Pseudosphaerexochus

Pseudosphaerexochus hemicranium, from here.

Belongs within: Cyrtometopinae.

Pseudosphaerexochus is a genus of trilobites known from warm-water deposits of the Middle and Late Ordovician of Eurasia (Přibyl et al. 1985).

Characters (from Přibyl et al. 1985): Glabella greatly vaulted. Pygidium with 3(+1) axial rings and four pairs of pygidial pleurae, elongated into spines of varying lengths.

<==Pseudosphaerexochus Schmidt 1881 PVP85
    |--*P. hemicranium (Kutorga 1854) PVP85
    |--P. approximatus (Eichwald 1860) PVP85
    |--P. bocagei (Delgado 1897) PVP85
    |--P. bulbosus Nikolaisen 1965 PVP85
    |--P. conformis (Angelin 1854) PVP85
    |    |--P. c. conformis PVP85
    |    `--P. c. major Warburg 1925 PVP85
    |--P. densigranulatus Nikolaisen 1965 PVP85
    |--P. elongatus Thorslund 1940 PVP85
    |--P. granulatus (Angelin 1854) PVP85
    |--P. laticeps (Linnarsson 1866) PVP85
    |--P. latilobus (Linnarsson 1866) PVP85
    |--P. neglectus Kummerow 1928 PVP85
    |--P. octolobatus (McCoy 1849) PVP85
    |--P. ornatus (Ancygin 1977) PVP85
    |--P. orvikui Männil 1958 PVP85
    |--P. pectinifer (Barrande 1872) PVP85
    |--P. platycranium (Kutorga 1854) PVP85
    |--P. ravni Olin 1906 PVP85
    |--P. roemeri Schmidt 1881 PVP85
    |--P. tectus Ingham 1974 PVP85
    |--P. tenuispinus (Törnquist 1884) PVP85
    |--P. tumefectus Ancygin 1977 PVP85
    |--P. tvaerensis Thorslund 1940 PVP85
    |--P. warburgae Koroleva 1959 PVP85
    `--P. wolkae Kielan 1960 PVP85

*Type species of generic name indicated

REFERENCES

Přibyl, A., J. Vaněk & I. Pek. 1985. Phylogeny and taxonomy of family Cheiruridae (Trilobita). Acta Universitatis Palackianae Olomucensis Facultas Rerum Naturalium Geographica-Geologica XXIV 83: 107–193.