Pampatheriidae ("

Pampas The Pampas (; from Quechua 'plain'), also known as the Pampas Plain, are fertile South American low grasslands that cover more than and include the Argentine provinces of Buenos Aires, La Pampa, Santa Fe, Entre Ríos, and Córdoba; all o ...

beasts") is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

family of large cingulates related to

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 ...

s. They first appeared in South America during the mid-

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

, and '' Holmesina'' and '' Pampatherium'' spread to

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 ...

during 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 ...

after the formation of the

Isthmus of Panama The Isthmus of Panama, 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 America, North and South America. The country of Panama is located on the i ...

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 land ...

. They became extinct as part of the end-Pleistocene extinction event, about 12,000 years ago.

Taxonomy

The placement of the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

genus '' Machlydotherium'' in the family is considered doubtful. The oldest undoubted member of the group is '' Scirrotherium'' from La Venta, Colombia, dating to the mid-Miocene. Analysis of ear morphology suggests that they are most closely related to the much larger glyptodonts, which genetic evidence indicates is nested with modern armadillos as part of the family Chlamyphoridae, which by extension also places pampatheres within this group. Phylogeny after Tambusso et al. (2021):

Description

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

glyptodont Glyptodonts are an extinct clade of large, heavily armoured armadillos, reaching up to in height, and maximum body masses of around 2 tonnes. They had short, deep skulls, a fused vertebral column, and a large bony carapace made up of hundreds o ...

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

scute A scute () or scutum (Latin: ''scutum''; plural: ''scuta'' "Scutum (shield), 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 Bird anatomy#Scales, birds. The ter ...

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 amph ...

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''. It is the key structural material making up Scale (anatomy), scales, hair, Nail (anatomy), nails, feathers, horn (anatomy), horns, claws, Hoof, hoove ...

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

, and least pronounced in '' Holmesina occidentalis'', which lived in humid lowlands.

Distribution

Pampatheres were widely distributed across South America during the Pleistocene ranging from northern Argentina, eastwards to northeastern Brazil, and westwards to Colombia and Peru. As part of the

, pampatheres dispersed northwards into Central and North America, with members of the genus '' Holmesina'' reaching the United States, as far north as Kansas, and as far east as Florida and South Carolina.

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