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Sparassodonta (from
Almost all sparassodonts have an exceptionally shortened snout—most especially thylacosmylids. Hathliacynids usually have a longer snout than the other groups. 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 ...
to tear, rend; and , gen. , ' tooth) is an extinct
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
order
Order, ORDER or Orders may refer to:
* A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
...
of carnivorous
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...
metatheria
Metatheria is a mammalian clade that includes all mammals more closely related to marsupials than to placentals. First proposed by Thomas Henry Huxley in 1880, it is a more inclusive group than the marsupials; it contains all marsupials as wel ...
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 ...
s native to South America, related to modern marsupial
Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...
s. They were once considered to be true marsupials, but are now thought to be a separate side branch that split before the last common ancestor of all modern marsupials.
A number of these mammalian predators closely resemble placental
Placental mammals (infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguished ...
predators that evolved separately on other continents, and are cited frequently as examples of convergent evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last comm ...
. They were first described 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, especial ...
, from fossils found in the Santa Cruz beds of Patagonia
Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers ...
. Sparassodonts were present throughout South America's long period of "splendid isolation" during the Cenozoic
The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...
; during this time, they shared the niches for large warm-blooded predators with the flightless terror bird
Phorusrhacids, colloquially known as terror birds, are an extinct family of large carnivorous, mostly flightless birds that were among the largest apex predators in South America during the Cenozoic era. Their definitive fossil records range from ...
s. Previously, it was thought that these mammals died out in the face of competition from "more competitive" placental
Placental mammals (infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguished ...
carnivorans
Carnivora ( ) is an Order (biology), order of Placentalia, placental mammals specialized primarily in eating flesh, whose members are formally referred to as carnivorans. The order Carnivora is the sixth largest order of mammals, comprising at ...
during the Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Great 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 land ...
, but more recent research has shown that sparassodonts died out long before eutherian carnivores arrived in South America (aside from procyonids, which sparassodonts probably did not directly compete with).
Sparassodonts have been referred to as borhyaenoids by some authors, but currently the term Borhyaenoidea refers to a restricted subgroup of sparassodonts comprising borhyaenids and their close relatives.
Anatomy
Almost all sparassodonts have an exceptionally shortened snout—most especially thylacosmylids. Hathliacynids usually have a longer snout than the other groups. The nasal bone
The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face and by their junction, form the bridge of the upper one third of the nose.
Eac ...
s extend past the eye sockets, often reaching the lacrimal bone
The lacrimal bones are two small and fragile bones of the facial skeleton; they are roughly the size of the little fingernail and situated at the front part of the medial wall of the orbit. They each have two surfaces and four borders. Several bon ...
. Except for thylacosmylids beyond ''Patagosmilus
''Patagosmilus'' ("Patagonian knife" in Greek) is an extinct genus of meat-eating metatherian mammal of the family Thylacosmilidae, that lived in the Middle Miocene in South America.postorbital processes which would otherwise form the
The
The early history of the Sparassodonta is poorly known, as most
Sparassodonts were carnivorous, and with the exception of some basal members of all members of this group were
postorbital bar
The postorbital bar (or postorbital bone) is a bony arched structure that connects the frontal bone of the skull to the zygomatic arch, which runs laterally around the eye socket. It is a trait that only occurs in mammalian taxa, such as most strep ...
connecting the forehead to the cheek, thus framing the eye. They exhibit marked postorbital constriction. The orbital process
In the human skull, the zygomatic bone (from ), also called cheekbone or malar bone, is a paired irregular bone, situated at the upper and lateral part of the face and forming part of the lateral wall and floor of the orbit, of the temporal fossa ...
(between the cheek and the eye socket) is usually diminished, though the zygomatic arch
In anatomy, the zygomatic arch (colloquially known as the cheek bone), is a part of the skull formed by the zygomatic process of temporal bone, zygomatic process of the temporal bone (a bone extending forward from the side of the skull, over the ...
(the cheekbone) is strong. They feature a prominent sagittal crest
A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull (at the sagittal suture) of many mammalian and reptilian skulls, among others. The presence of this ridge of bone indicates that there are excepti ...
along the midline of the flattened skull, the crest strength is quite variable among borhyaenids. They have an expanded occipital bone
The occipital bone () is a neurocranium, cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone lies over the occipital lob ...
with a well defined nuchal crest.
Sparassodonts spanned a wide range of body sizes, from 2.2-pound (1 kg) weasel
Weasels are mammals of the genus ''Mustela'' of the family Mustelidae. The genus ''Mustela'' includes the least weasels, polecats, stoats, ferrets, and European mink. Members of this genus are small, active predators, with long and slend ...
or civet
A civet () is a small, lean, mostly nocturnal mammal native to tropical Asia and Africa, especially the tropical forests. The term ''civet'' applies to over a dozen different species, mostly from the family Viverridae. Most of the species's div ...
-like forms to '' Thylacosmilus'', which was the size of a leopard
The leopard (''Panthera pardus'') is one of the five extant cat species in the genus ''Panthera''. It has a pale yellowish to dark golden fur with dark spots grouped in rosettes. Its body is slender and muscular reaching a length of with a ...
. Along with the Australian thylacoleonids, sparassodonts include some of the largest metatherian carnivores.
Sparassodonts have highly reduced epipubic
Epipubic bones are a pair of bones projecting forward from the pelvic bones of modern marsupials, monotremes and fossil mammals like multituberculates, and even basal eutherians (the ancestors of placentals, who lack them).
They first occur in ...
bones (pelvic bones which support the pouch), to the point that early analysis could not even find evidence for them. This is a characteristic shared with the Australian thylacine
The thylacine (; binomial name ''Thylacinus cynocephalus''), also commonly known as the Tasmanian tiger or Tasmanian wolf, was a carnivorous marsupial that was native to the Mainland Australia, Australian mainland and the islands of Tasmani ...
