Gondwanatheria is an extinct group of
mammaliaform
Mammaliaformes ("mammalian forms") is a clade of synapsid tetrapods that includes the crown group mammals and their closest extinct relatives; the group radiated from earlier probainognathian cynodonts during the Late Triassic. It is defined a ...
s that lived in parts of
Gondwana
Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...
, including Madagascar, India, South America, Africa, and Antarctica during the
Upper 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 ''cret ...
through the
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 ...
(and possibly much earlier, if ''
Allostaffia'' is a member of this group
). 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
Allotheria (meaning "other beasts", from the Ancient Greek language, Greek , '–other and , '–wild animal) is an extinct clade of mammals known from the Mesozoic and early Cenozoic. Shared characteristics of the group are the presence of lower ...
.
Classification

For several decades the affinities of the group were not clear, being first interpreted as early
xenarthra
Xenarthra (; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a superorder and major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and ...
ns, or "toothless" mammals similar to the modern
anteater
Anteaters are the four extant mammal species in the suborder Vermilingua (meaning "worm tongue"), commonly known for eating ants and termites. The individual species have other names in English and other languages. Together with sloths, they ar ...
. A variety of studies have placed them as
allotheres related to
multituberculates, possibly even true multituberculates, closer to
cimolodonts than "
plagiaulacida
Plagiaulacida is a group of extinct Multituberculata, multituberculate mammals. Multituberculates were among the most common mammals of the Mesozoic, "the age of the dinosaurs". Plagiaulacids are a paraphyletic grouping, containing all multituber ...
ns" are.
However, a more recent study recovered them as nested among
haramiyida
Haramiyida is a possibly Paraphyly, paraphyletic order of Mammaliaformes, mammaliaform cynodonts or mammals of controversial taxonomic affinites. Their teeth, which are by far the most common remains, resemble those of the multituberculates. Howe ...
ns, rendering them as non-mammalian cynodonts. A more recently described specimen has since recovered them as allotheres closely related to
multituberculates,
but this was soon after followed by a study recovering them as part of
Euharamiyida, which itself was placed inside crown-group Mammalia.
There are three known
families
Family (from ) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictability, structure, and safety as ...
within Gondwanatheria. The family Sudamericidae was named by Scillato-Yané and Pascual in 1984, and includes the vast majority of named taxa. The family Ferugliotheriidae was named by
José Bonaparte in 1986, and includes one genus, ''
Ferugliotherium'', and possibly a few other forms like ''
Trapalcotherium'' from the Late Cretaceous of South America. Ferugliotheriidae are considered the most basal gondawanatherians, and are sometimes recovered outside the group.

Further
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...
s have come from
India
India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...
,
Madagascar
Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...
and Antarctica. A possible ''Ferugliotherium''-like species occurs in
Maastrichtian
The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...
deposits of
Mexico
Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
, extending the clade to
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
.
The youngest gondwanatherians are known from the
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 ...
of South America and Antarctica. The Eocene genus ''
Groeberia'' and Miocene genus ''
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 ...
,'' two mammals from South America with unusual tooth morphologies usually considered
metatherians
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 ...
, were considered by one paper to be gondwanatheres.
However, their conclusions have generally not been accepted.
Biology
Gondwanatheres known from cranial remains almost universally have deep, robust snouts, as befitting their specialised herbivorous lifestyle. ''
Vintana'' possesses bizarre
jugal flanges similar to those of
xenarthra
Xenarthra (; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a superorder and major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and ...
ns like
ground sloth
Ground sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. They varied widely in size with the largest, belonging to genera '' Lestodon'', ''Eremotherium'' and ''Megatherium'', being around the size of elephants. ...
s, though they had a palinal (front-to-back) chewing method as in most allotheres and unlike almost any
therian.
Most gondwanatheres are specialised
grazers, even being among the first mammals to have specialised for
grass-eating long before any therians did, with the exceptions of
Groeberidae and
Ferugliotheriidae, which lack hypsodont teeth and therefore had more generalistic herbivorous habits.
