~{{fossil range|13.8|5.3}}"},"image":{"wt":"Magdalenabradys.jpg"},"image_caption":{"wt":"Mandible of ''Magdalenabradys confusum''"},"taxon":{"wt":"Magdalenabradys"},"authority":{"wt":"Rincón and McDonald, [[2020 in paleomammalogy|2020]]"},"type_species":{"wt":"†'''''Magdalenabradys confusum'''''"},"type_species_authority":{"wt":"Hirschfeld (1985)"},"subdivision_ranks":{"wt":"Other species"},"subdivision":{"wt":"*†'''''M. kolossiaia''''' {{small|Rincón and McDonald 2020}}"},"synonyms":{"wt":"''[[Pseudoprepotherium]] confusum'' {{small| Hirschfeld (1985)}}"}},"i":0}}]}" id="mwBA">
Magdalenabradys | |
---|---|
Mandible of Magdalenabradys confusum | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Pilosa |
Family: | † Mylodontidae |
Tribe: | † Lestodontini |
Genus: | † Magdalenabradys Rincón and McDonald, 2020 |
Type species | |
†Magdalenabradys confusum Hirschfeld (1985) | |
Other species | |
| |
Synonyms | |
Pseudoprepotherium confusum Hirschfeld (1985) |
Magdalenabradys is an extinct genus of mylodontid ground sloths that lived during the Middle Miocene and Early Pliocene of what is now Colombia and Venezuela. Fossils have been found in the Villavieja Formation of the Honda Group in Colombia, and the Codore and Urumaco Formations of Venezuela.
The first remains of Magdalenabradys were found in the Villavieja Formation of the Honda Group in the strata of the Tatacoa Desert of the Huila Department. The holotype of M. confusum was found about 9 km east of Villavieja and 2.5 km northeast of Hacienda Argentina, Huila. The holotype consisted of a crushed and distorted skull. The femur is based on eight specimens from six localities, including one femur from a partial skeleton that included a skull and mandible (specimens UCMP 3800, 37999). The cranium and partial mandible of both species were originally assigned to Bolivartherium urumaquensis .
The generic name, Magdalenabradys is derived from the Magdalena River, in which the type specimen was found and confusum meaning "confused" in reference to the fact that it has originally been confused with Pseudoprepotherium . A second species, M. kolossiaia, was named in 2020. The specific epithet means "colossal". [1]
Magdalenabradys confusum was originally assigned to the genus Pseudoprepotherium by Sue Ellen Hirschfeld in 1985. [2] However, it was subsequently found to be a distinct genus 35 years later in 2020. Magdalenabradys is considered to be a derived mylodontid, closely related to Lestodon , Pseudoprepotherium, and Thinobadistes . [1]
Below is a phylogenetic tree of the Mylodontidae, based on the work of Rincón and McDonald 2020, showing the position of Magdalenabradys.
The most extensive fossil material to date belongs to the Urumaco sequence, a complex depositional unit that is predominantly exposed in the approximately 36,000 km2 large Falcón Basin in the Venezuelan state of Falcón. It is composed of the lithostratigraphic units of the Urumaco and Codore Formations, with remains of Magdalenabradys being limited to the former formation. The Urumaco sequence covers the Middle Miocene to the Early Pliocene. The main components are different layers of sand, clay and/silt and limestone in which individual coal seams are embedded, at least in the Urumaco Formation. The rock strata were formed in what was originally a coastal area under the influence of a river delta. [3] From the entire Urumaco sequence, a large number of sites are documented, the exploration of which began as early as the 1950s. They are distributed over a good 60 different stratigraphic levels. The find material consists mainly of fish, especially sharks and rays. In addition, there are also reptiles such as turtles, crocodilians and isolated snakes, as well as mammals appearing with rodents, South American ungulates, manatees, and minor jointed animals among others. The secondary articulated animals show a high diversity, which almost reaches that of the contemporary fauna of southern South America in the Pampas region or in Mesopotamia. Armadillos such as the Pampatheriidae and Glyptodontinae as well as sloths have been found. [4] [5] [6] Mainly in the late 20th and early 21st century, numerous new forms were described, such as Urumacocnus and Pattersonocnus from the family Megalonychidae, Urumaquia and Proeremotherium as representatives of the large family Megatheriidae and Bolivartherium , Pseudoprepotherium , Eionaletherium and Urumacotherium from the family Mylodontidae and their immediate relatives. As a special circumstance of taphonomy, the frequent tradition of limb elements in sloths is to be evaluated, however, from Magdalenabradys, skull remains are also documented. [7] [8]
The Honda Group in Colombia is known for its diverse abundance of fauna, such as xenarthrans, ungulates, primates, rodents, metatherians, crocodilians, turtles, snakes, birds, and fish. There are 2 subunits of the Honda Group; the Villavieja Formation and the La Victoria Formation. Magdalenabradys fossils are only known from the former formation of the Honda Group.
