Ferugliotheriidae

Last updated

Ferugliotheriidae
Temporal range: Late Cretaceous; Paleogene?
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Clade:† Gondwanatheria
Family:† Ferugliotheriidae
Bonaparte, 1986
Type genus
Ferugliotherium
Bonaparte, 1986
Genera

Ferugliotheriidae is one of three known families in the order Gondwanatheria, an enigmatic group of extinct mammals. Gondwanatheres have been classified as a group of uncertain affinities or as members of Multituberculata, a major extinct mammalian order. The best-known representative of Ferugliotheriidae is the genus Ferugliotherium from the Late Cretaceous epoch in Argentina. A second genus, Trapalcotherium , is known from a single tooth, a first lower molariform (molar-like tooth), from a different Late Cretaceous Argentinean locality. Another genus known from a single tooth (in this case, a fourth lower premolar), Argentodites , was first described as an unrelated multituberculate, but later identified as possibly related to Ferugliotherium. Finally, a single tooth from the Paleogene of Peru, LACM 149371, perhaps a last upper molariform, and a recent specimen from Mexico, [1] may represent related animals.

Contents

Ferugliotheriids are known from isolated, low-crowned (brachydont) teeth and possibly a fragment of a lower jaw. Ferugliotherium is estimated to have weighed 70 g (2.5 oz). The incisors are long and procumbent and contain a band of enamel on only part of the tooth. The jaw fragment contains a long tooth socket for the incisor and bears a bladelike fourth lower premolar, resembling those of multituberculates. The premolar of Argentodites is similar. Two upper premolars also resemble multituberculate teeth, but whether these premolars are referable to Ferugliotheriidae is controversial. Molariforms are rectangular and brachydont and consist of longitudinal rows of cusps, connected by transverse crests and separated by transverse furrows. Lower molariforms have two cusp rows, and the single known putative upper molariform has three. Low-crowned and bladelike teeth as seen in ferugliotheriids may have been evolutionary precursors of the high-crowned (hypsodont) teeth of the other gondwanathere family, Sudamericidae.

Most ferugliotheriids come from the Late Cretaceous epoch (Campanian–Maastrichtian ages, 84–66 million years ago, or mya) of Argentina, where they may have lived in a marshy or seashore environment. They coexisted with mammals such as dryolestoids and a variety of other animals, including dinosaurs. Ferugliotheriids may have been herbivores or omnivores.

Taxonomy

The first member of the family Ferugliotheriidae to be discovered, Ferugliotherium windhauseni , was named in 1986 by Argentinean paleontologist José F. Bonaparte on the basis of a tooth from the Late Cretaceous Los Alamitos Formation of Argentina. [2] Bonaparte placed Ferugliotherium as the only member of the new family Ferugliotheriidae, which he tentatively assigned to the order Multituberculata, a large group of extinct mammals (distinct from both monotremes and therians, the two major groups of living mammals) that was particularly widespread in the northern continents (Laurasia), but had never previously been found in the south (Gondwana). [3] In 1990, Bonaparte named another species, Vucetichia gracilis, from Los Alamitos. [4] He placed it in the family Gondwanatheriidae, together with Gondwanatherium , another Los Alamitos mammal, within the order Gondwanatheria, which also contained the family Sudamericidae, then with the single genus Sudamerica . Bonaparte considered the gondwanatheres to be probably most closely related to the xenarthrans (sloths, armadillos, and anteaters) within a group called Paratheria. [5]