An articulated specimen found in the
Maevarano Formation offers insight to the postcranial skeleton of these animals. Among the bizarre and unique features are a mediolaterally compressed and antero-posteriorly bowed tibia, a double
trochlea (grooved structure) on the
talus bone
The talus (; Latin for ankle or ankle bone; : tali), talus bone, astragalus (), or ankle bone is one of the group of Foot#Structure, foot bones known as the tarsus (skeleton), tarsus. The tarsus forms the lower part of the ankle joint. It transmit ...
, a fully developed
humeral trochlea, and an unusually high number of trunk vertebrae. The new taxon has at least 19 rib-bearing (thoracic) and 11 non-rib-bearing (lumbar) vertebrae. Aside from these derived features, the Malagasy mammal has a mosaic pectoral girdle morphology: the procoracoid is lost, the
coracoid
A coracoid is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (marsupials and placentals). In therian mammals (including humans), a coracoid process is present as part of the scapula, but this is n ...
is extremely well developed (into an enlarged process that contributes to half of the
glenoid fossa), the interclavicle is small, and the
sternoclavicular joint
The sternoclavicular joint or sternoclavicular articulation is a Synovial joint, synovial Saddle joint, saddle joint between the sternum#Manubrium, manubrium of the sternum, and the clavicle bone, clavicle, and the first costal cartilage. The joi ...
appears mobile. A ventrally-facing glenoid and the well-developed humeral trochlea suggest a relatively parasagittal posture for the forelimbs. Remarkable features of the hind limb and pelvic girdle include a large
obturator foramen
The obturator foramen is the large, Bilateral symmetry, bilaterally paired opening of the bony pelvis. It is formed by the pubis and ischium. It is mostly closed by the obturator membrane except for a small opening, the obturator canal, through wh ...
similar in size to that of
theria
Theria ( or ; ) is a scientific classification, subclass of mammals amongst the Theriiformes. Theria includes the eutherians (including the Placentalia, placental mammals) and the metatherians (including the marsupials) but excludes the egg-lay ...
ns, a large parafibula, and the presence of an
epipubic bone.
The fully described animal, now named ''
Adalatherium hui'', is a comparatively large sized mammal, compared in size to a large cat. It has more erect limbs than other allotheres.
Taxonomy
Order †Gondwanatheria
[Mikko's Phylogeny Archiv]
[Paleofile.com (net, info) . ] McKenna 1971 Krause & Bonaparte 1993">ondwanatheroidea Krause & Bonaparte 1993*?†''
Allostaffia''
*†''
Adalatherium''
*?†''
Galulatherium''
*Family †
Ferugliotheriidae Bonaparte 1986
** †''
Ferugliotherium windhauseni''
Bonaparte 1986a 'Vucetichia''
Bonaparte 1990; ''Vucetichia gracilis">Vucetichia.html" ;"title="'Vucetichia">'Vucetichia''
Bonaparte 1990; ''Vucetichia gracilis''
Bonaparte 1990]
** †''Trapalcotherium matuastensis''
Rougier et al. 2008
**? †''Magallanodon baikashkenke''
Goin et al. 2020
*Family †Sudamericidae
Scillato-Yané & Pascual 1984 Bonaparte 1986">ondwanatheridae Bonaparte 1986** †''
Greniodon sylvanicum''
Goin et al. 2012
** †''
Vintana sertichi''
Krause et al. 2014
** †''
Dakshina jederi''
Wilson, Das Sarama & Anantharaman 2007
** †''
Gondwanatherium patagonicum''
Bonaparte 1986
** †''
Sudamerica ameghinoi''
Scillato-Yané & Pascual 1984
** †''
Lavanify miolaka''
Krause et al. 1997
** †''
Bharattherium bonapartei''
Prasad et al. 2007
** †''
Patagonia peregrina''
Pascual & Carlini 1987
** †''
Galulatherium''
O'Connor et al. 2019
References
External links
Mesozoic Mammals - Gondwanatheria
{{Taxonbar, from=Q133234
Burdigalian extinctions
Taxa named by Álvaro Mones
Maastrichtian first appearances