
Belongs within: Apodida.
Theelia is a genus of wheel sclerites known from the Triassic (possibly the Late Carboniferous) to the Pleistocene (Frizzell & Exline 1966).
Characters (from Frizzell & Exline 1966): Spokes 6–10; rim inclined to plane of wheel, curving upward and inward, denticulate on inner margin, teeth not extending to periphery as seen from above; center imperforate, typically with hemispherical or conical tubercle or button.
<==Theelia Schlumberger 1891 [incl. Chiridotites Deflandre-Rigaud 1949]FE66 |--*T. undulata (Schlumberger 1888) [=Chirodota undulata]FE66 |--T. agariciformisFE66 |--T. angulataFE66 |--T. atavaFE66 |--T. clavataFE66 |--T. convexaFE66 |--T. crassidentataFE66 |--T. curriculumFE66 |--T. deflandreaeFE66 |--T. eisenstadtensisFE66 |--T. florealisFE66 |--T. floridaFE66 |--T. guembeliFE66 |--T. heptalampraFE66 |--T. hexacneme Summerson & Campbell 1958SG93 |--T. ingensFE66 |--T. lanceolataFE66 |--T. liptovskaensis Gazdzicki et al. 1978SG93 |--T. mortenseniFE66 |--T. muellendorfensisFE66 |--T. petasiformisFE66 |--T. pralongiaeFE66 |--T. quinquelobataFE66 |--T. raraFE66 |--T. rigaudaeFE66 |--T. rosettaFE66 |--T. rotulaFE66 |--T. sinaiensisFE66 |--T. speciosaFE66 |--T. synapta Gilliland 1992SG93 |--T. tuberculaFE66 |--T. venustaFE66 |--T. vetustaFE66 `--T. wessexensisFE66
*Type species of generic name indicated
References
[FE66] Frizzell, D. L., & H. Exline. 1966. Holothuroidea—fossil record. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 2 pp. U646–U672. The Geological Society of America, Inc., and The University of Kansas Press.
[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.