Misplaced Pages

Trechnotheria Temporal range: Middle Jurassic–Recent PreꞒ Ꞓ O S D C P T J K Pg N
Fossil of Zhangheotherium, a symmetrodont
Red fox, a modern-day trechnotherian
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Clade:	Theriiformes
Clade:	Trechnotheria McKenna, 1975
Subgroups
†Tinodontidae* †Spalacotheriida* †Spalacotheriidae †Zhangheotheriidae* Cladotheria

Trechnotheria is a group of mammals that includes the therians and some fossil mammals from the Mesozoic Era. It includes both the extinct symmetrodonts and the living Cladotheria.

Trechnotheria has been assigned various ranks, but was originally described as a "superlegion" by the naming authority. A later node-based definition for Trechnotheria was the clade comprising the last common ancestor of Zhangheotherium and living therian mammals, and all its descendants. Alternatively it can be defined as the group with true symmetrodontia, being defined as an apomorphy rather than being defined as a node, the redefinition includes the Tinodontids.

Characteristics

Like most Mesozoic mammal groups, early trechnotherians are known mainly from their teeth. Hence, one of the most prominent features of this group is the "hypertrophied postvallum/prevallid shearing mechanism", along with other dental characters. Features of the shoulder blade, tibia, humerus, and ankle joint also diagnose this clade.

Phylogeny

A cladogram based on Luo, Cifelli & Kielan-Jaworowska, 2001, Luo, Kielan-Jaworowska & Cifelli, 2002 and, Kielan-Jaworowska, Cifelli & Luo, 2004.

• Unassigned Trechnotheria:
  • †Austrotriconodon mckennai Bonaparte 1986 {Austrotriconodontidae Bonaparte 1990}
  • †Chaoyangodens lii Hou & Meng 2014
• Paraphyletic Symmetrodonta Simpson 1925
  • †Atlasodon monbaroni Sigogneau-Russell 1991
  • †Kennetheredium leesi Sigogneau-Russell 2003a
  • †Kotatherium haldanei Datta 1981
  • †Trishulotherium kotaensis Yadagiri 1985
• Unassigned Cladotheria:
  • †Afriquiamus nesovi Sigogneau-Russell 1999
  • †Butlerigale Kühne 1968
  • †Chunnelodon alopekodes Ensom & Sigogneau-Russell 1998
  • †Guimarota freyi Kuhne 1968
• Unassigned Zatheria:
  • †Arguimus khoshajari Dashzeveg 1979 {Arguimuridae Dashzeveg 1994 }
  • †Minimus richardfoxi Sigogneau-Russell 1999
  • †Magnimus ensomi Sigogneau-Russell 1999
  • †Mozomus shikamai Li et al. 2005 {Mozomuridae Li et al. 2005}
  • †Nanolestes Martin 2002
    • †N. drescherae Martin 2002
    • †N. krusati Martin 2002
    • †N. mackennai Martin, Averianov & Pfretzschner 2010
• Unassigned Boreosphenida:
  • †Argaliatherium robustum Cifelli & Davis 2015
  • †Carinalestes murensis Cifelli & Davis 2015
  • †Hypomylos Sigogneau-Russell 1992
    • †H. phelizoni Sigogneau-Russell 1992
    • †H. micros Sigogneau-Russell 1994
  • †Picopsidae Fox 1980
    • †Picopsis pattersoni Fox 1980
    • †Tirotherium aptum Montellano-Ballesteros & Fox 2015

Alternatively, the zanjeotherids would be ancestral to both the spalacotherids and the cladotherians (driolestoids and prototribosphenids), with the tinodontids equally paraphyletic. The group that contains the Spalacotheriidae and Cladotheria is called Alethinotheria (sensu Alexander O Averianov. 2013), which was initially proposed to highlight the closeness between the spalacotherids and the meridiolestids.

Sources

1. ^ Luo, Z.−X.; Kielan−Jaworowska, Z.; Cifelli, R.L (2002). "In quest for a phylogeny of Mesozoic mammals" (PDF). Acta Palaeontologica Polonica. 47 (1): 1–78.
2. McKenna, Malcolm C.; Bell, Susan K. (1997). Classification of Mammals: Above the Species Level. Columbia University Press. p. 43. ISBN 978-0-231-52853-5.
3. Kielan-Jaworowska, Zofia; Cifelli, Richard; Luo Zhe-Xi (5 February 2005). Mammals from the age of dinosaurs: origins, evolution, and structure. Columbia University Press. p. 366. ISBN 978-0-231-11918-4.
4. ^ Lasseron, Maxime; Martin, Thomas; Allain, Ronan; Haddoumi, Hamid; Jalil, Nour-Eddine; Zouhri, Samir; Gheerbrant, Emmanuel (2022-06-02). "An African Radiation of 'Dryolestoidea' (Donodontidae, Cladotheria) and its Significance for Mammalian Evolution". Journal of Mammalian Evolution. 29 (4): 733–761. doi:10.1007/s10914-022-09613-9. ISSN 1064-7554. S2CID 249324444.
5. Haaramo, Mikko. "Holotheria – holotheres". Mikko's Phylogeny Archive.
6. Averianov, Alexander O.; Martin, Thomas; Lopatin, Alexey V. (April 2013). "A new phylogeny for basal Trechnotheria and Cladotheria and affinities of South American endemic Late Cretaceous mammals". Die Naturwissenschaften. 100 (4): 311–326. Bibcode:2013NW....100..311A. doi:10.1007/s00114-013-1028-3. ISSN 1432-1904. PMID 23494201. Retrieved 2024-07-14.