, and historically argued as a synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel Phenotypic trait, character or character state that has evolution, evolved from its ancestral form (or Plesiomorphy and symplesiomorphy, plesiomorphy). A synapomorphy is an apomorphy sh ...
, though nowadays it is considered to have developed independently for poorly understood reasons. As with thylacines, it is very likely that they possessed long cartilaginous elements instead.
Teeth
The dental formula
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiology ...
of sparassodonts varies considerably. In borhyaenids, it is , with three upper and 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, one upper and lower canine, three upper and lower premolar
The premolars, also called premolar Tooth (human), teeth, or bicuspids, are transitional teeth located between the Canine tooth, canine and Molar (tooth), molar teeth. In humans, there are two premolars per dental terminology#Quadrant, quadrant in ...
s, and four upper and lower molars
The molars or molar teeth are large, flat tooth, teeth at the back of the mouth. They are more developed in mammal, mammals. They are used primarily to comminution, grind food during mastication, chewing. The name ''molar'' derives from Latin, '' ...
in each half of either jaw. Proborhyaenids usually only have two lower incisors instead of three, except for '' Callistoe''. Thylacosmylids have at least two upper and only two lower incisors (the uppers grew into elongated sabers
A sabre or saber ( ) is a type of backsword with a curved blade associated with the light cavalry of the early modern and Napoleonic periods. Originally associated with Central European cavalry such as the hussars, the sabre became widesp ...
), and two upper and lower premolars. Some specimens of '' Borhyaena'' and '' Arctodictis'' are also missing the last upper molar, showing that the presence of this tooth was variable in these species.
Sparassodonta is characterized by dental synapomorphies
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to ...
that distinguish the group from other closely related mammals. Unequivocal traits uniting the earliest Sparassodonts include:
* a snout that forms a pronounced bulge around the canine teeth when viewed from above
* a ridge on the upper molar (preparacrista) oriented anterobuccally (towards the cheek) with respect to the long axis of the tooth.
* a pronounced keel near the base of the front of the paraconid
* ridges on lower molars (postprotocristid-metacristid) parallel or oblique with respect to lower jaw axis.
* a very tall protoconid (>90% tooth length, secondarily lost in ''Hondadelphys'' and ''Stylocynus'') that bulges to the side and is wider at its midpoint than its base
* talonid (crushing end) of lower molar narrow in relation to trigonid (shearing end).
In borhyaenids, only the third premolar was ever replaced in the animal's lifetime, similar to other metatherians. In thylacosmilids, only the lower third premolar was replaced.
The cusps of the sparassodont molar correlate to a cutting function rather than a crushing one. In the upper molars, the paracone (on the lingual, or tongueward, side) is reduced and fused to the metacone (distal, towards the back of the mouth), inflating the postmetacrista (the lingual border of the metacone); and they almost always lack the stylar shelf (on the buccal, or cheekward, side) and associated stylar cusps. In the lower molars, the trigonids (the buccal shearing side) have an inflated paracristid and marginalized or absent metaconid; and the talonid (the distal, or backendwards, crushing side) is either reduced or gone.
Taxonomy
Classification
Sparassodonts can be divided into six major groups; basal sparassodonts (?earliestPaleocene
The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...
-late Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
), species that cannot be easily assigned to any of the other sparassodont groups and whose teeth often exhibit adaptations for omnivory; hathliacynids (late Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
-early Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58marten
A marten is a weasel-like mammal in the genus ''Martes'' within the subfamily Guloninae, in the family Mustelidae. They have bushy tails and large paws with partially retractile claws. The fur varies from yellowish to dark brown, depending on ...
to a thylacine
The thylacine (; binomial name ''Thylacinus cynocephalus''), also commonly known as the Tasmanian tiger or Tasmanian wolf, was a carnivorous marsupial that was native to the Mainland Australia, Australian mainland and the islands of Tasmani ...
in size, and have long, fox-like muzzles and teeth strongly suited for carnivory
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...
; basal borhyaenoids (middle Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
-late Miocene), borhyaenoids which are unable to be easily classified into the families Borhyaenidae
Borhyaenidae is an extinct metatherian family of low-slung, heavily built predatory mammals in the order Sparassodonta. Borhyaenids are not true marsupials, but members of a sister taxon, Sparassodonta. Like most metatherians, borhyaenids and oth ...
, Thylacosmilidae
Thylacosmilidae is an extinct family of metatherian predators, related to the modern marsupials, which lived in South America between the Miocene and Pliocene epochs. Like other South American mammalian predators that lived prior to the Great Ame ...
, or Proborhyaenidae
Proborhyaenidae is an extinct Family (biology), family of metatherian mammals of the order Sparassodonta, which lived in South America from the Eocene (Mustersan) until the Oligocene (Deseadan). Sometimes it has been included as a subfamily of th ...
and range in form and size; borhyaenids (early-late Miocene), the sparassodont group most specialized for running, but not as much as living carnivorans
Carnivora ( ) is an Order (biology), order of Placentalia, placental mammals specialized primarily in eating flesh, whose members are formally referred to as carnivorans. The order Carnivora is the sixth largest order of mammals, comprising at ...
or even thylacines; proborhyaenids (middle Eocene-late Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
), robust, wolverine
The wolverine ( , ; ''Gulo gulo''), also called the carcajou or quickhatch (from East Cree, ''kwiihkwahaacheew''), is the largest land-dwelling species, member of the family Mustelidae. It is a muscular carnivore and a solitary animal. The w ...
