Euharamiyida

Euharamiyida also known as Eleutherodontida, is clade of early mammals or mammal-like cynodonts from the Middle Jurassic to Early Cretaceous of Eurasia and possibly North America. The group is sometimes considered a sister group to Multituberculata,^[1] or part of an earlier divergence within the synapsid line.^[2][3] It is disputed whether or not they are related to the Haramiyids from the Late Triassic, such as Haramiyavia.^[4] The morphology of their teeth indicates that they were herbivorous or omnivorous. Some members of the group are known to be arboreal, including gliding forms similar to modern flying squirrels or colugos.^[1][5]

Euharamiyida Temporal range: Middle Jurassic–Early Cretaceous PreꞒ Ꞓ O S D C P T J K Pg N
Life restoration of Shenshou
Skull of Xianshou
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Clade:	Therapsida
Clade:	Cynodontia
Clade:	Mammaliaformes
Order:	†Haramiyida
Clade:	†Euharamiyida Bi et al. 2014

Evolution

The position of euharamyidans is contested. They are either considered crown group mammals as members of Allotheria, related to multituberculates, or they are considered to stem-group mammals within the Mammaliaformes.^[1][3] The position is often dependent on the relationships of euharamiyids to the Late Triassic haramiyids such as Haramiyavia and Thomasia. In some studies, the two groups are recovered as unrelated.^[6][4]

Phylogeny

Huttenlocker et al. 2018[7]	Mao et al. 2022[8]
Euharamiyida (=Eleutherodontida) Megaconus Cifelliodon Hahnodon Gondwanatheria Vintana Eleutherodontidae Maiopatagium Shenshou Millsodon Eleutherodon Sineleutherus Xianshou Arboroharamiya Vilevolodon	Euharamiyida Maiopatagium furculiferum Maiopatagium sibiricum Cryoharamiya Sharypovia Shenshouidae Qishou Shenshou Allostaffia Sineleutherus Butlerodon Woodeatonia Kermackodontidae Kermackodon Arboroharamiyidae Xianshou Arboroharamiya allinhopsoni Arboroharamiya jenkinsi Vilevolodon

Taxa

The following taxonomy follows Mao et al. (2022)^[8] unless otherwise cited.

• Cryoharamiya
• Maiopatagium
• Millosodon^[7]
• Sharypovoia
• Sineleutherus
• Woodeatonia
•  ?Allostaffia
•  ?Hahnodontidae Sigogneau-Russell, 1991^[7]
•  ?Megaconus^[7]
•  ?Gondwanatheria^[7][9]
• Arboroharamiyidae Zheng et al., 2013
  • Arboroharamiya
  • Vilevolodon
  • Xianshou
• Kermackodontidae Butler and Hooker, 2005 (="Eleutherodontidae" Kermack et al., 1998) (considered by other studies to be multituberculates)
  • Kermackodon
  • Butlerodon
• Shenshouidae Mao and Meng, 2019
  • Qishou
  • Shenshou

References

1. Bi, Shundong; Wang, Yuanqing; Sheng, Xia; Meng, Jin (10 September 2014). "Three new Jurassic euharamiyidan species reinforce early divergence of mammals". Nature. 514 (7524). Nature Publishing Group: 579–584. Bibcode:2014Natur.514..579B. doi:10.1038/nature13718. PMID 25209669. S2CID 4471574.
2. Chang, Kenneth (16 November 2015). "Jawbone in Rock May Clear Up a Mammal Family Mystery". The New York Times. Retrieved 17 November 2015.
3. Luo, Zhe-Xi; Gates, Stephen M.; Jenkins Jr., Farish A.; Amaral, William W.; Shubin, Neil H. (16 November 2015). "Mandibular and dental characteristics of Late Triassic mammaliaform Haramiyavia and their ramifications for basal mammal evolution". PNAS. 112 (51): E7101–E7109. Bibcode:2015PNAS..112E7101L. doi:10.1073/pnas.1519387112. PMC 4697399. PMID 26630008.
4. 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. doi:10.1080/02724634.2020.1801706. ISSN 0272-4634. S2CID 230968231.
5. Han, Gang; Mao, Fangyuan; Bi, Shundong; Wang, Yuanqing; Meng, Jin (November 2017). "A Jurassic gliding euharamiyidan mammal with an ear of five auditory bones". Nature. 551 (7681): 451–456. Bibcode:2017Natur.551..451H. doi:10.1038/nature24483. ISSN 0028-0836. PMID 29132143. S2CID 4466953.
6. X.-Z. Luo, Q.-J. Meng, D. M. Grossnickle, D. Lui, A. I. Neander, Y.-G. Zhang, and Q. Ji. 2017. New evidence for mammaliaform ear evolution and feeding adaptation in a Jurassic ecosystem. Nature 548:326-329.
7. Huttenlocker, Adam K.; Grossnickle, David M.; Kirkland, James I.; Schultz, Julia A.; Luo, Zhe-Xi (2018). "Late-surviving stem mammal links the lowermost Cretaceous of North America and Gondwana". Nature. 558 (7708): 108–112. Bibcode:2018Natur.558..108H. doi:10.1038/s41586-018-0126-y. PMID 29795343. S2CID 43921185.
8. Mao, Fangyuan; Brewer, Philippa; Hooker, Jerry J.; Meng, Jin (2022). "New allotherian specimens from the Middle Jurassic Woodeaton Quarry (Oxfordshire) and implications for haramiyidan diversity and phylogeny". Journal of Systematic Palaeontology. 20: 1–37. doi:10.1080/14772019.2022.2097021. S2CID 251708147.
9. King, Benedict; Beck, Robin M. D. (2020). "Tip dating supports novel resolutions of controversial relationships among early mammals". Proceedings of the Royal Society B: Biological Sciences. 287 (1928). doi:10.1098/rspb.2020.0943. PMC 7341916. PMID 32517606.