''Falcontoxodon'' 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 ...

toxodontid Toxodontidae is an extinct family of notoungulate mammals, known from the Oligocene to the Holocene (11,000 BP) of South America, with one genus, ''Mixotoxodon'', also known from the Pleistocene of Central America and southwestern North Americ ...

notoungulate that lived from the late

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

in what is now

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s of this genus have been found in the

Chapadmalalan The Chapadmalalan age is a period of geologic time (4.0–3.0 Ma) within the Pliocene epoch of the Neogene used more specifically with South American Land Mammal Ages. It follows the Montehermosan and precedes the Uquian age. Fossil content F ...

Uquian The Uquian age is a period of geologic time (3.0–1.5 Ma) within the Pliocene and Pleistocene epochs of the Neogene used more specifically with South American Land Mammal Ages. It follows the Montehermosan and precedes the Ensenadan The Ensenad ...

Codore Formation, as well as in the more recent

Ensenadan The Ensenadan age is a period of geologic time (1.2–0.8 Ma) within the Early Pleistocene epoch of the Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the ...

San Gregorio Formation.

Description

The genus ''Falcontoxodon'' was described in 2018 by Carrillo ''et al'' with AMU-CURS 765, an almost complete skull with a well-preserved dentition found in the Algodones Member of the Codore Formation. In the same article, two other specimens assigned to ''Falcontoxodon'' were described from the Vergel Member of the San Gregorio Formation, assigned respectively to ''Falcontoxodon'' aff. ''aguilerai'' and ''Falcontoxodon'' sp. In 2021, an analysis of the San Gregorio Formation by Carrillo-Briceño ''et al'' uncovered thirty-three additional remains, mostly teeth, that were assigned to the genus. The name of the genus, ''Falcontoxodon'', refers to its relative, ''

Toxodon ''Toxodon'' (meaning "bow tooth" in reference to the curvature of the teeth) is an extinct genus of South American mammals from the Late Miocene to early Holocene epochs (Mayoan to Lujanian in the SALMA classification) (about 11.6 million to 11 ...

'', and to the Venezuelan state of

Falcón ) , anthem = , image_map = Falcon in Venezuela.svg , map_alt = , map_caption = Location within Venezuela , pushpin_map = , pushpin_map_alt = , pushpin_mapsiz ...

in Northern Venezuela, where the holotype remains have been found. The species' name, ''aguillerai'', honours the Venezuelan

paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

Orangel Aguilera. ''Falcontoxodon'' was a medium-sized

Toxodontinae Toxodontidae is an extinct family of notoungulate mammals, known from the Oligocene to the Holocene (11,000 BP) of South America, with one genus, ''Mixotoxodon'', also known from the Pleistocene of Central America and southwestern North Americ ...

, estimated to have weighted around 800 kg, roughly half the weight of ''

''. It had a pear-shaped, 55 cm long skull in frontal view, with an elongated nasal. The third upper incisor was absent and the canine was reduced. The lower molars were

hypsodont Hypsodont is a pattern of dentition with high-crowned teeth and enamel extending past the gum line, providing extra material for wear and tear. Some examples of animals with hypsodont dentition are cows and horses; all animals that feed on gritt ...

, and the second lower incisor was developed like a

tusk Tusks are elongated, continuously growing front teeth that protrude well beyond the mouth of certain mammal species. They are most commonly canine teeth, as with pigs and walruses, or, in the case of elephants, elongated incisors. Tusks share c ...

Phylogeny

The 2018 study that described ''Falcontoxodon'' recovers it, along with ''

Mixotoxodon ''Mixotoxodon'' ("mixture ''Toxodon''") is an extinct genus of notoungulate of the family Toxodontidae inhabiting South America, Central America and parts of southern North America during the Pleistocene epoch, from 1,800,000—12,000 years ago. ...

'', ''

Gyrinodon ''Gyrinodon'' is an extinct genus of toxodontid notoungulate that lived from the Late Miocene and Early Pliocene in what is now Brazil and Colombia. Description This animal was approximately the size of a modern rhinoceros, and they were sim ...

'' and ''

Piauhytherium ''Piauhytherium'' is an extinct genus of herbivorous notoungulate mammal of the family Toxodontidae. It lived during the Late Pleistocene, about 10,000 years ago; fossils have been found in Brazil. The only known species is ''Piauhytherium capi ...

'', to be in the same monophyletic clade within the subfamily

. Below is a parsimony tree establishing the relationships between the genera of Toxodontidae, as proposed by Carrillo ''et al'', 2018.

