Asaphacea

Norinia convexa in the National Museum of Nature and Science, Tokyo. Copyright Daderot.

Belongs within: Ptychopariida.

The Asaphacea are a group of trilobites known from the Upper Cambrian to the Upper Ordovician (Harrington et al. 1959).

Characters (from Harrington et al. 1959): Thoracic segments usually 8 (occasionally 7). Eyes commonly more or less conical, short or moderate in length; eyes ridges present in a few genera, faint or scarcely discernible. Pygidium rounded or with one or two terminal spines.

<==Asaphacea
    |  i. s.: Megalaspides S80
    |         Notopeltis S80
    |         Megalaspidella S80
    |--Asaphiscidae S80
    |    |--Blountia S80
    |    `--Asaphiscus Meek 1872 W77
    |         `--A. wheeleri (Meek 1872) [=Bathyurellus (Asaphiscus) wheeleri] W77
    `--Asaphidae S80
         |  i. s.: Atopasaphus Shergold 1972 S80
         |           |--*A. petasatus Shergold 1972 S80
         |           `--A. stenocanthus Shergold 1975 S80
         |         Asaphus F71
         |           |  i. s.: A. kowalewskii FO99
         |           |--A. (*Basilicus) tyrannus R27
         |           `--A. (Megalaspis Angelin 1854) F71, W77
         |                |--‘Megalaspis’ belemnurus White 1874 W77
         |                |--‘Megalaspis’ extenuatus H04
         |                |--A. (M.) goniocercus W77
         |                `--A. (M.) howchini Etheridge 1894 F71
         |         Ogygites R27
         |           |--O. birmanicus R27
         |           |--O. collingwoodensis Reed 1927 R27
         |           |--‘Basilicus’ kegelensis R27
         |           |--O. kuckersianus [=Asaphus (Basilicus) kuckersianus] R27
         |           |--‘Basilicus’ lawrowi R27
         |           `--O. yunnanensis R27
         |         Ogygyinus FO99
         |           |--O. armoricanus FO99
         |           `--‘Ogygia’ corndensis R27
         |         Asaphelus catamarcensis FO99, SV03
         `--Niobinae S80
              |--Niobe morrisi FO99
              `--Norinia Troedsson 1937 S80
                   `--*N. convexa Troedsson 1937 S80

*Type species of generic name indicated

REFERENCES

[F71] Fletcher, H. O. 1971. Catalogue of type specimens of fossils in the Australian Museum, Sydney. Australian Museum Memoir 13: 1-167.

[FO99] Fortey, R. A. & R. M. Owens. 1999. Feeding habits in trilobites. Palaeontology 42 (3): 429-465.

[H04] Haeckel, E. 1899-1904. Kunstformen der Natur. Bibliographisches Institut: Leipzig und Wien.

Harrington, H. J., G. Henningsmoen et al. 1959. Systematic descriptions. In Treatise on Invertebrate Paleontology pt O. Arthropoda 1 pp. O170-O540. Geological Society of America and University of Kansas Press.

[R27] Reed, F. R. C. 1927. New trilobites from the Ordovician beds of New Zealand. Transactions and Proceedings of the New Zealand Institute 57: 310-314.

[SV03] Sánchez, T. M., & N. E. Vaccari. 2003. Ucumariidae new family (Bivalvia, Anomalodesmata) and other bivalves from the Early Ordovician (Tremadocian) of northwestern Argentina. Ameghiniana 40 (3): 415-424.

[S80] Shergold, J. H. 1980. Late Cambrian trilobites from the Chatsworth Limestone, western Queensland. Bureau of Mineral Resources, Geology and Geophysics—Bulletin 186: 1-111.

[W77] White, C. A. 1877. Report upon the invertebrate fossils collected in portions of Nevada, Utah, Colorado, New Mexico, and Arizona, by parties of the expeditions of 1871, 1872, 1873, and 1874. U.S. Geographical Surveys West of the One Hundredth Meridian 4 (1): 1-219, pls 211-221.