Pampatheriidae ("
Pampas
The Pampas (from the qu, pampa, meaning "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 of Uruguay; and Brazi ...
beasts") is an
extinct family of large
plantigrade 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 f ...
armadillos related to extant
armadillos 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 ar ...
. 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'', " ...
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 Divisader ...
age, .
Pampatheres evolved in
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...
during its long period of
Cenozoic 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 wa ...
'' spread to
North America after the formation of the
Isthmus of Panama as part of the
Great American Interchange. 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
glyptodonts, 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 po ...
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 (extinc ...
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, ho ...
ized scute, unlike osteoderms of armadillos, which have more than one scute.
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
The Pampas (from the qu, pampa, meaning "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 of Uruguay; and Brazi ...
, and least pronounced in ''
Holmesina occidentalis
''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 was ...
'', 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