Also in 1990, Bonaparte merged the family Gondwanatheriidae into Sudamericidae and, together with David Krause, redefined Gondwanatheria as a multituberculate suborder that included both Ferugliotheriidae and Sudamericidae, thus rejecting a relationship between gondwanatheres and xenarthrans. [6] Krause, Bonaparte, and Zofia Kielan-Jaworowska redescribed Ferugliotherium in 1992 and suggested that the teeth that Vucetichia was based on may have been worn specimens of Ferugliotherium. [7] They placed Ferugliotherium among multituberculates and suggested that it may be part of the suborder Plagiaulacoidea. [8] The following year, Krause confirmed that Vucetichia gracilis is a synonym of Ferugliotherium windhauseni. [2] Together with Bonaparte, he also proposed to classify gondwanatheres as a superfamily (Gondwanatherioidea) within Plagiaulacoidea, including the families Ferugliotheriidae and Sudamericidae. [9] In 1996, Kielan-Jaworowska and Bonaparte tentatively identified a lower jaw fragment with a multituberculate-like fourth lower premolar (p4) from Los Alamitos as Ferugliotherium. [10] On the basis of the morphological features of the jaw fragment, they argued that gondwanatheres are not closely related to any other multituberculate group, and consequently placed them in a suborder of their own, Gondwanatheria. [11]

In 1999, Rosendo Pascual and colleagues described a lower jaw of Sudamerica, which had previously only been known from isolated teeth. This jaw fragment showed that Sudamerica had four molariform teeth on each side of the lower jaws, more than any multituberculate, and consequently they removed gondwanatheres from Multituberculata and regarded their affinities as uncertain. [12] As a consequence, Kielan-Jaworowska and colleagues excluded Gondwanatheria from multituberculates, but identified the jaw fragment and a few upper premolars of Ferugliotherium as indeterminate multituberculates in a 2001 paper and a 2004 book. [13] However, in 2009 Yamila Gurovich and Robin Beck identified these fossils as Ferugliotherium and argued in favor of a close relationship between gondwanatheres (including Ferugliotheriidae) and multituberculates. [14]

In the 2000s, additional members of Ferugliotheriidae were described. In 2004, Francisco Goin and colleagues described a single enigmatic tooth from the Paleogene of Peru, LACM 149371; their best estimate was that it represented a member of Ferugliotheriidae. [15] On the basis of a single p4, Kielan-Jaworowska and colleagues named Argentodites coloniensis , from the Late Cretaceous La Colonia Formation of Argentina, in 2007 as a multituberculate, possibly referable to the suborder Cimolodonta. [16] Gurovich and Beck argued, however, that the p4 of Argentodites did not differ materially from that in the jaw they allocated to Ferugliotherium, and that Argentodites was based on a specimen of either Ferugliotherium or a closely related animal. [17] Guillermo Rougier and colleagues described mammals from the Allen Formation, a third Argentinean formation of similar age, in 2009, including a new ferugliotheriid, Trapalcotherium matuastensis . [18] They also regarded Argentodites as a likely relative of Ferugliotherium and suggested that Ferugliotheriidae are either multituberculates or closely related to them. [19] Some studies have recovered Ferugliotheriidae as unrelated to the rest of Gondwanatheria, but instead nested within the Multituberculates. [20]

Description

Ferugliotheriids are known from a few dozen isolated teeth and a questionably allocated jaw fragment. Most fossils are referred to Ferugliotherium; Trapalcotherium and Argentodites were each described on the basis of a single tooth. [21] Their precise dental formula is unknown, but incisors, premolars, and molariform teeth have been identified. Gurovich suggested that Ferugliotherium had one incisor (possibly two in the upper jaw), no canines, one or two premolars, and two molars on each side of the lower and upper jaws. [22]

Unlike the very high-crowned (hypsodont) sudamericids, ferugliotheriid teeth were low-crowned (brachydont). Furthermore, sudamericid molariforms tend to be larger and are supported by one large root, but the smaller ferugliotheriids have at least two roots under their molariforms. [9] Ferugliotherium is estimated to have weighed 70 g (2.5 oz). [23]

The incisors, known only from Ferugliotherium, are procumbent and long. Three lower and four upper incisors are known. As is usual in mammals with similarly shaped (gliriform) incisors, the lower incisors are more laterally compressed, are less curved, form a greater angle between the front side and the wear facet at the tip, and are less elliptical in shape than the uppers. The enamel band is restricted to the side that faces the lips in both the lower and upper incisors (the lower side in the lowers and the upper side in the uppers). [24]

