Solutans are a small clade of extinct non-radiate echinoderms. Their stratigraphic range extends from the middle Cambrian (Miaolingian, Drumian) to the Lower Devonian (Emsian). Solutans are characterized by two distinct and unequal appendages inserted at opposite ends of their theca: a single free ambulacral structure (brachiole), and a longer stem-like appendage (homoiostele). Due to their unusual morphology, the taxonomic position of the class is still controversial. Solutans are considered either as a distinct class of blastozoans or as basal, preradial hemichordate-like echinoderms. This contribution aims at reviewing the major advances achieved since Caster's (1968) chapter on Soluta in the Treatise on Invertebrate Paleontology, with a special emphasis on the main results obtained since the last IEC in Nagoya (2018) and ongoing studies. The description of Pahvanticystis utahensis (Guzhangian, Utah) confirmed the probable Laurentian origin of the class (Lefebvre & Lerosey-Aubril, 2018). Work in progress lead by S. Zamora and X. Zhu will describe the earliest non-Laurentian solutan from the Guole Biota (Jiangshanian, South China). The Fezouata Biota (late Tremadocian-late Floian) yielded exceptionally preserved soft parts (gut) in a Castericystis-like solutan, as well as abundant remains of Plasiacystis mobilis (originally described in the Darriwilian of the Czech Republic) and a new taxon, morphologically intermediate between Minervaecystis and Plasiacystis (Dupichaud & Lefebvre, 2022). The revision of late Tremadocian solutans from the Montagne Noire provided the first detailed reconstruction of M. vidali and the first report of P. mobilis in that region (Dupichaud et al., in press). The very unusually-shaped Hope Shale solutan (Darriwilian, Shropshire) is still awaiting description (work in progress by K. Derstler & B. Lefebvre). The Late Ordovician genus Dendrocystites was reported for the first time in North Africa (Nohejlová & Lefebvre, 2022) and from a new echinoderm Lagerstätte in the Prague Basin (Nohejlová et al., 2019). The Neuville Formation (lower Katian, Quebec) yielded abundant remains of a new solutan, with a surprisingly plesiomorphic ('Castericystis-like') morphology (work in progress by K. Derstler). Finally, the first ever described Silurian solutan, Dehmicystis ariasi, was recently documented in the Ludlow of Spain (Zamora & Gutiérrez-Marco, in press), thus filling a long stratigraphic gap between the Late Ordovician and the Early Devonian. Another Silurian solutan from Wales is also awaiting description (Dupichaud, in progress).