Palaeoecology

Paleofauna of the San Gregorio Formation

''Falcontoxodon'' lived in a tropical environment in an area of northern

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 ...

that was left relatively untouched by 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 lan ...

, the only non-native species of mammal known in the area of the Falcón Basin being the

procyonid Procyonidae is a New World family of the order Carnivora. It comprises the raccoons, ringtails, cacomistles, coatis, kinkajous, olingos, and olinguitos. Procyonids inhabit a wide range of environments and are generally omnivorous. Character ...

Cyonasua ''Cyonasua'' (meaning "dog-coati" in Greek) is an extinct genus of procyonid from the Late Miocene to Middle Pleistocene of South America. Fossils of ''Cyonasua'' have been found in Argentina ( Ituzaingó, Epecuén, Huayquerías, Monte Hermoso, ...

'' and ''

Chapalmalania ''Chapalmalania'' is an extinct genus of procyonid from the Pliocene (Chapadmalalan to Uquian) of Argentina and Colombia (Ware Formation, Cocinetas Basin, La Guajira). Description Though related to raccoons and coatis, ''Chapalmalania'' was a ...

'', and, potentially, a

Camelidae Camelids are members of the biological family Camelidae, the only currently living family in the suborder Tylopoda. The seven extant members of this group are: dromedary camels, Bactrian camels, wild Bactrian camels, llamas, alpacas, vicuñas, ...

still unassigned to a specific genus. Its environment was continental, an open, forested

grassland A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natur ...

area with

rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...

elements, near

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

. It coexisted with

pampathere Pampatheriidae ("Pampas beasts") is an extinct family of large plantigrade armored armadillos related to extant armadillos in the order Cingulata. However, pampatheriids have existed as a separate lineage since at least the middle Eocene Mus ...

s such as ''

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 ...

'' and '' Plaina'',

proterotheriidae Proterotheriidae is an extinction, extinct family of fossil ungulates from the Cenozoic era that displays toe reduction. Despite resembling primitive, small horses, they were only distantly related to them, and instead belonged to the native Sou ...

, the

glyptodont Glyptodonts are an extinct subfamily of large, heavily armoured armadillos. They arose in South America around 48 million years ago and spread to southern North America after the continents became connected several million years ago. The best-kn ...

Boreostemma ''Boreostemma'' is an extinct genus of glyptodonts from northern South America. Fossils assigned to the genus were first described as belonging to '' Asterostemma'' from southern South America, but have been placed in the new genus ''Boreostemma' ...

'', the

dasypodidae Dasypodidae is a family of mostly extinct genera of armadillos. One genus, '' Dasypus'', is extant, with at least seven living species. __TOC__ Classification Below is a taxonomy of armadillos in this family. Family Dasypodidae *† Genus ...

'' Pliodasypus'' and the

ground sloth Ground sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. The term is used to refer to all extinct sloths because of the large size of the earliest forms discovered, compared to existing tree sloths. The Caribbe ...

Proeremotherium ''Proeremotherium'' is an extinct genus of megatheriine ground sloths in the family Megatheriidae. It lived during the Late Miocene and Early Pliocene of what is now Venezuela. So far, two largely complete skulls have been recovered in the Falcó ...

'', as well as several species of

caviomorph Caviomorpha is the rodent infraorder or parvorder that unites all New World hystricognaths. It is supported by both fossil and molecular evidence. The Caviomorpha was for a time considered to be a separate order outside the Rodentia, but is now a ...

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

s such as '' Caviodon'', '' Hydrochoeropsis'', ''

Marisela Marisela Hernandez (born April 24, 1966 as Marisela Esqueda), commonly known as Marisela, is a Mexican-American singer. In 1984, she recorded her first album at the age of 18, and continued to release albums into the 1990s. Her cover version of ...

'' and '' Neoepiblema'', and the

crocodile Crocodiles (family (biology), family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to inclu ...

Crocodylus falconensis ''Crocodylus falconensis'' is an extinct species of crocodile known from the early Pliocene of the lower part of the Vergel Member of the San Gregorio Formation of Venezuela. ''C. falconensis'' was named in 2013 after Falcón State and is though ...

References

{{Meridiungulata, N., state=autocollapse Toxodonts Pleistocene mammals of South America Pliocene mammals of South America Pleistocene genus extinctions Neogene Venezuela Pleistocene Venezuela Fossils of Venezuela Fossil taxa described in 2018 Prehistoric placental genera