Mammals from the Honda Group included the fellow mylodontid sloths Brievabradys and Glossotheriopsis , [9] as well as the scelidotheriid Neonematherium , the basal megatherioid Hapalops and the nothrotheriid Huilabradys , cingulates such as the dasypodids Anadasypus and Nanoastegotherium , the pachyarmathere Neoglyptatelus , the pampathere Scirrotherium , and the glyptodont Boreostemma. In addition, the anteater Neotamandua was also present. Ungulates from the Honda Group included the astrapotheres Granastrapotherium , Hilarcotherium , and Xenastrapotherium , the litopterns Megadolodus , [10] Mesolicaphrium , Neodolodus , Theosodon , and Villarroelia , and the notoungulates Huilatherium , Pericotoxodon , and Miocochilius . [11] [12] Metatherians from the Honda group included the sparassodonts Anachlysictis , Dukecynus , Hondadelphys , and Lycopsis , the microbiotherians Micoureus Pachybiotherium , the didelphid Thylamys , the paucituberculates Hondathentes and Pitheculites . Rodents of the Honda Group included various genera of caviomorphs, such as Acarechimys , Eodolichotis , Microscleromys , Microsteiromys , Neoreomys , Olenopsis Prodolichotis , Rhodanodolichotis , Ricardomys , Scleromys , and Steiromys . Birds of the Honda Group included the species Aramus paludigrus , Galbula hylochoreutes , and Hoazinoides magdalenae . Reptiles of the Honda Group included crocodylomorphs, snakes, and turtles, such as the sebecid Langstonia , the alligatorids Balanerodus , Eocaiman , Mourasuchus and Purussaurus the gavialid Gryposuchus , and the crocodile Charactosuchus , the turtles Chelus colombiana , Podocnemis medemi , and Geochelone hesterna , and the snakes Colombophis and Eunectes stirtoni . [13]
Purussaurus is an extinct genus of giant caiman that lived in South America during the Miocene epoch, from the Friasian to the Huayquerian in the SALMA classification. It is known from skull material found in the Brazilian and Peruvian Amazon, Colombian Villavieja Formation, Panamanian Culebra Formation, Urumaco and Socorro Formations of northern Venezuela.
The Laventan age is a period of geologic time 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.
Gryposuchus is an extinct genus of gavialid crocodilian. Fossils have been found from Argentina, Colombia, Venezuela, Brazil and the Peruvian Amazon. The genus existed during the Miocene epoch. One recently described species, G. croizati, grew to an estimated length of 10 metres (33 ft). Gryposuchus is the type genus of the subfamily Gryposuchinae, although a 2018 study indicates that Gryposuchinae and Gryposuchus might be paraphyletic and rather an evolutionary grade towards the gharial.
Ikanogavialis is an extinct genus of gavialid crocodilian. Fossils have been found in the Urumaco Formation in Urumaco, Venezuela and the Solimões Formation of Brazil. The strata from which remains are found are late Miocene in age, rather than Pliocene as was once thought. A possible member of this genus survived into the Late Holocene on Muyua or Woodlark Island in Papua New Guinea.
Lestobradys is an extinct genus of ground sloth, which existed in Uruguay during the Late Miocene period; Huayquerian in the South American land mammal age (SALMA). The type species is L. sprechmanni, found in the Camacho Formation of Uruguay.