-like forms with ever-growing upper and lower canines; and thylacosmilids (early Miocene-late Pliocene), another terrestrially specialized group with ever-growing saber-like upper canines.
The taxonomic classification below follows the latest review of the group, that of Prevosti and Forasiepi (2018), with additions from more recent studies. Although ''Mayulestes'' was originally described as a sparassodont, later phylogenetic analyses have shown that it most likely does not belong to this group; however more recent studies show it to be closely related to sparassodonts. Similarly, while basal borhyaenoids such as ''Lycopsis'' and ''Prothylacynus'' were once thought to belong to a distinct family (Prothylacynidae), phylogenetic analyses have found that these animals do not represent a monophyletic
In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria:
# the grouping contains its own most recent co ...
group. The exact age of most Eocene species of sparassodonts is uncertain, given the lack of precise stratigraphic information associated with most specimens and the recent division of the Casamayoran
The Casamayoran () age is a period of geologic time (50.0–48.0 Ma) within the Early Eocene epoch of the Paleogene, used more specifically within the South American land mammal age (SALMA) classification. It follows the Itaboraian and precedes th ...
SALMA into the Vacan and Barrancan SALMAs.
* Order Sparassodonta
** Genus '' Allqokirus''
***''Allqokirus australis'' (earliest Paleocene
The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...
, Tiupampan
The Tiupampan () age is a period of geologic time (64.5–62.5 Ma) within the Paleocene epoch of the Paleogene
The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from th ...
SALMA)
** Genus '' Mayulestes''
***''Mayulestes ferox'' (earliest Paleocene
The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...
, Tiupampan
The Tiupampan () age is a period of geologic time (64.5–62.5 Ma) within the Paleocene epoch of the Paleogene
The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from th ...
SALMA)
** Genus '' Argyrolestes''
** Genus '' Nemolestes''
***''Nemolestes spalacotherinus'' (late middle Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
, Barrancan SALMA)
** Genus '' Patene''
***''Patene campbelli'' (late ?Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
, Santa Rosa local fauna
The Santa Rosa local fauna consists of the animals found in the Paleogene fossil site of Santa Rosa in eastern Peru. The age of the Santa Rosa fauna is difficult to determine, but may be Eocene ( Mustersan) or Oligocene (Deseadan).
History and c ...
)
***''Patene coloradensis'' (middle Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
)
***''Patene coluapiensis'' (middle Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
, Barrancan SALMA)
***''Patene simpsoni'' (late Paleocene
The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...
/early Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
, Itaboraian
The Itaboraian () age is a period within the Early Eocene geologic time (53.0–50.0 Ma) epoch of the Paleogene, used more specifically with South American land mammal ages (SALMA). It follows the Riochican and precedes the Casamayoran age.
E ...
SALMA)
** Genus '' Procladosictis''
***''Procladosictis anomala'' (late Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
, Mustersan The Mustersan age is a period of geologic time (48.0–42.0 Mya (unit), Ma) within the Eocene epoch of the Paleogene, used more specifically within the South American land mammal age (SALMA) classification. It follows the Casamayoran and precedes th ...
SALMA)
** Family Hondadelphidae
''Hondadelphys'' is an extinct genus of carnivorous sparassodonts, known from the Middle Miocene of Colombia. The type species, ''H. fieldsi'', was described in 1976 from the fossil locality of La Venta, which hosts fossils from the Villavieja F ...
*** Genus '' Hondadelphys''
****''Hondadelphys fieldsi'' (late middle Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, 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.
...
SALMA)
*** Genus '' Stylocynus''
****''Stylocynus paranensis'' (latest Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Huayquerian
The Huayquerian () age is a period of geologic time (9.0–6.8 Ma) within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification. It follows the Chasicoan and precedes the Montehermosan age.
Etymology
T ...
SALMA)
** Family Hathliacynidae
*** Genus '' Acyon''
****''Acyon ?herrerae'' (early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Colhuehuapian
The Colhuehuapian age is a period of geologic time (21.0–17.5 Ma) within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Deseadan and precedes the Santacrucian ag ...
SALMA)
****''Acyon myctoderos'' (late middle Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, 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.
...
SALMA)
****''Acyon tricuspidatus'' (late early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Santacrucian
The Santacrucian age is a period of geologic time (17.5 – 16.3 Mya (unit), Ma) within the Early Miocene epoch of the Neogene, used more specifically with South American land mammal age, SALMA classification in South America. It follows the Colhue ...
SALMA)
*** Genus '' Australogale''
****''Australogale leptognathus'' (late middle Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, 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.
...
SALMA)
*** Genus '' Borhyaenidium''
****''Borhyaenidium altiplanicus'' (latest Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Huayquerian
The Huayquerian () age is a period of geologic time (9.0–6.8 Ma) within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification. It follows the Chasicoan and precedes the Montehermosan age.
Etymology
T ...
SALMA)
****''Borhyaenidium riggsi'' (unknown, either early or late Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Montehermosan
The Montehermosan age is a period of geologic time (6.8–4.0 Mya (unit), Ma) within the Miocene and Pliocene epochs of the Neogene used more specifically with South American Land Mammal Ages. It follows the Huayquerian and precedes the Chapadmalal ...
or 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
...
SALMA)
****''Borhyaenidium musteloides'' (latest Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Huayquerian
The Huayquerian () age is a period of geologic time (9.0–6.8 Ma) within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification. It follows the Chasicoan and precedes the Montehermosan age.
Etymology
T ...
SALMA)
*** Genus '' Chasicostylus''
****''Chasicostylus castroi'' (early late Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Chasicoan SALMA)
*** Genus '' Cladosictis''
****''Cladosictis centralis'' (early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Colhuehuapian
The Colhuehuapian age is a period of geologic time (21.0–17.5 Ma) within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Deseadan and precedes the Santacrucian ag ...