The specimen MACN Pv-RN 975, first described by Kielan-Jaworowska and Bonaparte in 1996, may be a jaw fragment of Ferugliotherium, although it has also been identified as an unrelated multituberculate. [25] The fossil preserves a bladelike premolar, identified as the fourth premolar, and the piece of the jawbone below it. A diastema (gap) is present between the premolar and the incisor that would have been located in front of it. The alveolus (socket) of the lower incisor extends all the way through the fossil. [26] The p4 bears eight ridges on both sides of the longitudinal crest and is supported by two roots at the front and back. [27] The p4 assigned to Argentodites also has eight ridges on both sides, which descend from cusps on the upper margin, and roots at the front and back. According to Kielan-Jaworowska and colleagues, it differs from that of MACN Pv-RN 975 in its rounded, as opposed to angular shape. [28] However, Gurovich and Beck attribute this difference to the fact that the latter has undergone much more wear. [17]

Two fossils have been interpreted as isolated lower premolars of Ferugliotherium, but neither is still regarded as such. [29] Two other teeth have been identified as upper premolars of Ferugliotherium; as with the jaw fragment, they may also represent an indeterminate multituberculate. [25] One of the two preserves two longitudinal rows of cusps, of which one contains four and the other at least two cusps. The other is more poorly preserved, but may represent the same tooth position. These teeth resemble multituberculate upper premolars. [30]

Four putative first lower molariforms (mf1s) of Ferugliotherium are known, [31] and the only known tooth of Trapalcotherium is also thought to be an mf1. [18] Ferugliotherium mf1s are roughly rectangular, with rounded corners, and bear two longitudinal rows of cusps. There are four cusps in the lingual row (on the side of the tongue) and three in the labial row (the side of the lips). The cusps are connected to cusps in the other row by transverse ridges and separated from cusps in their own rows by three transverse furrows. [32] Two heavily worn Ferugliotherium mf1s were originally identified as upper molars of Vucetichia gracilis by Bonaparte in 1990. One of the two preserves the roots; at the front and back, there were two roots, fused at their bases. [33] The mf1 of Trapalcotherium differs only in some details; among others, the cusps are less distinct from the crests. [18] The sole mf2 of Ferugliotherium is the holotype. It bears two rows of two cusps. The cusps in the front and back pairs are connected by a broad ridge and the two pairs are separated by a deep furrow. [34] Transverse ridges between the cusps similar to those seen in ferugliotheriids are not known in any multituberculate. [8] On the other hand, overall patterns of cusps and ridges are essentially similar among Ferugliotherium, Gondwanatherium, and Sudamerica, indicating that the three are closely related. [35]

One Ferugliotherium tooth is thought to be a first upper molariform (MF1). It is almost rectangular and bears three longitudinal rows of cusps. There are five cusps in the middle row, which is oriented obliquely, four cusps in one of the rows on the side of the tooth, and two or three in the other row on the side. As in the lower molariforms, the cusps are connected by transverse ridges and separated by furrows. [36] LACM 149371, the enigmatic possibly ferugliotheriid tooth from Peru, is a triangular tooth bearing six or seven cusps, which are connected by crests and surround two deep fossae (basins) and a third shallower fossa. [37]

Range, ecology, and evolution

With its low-crowned teeth, Ferugliotherium may have been an insectivore or omnivore, like similar multituberculates such as Mesodma , which is thought to have eaten insects, other arthropods, seeds, and/or nuts. The wear on Ferugliotherium teeth suggests that the animal may have eaten some plant material. [38] The high-crowned sudamericids are thought to have been herbivores feeding on abrasive vegetation, although their precise diet is not known. [39] In the evolutionary history of gondwanatheres, hypsodont teeth are thought to have evolved from brachydont precursors. Gurovich hypothesizes that the anterior molariforms of sudamericids may have evolved from bladelike premolars as seen in Ferugliotherium. [40]

