genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
astrapothere
Astrapotheria is an extinct Order (biology), order of South American and Antarctic ungulate, hoofed mammals that existed from the late Paleocene to the Middle Miocene, ."The uruguaytheriine Astrapotheriidae from the rich middle Miocene Honda Grou ...
herbivorous
A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...
mammal
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
, native to
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...
Laventan
The Laventan () age is a period of geologic time (13.8 to 11.8 Ma) within the Middle Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Colloncuran and precedes the Mayoan age.
...
subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...
Uruguaytheriinae, large astrapotheres, equipped with a trunk-like nose and protruding teeth, similar to the elephants, but their tusks were the canine teeth, not the incisors. ''Xenastrapotherium'' (named after the
Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
word ''xenos'' "strange" add to the genus ''
Astrapotherium
''Astrapotherium'' ("lightning beast") is an extinct genus of large Astrapotheria, astrapotherian ungulate native to South America during the early-middle Miocene. It is the best known member of the group. The type species. ''A. magnus'' have bee ...
'', "lightning beast") was a genus widely distributed in northern South America, in contrast to other species of astrapotheres which lived in the area of the Southern Cone of the continent. It differed from other astrapotheres by having two lower
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, wher ...
s on each side of the jaw and the
tusk
Tusks are elongated, continuously growing front teeth that protrude well beyond the mouth of certain mammal species. They are most commonly canine tooth, canine teeth, as with Narwhal, narwhals, chevrotains, musk deer, water deer, muntjac, pigs, ...
s have a pronounced longitudinal curvature, although their general shape and size are probably very similar to ''Astrapotherium'', whose weight would be 900 to 1,500
kilogram
The kilogram (also spelled kilogramme) is the base unit of mass in the International System of Units (SI), equal to one thousand grams. It has the unit symbol kg. The word "kilogram" is formed from the combination of the metric prefix kilo- (m ...
s, comparable to the current
black rhinoceros
The black rhinoceros (''Diceros bicornis''), also called the black rhino or the hooked-lip rhinoceros, is a species of rhinoceros native to East Africa, East and Southern Africa, including Angola, Botswana, Eswatini, Kenya, Lesotho, Malawi, Moza ...
.Johnson, S. C. & Madden, R. H. 1997. Uruguaytheriine astrapotheres of tropical South America. In Kay, R. F., Madden, R. H., Cifelli, R. L. & Flynn, J. J. (eds) ''Vertebrate Paleontology in the Neotropics: The Miocene fauna of La Venta, Colombia''. Smithsonian Institution Press (Washington, D.C.), pp. 355-381.
Species
Several species of ''Xenastrapotherium'' have been described, although none is known from complete remains; they are distinguished by features of their teeth and jaws, and their geographical and temporal distribution. The species currently recognized are:
* ''X. christi'' : the first known species, originally classified by Stehlin (1929) as ''Astrapotherium christi'', and later reclassified to the current genus. It was found in
Venezuela
Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...
near Zaraza in the state of Guarico, based on a full lower jaw.
* ''X. kraglievichi'' : based on several teeth and some jaws, discovered in the area of
La Venta
La Venta is a pre-Columbian archaeological site of the Olmec civilization located in the present-day Mexican state of Tabasco. Some of the artifacts have been moved to the museum "Parque - Museo de La Venta", which is in nearby Villaherm ...
Colombia
Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...
, dating from the middle Miocene, about 13 to 11 million years. Distinguished by their lower tusks, which were more horizontal and rounded in cross-section. This species was contemporary with its great relative, '' Granastrapotherium''.
* ''X. aequatorialis'' : Based on a piece of right lower jaw, found in the river Burgaya in the province of Cañar,
Ecuador
Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...
, in the
Biblián Formation
The Biblián Formation is an Early Miocene (Colhuehuapian in the SALMA classification) geologic formation of the Cuenca Basin in Ecuador. Fossils of '' Xenastrapotherium aequatorialis'' have been found in the formation.molar with buccal and labial cingulum, and the first molar was lophodont and had roots. This species is older than the fossils of La Venta, contemporary with Astrapotheriinae like ''Astrapotherium'', ''
Astrapothericulus
''Astrapothericulus'' is an extinct genus of mammals, belonging to the order Astrapotheria. It lived during the Lower Miocene in what is now South America.
Description
This animal was possibly as large as a tapir, and may have looked like them, ...
'' and ''
Parastrapotherium
''Parastrapotherium'' is an extinct genus of South American land mammal that existed from the Late Oligocene (Deseadan SALMA) to the Early Miocene (Colhuehuapian SALMA). The genus includes some of the largest and smallest known astrapotherians, ...
''.
* ''X. chaparralensis'' : Another species known from Colombia, was found near to
Chaparral
Chaparral ( ) is a shrubland plant plant community, community found primarily in California, southern Oregon, and northern Baja California. It is shaped by a Mediterranean climate (mild wet winters and hot dry summers) and infrequent, high-intens ...
in
department of Tolima
Tolima () is one of the 32 departments of Colombia, located in the Andean region, in the center-west of the country. It is bordered on the north and the west by the department of Caldas; on the east by the department of Cundinamarca; on the ...
, in the Tuné Formation (early Miocene). It is distinguished by its greater molar area, a high molar buccal cingulum, with canines very similar to those of ''X. kraglievichi''.
* ''X. amazonense'' : Based on jaw fragments found in the vicinity of the river Breu, Pedra Pintada,
Brazil
Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...
Peru
Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...
. It is distinguished by the large size of the third molar, compared to other species of ''Xenastrapotherium''. It was classified originally in its own genus, ''Synastrapotherium''. A tusk assigned to this species was found in the zone of
Acre
The acre ( ) is a Unit of measurement, unit of land area used in the Imperial units, British imperial and the United States customary units#Area, United States customary systems. It is traditionally defined as the area of one Chain (unit), ch ...
in Brazil, in deposits from the late Miocene, which make it the most recent record for the astrapotheres; but this idea has been challenged, since the fossil could not be from an astrapothere.
Phylogeny
Cladogram
A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...
based in the
phylogenetic analysis
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data ...
published by Vallejo Pareja ''et al''., 2015, showing the position of ''Xenastrapotherium'':
Fossilworks
Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world.
History
Fossilworks was cr ...
Colombia
Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...
*
Biblián Formation
The Biblián Formation is an Early Miocene (Colhuehuapian in the SALMA classification) geologic formation of the Cuenca Basin in Ecuador. Fossils of '' Xenastrapotherium aequatorialis'' have been found in the formation.Ecuador
Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...
Peru
Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...
*
Solimões Formation
The Pebas Formation is a lithostratigraphic unit of Miocene age, found in western Amazonia. The formation extends over , including parts of Brazil, Peru, Ecuador and Colombia.Wesselingh et al., 2006 It is interpreted as representing the deposit ...
,
Brazil
Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...
Bolivia
Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...