SALMA)
****''Cladosictis patagonica'' (late early to earliest middle Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Santacrucian
The Santacrucian age is a period of geologic time (17.5 – 16.3 Mya (unit), Ma) within the Early Miocene epoch of the Neogene, used more specifically with South American land mammal age, SALMA classification in South America. It follows the Colhue ...
- Friasian SALMA)
*** Genus '' Notictis''
****''Notictis ortizi'' (latest Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Huayquerian
The Huayquerian () age is a period of geologic time (9.0–6.8 Ma) within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification. It follows the Chasicoan and precedes the Montehermosan age.
Etymology
T ...
SALMA)
*** Genus '' Notocynus''
****''Notocynus hermosicus'' (early Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Montehermosan
The Montehermosan age is a period of geologic time (6.8–4.0 Mya (unit), Ma) within the Miocene and Pliocene epochs of the Neogene used more specifically with South American Land Mammal Ages. It follows the Huayquerian and precedes the Chapadmalal ...
SALMA)
*** Genus '' Notogale''
****''Notogale mitis'' (late Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
, Deseadan
The Deseadan () age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Tingu ...
SALMA)
*** Genus '' Pseudonotictis''
****''Pseudonotictis chubutensis'' (early middle Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Colloncuran SALMA)
****''Pseudonotictis pusillus'' (late early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Santacrucian
The Santacrucian age is a period of geologic time (17.5 – 16.3 Mya (unit), Ma) within the Early Miocene epoch of the Neogene, used more specifically with South American land mammal age, SALMA classification in South America. It follows the Colhue ...
SALMA)
*** Genus '' Perathereutes''
****''Perathereutes pungens'' (late early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Santacrucian
The Santacrucian age is a period of geologic time (17.5 – 16.3 Mya (unit), Ma) within the Early Miocene epoch of the Neogene, used more specifically with South American land mammal age, SALMA classification in South America. It follows the Colhue ...
SALMA)
*** Genus '' Sallacyon''
****''Sallacyon hoffstetteri'' (late Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
, Deseadan
The Deseadan () age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Tingu ...
SALMA)
*** Genus '' Sipalocyon''
****''Sipalocyon externus'' (early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Colhuehuapian
The Colhuehuapian age is a period of geologic time (21.0–17.5 Ma) within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Deseadan and precedes the Santacrucian ag ...
SALMA)
****''Sipalocyon gracilis'' (late early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Santacrucian
The Santacrucian age is a period of geologic time (17.5 – 16.3 Mya (unit), Ma) within the Early Miocene epoch of the Neogene, used more specifically with South American land mammal age, SALMA classification in South America. It follows the Colhue ...
SALMA)
****''Sipalocyon "obusta"'' (late early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Santacrucian
The Santacrucian age is a period of geologic time (17.5 – 16.3 Mya (unit), Ma) within the Early Miocene epoch of the Neogene, used more specifically with South American land mammal age, SALMA classification in South America. It follows the Colhue ...
SALMA)
** Superfamily Borhyaenoidea
*** Genus '' Angelocabrerus''
****''Angelocabrerus daptes'' (middle Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
)
*** Genus '' Chlorocyon''
****''Chlorocyon phantasma'' (late Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
, Mustersan The Mustersan age is a period of geologic time (48.0–42.0 Mya (unit), Ma) within the Eocene epoch of the Paleogene, used more specifically within the South American land mammal age (SALMA) classification. It follows the Casamayoran and precedes th ...
SALMA)
*** Genus '' Dukecynus''
****''Dukecynus magnus'' (late middle Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, 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.
...
SALMA)
*** Genus '' Eomakhaira''
****''Eomakhaira molossus'' (early Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
, ?Tinguirirican
The Tinguirirican () age is a period of geologic time (36.0–29.0 Mya (unit), Ma) within the Eocene, Late Eocene and Oligocene, Early Oligocene epochs of the Paleogene, used more specifically within the South American land mammal age, SALMA classi ...
SALMA)
*** Genus '' Fredszalaya''
****''Fredszalaya hunteri'' (late Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
, Deseadan
The Deseadan () age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Tingu ...
SALMA)
*** Genus ''Lycopsis
''Lycopsis'' is an extinct genus of South American metatherian that lived during the Miocene in Argentina and Colombia.
History
Although not named until 1927, Florentino Ameghino described a species now seen as synonymous with ''Lycopsis torre ...
''
****''Lycopsis longirostrus'' (late middle Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, 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.
...
SALMA)
****''Lycopsis padillai'' (middle Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Colloncuran SALMA)
****''Lycopsis torresi'' (early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Colhuehuapian
The Colhuehuapian age is a period of geologic time (21.0–17.5 Ma) within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Deseadan and precedes the Santacrucian ag ...
SALMA)
****''Lycopsis viverensis'' (early late Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Chasicoan SALMA))
*** Genus '' Pharsophorus''
****''Pharsophorus lacerans'' (middle to late Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
, La Cantera Local Fauna to Deseadan
The Deseadan () age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Tingu ...
SALMA)
****''Pharsophorus tenax'' (late Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
, Deseadan
The Deseadan () age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Tingu ...
SALMA)
*** Genus '' Plesiofelis''
****''Plesiofelis schlosseri'' (late Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
, Mustersan The Mustersan age is a period of geologic time (48.0–42.0 Mya (unit), Ma) within the Eocene epoch of the Paleogene, used more specifically within the South American land mammal age (SALMA) classification. It follows the Casamayoran and precedes th ...
