Key to sessile gnesiotrochan rotifers: Families, monospecific species in Flosculariidae, species of Atrochidae, Conochilidae, and Limnias Author Davies, Natalie Department of Biology, Ripon College, Ripon, WI, 54971, USA Author Lafleur, Alexandre Department of Biology, Ripon College, Ripon, WI, 54971, USA Author Hochberg, Rick University of Massachusetts Lowell, Lowell, MA, 01854, USA Author Walsh, Elizabeth J. Department of Biological Sciences, University of Texas at El Paso, El Paso, TX, 79968, USA Author Wallace, Robert L. Department of Biology, Ripon College, Ripon, WI, 54971, USA text Zootaxa 2024 2024-01-08 5397 4 497 520 http://dx.doi.org/10.11646/zootaxa.5397.4.3 journal article 10.11646/zootaxa.5397.4.3 1175-5326 10469053 3EE9F78B-0133-4466-872C-F14CEF87E928 Superorder Gnesiotrocha de Beauchamp, 1965 Within the diversity exhibited by rotifers, superorder Gnesiotrocha are distinct from superorder Pseudotrocha (order Ploima ) in that all gnesiotrochans (1) possess a foot that lack toes, (2) their anterior end is either a funnel-shaped structure or possesses ciliated lobes, and (3) their trophi are either malleoramate or uncinate ( Edmondson 1959 ; Koste 1978 ; Ruttner-Kolisko 1974 ; Wallace & Snell 2010 ; Wallace et al. 2006 ). Ploimids may lack a foot, and, if present, may possess toes; their anterior end and trophi do not resemble that of the sessile taxa. Uncinate trophi possess few teeth: usually one or more large, pincer-like teeth and a few smaller teeth ( Fig. 2A ); malleoramate trophi possess crescent-shaped manubria and unci with numerous club-shaped teeth ( Fig. 2B ). Teeth close to the fulcrum are usually larger than those more distant. Trophi in the Flosculariaceae characteristically exhibit a grinding or pounding-like action, which is not seen in the Collothecacea .