Fossils of Argentinean ferugliotheriids come from the Los Alamitos (Ferugliotherium), La Colonia (Ferugliotherium and Argentodites), and Allen Formations (Trapalcotherium). [41] All three are approximately the same age, dating to the Campanian (84–71 mya) or more likely the Maastrichtian (71–66 mya), but the La Colonia Formation is perhaps a little younger. [42] The Los Alamitos and Allen Formations may have been deposited in a marshy environments, [42] and the depositional environment of the La Colonia Formations may have been an estuary, tidal flat, or coastal plain. [43]

In each of the three formations, the mammalian fauna is dominated by the archaic group Dryolestoidea; [44] the Los Alamitos Formation has also produced the sudamericid Gondwanatherium. [45] Only seven mammalian teeth have been found in the Allen Formation. [46] All three also contain remains of numerous other animals, including dinosaurs, amphibians, and fish. [47]

The Santa Rosa fossil site, where LACM 149371 was found, is in the Ucayali Region of Peru. [48] The Santa Rosa fauna also contains fossils of various unique species of marsupials and hystricognath rodents, a possible bat, and some notoungulates (a unique extinct group of South American ungulates). [49] The age of this fauna is unclear, and estimates range from near the Eocene–Oligocene boundary (~35 mya) to the late Oligocene (~25 mya). [50] The Santa Rosa mammals may have lived in a savanna habitat that contained rivers. [51]

More recently, a specimen has been found in the Cerro del Pueblo Formation of Mexico, bearing several similarities to Ferugliotherium . If a ferugliotheriid, this would extend the clade's range into the Maastrichtian of North America. [52]

The range of the Ferugliotheriidae is overall more limited, both in extent and time, than that of Sudamericidae; sudamericids have been recorded from the Late Cretaceous to Miocene of Argentina, the Late Cretaceous of Madagascar and India, the Middle Eocene of Antarctica, and perhaps the Cretaceous of Tanzania (TNM 02067, tentatively referred to Sudamericidae). [53] Nevertheless, ferugliotheriids may be the only gondwanatheres to have had a presence in the northern hemisphere. [54]

Related Research Articles

<span class="mw-page-title-main">Multituberculata</span> Extinct order of mammals

Multituberculata is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, and reached a peak diversity during the Late Cretaceous and Paleocene. They eventually declined from the mid-Paleocene onwards, disappearing from the known fossil record in the late Eocene. They are the most diverse order of Mesozoic mammals with more than 200 species known, ranging from mouse-sized to beaver-sized. These species occupied a diversity of ecological niches, ranging from burrow-dwelling to squirrel-like arborealism to jerboa-like hoppers. Multituberculates are usually placed as crown mammals outside either of the two main groups of living mammals—Theria, including placentals and marsupials, and Monotremata—but usually as closer to Theria than to monotremes. They are considered to be closely related to Euharamiyida and Gondwanatheria as part of Allotheria.

<i>Catopsbaatar</i> Extinct species of mammal

Catopsbaatar is a genus of multituberculate, an extinct order of rodent-like mammals. It lived in what is now Mongolia during the late Campanian age of the Late Cretaceous epoch, about 72 million years ago. The first fossils were collected in the early 1970s, and the animal was named as a new species of the genus Djadochtatherium in 1974, D. catopsaloides. The specific name refers to the animal's similarity to the genus Catopsalis. The species was moved to the genus Catopsalis in 1979, and received its own genus in 1994. Five skulls, one molar, and one skeleton with a skull are known; the last is the genus' most complete specimen. Catopsbaatar was a member of the family Djadochtatheriidae.

<span class="mw-page-title-main">Gondwanatheria</span> Extinct group of Mammaliaformes that lived during the Upper Cretaceous through the Miocene

Gondwanatheria is an extinct group of mammaliaforms that lived in parts of Gondwana, including Madagascar, India, South America, Africa and Antarctica during the Upper Cretaceous through the Paleogene. Until recently, they were known only from fragmentary remains. They are generally considered to be closely related to the multituberculates and likely the euharamiyidians, well known from the Northern Hemisphere, with which they form the clade Allotheria.

