Laurasiatheria (; "Laurasian beasts") is a

superorder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

of placental mammals that groups together true insectivores (

eulipotyphla Eulipotyphla (, from '' eu-'' + '' Lipotyphla'', meaning truly lacking blind gut; sometimes called true insectivores) is an order of mammals comprising the Erinaceidae ( hedgehogs and gymnures); Solenodontidae (solenodons); Talpidae ( mole ...

ns), bats (

chiroptera Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

ns),

carnivora Carnivora ( ) is an order of 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 least 279 species. Carnivor ...

ns, pangolins ( pholidotes), even-toed ungulates ( artiodactyls), odd-toed ungulates ( perissodactyls), and all their extinct relatives ( pan-euungulates). From

systematics Systematics is the study of the diversification of living forms, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees (synonyms: phylogenetic trees, phylogenies). Phy ...

and

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

perspectives, it is subdivided into order

Eulipotyphla Eulipotyphla (, from '' eu-'' + '' Lipotyphla'', meaning truly lacking blind gut; sometimes called true insectivores) is an order of mammals comprising the Erinaceidae ( hedgehogs and gymnures); Solenodontidae (solenodons); Talpidae ( mole ...

and clade Scrotifera. It is a sister group to Euarchontoglires with which it forms the magnorder

Boreoeutheria Boreoeutheria (, "northern eutherians") is a magnorder of Placentalia, placental mammals that groups together superorders Euarchontoglires and Laurasiatheria. The clade includes groups as diverse as giraffes, Sus (genus), pigs, zebras, Rhinoceros ...

. Laurasiatheria was discovered on the basis of the similar gene sequences shared by the mammals belonging to it; no

anatomical Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

features have yet been found that unite the group, although a few have been suggested such as a small coracoid process, a simplified hindgut (reversed in artiodactyls), high intelligence, lack of grasping hands (though mimicry of grasping is observed in felines) and allantoic vessels that are large to moderate in size. The Laurasiatheria clade is based on DNA sequence analyses and

retrotransposon Retrotransposons (also called Class I transposable elements) are mobile elements which move in the host genome by converting their transcribed RNA into DNA through reverse transcription. Thus, they differ from Class II transposable elements, or ...

presence/absence data. The superorder originated on the northern

supercontinent In geology, a supercontinent is the assembly of most or all of Earth's continent, continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", ...

Laurasia Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pa ...

, after it split from

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 ...

when

Pangaea Pangaea or Pangea ( ) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous period approximately 335 mi ...

broke up. Its

last common ancestor A most recent common ancestor (MRCA), also known as a last common ancestor (LCA), is the most recent individual from which all organisms of a set are inferred to have descended. The most recent common ancestor of a higher taxon is generally assu ...

is supposed to have lived between ca. 76 to 90 million years ago.

Etymology

The name of this superorder derives from the theory that this group of mammals originated on the supercontinent of

. In contrast, extinct primitive mammals called

Gondwanatheria 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 Miocene (and possibly much earlier, if '' Allostaffia' ...

existed in the supercontinent of

Classification and phylogeny

History of phylogeny

OrthoMaM v10b 2019 116genera circular tree

Uncertainty still exists regarding the

phylogenetic tree A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA. In ...

for extant laurasiatherians, primarily due to disagreement about the placement of orders

Chiroptera Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

(bats) and

Perissodactyla Perissodactyla (, ), or odd-toed ungulates, is an order of ungulates. The order includes about 17 living species divided into three families: Equidae (horses, asses, and zebras), Rhinocerotidae (rhinoceroses), and Tapiridae (tapirs). They t ...

. Based on morphological grounds, bats had long been classified in the superorder

Archonta The Archonta are a now-abandoned group of mammals, considered a superorder in some classifications, which consists of these orders: *Primates *Plesiadapiformes (extinct primate-like archontans) * Scandentia (treeshrews) * Dermoptera (colugos) W ...

(e.g. along with

primate Primates is an order (biology), order of mammals, which is further divided into the Strepsirrhini, strepsirrhines, which include lemurs, galagos, and Lorisidae, lorisids; and the Haplorhini, haplorhines, which include Tarsiiformes, tarsiers a ...

s, treeshrews and the gliding

colugo Colugos (), flying lemurs, or cobegos (), are arboreal gliding euarchontogliran mammals that are native to Southeast Asia. Their closest evolutionary relatives are primates. There are just two living species of colugos: the Sunda flying lemur ...

s) until genetic research instead showed their kinship with the other laurasiatheres. The studies conflicted in terms of the exact placement of Chiroptera, however, with it being linked most closely to groups such as order Eulipotyphla in the clade Insectiphillia. Two 2013 studies retrieve that bats,

pangolin Pangolins, sometimes known as scaly anteaters, are mammals of the order Pholidota (). The one extant family, the Manidae, has three genera: '' Manis'', '' Phataginus'', and '' Smutsia''. ''Manis'' comprises four species found in Asia, while ' ...

ns and euungulates form a clade Scrotifera, indicating that Eulipotyphla might be the sister group to all other Laurasiatheria taxa.

Taxonomy

Phylogeny

The phylogenetic relationships of superorder Laurasiatheria are shown in the following cladogram, reconstructed from mitochondrial and nuclear DNA and protein characters, as well as the fossil record.Frank Zachos (2020.
"Mammalian Phylogenetics: A Short Overview of Recent Advances"
In book: "Mammals of Europe - Past, Present, and Future" (pp.31-48)Xue Lv, Jingyang Hu, Yiwen Hu, Yitian Li, Dongming Xu, Oliver A. Ryder, David M. Irwin, Li Yu (2021.
"Diverse phylogenomic datasets uncover a concordant scenario of laurasiatherian interordinal relationships"
Molecular Phylogenetics and Evolution, Volume 157

References

External links

* {{Taxonbar, from=Q27379 Mammal taxonomy Mammal superorders Extant Paleocene first appearances