Leiostegiacea

Reconstructed exoskeletal components of Peichiashania secunda, from Shergold (1980).

Belongs within: Ptychopariida.

The Leiostegiacea are a Middle Cambrian to Lower Ordovician group of trilobites. The position of the Missisquoiidae among trilobites has been the subject of some debate; cranidial characters suggest a relationship to Leiostegiidae, though the pygidia of the two taxa are somewhat different (Lee & Chatterton 2007).

Characters (from Lee & Chatterton 2007): Cranidial outline trapezoidal; glabella subrectangular or slightly forward-tapering; preglabellar field absent; fixigenae with inflated palpebral area.

<==Leiostegiacea
    |--Parakoldinioida Endo in Endo & Resser 1937 [Missisquoiidae] S80
    |    |--*P. typicalis Endo in Endo & Resser 1937 S80
    |    `--P. bigranulosa Shergold 1975 S80
    `--Leiostegiidae S80
         |  i. s.: Iranochuangia S80
         |         Chuangia S80
         |           |--*C. batia Walcott 1911 S80
         |           `--C. transversalis S80
         |--Pagodiinae S80
         |    |--Pagodia S80
         |    |    |--P. (Pagodia) lotos Walcott 1913 S80
         |    |    `--P. (Idamea) baccata S80
         |    |--Lotosoides Shergold 1975 S80
         |    |    |--*L. calcarata (Shergold 1975) [=Pagodia (Lotosoides) calcarata] S80
         |    |    |--L. bathyora Shergold 1980 S80
         |    |    `--L. turbinata (Shergold 1975) [=Pagodia (Lotosoides) turbinata] S80
         |    `--Prochuangia Kobayashi 1935 S80
         |         |--*P. mansuyi Kobayashi 1935 S80
         |         |--P. angusta Kobayashi 1935 S80
         |         |--P. glabella Shergold 1980 S80
         |         |--P. granulosa Lu 1956 S80
         |         |--P. imamurai Endo 1944 S80
         |         |--P. posterospina Kobayashi 1935 S80
         |         `--P. quadriceps (Dames 1883) (see below for synonymy) S80
         `--Mansuyiinae S80
              |--Mansuyites Shergold 1972 S80
              |--Mansuyia Sun 1924 S80
              |--Taipaikia Kobayashi 1960 S80
              |--Mansuyella lilia Endo in Endo & Resser 1937 S80
              |--Hapsidocare Shergold 1975 S80
              |    |--*H. chydaeum Shergold 1975 S80
              |    |--H. grossum Shergold 1975 S80
              |    `--H. lilyensis Shergold 1980 S80
              `--Peichiashania Chang 1957 S80
                   |--*Eymekops rectangularis Endo in Endo & Resser 1937 S80
                   |--P. lunatula Öpik 1967 S80
                   |--P. pelta Öpik 1967 S80
                   |--P. planilimbata (Endo in Endo & Resser 1937) [=Paramansuyella planilimbata] S80
                   |--P. prima Shergold 1980 S80
                   |--P. quarta Shergold 1980 S80
                   |--P. secunda Shergold 1980 S80
                   `--P. tertia Shergold 1980 S80

Prochuangia quadriceps Dames 1883 [=Conocephalites quadriceps, Kaolishania quadriceps, Schantungia quadriceps]

*Type species of generic name indicated

REFERENCES

Lee, D.-C., & B. D. E. Chatterton. 2007. Protaspides of uppermost Cambrian trilobite Missisquoia, with implications for suprafamilial level classification of the genus. Canadian Journal of Earth Sciences 44: 493-506.

[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.