Diplagnostidae

Belongs within: Agnostina.
Contains: Pseudagnostus.

The Diplagnostidae are a Middle Cambrian to Lower Ordovician group of agnostid trilobites.

Characters (from Harrington et al. 1959): Glabella with two main lobes, anterior one medially indented by longitudinal furrow; pygidial axis trilobed; surface of cephalon smooth, corrugated or rugose; surface of pygidium smooth.

Diplagnostidae
    |--OidalagnostinaeRC93
    |--DiplagnostinaeS80
    |    |--Diplagnostus abbatiae Rushton 1979RC93
    |    `--Connagnostus Öpik 1967S80
    |         |--*C. venerabilis Öpik 1967S80
    |         |--C. aversus Shergold 1980S80
    |         |--C. conspectus Shergold 1975S80
    |         `--C. junior Shergold 1972S80
    `--PseudagnostinaeS80
         |--PseudagnostusS80
         |--Rhaptagnostus Whitehouse 1936S80
         |    |--*R. cyclopygeformis (Sun 1924) [=Agnostus cyclopygeformis]S80
         |    |--R. apsis Shergold 1980S80
         |    |--R. auctor Shergold 1980S80
         |    |--R. changshanensisCT83
         |    |--R. clarki (Kobayashi 1935) [=Pseudagnostus (Plethagnostus) clarki]S80
         |    |    |--R. c. clarkiS80
         |    |    |--R. c. laevis Palmer 1955S80
         |    |    |--R. c. patulus (Shergold 1975)S80
         |    |    `--R. c. prolatus Shergold 1975S80
         |    |--R. convergens (Palmer 1955) [=Pseudagnostus convergens]S80
         |    `--R. impressus (Lermontova 1940)S80
         `--Neoagnostus Kobayashi 1955 (see below for synonymy)S80
              |--*N. aspidoides Kobayashi 1955S80
              |--N. araneavelatus (Shaw 1951) [=Pseudagnostus araneavelatus]S80
              |--N. bilobusS80
              |--N. canadensisS80
              |--N. cavernosus (Rosova 1960)S80
              |--N. clavus (Shergold 1972) [=Pseudagnostus clavus]S80
              |--N. coronatus (Shergold 1975)S80
              |--N. denticulatus (Shergold 1975)S80
              |--N. felix Shergold 1980S80
              |--N. greeni Shergold 1980S80
              `--N. vulgaris (Rosova 1960)S80

Neoagnostus Kobayashi 1955 [incl. Euplethagnostus Lermontova 1940, Hyperagnostus Kobayashi 1955, Machairagnostus Harrington & Leanza 1957, Pseudorhaptagnostus Lermontova 1940]^S80

*Type species of generic name indicated

References

[CT83] Chen J.-Y. & C. Teichert. 1983. Cambrian Cephalopoda of China. Palaeontographica Abteilung A: Paläozoologie—Stratigraphie 181 (1–3): 1–102.

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.

[RC93] Romano, M., W. T. Chang, W. T. Dean, G. D. Edgecombe, R. A. Fortey, D. J. Holloway, P. D. Lane, A. W. Owen, R. M. Owens, A. R. Palmer, A. W. A. Rushton, J. H. Shergold, D. J. Siveter & M. A. Whyte. 1993. Arthropoda (Trilobita). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 279–296. Chapman & Hall: London.

[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.