Ferugliotherium is a genus of fossil mammals in the family Ferugliotheriidae from the Campanian and/or Maastrichtian period of Argentina. It contains a single species, Ferugliotherium windhauseni, which was first described in 1986. Although originally interpreted on the basis of a single brachydont (low-crowned) molar as a member of Multituberculata, an extinct group of small, rodent-like mammals, it was recognized as related to the hypsodont (high-crowned) Sudamericidae following the discovery of additional material in the early 1990s. After a jaw of the sudamericid Sudamerica was described in 1999, these animals were no longer considered to be multituberculates and a few fossils that were previously considered to be Ferugliotherium were assigned to unspecified multituberculates instead. Since 2005, a relationship between gondwanatheres and multituberculates has again received support. A closely related animal, Trapalcotherium, was described in 2009 on the basis of a single tooth.

Lavanify is a mammalian genus from the late Cretaceous of Madagascar. The only species, L. miolaka, is known from two isolated teeth, one of which is damaged. The teeth were collected in 1995–1996 and described in 1997. The animal is classified as a member of Gondwanatheria, an enigmatic extinct group with unclear phylogenetic relationships, and within Gondwanatheria as a member of the family Sudamericidae. Lavanify is most closely related to the Indian Bharattherium; the South American Sudamerica and Gondwanatherium are more distantly related. Gondwanatheres probably ate hard plant material.

<span class="mw-page-title-main">Allotheria</span> Extinct subclass of mammals

Allotheria is an extinct clade of mammals known from the Mesozoic and early Cenozoic. Shared characteristics of the group are the presence of lower molariform teeth equipped with longitudinal rows of cusps and enlarged incisors. Typically, the canine teeth are also lost. Allotheria includes Multituberculata, Gondwanatheria, and probably Haramiyida, although some studies have recovered haramiyidans to be basal mammaliaforms unrelated to multituberculates. Allotherians are often placed as crown group mammals, more closely related to living marsupials and placentals (Theria) than to monotremes or eutriconodonts.

<span class="mw-page-title-main">Eutriconodonta</span> Extinct order of mammals

Eutriconodonta is an order of early mammals. Eutriconodonts existed in Asia, Africa, Europe, North and South America during the Jurassic and the Cretaceous periods. The order was named by Kermack et al. in 1973 as a replacement name for the paraphyletic Triconodonta.

<i>Gobiconodon</i> Extinct genus of mammals

Gobiconodon is an extinct genus of carnivorous mammals belonging to the family Gobiconodontidae. Undisputed records of Gobiconodon are restricted to the Early Cretaceous of Asia and North America, but isolated teeth attributed to the genus have also been described from formations in England and Morocco dating as far back as the Middle Jurassic. Species of Gobiconodon varied considerably in size, with G. ostromi, one of the larger species, being around the size of a modern Virginia opossum. Like other gobiconodontids, it possessed several speciations towards carnivory, such as shearing molariform teeth, large canine-like incisors and powerful jaw and forelimb musculature, indicating that it probably fed on vertebrate prey. Unusually among predatory mammals and other eutriconodonts, the lower canines were vestigial, with the first lower incisor pair having become massive and canine-like. Like the larger Repenomamus there might be some evidence of scavenging.

<i>Ambondro mahabo</i> Species of small mammal from the middle Jurassic of Madagascar

Ambondro mahabo is a mammal from the Middle Jurassic (Bathonian) Isalo III Formation of Madagascar. The only described species of the genus Ambondro, it is known from a fragmentary lower jaw with three teeth, interpreted as the last premolar and the first two molars. The premolar consists of a central cusp with one or two smaller cusps and a cingulum (shelf) on the inner, or lingual, side of the tooth. The molars also have such a lingual cingulum. They consist of two groups of cusps: a trigonid of three cusps at the front and a talonid with a main cusp, a smaller cusp, and a crest at the back. Features of the talonid suggest that Ambondro had tribosphenic molars, the basic arrangement of molar features also present in marsupial and placental mammals. It is the oldest known mammal with putatively tribosphenic teeth; at the time of its discovery it antedated the second oldest example by about 25 million years.

