''Astrapothericulus'' 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 ...

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 ...

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, belonging to the order

Astrapotheria Astrapotheria is an extinct order of South American and Antarctic hoofed mammals that existed from the late Paleocene to the Middle Miocene, ."The uruguaytheriine Astrapotheriidae from the rich middle Miocene Honda Group of the upper Magdalena ...

. It lived during the Lower

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 ...

in what is now

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 ...

Description

This animal was as large than a

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 ...

, and may have looked like them, as it had a short trunk and a robust and elongated body. Compared to its better known relative ''

Astrapotherium ''Astrapotherium'' ("lightning beast") is an extinct genus of South American mammals that vaguely resembled a small elephant or large tapir. However, it was unrelated to elephants or tapirs, but was instead related to other extinct South American ...

'', ''Astrapothericulus'' was approximately 30% smaller in size, hence its name, meaning "Small ''Astrapotherium''".F. Ameghino. (1902). Première contribution à la connaissance de la fauna mammalogique des couches à Colpodon irst contribution to the knowledge of the mammalian fauna of the Colopdon Beds Boletin de la Academia Nacional de Ciencias de Córdoba 17:71-141 The dental formula was identical to ''Astrapotherium'', but there was some differences in the characteristics of the teeth : the

incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whe ...

s were proportionally narrower and longer, and the lower

canines Canine may refer to: Zoology and anatomy * a dog-like Canid animal in the subfamily Caninae ** ''Canis'', a genus including dogs, wolves, coyotes, and jackals ** Dog, the domestic dog * Canine tooth, in mammalian oral anatomy People with the surn ...

were inserted into the mandible more vertically. The

premolar The premolars, also called premolar teeth, or bicuspids, are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant in the permanent set of teeth, making eight premolars total in the mouth ...

s and

molars The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone to ...

were lower crowned and had larger and a more prominent basal cingulum. The lower molars were similar to ''Astrapotherium'', but vaguely

bunodont The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone to ...

. The mandibular symphysis was short, narrow and concave, unlike ''Astrapotherium'' and '' Parastrapotherium''. The horizontal branch of the mandible was narrower and higher, without the lateral swelling formed by the base of the canine, typical of the two previous genera. The nasal bones were much larger than in ''Astrapotherium'', and with considerable contact with the maxillary bones. In general, the head of ''Astrapothericulus'' was shorter and higher than that of ''Astrapotherium'', and vaguely resembled that of its more ancient relative, ''

Astraponotus ''Astraponotus'' is an extinct genus of astrapotheriids. It lived during the Middle-Late Eocene (in the Mustersan and Tinguirirican of the South American land mammal ages (SALMA), 48-33.9 million years ago) and its fossil remains have been fou ...

''.

Classification

The genus ''Astrapothericulus ''was first described in 1902 by

Florentino Ameghino Florentino Ameghino (born Giovanni Battista Fiorino Giuseppe Ameghino September 19, 1853 – August 6, 1911) was an Argentine naturalist, paleontologist, anthropologist and zoologist, whose fossil discoveries on the Argentine Pampas, especially ...

, based on fossil remains from

Argentine Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and gl ...

; the type species is ''Astrapothericulus iheringi'', but the species ''A. emarginatus'' and ''A. peninsulatus'', described by Ameghino in 1904,Ameghino, F. (1904)
MAMÍFEROS CRETÁCEOS Y TERCIARIOS.
In ''Anales de la Sociedad Científica Argentina'' (Vol. 58, p. 35). are also assigned to this genus ; more recent studies indicate as valid only ''A. emarginatus'' and the type species.Kramarz, A.G. 2009. Adiciones al conocimiento de Astrapothericulus (Mammalia, Astrapotheria): anatomía cráneo-dentaria, diversidad y distribución. Revista Brasileira de Paleontología 12: 55-66. Fossils of ''Astrapothericulus'' are found in the

Cerro Bandera Formation The Cerro Bandera Formation is a geological formation in Neuquén Province, Argentina, in northern Patagonia, which dates to the Early Miocene, around 21 to 17.5 million years ago. It predominantly consists of pyroclastic deposits, which were depo ...

Neuquén Province Neuquén () is a province of Argentina, located in the west of the country, at the northern end of Patagonia. It borders Mendoza Province to the north, Rio Negro Province to the southeast, and Chile to the west. It also meets La Pampa Province a ...

and in the Pinturas Formation of Santa Cruz Province, in terrains dated to the end of the Lower

. ''Astrapothericulus'' was a member of

, a clade of South American ungulates, vaguely evocating the shape of

s or

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 ...

, but not closely related to either of them. ''Astrapothericulus'' is considered a specialized member of the family

Astrapotheriidae Astrapotheriidae is an extinct family of herbivorous South American land mammals that lived from the Late Eocene (Mustersan SALMA) to the Middle Miocene (Laventan SALMA) . The most derived of the astrapotherians, they were also the largest and mo ...

, comprising the more derived forms of the group, and may have been ancestral to the genus ''Astrapotherium''.

References

{{Taxonbar, from=Q63522524 Meridiungulata Miocene mammals of South America Neogene Argentina Fossils of Argentina Fossil taxa described in 1902 Prehistoric placental genera Neuquén Basin Cerro Bandera Formation