SALMA)
*** Genus '' Prothylacynus''
****''Prothylacynus patagonicus'' (late early to earliest middle Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Santacrucian
The Santacrucian age is a period of geologic time (17.5 – 16.3 Mya (unit), Ma) within the Early Miocene epoch of the Neogene, used more specifically with South American land mammal age, SALMA classification in South America. It follows the Colhue ...
- Friasian SALMA)
*** Genus '' Pseudolycopsis''
****''Pseudolycopsis cabrerai'' (early late Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Chasicoan SALMA
*** Genus '' Pseudothylacynus''
****''Pseudothylacynus rectus'' (early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Colhuehuapian
The Colhuehuapian age is a period of geologic time (21.0–17.5 Ma) within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Deseadan and precedes the Santacrucian ag ...
SALMA)
*** Family Borhyaenidae
Borhyaenidae is an extinct metatherian family of low-slung, heavily built predatory mammals in the order Sparassodonta. Borhyaenids are not true marsupials, but members of a sister taxon, Sparassodonta. Like most metatherians, borhyaenids and oth ...
**** Genus '' Acrocyon''
*****''Acrocyon riggsi'' (early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Colhuehuapian
The Colhuehuapian age is a period of geologic time (21.0–17.5 Ma) within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Deseadan and precedes the Santacrucian ag ...
SALMA)
*****''Acrocyon sectorius'' (late early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Santacrucian
The Santacrucian age is a period of geologic time (17.5 – 16.3 Mya (unit), Ma) within the Early Miocene epoch of the Neogene, used more specifically with South American land mammal age, SALMA classification in South America. It follows the Colhue ...
SALMA)
**** Genus '' Arctodictis''
*****''Arctodictis munizi'' (late early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Santacrucian
The Santacrucian age is a period of geologic time (17.5 – 16.3 Mya (unit), Ma) within the Early Miocene epoch of the Neogene, used more specifically with South American land mammal age, SALMA classification in South America. It follows the Colhue ...
SALMA)
*****''Arctodictis sinclairi'' (early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Colhuehuapian
The Colhuehuapian age is a period of geologic time (21.0–17.5 Ma) within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Deseadan and precedes the Santacrucian ag ...
SALMA)
**** Genus '' Australohyaena''
*****''Australohyaena antiquua'' (late Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
, Deseadan
The Deseadan () age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Tingu ...
SALMA)
**** Genus '' Borhyaena''
*****''Borhyaena macrodonta'' (early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Colhuehuapian
The Colhuehuapian age is a period of geologic time (21.0–17.5 Ma) within the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Deseadan and precedes the Santacrucian ag ...
SALMA)
*****''Borhyaena tuberata'' (late early Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Santacrucian
The Santacrucian age is a period of geologic time (17.5 – 16.3 Mya (unit), Ma) within the Early Miocene epoch of the Neogene, used more specifically with South American land mammal age, SALMA classification in South America. It follows the Colhue ...
SALMA)
**** ?Genus '' Eutemnodus''
*** Family Proborhyaenidae
Proborhyaenidae is an extinct Family (biology), family of metatherian mammals of the order Sparassodonta, which lived in South America from the Eocene (Mustersan) until the Oligocene (Deseadan). Sometimes it has been included as a subfamily of th ...
**** Genus '' Arminiheringia''
**** Genus '' Callistoe''
*****''Callistoe vincei'' (middle Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
, Vacan- Barrancan SALMA)
**** Genus '' Paraborhyaena''
*****''Paraborhyaena boliviana'' (late Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
, Deseadan
The Deseadan () age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Tingu ...
SALMA)
**** Genus '' Proborhyaena''
*****''Proborhyaena gigantea'' (late Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
, Deseadan
The Deseadan () age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America. It follows the Tingu ...
SALMA)
***Unranked clade Thylacosmiliformes
**** Genus '' Dimartinia''
*****''Dimartinia pristina'' (late Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Chasicoan SALMA)
**** Family Thylacosmilidae
Thylacosmilidae is an extinct family of metatherian predators, related to the modern marsupials, which lived in South America between the Miocene and Pliocene epochs. Like other South American mammalian predators that lived prior to the Great Ame ...
***** Genus '' Anachlysictis''
******''Anachlysictis gracilis'' (late middle Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, 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.
...
SALMA)
***** Genus ''Patagosmilus
''Patagosmilus'' ("Patagonian knife" in Greek) is an extinct genus of meat-eating metatherian mammal of the family Thylacosmilidae, that lived in the Middle Miocene in South America.Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, Colloncuran SALMA)
***** Genus '' Thylacosmilus''
******''Thylacosmilus atrox'' (latest Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
to late Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Huayquerian
The Huayquerian () age is a period of geologic time (9.0–6.8 Ma) within the Late Miocene epoch of the Neogene, used more specifically within the SALMA classification. It follows the Chasicoan and precedes the Montehermosan age.
Etymology
T ...
-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
...
SALMA)
Several other metatherian taxa have been suggested to be sparassodonts or closely related to sparassodonts. The australian Murgon
Murgon () is a rural town and Suburbs and localities (Australia), locality in the South Burnett Region, Queensland, Australia. In the , the locality of Murgon had a population of 2,220 people.
Geography
Murgon is in the region of Queensland ...
taxa '' Archaeonothos'' has been noted as being similar to sparassodonts, but currently its relationships are not fully concluded. Carneiro (2018) recovered the genus '' Varalphadon'' from the Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...
of North America as a basal member of Sparassodonta. However, this interpretation of ''Varalphadon'' as a sparassodont has not been supported by later phylogenetic analyses, and most of the purported synapomorphies between ''Varalphadon'' and sparassodonts are not actually present in ''Varalphadon'' or have been suggested to be due to convergent evolution. Sparassodonts have sometimes been considered closely related to the " Gurlin Tsav skull" an unnamed metatherian known from a partial skull found in the Late Cretaceous Nemegt Formation
The Nemegt Formation (also known as Nemegtskaya Svita) is a geological formation in the Gobi Desert of Mongolia, dating to the Late Cretaceous. The formation consists of river channel sediments and contains fossils of fish, turtles, crocodilians ...
of Mongolia.