Several mammals are known from the Mesozoic of Madagascar. The Bathonian Ambondro, known from a piece of jaw with three teeth, is the earliest known mammal with molars showing the modern, tribosphenic pattern that is characteristic of marsupial and placental mammals. Interpretations of its affinities have differed; one proposal places it in a group known as Australosphenida with other Mesozoic tribosphenic mammals from the southern continents (Gondwana) as well as the monotremes, while others favor closer affinities with northern (Laurasian) tribosphenic mammals or specifically with placentals. At least five species are known from the Maastrichtian, including a yet undescribed species known from a nearly complete skeleton that may represent a completely new group of mammals. The gondwanathere Lavanify, known from two teeth, is most closely related to other gondwanatheres found in India and Argentina. Two other teeth may represent another gondwanathere or a different kind of mammal. One molar fragment is one of the few known remains of a multituberculate mammal from Gondwana and another has been interpreted as either a marsupial or a placental.

<i>Galulatherium</i> Fossil taxon

Galulatherium is an extinct genus of possibly gondwanathere mammal, from the Late Cretaceous (Turonian-Campanian)-aged Galula Formation of Tanzania. It is known solely from the type specimen TNM 02067 a fragmentary fossil dentary. The short, deep bone is about 19.5 mm (0.77 in) long, but the back part is broken off. It contains a large, forward-inclined incisor with a root that extends deep into the jaw, separated by a diastema (gap) from five cheekteeth. Very little remains of the teeth, but enough to determine that they are hypsodont (high-crowned). The third cheektooth is the largest and the roots of the teeth are curved. First described in 2003, TNM 02067 has been tentatively identified as a sudamericid—an extinct family of high-crowned gondwanathere mammals otherwise known from South America, Madagascar, India, and Antarctica. If truly a gondwanathere, it would be the only African member of the group and may be the oldest. The describers could not exclude other possibilities, such as that the jaw represents some mammalian group known only from younger, Cenozoic times. In 2019 the fossil was CT scanned, which revealed additional details of the specimen.

Argentodites is a possible multituberculate mammal from the Cretaceous of Argentina. The single species, Argentodites coloniensis, is known from a single blade-like fourth lower premolar (p4) from the La Colonia Formation, which is mostly or entirely Maastrichtian in age. The p4 is 4.15 mm long and bears eight cusps on its upper margin and long associated ridges on both sides. The enamel consists of prisms that are completely or partly surrounded by a sheath and that are on average 6.57 μm apart. Zofia Kielan-Jaworowska, who described and named the fossil in 2007, regarded it as a multituberculate, perhaps a cimolodontan—and thus, a member of a mostly Laurasian (northern) group and an immigrant to Argentina from North America—on the basis of the shape of the tooth and features of its enamel. In 2009, however, two teams argued that Argentodites may in fact be close to or identical with Ferugliotherium, a member of the small Gondwanan (southern) group Gondwanatheria; although their relationships are disputed, gondwanatheres may themselves be multituberculates.

LACM 149371 is an enigmatic fossil mammalian tooth from the Paleogene of Peru. It is from the Santa Rosa fossil site, which is of uncertain age but possibly late Eocene or Oligocene. The tooth is poorly preserved and may have been degraded by acidic water or because it passed through a predator's digestive tract. Its largest dimension is 2.65 mm. It is triangular in shape and bears six cusps that surround the middle of the tooth, where there are three basins (fossae). Crests connects the cusps and separate the fossae. The microscopic structure of the enamel is poorly preserved.

Trapalcotherium is a fossil mammal from the Cretaceous of Argentina in the family Ferugliotheriidae. The single species, T. matuastensis, is known from one tooth, a first lower molar. It is from the Allen Formation, which is probably Maastrichtian in age, and was first described in 2009. The tooth bears two rows of cusps, one at the inner (lingual) side and the other at the outer (labial) side, which are connected by transverse ridges separated by deep valleys. This pattern is reminiscent of Ferugliotherium, a gondwanathere mammal from similarly aged deposits in Argentina, and Trapalcotherium is therefore recognized as a member of the same family Ferugliotheriidae. Ferugliotheriidae is one of two families of gondwanatheres, an enigmatic group without close relationships to any living mammals.

