''Astrapotherium'' ("lightning beast") is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 southe ...

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

s that vaguely resembled a small

elephant Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae an ...

or large

tapir Tapirs ( ) are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a pig, with a short, prehensile nose trunk. Tapirs inhabit jungle and forest regions of South and Central America, with one species inhabit ...

. However, it was unrelated to elephants or tapirs, but was instead related to other extinct South American ungulates. Fossils have been dated from the Early to Middle

Miocene The Miocene ( ) is the first 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 means "less recen ...

. Fossil remains of the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

''A. magnus'' have been found in the

Santa Cruz Formation The Santa Cruz Formation is a geological formation in the Magallanes/Austral Basin in southern Patagonia in Argentina and in adjacent areas of Chile. It dates to the late Early Miocene epoch, and is contemporaneous with eponymous Santacrucian S ...

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

. Other fossils have been found in the

Deseado Deseado may refer to: Geographic names and features * Deseado (crater), a crater on the planet Mars * Deseado Department, a department in Santa Cruz Province, Argentina * Deseado Massif, a geological formation in Santa Cruz Province, Argentina * De ...

Sarmiento Sarmiento may refer to: Places Argentina *Sarmiento Department, San Juan, a subdivision of the San Juan Province *Sarmiento Department, Santiago del Estero, a subdivision of the Santiago del Estero Province *Sarmiento Department, Chubut, a subdivi ...

, and Aisol Formations of Argentina and

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

(

Cura-Mallín Group Cura-Mallín Group ( es, Grupo Cura-Mallín) is a heterogeneous group of volcano-sedimentary formations of Oligocene-Miocene age, Colhuehuapian to Laventan in the SALMA classification, in south-central Chile and nearby parts of Argentina.Pedroza ...

).''Astrapotherium''
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.org

Description

''Astrapotherium'' had an elongated body, with a total length around , a weight of nearly , and relatively short limbs. Larger estimates suggest its body mass was up to . It had small

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 ...

feet, and the hind limbs were significantly weaker than the fore limbs. Its four canine teeth were elongated to form short tusks, and it had broad, protruding lower incisors, which likely ground against a horny pad in the upper jaw, as in many modern

ruminant Ruminants (suborder Ruminantia) are ungulate, hoofed herbivorous grazing or browsing mammals that are able to acquire nutrients from plant-based food by Enteric fermentation, fermenting it in a specialized stomach prior to digestion, principally ...

The nostrils were placed high on the head, which might indicate the presence of a trunk, but could equally be due to other reasons, such as an inflatable nasal cavity.Wall, W. P. (1980)
Cranial evidence for a proboscis in Cadurcodon and a review of snout structure in the family Amynodontidae (Perissodactyla, Rhinocerotoidea).
''Journal of Paleontology'', 968-977.

Classification

Cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

based in the

phylogenetic analysis In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

published by Vallejo-Pareja ''et al''., 2015, showing the position of ''Astrapotherium'':

Paleobiology

The animal was probably at least partially aquatic, living in shallow water and feeding on marsh plants in a similar manner to a modern

hippopotamus The hippopotamus ( ; : hippopotamuses or hippopotami; ''Hippopotamus amphibius''), also called the hippo, common hippopotamus, or river hippopotamus, is a large semiaquatic mammal native to sub-Saharan Africa. It is one of only two extan ...

References

External links

"Astrapotherium" (Picture library, Natural History Museum, London)
{{Taxonbar, from=Q135724 Meridiungulata Miocene mammals of South America Oligocene mammals of South America Colloncuran Friasian Santacrucian Colhuehuapian Deseadan Neogene Argentina Paleogene Argentina Fossils of Argentina Neogene Chile Fossils of Chile Fossil taxa described in 1879 Taxa named by Hermann Burmeister Prehistoric placental genera Golfo San Jorge Basin Sarmiento Formation Austral or Magallanes Basin Santa Cruz Formation