Euharamiyida also known as Eleutherodontida, is clade of early or mammal-like from the Middle Jurassic to Early Cretaceous of Eurasia and possibly North America. The group is sometimes considered a sister group to Multituberculata, or part of an earlier divergence within the synapsid line. It is disputed whether or not they are related to the Haramiyida from the Late Triassic, such as Haramiyavia. 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 squirrel or Colugo.
Evolution
The position of euharamiyidans is contested. They are either considered crown group mammals as members of
Allotheria, related to multituberculates, or stem-group mammals within
Mammaliaformes.
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.
[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.]
Phylogeny
Taxa
The following taxonomy follows Mao et al. (2022)
unless otherwise cited.