
Belongs within: Irregularia.
The Oligopygidae are a group of smaller irregular echinoids known from the Upper Cretaceous to the Oligocene (Wagner & Durham 1966).
Characters (from Wagner & Durham 1966): Small to medium-sized; periproct small; without oral funnel; auricles partially recumbent.
<==Oligopygidae [Oligopyginae, Oligopygoida]WD66 |--Bonaireaster Pijpers 1933WD66 | `--*B. rutteni Pijpers 1933WD66 |--Microlampas Cotteau 1889 [=Microsoma Cotteau 1887 non Cotteau 1886]WD66 | `--*M. conicus (Cotteau 1887) [=*Microsoma conicum]WD66 |--Ovulechinus Lambert 1918WD66 | `--*O. pilula Lambert 1918WD66 |--Protolampas Lambert 1918WD66 | `--*P. arnaudi (Cotteau 1891) [=Echinolampas arnaudi]WD66 |--Haimea Michelin 1851 [incl. Pauropygus Arnold & Clark 1927]WD66 | |--*H. caillaudi Michelin 1851WD66 | `--‘*Pauropygus’ platypetalus Arnold & Clark 1927WD66 `--Oligopygus de Loriol 1887WD66 |--*O. wetherbyi de Loriol 1887WD66 |--O. haldemani (Conrad 1850)SG93 `--O. phelani Kier 1967SG93
*Type species of generic name indicated
References
[SG93] Simms, M. J., A. S. Gale, P. Gilliland, E. P. F. Rose & G. D. Sevastopulo. 1993. Echinodermata. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 491–528. Chapman & Hall: London.
[WD66] Wagner, C. D., & J. W. Durham. 1966. Holectypoids. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 2 pp. U440–U450. The Geological Society of America, Inc., and The University of Kansas Press.