Theriimorpha

Theriimorpha Temporal range: Toarcian–Present PreꞒ Ꞓ O S D C P T J K Pg N
Skeleton of Gobiconodon ostromi (Eutriconodonta)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Clade:	Theriimorpha Rowe, 1993
Subgroups
†Eutriconodonta †Fruitafossor? Theriiformes Trechnotheria

Theriimorpha is a clade of mammals defined as including all mammals more closely related to therians (including placentals and marsupials) than to monotremes. Eutriconodonta is usually considered among the most basal members of this group, with other members more closely related to therians like Allotherians placed in the subclade Theriiformes,^[1] though Eutriconodonta has also been recovered as less closely related to therians than monotremes are in some analyses, placing them outside the crown group of Mammalia.^[2][3] The unusual Late Jurassic digging mammal Fruitafossor has also been suggested to be a basal theriimorph in some studies.^[4] The position of Allotheria (which contains the multituberculates, among others) within Theriimorpha is controversial. While many studies recover Allotheria within crown Mammalia as more closely related to therians than to monotreme as a member of the clade Theriiformes, some studies recover the group as outside of crown Mammalia.^[5]

References

1. Rowe T (1993). "Phylogenetic Systematics and the Early History of Mammals". In Szalay FS, Novacek MJ, McKenna MC (eds.). Mammal Phylogeny. New York, NY: Springer New York. pp. 129–145. doi:10.1007/978-1-4613-9249-1_10. ISBN 978-1-4613-9251-4.
2. Luo, Zhe-Xi; Gatesy, Stephen M.; Jenkins, Farish A.; Amaral, William W.; Shubin, Neil H. (2015-12-22). "Mandibular and dental characteristics of Late Triassic mammaliaform Haramiyavia and their ramifications for basal mammal evolution". Proceedings of the National Academy of Sciences. 112 (51): E7101-9. Bibcode:2015PNAS..112E7101L. doi:10.1073/pnas.1519387112. ISSN 0027-8424. PMC 4697399. PMID 26630008.
3. Hoffmann, Simone; Beck, Robin M. D.; Wible, John R.; Rougier, Guillermo W.; Krause, David W. (2020-12-14). "Phylogenetic placement of Adalatherium hui (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar: implications for allotherian relationships". Journal of Vertebrate Paleontology. 40 (sup1): 213–234. Bibcode:2020JVPal..40S.213H. doi:10.1080/02724634.2020.1801706. ISSN 0272-4634. S2CID 230968231.
4. Hughes EM, Wible JR, Spaulding M, Luo ZX (May 2015). "Mammalian petrosal from the Upper Jurassic Morrison Formation of Fruita, Colorado". Annals of Carnegie Museum. 83 (1): 1–17. doi:10.2992/007.083.0101. S2CID 83598504.
5. Mao, Fangyuan; Li, Zhiyu; Wang, Zhili; Zhang, Chi; Rich, Thomas; Vickers-Rich, Patricia; Meng, Jin (2024-04-03). "Jurassic shuotheriids show earliest dental diversification of mammaliaforms". Nature. 628 (8008): 569–575. Bibcode:2024Natur.628..569M. doi:10.1038/s41586-024-07258-7. ISSN 0028-0836. PMID 38570681.