musculature was more powerful and more adapted for transverse movements than that of armadillos, leading to the conclusion that much of their diet was coarse vegetation. They are thought to have been primarily grazers, unlike armadillos, which are omnivorous or insectivorous. The variation between species in the expression of adaptations for grinding coarse vegetation correlates with the aridity of their habitat; such adaptations are most pronounced in '' Pampatherium typum'', which lived in the arid Pampas, and least pronounced in '' Holmesina occidentalis'', which lived in humid lowlands.

References

External links

Paleodatabase
† Prehistoric cingulates Oligocene first appearances Holocene extinctions Paleogene mammals of South America Neogene mammals of South America Pleistocene mammals of South America Pleistocene mammals of North America Prehistoric mammal families {{Paleo-mammal-stub