Laurasiatheria (; "Laurasian beasts") is a superorder of placental mammals that groups together true insectivores (eulipotyphlans), bats (chiropterans), carnivorans, pangolins (pholidotes), even-toed ungulates (artiodactyls), odd-toed ungulates (perissodactyls), and all their extinct relatives (pan-euungulates). From systematics and phylogenetic perspectives, it is subdivided into order Eulipotyphla and clade Scrotifera. It is a sister group to Euarchontoglires with which it forms the magnorder Boreoeutheria. Laurasiatheria was discovered on the basis of the similar gene sequences shared by the mammals belonging to it; no anatomical 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 presence/absence data. The superorder originated on the northern supercontinent of Laurasia, after it split from Gondwana when Pangaea broke up. Its most recent common ancestor is supposed to have lived between ca. 76 to 90 million years ago.
Etymology The name of this superorder derives from its origin on the supercontinent of Laurasia. In contrast, extinct primitive mammals called Gondwanatheria existed in the supercontinent of Gondwana.
Classification and phylogeny History of phylogeny
Uncertainty still exists regarding the phylogenetic tree for extant laurasiatherians, primarily due to disagreement about the placement of orders Chiroptera (bats) and Perissodactyla. Based on morphological grounds, bats had long been classified in the superorder Archonta (e.g. along with primates, treeshrews and the gliding colugos) 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, pangolins, carnivorans and euungulates form a clade Scrotifera, indicating that Eulipotyphla might be the sister group to all other Laurasiatheria taxa.
Taxonomy Former classification: Current classification: Superorder: Laurasiatheria (laurasian placental mammals) Grandorder: Ferungulata Mirorder: Euungulata (true ungulates) Mirorder: Ferae Clade: Insectiphillia Order: Chiroptera (bats) Order: Eulipotyphla (true insectivores) Superorder: Laurasiatheria (laurasian placental mammals) Order: Eulipotyphla (true insectivores) Clade: Scrotifera Grandorder: Ferungulata Clade: Apo-Chiroptera (bats) Family: †Eosoricodontidae Genus: †Acmeodon Genus: †Avunculus Genus: †Gelastops Incertae sedis: †"Wyonycteris" microtis
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
See also Mammal classification Boreoeutheria Gondwanatheria – a clade of mammaliaforms named after supercontinent of Gondwana
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