Sangarotherium

Sangarotherium Temporal range: Early Cretaceous (Berriasian? – Barremian) PreꞒ Ꞓ O S D C P T J K Pg N
Holotype jaw fragment with a close-up view of the tooth crown
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Eutriconodonta
Genus:	†Sangarotherium Averianov et al., 2018
Type species
†Sangarotherium aquilonium Averianov et al., 2018

Sangarotherium is an extinct genus of eutriconodont mammal from the Early Cretaceous of Russia. It contains a single species, Sangarotherium aquilonium, known from a lower jaw fragment with one fully erupted tooth and fragments of two other teeth. This fossil was discovered at Teete, a microvertebrate site from the Batylykh Formation of the Sangar Series, in the Siberian Republic of Yakutia.^[1]

Like most other eutriconodonts, the complete molariform tooth has five pointed cusps aligned in a straight line (from front to back, cusps e, b, a, c, and d). The largest cusps (in order) are a, b, and c, while cusps e and d are very small. These cusp proportions differ from known eutriconodont families, so Sangarotherium is classified as Eutriconodonta incertae sedis. Sangarotherium also bears an extensive Meckel's groove, and it is the only eutriconodont with a prominent rugose coronoid facet.^[1] Bajpai et al 2024 recovers it as closely related to Volaticotherini.^[2]

During the Early Cretaceous, the Teete site may have been located at up to 70° North, above the Arctic Circle. This would make Sangarotherium the most northerly known mammal of the Early Cretaceous. Despite its arctic latitude, the Teete site would have had a temperate climate according to the presence of lizards, salamanders, and turtles, though the latter are exceptionally rare. Docodontan and haramiyidan mammaliaform fossils have also been reported, as well as dinosaur teeth.^[1]

References

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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 Steropodon Parvopalus? †Teinolophidae Stirtodon? Teinolophos Ornithorhynchoidea †Opalionidae 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 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 Lakotalestes? Paraungulatum Quirogatherium Cronopioidea Cronopio Leonardus Necrolestes Mesungulatoidea Coloniatherium Mesungulatum Orretherium Peligrotherium Reigitherium †Donodontidae Amazighodon Anoualestes Donodon Stylodens Prototribosphenida †Abelodon †Arguimus †Brancatherulum? †Chunnelodon †Magnimus †Minimus †Mozomus †Nanolestes †Vincelestes †Amphitheriidae Amphibetulimus Amphitherium Palaeoxonodon Zatheria †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 Saint Bathans Mammal UA 8699 Other groups Prototheria Yinotheria Eutriconodonta Amphilestidae Theriiformes Pantotheria Symmetrodonta Paurodontidae