The following 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 ...
of sparassodont interrelationships is after Engelman ''et al.'', 2020. Not all studies agree on the sister group
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree.
Definition
The expression is most easily illustrated by a cladogram:
Taxon A and ...
relationship between Thylacosmilidae
Thylacosmilidae is an extinct family of metatherian predators, related to the modern marsupials, which lived in South America between the Miocene and Pliocene epochs. Like other South American mammalian predators that lived prior to the Great Ame ...
and Borhyaenidae
Borhyaenidae is an extinct metatherian family of low-slung, heavily built predatory mammals in the order Sparassodonta. Borhyaenids are not true marsupials, but members of a sister taxon, Sparassodonta. Like most metatherians, borhyaenids and oth ...
recovered here, with other studies finding thylacosmilids to be within Proborhyaenidae
Proborhyaenidae is an extinct Family (biology), family of metatherian mammals of the order Sparassodonta, which lived in South America from the Eocene (Mustersan) until the Oligocene (Deseadan). Sometimes it has been included as a subfamily of th ...
. The relationships among hathliacynids are also relatively unstable.
Within Metatheria
Metatheria is a mammalian clade that includes all mammals more closely related to marsupials than to placentals. First proposed by Thomas Henry Huxley in 1880, it is a more inclusive group than the marsupials; it contains all marsupials as wel ...
, a 2016 phylogenetic analysis group found that borhyaenids form a clade with the Asian "Gurlin Tsav skull" as well as other South American taxa. The same phylogeny found that marsupials group among various North American Cretaceous species. The phylogenetic tree is reproduced below.
Evolution
The early history of the Sparassodonta is poorly known, as most Paleocene
The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...
and Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
members of this group are only known from isolated teeth and fragmentary jaws. However, one species, the middle Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
''Callistoe vincei'', is known from a nearly complete, articulated skeleton. As ''Callistoe'' belongs to one of the most specialized groups of sparassodonts, this indicates that the other major groups (e.g. borhyaenids, hathliacynids, etc.) must have also arisen by this time. Originally, the early Paleocene metatherian
Metatheria is a mammalian clade that includes all mammals more closely related to marsupials than to placentals. First proposed by Thomas Henry Huxley in 1880, it is a more inclusive group than the marsupials; it contains all marsupials as well ...
'' Mayulestes'' was considered to be the earliest known member of the Sparassodonta, but phylogenetic analyses suggest that this species represents an independent radiation of carnivorous metatheria
Metatheria is a mammalian clade that includes all mammals more closely related to marsupials than to placentals. First proposed by Thomas Henry Huxley in 1880, it is a more inclusive group than the marsupials; it contains all marsupials as wel ...
ns more closely related to '' Pucadelphys''; however, recent studies show that these taxa were closely related to borhyaenids. As of this writing, the earliest known true sparassodonts are either ''Allqokirus australis'', a species from the same site as ''Mayulestes'' that may turn out to not be a sparassodont, and an isolated astragalus
Astragalus may refer to:
* ''Astragalus'' (plant), a large genus of herbs and small shrubs
*Astragalus (bone)
The talus (; Latin for ankle or ankle bone; : tali), talus bone, astragalus (), or ankle bone is one of the group of foot bones known ...
from the earliest Paleocene site of Punta Peligro, Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
.
Sparassodonts have been suggested to be related to a variety of other groups of metatherians. 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, especial ...
, who first described fossils of the group, thought that sparassodonts were closely related to creodonts and were a transitional group between metatherians and carnivorous placentals (including modern carnivorans
Carnivora ( ) is an Order (biology), order of Placentalia, placental mammals specialized primarily in eating flesh, whose members are formally referred to as carnivorans. The order Carnivora is the sixth largest order of mammals, comprising at ...
). Contemporary authors in the late 19th and early 20th century rejected this hypothesis and considered sparassodonts to be closely related to Australian thylacines and dasyurids. The most popular hypothesis for much of the 20th century was that sparassodonts were closely related to opossums
Opossums () are members of the marsupial order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 126 species in 18 genera. Opossums originated in South America and entered North A ...
. In 1990, Marshall et al. (1990) considered the Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
stagodontids to be members of Sparassodonta, but this was criticized by later authors. Marshall and Kielan-Jaworowska (1992) considered sparassodonts to be closely related to deltatheroida
Deltatheroida is an extinct group of basal metatherians that were distantly related to modern marsupials. The majority of known members of the group lived in the Cretaceous; one species, '' Gurbanodelta kara'', is known from the late Paleocene ( ...
ns, but this was also criticized. Most of these hypotheses were based on similar adaptations for carnivorous
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...
diets in sparassodonts, opossums, dasyuromorphians, stagodonts, and deltatheroidans, which are highly prone to convergent evolution within mammals. Szalay (1994) considered sparassodonts to be closely related to paucituberculata
Paucituberculata is an order of South American marsupials. Although currently represented only by the seven living species of shrew opossums, this order was formerly much more diverse, with more than 60 extinct species named from the fossil rec ...
ns based on features of the ankle. In recent years there has been a growing consensus that sparassodonts are positioned just outside of crown-group
In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...
Marsupialia
Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a ...
, in a broader clade ( Pucadelphyida) including pucadelphyids as well as sparassodonts.
Sparassodonts are presently regarded as an endemic
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
South American group, and have not even been found in nearby continents like Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...