Eionaletherium is an extinct genus of ground sloth from the Late Miocene coasts of Venezuela containing one species: E. tanycnemius.
The Castilletes Formation is a fossiliferous geological formation of the Cocinetas Basin in the northernmost department of La Guajira, Colombia. The formation consists of fossiliferous mudstones, siltstones and medium-grained to conglomeratic fossiliferous lithic to quartzitic sandstones. The Castilletes Formation dates to the Neogene period; Burdigalian to Langhian stages, Colloncuran and Friasian in the SALMA classification, and has a maximum thickness of 440 metres (1,440 ft).
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 by Carlini et al. in 2008. The type species is B. pliocena. Fossils of Boreostemma have been found in the Honda Group of Colombia, in Peru and Venezuela.
Miocochilius is an extinct genus of small notoungulate mammals (typotheres) native to South America. The genus lived during the Middle Miocene epoch. The genus contains two described species, the type species M. anomopodus described in 1953 by Ruben Arthur Stirton and M. federicoi, described and included in the genus by Darin A. Croft.
The Urumaco Formation is a formation in Venezuela that includes deposits from the Late Miocene. It is the site of several "giant forms": the turtles, crocodiles, sloths and rodents of Urumaco are among the largest of their groups.
Cullinia is an extinct genus of litoptern, an order of South American native ungulates that included horse-like and camel-like animals such as Macrauchenia. It is only known from fragmentary remains. Cullinia levis is known from Chasicoan remains found in the Arroyo Chasicó Formation of Argentina, and remains from the Brazilian state of Acre and the Huayquerian Ituzaingó Formation have been assigned to Cullinia sp..
Megadolodus is an extinct genus of proterotheriid litopterns.
Pseudoprepotherium is an extinct genus of sloths of the family Mylodontidae. It was widespread across northern South America during the Early to Late Miocene epoch around 21 to 5.3 million years ago. Fossils of the animal have been found in Brazil, Venezuela, and Peru. Pseudoprepotherium lived in a tropical climate with a water-rich environment. Their known remains are limited to limb bones, except for a few skulls and teeth. Based on these remains, they were most likely medium to large-sized mylodontid. The genus was described in 1961 and currently contains three species, which were originally assigned to the genus Prepotherium.
Pattersonocnus is an extinct genus of megalonychid sloth that lived during the Miocene in Venezuela 11.6 million years ago. The genus contains one known species, Pattersonocnus diazgameroi. Fossils have been found in the Urumaco Formation of Venezuela.
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 Falcón Basin in Venezuela. The finds identify the animals as medium-sized representatives of the Megatheriidae. In the cranial anatomy, Proeremotherium resembles the later and giant Eremotherium. It is therefore assumed that the two ground sloths are directly related to each other.
Urumacotherium is an extinct genus of ground sloths of the family Mylodontidae. It lived from the Middle Miocene to the Early Pliocene of what is now Brazil, Peru and Venezuela.
Baraguatherium is an extinct genus of ground sloths of the family Mylodontidae that lived during the Early Miocene of what is now Venezuela. It dates to the Early Miocene, around 20.44 to 15.97 million years ago and represents the oldest representative of its family in the northern part of South America to date. The structure of the teeth suggests that the genus represents a rather basal form within the Mylodontidae. Unlike other mylodonts, which tended to prefer open grasslands, Baraguatherium lived in a riverine, coastal tropical rainforest.
Urumacocnus is an extinct genus of megalonychid sloth that lived during the Miocene in Venezuela. The genus contains one known species, Urumacocnus urbanii. Fossils have been found in the Urumaco Formation of Venezuela.
Bolivartherium is an extinct genus of mylodontine mylodontid sloth that lived during the Late Miocene and Late Pliocene in what is now Venezuela. Fossils have been found in the Codore and Urumaco Formations of Venezuela.
{{cite journal}}
: CS1 maint: DOI inactive as of November 2024 (link){{cite journal}}
: Cite journal requires |journal=
(help){{cite book}}
: |journal=
ignored (help)