Xystodesmoidea

Yellow flat-backed millipede Cherokia georgiana, copyright Sheryl Pollock.

Belongs within: Polydesmida.

The Xystodesmoidea are a group of millipedes with usually prominent paraterga and bodies incapable of rolling into a ball.

Characters (from Enghoff et al. 2015): Length ca. 8 to more than 80 mm, exceptionally smaller. Body not capable of volvation, broad and robust, width/length ratio usually <18%, usually parallel-sided on rings 3–16. Antennae rarely with more than four apical cones, not arranged in dyads. Paraterga mostly prominent, lateral calluses normally evident; metaterga usually without setae. Gonopod coxa with cannula; telopodite with neither acccssory seminal chamber nor hairy pulvillus.

<==Xystodesmoidea H90
    |--Eurymerodesmidae H90
    |    |--Eurymerodesmus H90
    |    `--Paresmus H90
    `--Xystodesmidae [Eurydesmidae, Fontariidae] H90
         |  i. s.: Xystocheir H90
         |         Amplocheir H90
         |         Paimokia H90
         |         Anombrocheir H90
         |         Wamokia H90
         |         Motyxia H90
         |         Harpaphe H90
         |         Hybaphe H90
         |         Isaphe H90
         |         Tubaphe H90
         |         Chonaphe H90
         |         Montaphe H90
         |         Metaxycheir H90
         |         Orophe H90
         |         Stenodesmus H90
         |         Gyalostethus H90
         |         Caralinda H90
         |         Pachydesmus H90
         |         Dicellarius H90
         |         Nannaria H90
         |         Oenomoea H90
         |         Apheloria H90
         |         Rudiloria H90
         |         Dixioria H90
         |         Sigmoria aberrans H90, I92
         |         Cleptoria H90
         |         Brachoria H90
         |         Dynoria H90
         |         Lyrranea H90
         |         Deltotaria H90
         |         Stelgipus H90
         |         Cheiropus H90
         |         Croatania H90
         |         Semionellus H90
         `--Rhysodesmini H62
              |--Rhysodesmus Cook 1895 H62
              |    `--R. violaceus (Brölemann 1900) [=Fontaria violacea] K54
              |--Erdelyia Hoffman 1962 H62
              |    `--*E. saucra Hoffman 1962 H62
              |--Cruzodesmus Chamberlin 1943 H62
              |--Acentronus Chamberlin 1943 H62
              |--Boraria Chamberlin 1943 H62
              |--Howellaria Hoffman 1950 H62
              |--Cherokia Chamberlin 1949 H62
              |    `--C. georgiana MG06
              `--Pleuroloma Rafinesque 1820 H62

*Type species of generic name indicated

REFERENCES

Enghoff, H., S. Golovatch, M. Short, P. Stoev & T. Wesener. 2015. Diplopoda—taxonomic overview. In: Minelli, A. (ed.) Treatise on Zoology—Anatomy, Taxonomy, Biology. The Myriapoda vol. 2 pp. 363–454. Brill: Leiden.

[H62] Hoffman, R. L. 1962. A new genus and species in the diplopod family Xystodesmidae (Polydesmida). Proceedings of the Biological Society of Washington 75: 181–188.

[H90] Hoffman, R. L. 1990. Diplopoda. In: Dindal, D. L. (ed.) Soil Biology Guide pp. 835–860. John Wiley & Sones: New York.

[I92] Imes, R. 1992. The Practical Entomologist. Aurum Press: London.

[K54] Kraus, O. 1954. Myriapoden aus El Salvador. Senckenbergiana Biologica 35 (5–6): 293–349.

[MG06] Mallatt, J., & G. Giribet. 2006. Further use of nearly complete 28S and 18S rRNA genes to classify Ecdysozoa: 37 more arthropods and a kinorhynch. Molecular Phylogenetics and Evolution 40: 772–794.