Bharattherium is a mammal that lived in India during the Maastrichtian and possibly the Paleocene. The genus has a single species, Bharattherium bonapartei. It is part of the gondwanathere family Sudamericidae, which is also found in Madagascar and South America during the latest Cretaceous. The first fossil of Bharattherium was discovered in 1989 and published in 1997, but the animal was not named until 2007, when two teams independently named the animal Bharattherium bonapartei and Dakshina jederi. The latter name is now a synonym. Bharattherium is known from a total of eight isolated fossil teeth, including one incisor and seven molariforms.

Coloniatherium is a meridiolestid mammal from the Late Cretaceous of Argentina. The single species, Coloniatherium cilinskii, was a large member of the family Mesungulatidae.

<span class="mw-page-title-main">Paratheria (mammals)</span> Former taxonomic group including xenarthran and similar mammals

Paratheria is an obsolete term for a taxonomic group including the xenarthran mammals and various groups thought to be related to them. It was proposed by Oldfield Thomas in 1887 to set apart the sloths, anteaters, armadillos, and pangolins, usually classified as placentals, from both marsupial and placental mammals, an arrangement that received little support from other workers. When teeth of the extinct gondwanathere mammals were first discovered in Argentina in the 1980s, they were thought to be related to xenarthrans, leading to renewed attention for the hypothesis that xenarthrans are not placentals. However, by the early 1990s, gondwanatheres were shown to be unrelated to xenarthrans, and xenarthrans are still considered to be placentals.

Groeberiidae is a family of strange non-placental mammals from the Eocene and Oligocene epochs of Patagonia, Argentina and Chile, South America. Originally classified as paucituberculate marsupials, they were suggested to be late representatives of the allothere clade Gondwanatheria. However, the relationship of the type genus, Groeberia, to Gondwanatheria has been firmly rejected by other scholars.

Patagonia is an extinct genus of non-placental mammal from the Miocene of Argentina. Traditionally considered a metatherian incertae sedis, one analysis suggested it to be a gondwanathere. However, this has been rejected by other authors.

<span class="mw-page-title-main">Plagiaulacoid</span> Mammalian tooth

A plagiaulacoid is a type of blade-like, most often serrated, tooth present in various mammal groups, usually a premolar. Among modern species it is present chiefly on diprotodontian marsupials, which have both the upper and lower first premolars converted into serrated blades. However, various other extinct groups also possessed plagiaulacoids. These would be multituberculates, some "Plesiadapiformes" such as Carpolestes and various metatherians such as Epidolops and various early diprotodontians. In many of these only a lower premolar became converted into a blade, while the upper premolars showed less specialisation.

