Laurasiatheria

Laurasiatheria
Temporal range: Paleocene–Recent
From top to right: European hedgehog, Lyle's flying fox, Siberian tiger, Indian pangolin, red deer and white rhino. Representing the living orders: Eulipotyphla, Chiroptera, Carnivora, Pholidota, Artiodactyla and Perissodactyla, comprising Laurasiatheria.
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Magnorder: Boreoeutheria
Superorder: Laurasiatheria
Waddell et al., 1999[1]
Subgroups
Synonyms
  • Hoplopoda (Goldfuss, 1820)
  • Laurasiaplacentalia (Arnason, 2008)[2]

Laurasiatheria (/lɔːrˌʒəˈθɪəriə, -θɛriə/; "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. From systematics and phylogenetic perspectives, it is subdivided into order Eulipotyphla and clade Scrotifera.[1][3][4] 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) and allantoic vessels that are large to moderate in size.[5] 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.[1] Its last common ancestor is supposed to have lived between ca. 76 to 90 million years ago.[6][7]

Etymology[edit]

The name of this superorder derives from the theory that this group of mammals originated on the supercontinent of Laurasia.[1] In contrast, extinct primitive mammals called Gondwanatheria existed in the supercontinent of Gondwana.

Classification and phylogeny[edit]

History of phylogeny[edit]

Phylogenetic position of laurasiatherians (in green) among placentals in a genus-level molecular phylogeny of 116 extant mammals inferred from the gene tree information of 14,509 coding DNA sequences.[8] The other major clades are colored: marsupials (magenta), xenarthrans (orange), afrotherians (red), and euarchontoglires (blue).

Uncertainty still exists regarding the phylogenetic tree for extant laurasiatherians, primarily due to disagreement about the placement of orders Chiroptera and Perissodactyla. Based on morphological grounds, bats (order Chiroptera) 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.[9] 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, carnivorans and euungulates form a clade Scrotifera, indicating that Eulipotyphla might be the sister group to all other Laurasiatheria taxa.[10][11]

Laurasiatheria is also posited to include several extinct orders and superorders. At least some of these are considered wastebasket taxa, historically lumping together several lineages based on superficial attributes and assumed relations to modern mammals. In some cases, these orders have turned out to either be paraphyletic assemblages, or to be composed of mammals now understood not to be laurasiatheres at all.

Taxonomy[edit]

  • Superorder: Laurasiatheria (Waddell, 1999)

See also[edit]

References[edit]

  1. ^ a b c d Waddell, Peter J.; Okada, Norihiro; Hasegawa, Masami (1999). "Towards Resolving the Interordinal Relationships of Placental Mammals". Systematic Biology. 48 (1): 1–5. doi:10.1093/sysbio/48.1.1. PMID 12078634.
  2. ^ Arnason U., Adegoke J. A., Gullberg A., Harley E. H., Janke A., Kullberg M. (2008.) "Mitogenomic relationships of placental mammals and molecular estimates of their divergences." Gene.; 421(1–2):37–51
  3. ^ Nikaido, M.; Rooney, A. P. & Okada, N. (1999). "Phylogenetic relationships among cetartiodactyls based on insertions of short and long interpersed elements: Hippopotamuses are the closest extant relatives of whales". Proceedings of the National Academy of Sciences. 96 (18): 10261–10266. Bibcode:1999PNAS...9610261N. doi:10.1073/pnas.96.18.10261. PMC 17876. PMID 10468596.
  4. ^ Groves, Colin; Grubb, Peter (1 November 2011). Ungulate Taxonomy. JHU Press. p. 27. ISBN 978-1-4214-0093-8. OCLC 708357723.
  5. ^ O'Leary, Maureen A.; Bloch, Jonathan I.; Flynn, John J.; Gaudin, Timothy J.; Giallombardo, Andres; Giannini, Norberto P.; Goldberg, Suzann L.; Kraatz, Brian P.; Luo, Zhe-Xi; Meng, Jin; Ni, Xijun; Novacek, Michael J.; Perini, Fernando A.; Randall, Zachary S.; Rougier, Guillermo W.; Sargis, Eric J.; Silcox, Mary T.; Simmons, Nancy B.; Spaulding, Michelle; Velazco, Paúl M.; Weksler, Marcelo; Wible, John R.; Cirranello, Andrea L. (2013). "The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals". Science. 339 (6120): 662–667. Bibcode:2013Sci...339..662O. doi:10.1126/science.1229237. hdl:11336/7302. PMID 23393258. S2CID 206544776.
  6. ^ dos Reis, Mario; Inoue, Jun; Hasegawa, Masami; Asher, Robert J.; Donoghue, Philip C. J.; Yang, Ziheng (7 September 2012). "Phylogenomic datasets provide both precision and accuracy in estimating the timescale of placental mammal phylogeny". Proceedings of the Royal Society B: Biological Sciences. 279 (1742): 3491–3500. doi:10.1098/rspb.2012.0683. ISSN 0962-8452. PMC 3396900. PMID 22628470.
  7. ^ Zhou, Xuming; Xu, Shixia; Xu, Junxiao; Chen, Bingyao; Zhou, Kaiya; Yang, Guang (1 January 2012). "Phylogenomic Analysis Resolves the Interordinal Relationships and Rapid Diversification of the Laurasiatherian Mammals". Systematic Biology. 61 (1): 150–64. doi:10.1093/sysbio/syr089. ISSN 1063-5157. PMC 3243735. PMID 21900649.
  8. ^ Scornavacca C, Belkhir K, Lopez J, Dernat R, Delsuc F, Douzery EJ, Ranwez V (April 2019). "OrthoMaM v10: Scaling-up orthologous coding sequence and exon alignments with more than one hundred mammalian genomes". Molecular Biology and Evolution. 36 (4): 861–862. doi:10.1093/molbev/msz015. PMC 6445298. PMID 30698751.
  9. ^ Pumo, Dorothy E.; Finamore, Peter S.; Franek, William R.; Phillips, Carleton J.; Tarzami, Sima; Balzarano, Darlene (1998). "Complete Mitochondrial Genome of a Neotropical Fruit Bat, Artibeus jamaicensis, and a New Hypothesis of the Relationships of Bats to Other Eutherian Mammals". Journal of Molecular Evolution. 47 (6): 709–717. Bibcode:1998JMolE..47..709P. doi:10.1007/PL00006430. PMID 9847413. S2CID 22900642.
  10. ^ Tsagkogeorga, G; Parker, J; Stupka, E.; Cotton, J. A.; Rossiter, S. J. (2013). "Phylogenomic analyses elucidate the evolutionary relationships of bats". Current Biology. 23 (22): 2262–2267. doi:10.1016/j.cub.2013.09.014. PMID 24184098.
  11. ^ Morgan, C. C.; Foster, P. G.; Webb, A. E.; Pisani, D.; McInerney, J. O.; O'Connell, M. J. (2013). "Heterogeneous models place the root of the placental mammal phylogeny". Molecular Biology and Evolution. 30 (9): 2145–2256. doi:10.1093/molbev/mst117. PMC 3748356. PMID 23813979.
  12. ^ Burger, Benjamin J., (2015.) "The systematic position of the saber-toothed and horned giants of the Eocene: the Uintatheres (order Dinocerata)", Utah State University Uintah Basin Campus, Vernal, Utah
  13. ^ Avilla, Leonardo S.; Mothé, Dimila (2021). "Out of Africa: A New Afrotheria Lineage Rises From Extinct South American Mammals". Frontiers in Ecology and Evolution. 9. doi:10.3389/fevo.2021.654302. ISSN 2296-701X.

Further reading[edit]

External links[edit]