(where other groups native to South America such as litopterns
Litopterna (from "smooth heel") is an extinction, extinct order of South American native ungulates that lived from the Paleocene to the Pleistocene-Holocene around 62.5 million to 12,000 years ago (or possibly as late as 3,500 years ago), and we ...
, astrapotheres, microbiotheres, and polydolopids) are present.
Paleobiology
Diet
Sparassodonts were carnivorous, and with the exception of some basal members of all members of this group were hypercarnivorous
A hypercarnivore is an animal that has a diet that is more than 70% meat, either via active predation or by scavenging. The remaining non-meat diet may consist of non-animal foods such as fungi, fruits or other plant material. Some extant example ...
(having diets composed of more than 70% meat). Only ''Hondadelphys'' and ''Stylocynus'' appear to have exhibited adaptations for omnivory, and even then ''Stylocynus'' may have had a more mesocarnivorous diet similar to canids than an omnivorous one. Medium-to-large caviomorph
Caviomorpha is the rodent 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 accepted as ...
rodents
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 n ...
and rodent-like mammals (e.g., small notoungulates) appear to have been common prey items of sparassodonts. The subadult holotype of '' Lycopsis longirostrus'' preserves remains of the dinomyid ''Scleromys colombianus'' as fossilized gut contents. Sparassodont coprolites
A coprolite (also known as a coprolith) is fossilized feces. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour (in this case, diet) rather than morphology. The name i ...
from the Santa Cruz Formation
The Santa Cruz Formation is a geological formation in the Magallanes Basin, Magallanes/Austral Basin in southern Patagonia in Argentina and adjacent areas of Chile. It dates to the late Early Miocene epoch, and is contemporaneous with the eponym ...
preserve the bones of chinchillid and octodontoid rodents inside them. Bite marks from medium-sized sparassodonts have been found on the small notoungulate
Notoungulata is an extinct order of ungulates that inhabited South America from the early Paleocene to the end of the Pleistocene, living from approximately 61 million to 11,000 years ago. Notoungulates were morphologically diverse, with forms re ...
'' Paedotherium''. Stable isotope data from the early late Miocene ''Lycopsis
''Lycopsis'' is an extinct genus of South American metatherian that lived during the Miocene in Argentina and Colombia.
History
Although not named until 1927, Florentino Ameghino described a species now seen as synonymous with ''Lycopsis torre ...
viverensis'' and '' Thylacosmilus atrox'' suggests that these species fed on C3 grazers in open habitats, likely notoungulates.
Bite marks likely pertaining to hathliacynid sparassodonts have been found on the remains of penguins and flightless marine ducks in ancient seabird nesting colonies, suggesting that sparassodonts raided seabird colonies for eggs, carrion, and other prey like many predatory mammals do today.
Borhyaenid and proborhyaenid sparassodonts have been interpreted as being capable of crushing bones similar to modern hyenas
Hyenas or hyaenas ( ; from Ancient Greek , ) are feliformia, feliform carnivoran mammals belonging to the Family (biology), family Hyaenidae (). With just four extant species (each in its own genus), it is the fifth-smallest family in the orde ...
, wolverines
The wolverine ( , ; ''Gulo gulo''), also called the carcajou or quickhatch (from East Cree, ''kwiihkwahaacheew''), is the largest land-dwelling member of the family Mustelidae. It is a muscular carnivore and a solitary animal. The wolverine ...
, or the Tasmanian devil
The Tasmanian devil (''Sarcophilus harrisii''; palawa kani: ''purinina'') is a carnivorous marsupial of the family Dasyuridae. It was formerly present across mainland Australia, but became extinct there around 3,500 years ago; it is now con ...
(''Sarcophilus harrisii'') based on their deep jaws, bulbous premolars with deep roots and pronounced wear at their tips, extensive fused or interlocking mandibular symphyses, large masseteric fossae, microfractures in their tooth enamel, and high estimated bite forces. ''Australohyaena antiquua'' shows particularly pronounced adaptations for bone-cracking, with a very deep jaw and strongly arched nasals similar to what is seen in modern hyaenids
Hyenas or hyaenas ( ; from Ancient Greek , ) are feliformia, feliform carnivoran mammals belonging to the Family (biology), family Hyaenidae (). With just four extant species (each in its own genus), it is the fifth-smallest family in the orde ...
.
Based on studies of the postcranial skeleton, it appears as though most sparassodonts were scansorial
Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally (scansorial), but others are exclusively arboreal. The habi ...
(adapted for climbing), although terrestrial adaptations evolved in ''Lycopsis
''Lycopsis'' is an extinct genus of South American metatherian that lived during the Miocene in Argentina and Colombia.
History
Although not named until 1927, Florentino Ameghino described a species now seen as synonymous with ''Lycopsis torre ...
longirostrus'', borhyaenids, proborhyaenids, and thylacosmilids. Most sparassodonts were 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. ...
, ''Borhyaena'' has been suggested to have been digitigrade
In terrestrial vertebrates, digitigrade ( ) locomotion is walking or running on the toes (from the Latin ''digitus'', 'finger', and ''gradior'', 'walk'). A digitigrade animal is one that stands or walks with its toes (phalanges) on the ground, and ...
but this has been questioned. The one exception was '' Thylacosmilus'', which has been interpreted as having a digitigrade forefoot and a semiplantigrade hindfoot, this has been supported by fossil tracks.
One unusual aspect of sparassodont paleoecology is that at most fossil localities their remains are nearly ten times rarer than would be expected based on comparisons with carnivorous mammals at fossil sites in other parts of the world. The exact reasons for this are not clear, though this appears to be a broader pattern applicable to other groups of Cenozoic South American terrestrial carnivores (i.e., terror birds
Phorusrhacids, colloquially known as terror birds, are an extinct family of large carnivorous, mostly flightless birds that were among the largest apex predators in South America during the Cenozoic era. Their definitive fossil records range from ...