References

  1. ↑ SVP 2015
  2. 1 2 Krause 1993, p. 321.
  3. ↑ Krause 1993, p. 321; Krause, Kielan-Jaworowska & Bonaparte 1992, p. 351.
  4. ↑ Bonaparte 1990, p. 77.
  5. ↑ Bonaparte 1990, pp. 82, 84–86.
  6. ↑ Gurovich 2005, p. 151; Krause & Bonaparte 1993, p. 9379.
  7. ↑ Krause, Kielan-Jaworowska & Bonaparte 1992, p. 362.
  8. 1 2 Krause, Kielan-Jaworowska & Bonaparte 1992, p. 372.
  9. 1 2 Krause & Bonaparte 1993, p. 9382.
  10. ↑ Kielan-Jaworowska & Bonaparte 1996, p. 1.
  11. ↑ Kielan-Jaworowska & Bonaparte 1996, p. 8.
  12. ↑ Pascual et al. 1999, p. 373.
  13. ↑ Kielan-Jaworowska & Hurum 2001, p. 411; Kielan-Jaworowska, Cifelli & Luo 2004, pp. 335–336.
  14. ↑ Gurovich & Beck 2009, p. 25.
  15. ↑ Goin et al. 2004, p. 152.
  16. ↑ Kielan-Jaworowska et al. 2007, p. 257.
  17. 1 2 Gurovich & Beck 2009, p. 32.
  18. 1 2 3 Rougier et al. 2009, p. 232.
  19. ↑ Rougier et al. 2009, p. 233.
  20. ↑ Hoffmann, Simone; Beck, Robin M. D.; Wible, John R.; Rougier, Guillermo W.; Krause, David W. (2020-12-14). "Phylogenetic placement of Adalatherium hui (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar: implications for allotherian relationships". Journal of Vertebrate Paleontology. 40 (sup1): 213–234. Bibcode:2020JVPal..40S.213H. doi:10.1080/02724634.2020.1801706. ISSN   0272-4634. S2CID   230968231.
  21. ↑ Kielan-Jaworowska et al. 2007, p. 258; Rougier et al. 2009, p. 232; Gurovich & Beck 2009, table 1.
  22. ↑ Gurovich 2005, p. 326.
  23. ↑ Gurovich 2008, table 2.
  24. ↑ Krause, Kielan-Jaworowska & Bonaparte 1992, pp. 352–355.
  25. 1 2 Gurovich & Beck 2009, pp. 30–31.
  26. ↑ Kielan-Jaworowska & Bonaparte 1996, p. 5; Gurovich 2005, pp. 327, 329.
  27. ↑ Kielan-Jaworowska & Bonaparte 1996, p. 5; Gurovich 2005, pp. 329–330.
  28. ↑ Kielan-Jaworowska et al. 2007, p. 260.
  29. ↑ Krause, Kielan-Jaworowska & Bonaparte 1992, p. 360; Pascual et al. 1999, p. 376.
  30. ↑ Krause, Kielan-Jaworowska & Bonaparte 1992, p. 355.
  31. ↑ Gurovich & Beck 2009, table 1; Krause 1993, p. 321.
  32. ↑ Krause 1993, pp. 321–323; Pascual et al. 1999, fig. 2.
  33. ↑ Krause, Kielan-Jaworowska & Bonaparte 1992, p. 362; Krause 1993, p. 324.
  34. ↑ Krause, Kielan-Jaworowska & Bonaparte 1992, pp. 354–355.
  35. ↑ Krause & Bonaparte 1993, p. 9380.
  36. ↑ Krause, Kielan-Jaworowska & Bonaparte 1992, p. 357.
  37. ↑ Goin et al. 2004, p. 146.
  38. ↑ Gurovich 2008, p. 1086.
  39. ↑ Gurovich 2008, pp. 1084, 1086.
  40. ↑ Gurovich 2005, pp. 249–250.
  41. ↑ Rougier et al. 2009, pp. 196–197; Gurovich & Beck 2009, table 3; Rougier et al. 2009, p. 232.
  42. 1 2 Rougier et al. 2009, p. 225.
  43. ↑ Rougier et al. 2009, p. 197.
  44. ↑ Rougier et al. 2009, p. 223; Rougier et al. 2009, pp. 196–197; Gurovich & Beck 2009, table 3.
  45. ↑ Gurovich & Beck 2009, table 3; Rougier et al. 2007, p. 10.
  46. ↑ Rougier et al. 2009, p. 223.
  47. ↑ Rougier et al. 2009, p. 233; Gurovich 2005, pp. 209, 212; Pascual et al. 2000, pp. 399–400.
  48. ↑ Goin et al. 2004, p. 145.
  49. ↑ Campbell 2004, pp. 156–159.
  50. ↑ Campbell 2004, pp. 159–160; Vucetich et al. 2010, pp. 201–202.
  51. ↑ Campbell 2004, p. 161.
  52. ↑ SVP 2015
  53. ↑ Gurovich & Beck 2009, pp. 26, 31–32.
  54. ↑ SVP 2015

Literature cited

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.