See also

• Allotheria
• Cladotheria

v t e Mammalia
Kingdom: Animalia Phylum: Chordata Clade: Synapsida Clade: Therapsida Clade: Cynodontia Clade: Mammaliaformes Synapsida see Synapsida Cynodontia see Cynodontia Mammalia see below↓
Mammalia Australosphenida? †Ambondro †Tendagurutherium? Monotremata? †Henosferidae Asfaltomylos Henosferus †Ausktribosphenidae Ausktribosphenos Bishops? Kryoparvus? Monotremata †Kollikodontidae? Kollikodon Kryoryctes? Sundrius †Steropodontidae Parvopalus? Steropodon †Teinolophidae Stirtodon? Teinolophos Ornithorhynchoidea †Opalios Ornithorhynchidae †Dharragarra? †Monotrematum? †Obdurodon Ornithorhynchus †Patagorhynchus? Tachyglossidae †Megalibgwilia †Murrayglossus Tachyglossus Zaglossus †Allotheria? see Allotheria includes multituberculates Theriimorpha see below↓
Theriimorpha Theriimorpha †Acinacodus †Amphidon †Amphilestes †Aploconodon †Chaoyangodens †Comodon †Condorodon †Dyskritodon? †Fruitafossor? †Hakusanodon †Indotriconodon †Juchilestes †Jueconodon †Kemchugia †Kryptotherium †Liaoconodon †Liaotherium †Manchurodon †Nakunodon †Phascolotherium †Sangarotherium †Tendagurodon †Allotheria? Monotremata? †Gobiconodontidae Fuxinoconodon Gobiconodon Hangjinia Huasteconodon? Meemannodon Repenomamus Spinolestes †Jeholodentidae Jeholodens Yanoconodon †Klameliidae? Ferganodon Klamelia †Triconodontidae Alticonodon Arundelconodon Astroconodon Corviconodon Eotriconodon Jugulator Meiconodon Priacodon Triconodon Trioracodon Victoriaconodon Volaticotheria? †Volaticotheria Argentoconodon Ichthyoconodon Triconolestes? Volaticotherium †Tinodontidae Gobiotheriodon? Tinodon Trishulotherium Yermakia Trechnotheria Monotremata? †Zhangheotheriidae Anebodon Kiyatherium Maotherium Ningchengodon Origolestes Zhangheotherium †Spalacotheriidae Akidolestes Aliaga Cifellitherium Heishanlestes Infernolestes Lactodens Shalbaatar Spalacolestes Spalacotheridium Spalacotherium Spalacotheroides Symmetrodontoides Symmetrolestes Yaverlestes Cladotheria see below↓
Cladotheria †Dryolestida Brancatherulum? Dorsetodon Drescheratherium Euthlastus Henkelotherium Paurodon Tathiodon Dryolestidae Achyrodon Amblotherium Anthracolestes Beckumia Crusafontia Dryolestes Groebertherium? Guimarotodus Hercynodon Krebsotherium Lakotalestes? Laolestes Minutolestes Phascolestes Portopinheirodon Treslagosodon †Meridiolestida Amarillodon Austrotriconodon Bondesius Casamiquelia Cronopio Groebertherium? Lakotalestes? Leonardus Necrolestes Paraungulatum Quirogatherium Solanutherium Mesungulatoidea Coloniatherium Mesungulatum Orretherium Peligrotherium Reigitherium †Donodontidae Amazighodon Anoualestes Donodon Stylodens Prototribosphenida †Abelodon †Amphibetulimus †Amphitherium †Arguimus †Brancatherulum? †Chunnelodon †Magnimus †Minimus †Mozomus †Nanolestes †Palaeoxonodon †Vincelestes Monotremata? †Peramuridae Afriquiamus? Kouriogenys Peramuroides Peramus Tendagurutherium? Tribosphenida / Boreosphenida †Aegialodon †Argaliatherium †Brasilestes †Carinalestes †Eomaia †Holoclemensia †Hypomylos †Juramaia †Kermackia †Kielantherium †Pappotherium †Picopsis †Tirotherium †Tribactonodon Theria †Patagomaia Eutheria see Eutheria includes placentals Metatheria see Metatheria includes marsupials
Other taxa Incertae sedis †Atlasodon †Chronoperates †Microderson †Thereuodon †Tingamarra Saint Bathans Mammal UA 8699 Other taxa Prototheria Yinotheria Eutriconodonta Amphilestidae Theriiformes Pantotheria Symmetrodonta Eupantotheria Paurodontidae Amphitheriidae Marsupionta

This article about a mammal is a stub. You can help Misplaced Pages by expanding it.

• v
• t
• e

• Trechnotheria
• Extant Middle Jurassic first appearances
• Taxa described in 1975
• Mammal stubs