).
Sociality
Little is known of the behavior and biology of sparassodonts outside of general locomotor and dietary habits. Argot (2004) proposed that ''Thylacosmilus atrox'' may have exhibited protracted parental care after weaning of the offspring, given that saber teeth in general have been suggested to require long juvenile periods for the young to gain the skill necessary to use them effectively. However, this has not been tested further. Sparassodonts have relatively large and complex brains for metatherians, comparable to those of some Australian marsupials like Australian possums, though the body masses used to produce these estimates of relative brain size are low compared later studies suggesting these values could be overestimated. Wounds have been documented on the face of specimens of ''Borhyaena tuberata'' and ''Sipalocyon gracilis'', potentially suggesting aggressive habits similar to the modernTasmanian devil
The Tasmanian devil (''Sarcophilus harrisii''; palawa kani: ''purinina'') is a carnivorous marsupial of the family Dasyuridae. It was formerly present across mainland Australia, but became extinct there around 3,500 years ago; it is now con ...
(''Sarcophilus harrisii'').
Senses
Sparassodonts appear to have had very littlebinocular vision Binocular vision is seeing with two eyes. The Field_of_view, field of view that can be surveyed with two eyes is greater than with one eye. To the extent that the visual fields of the two eyes overlap, #Depth, binocular depth can be perceived. Th ...
, with borhyaenids having the greatest degree of depth perception (but still lower than modern carnivorans) and the eyes of '' Thylacosmilus'' facing almost completely to the sides. However, later studies have found that ''Thylacosmilus'' likely held its head in a downward-facing position, which would have allowed for more binocular vision than previously thought.
Pathology
Several specimens of hathliacynids (''Sipalocyon'' and ''Cladosictis'') show a pathological disorder characterized by the presence of growths on the surface of the mandible, which in the most extreme cases can result in the loss of several teeth due to bony pathological growths. The exact cause of this condition (i.e., infection, virus, parasite) and why it seems to only occur in small sparassodonts is unknown, though this condition has also been documented inmicrobiotheria
Microbiotheria is an australidelphian marsupial order that encompasses two families, Microbiotheriidae and Woodburnodontidae, and is represented by only one extant species, the monito del monte, and a number of extinct species known from foss ...
ns.
Extinction
After the middle Miocene, sparassodonts began to slowly decline in diversity. Basal borhyaenoids are last known from the early late Miocene (''Pseudolycopsis cabrerai'' and ''Lycopsis viverensis''), and after this time were at least partially replaced by large-bodied basal sparassodonts such as ''Stylocynus''. Some have proposed that this shift in dominance was because of the more omnivorous habits of basal sparassodonts, which may have been more adapted to the more seasonal South American climates of the lateNeogene
The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of th ...
. Borhyaenids are last known from the latest Miocene
The Miocene ( ) is the first epoch (geology), 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 mea ...
, though only fragmentary remains of this group are known from this period. Later remains assigned to this group have since been reidentified as thylacosmilids or procyonids. By the Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Hathliacynidae and the Thylacosmilidae. Pliocene hathliacynid remains are rare, and it is possible that these animals may have competed with the large carnivorous didelphids such as '' Lutreolina'' that appeared around this time. Hathliacynids are last definitively known from the early Pliocene, though their remains are rare.
The thylacosmilids, on the other hand, were more successful and abundant, being some of the only large mammalian carnivores in South America during the Pliocene, before dying out during a faunal turnover in the middle of the epoch (the youngest specimens of thylacosmilids are ~3.3 Ma). It is still not certain why Sparassodonta declined in diversity and became extinct during the late Cenozoic, but it appears as though competition from
eutherian
Eutheria (from Greek , 'good, right' and , 'beast'; ), also called Pan-Placentalia, is the clade consisting of placental mammals and all therian mammals that are more closely related to placentals than to marsupials.
Eutherians are distingu ...
carnivorans
Carnivora ( ) is an Order (biology), order of Placentalia, placental mammals specialized primarily in eating flesh, whose members are formally referred to as carnivorans. The order Carnivora is the sixth largest order of mammals, comprising at ...
was not a factor, as the placental analogues of sparassodonts (dogs
The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers ...
, weasels, and saber-toothed cats
Machairodontinae (from Ancient Greek μάχαιρα ''Makhaira, machaira,'' a type of Ancient Greek sword and ὀδόντος ''odontos'' meaning tooth) is an extinct subfamily of carnivoran mammals of the cat family Felidae, representing the ...
) did not enter South America until the middle Pleistocene, several million years after their sparassodont counterparts became extinct. Sparassodonts did coexist with '' Cyonasua''-group procyonids during the late Miocene and Pliocene, but '' Cyonasua''-group procyonids appear to have been primarily omnivorous and filled ecological niches that sparassodonts never occupied, which may be one reason that these animals were able to colonize South America despite the diverse predator guild in the late Miocene. The overall decline in sparassodont diversity from the Late Miocene to the end of the Pliocene may be linked to the climatic cooling that characterised the Late Neogene and the onset of the Quaternary glaciation
The Quaternary glaciation, also known as the Pleistocene glaciation, is an alternating series of glacial period, glacial and interglacial, interglacial periods during the Quaternary period that began 2.58 Year#SI prefix multipliers, Ma (million ...
. Additionally, the increased aridity of South America caused by the uplift of the Andes was likely responsible as well.
References
Further reading
* *External links
{{Taxonbar, from=Q133041 Prehistoric metatherians Sparassodonta Cenozoic mammals of South America Paleocene first appearances Pliocene extinctions Fossil taxa described in 1894