Cyclopygidae

Microparia speciosa, from center.

Belongs within: Asaphida.

The Cyclopygidae are a group of Ordovician trilobites with extremely large eyes (Harrington et al. 1959).

Characters (from Harrington et al. 1959): Exoskeleton gibbous. Cephalon large, without marginal border; glabella large, usually fused with occipital ring; fixigenae reduced to minute band, palpebral lobes not defined; facial sutures cutting posterior margin close to axial furrows, not withdrawing from them along whole contour of glabella; librigenae usually reduced, angles rounded, united ventrally by doublure; eyes hypertrophied, vidual areas very convex, occupying nearly whole librigenae, continuing to ventral side where they may remain separated or unite, with 750 to 3500 biconvex lenses in each eye. Hypostoma incompletely known; no connective sutures or rostral plate. Thorax with five or six segments; sides parallel or diverging backward; axis broad, at least anteriorly; pleurae grooved, increasing backward in width. Pygidium of moderate size to large; axis with few rings (up to five); pleural fields with few ribs, generally no more than one or two distinct. Surface smooth or with fine striae, occasionally granulose. Most species small, a few up to 14 cm in length.

Cyclopygidae
| i. s.: Ellipsotaphrus monophthalmusO02
| Prospectatrix genatenta (Stubblefield 1927)RC93
| PsilacellaRC93
| SymphysopsRC93
|--PricyclopyginaeO02
| |--Emmrichops Marek 1961O02
| | `--*E. planicephalus Marek 1961 [=E. planicephala; incl. E. extensus Hughes 1979]O02
| `--Pricyclopyge Richter & Richter 1954O02
| |--*P. prisca (Barrande 1872) [=Aeglina prisca]O02
| |--P. binodosaFO99
| | |--P. b. binodosaFO99
| | `--P. b. eurycephalaFO99
| |--P. longicephalaO02
| `--‘Aeglina’ mirabilisO02
`--CyclopyginaeO02
|--CyclopygeO02
| |--C. bohemicaO02
| `--C. grandisFO99
| |--C. g. grandisFO99
| `--C. g. brevirhachisFO99
|--Sagavia Koroleva 1967O02
| |--*S. felix Koroleva 1967O02
| |--S. elongata Petrunina in Repina et al. 1975O02
| |--S. glans Fortey & Owens 1987O02
| `--S. novakelliformis Koroleva 1982O02
|--Degamella Marek 1961O02
| |--*D. princeps (Barrande 1872) [=Aeglina princeps]O02
| |--D. evansi Fortey & Owens 1987O02
| |--D. gigantea (Barrande 1872)O02
| |--D. nuda (Whittard 1961) [=Microparia nuda]O02
| `--D. wattisoni (Hughes 1979) [=Pricyclopyge (Bicylopyge) wattisoni]O02
`--Microparia Hawle & Corda 1847O02
| i. s.: M. broeggeriFO99
|--M. (Microparia)O02
| |--*M. (M.) speciosa Hawle & Corda 1847O02
| |--M. (M.) brachycephala (Klouček 1916)O02
| |--M. (M.) caliginosa [=Cyclopyge caliginosa]O02
| |--M. (M.) kloucekiO02
| |--M. (M.) lusca Marek 1961O02
| |--M. (M.) major (Salter 1853) [=Aeglina major, Cyclopyge major; incl. Microparia laevis Whittard 1961]O02
| `--M. (M.) plasiO02
`--M. (Heterocyclopyge)O02
|--M. (*H.) pachycephala (Hawle & Corda 1847) [=Cyclopyge pachycephala]O02
|--M. (H.) abunda Zhou, McNamara et al. 1994O02
|--M. (H.) nigra (Hörbinger & Vaněk 1985) [=Heterocyclopyge nigra]O02
`--M. (H.) shelvensis Whittard 1961O02

*Type species of generic name indicated

References

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

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.

[O02] Owens, R. M. 2002. Cyclopygid trilobites from the Ordovician Builth-Llandrindod Inlier, central Wales. Palaeontology 45 (3): 469–485.

[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.

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