Taxonomic review of Thoracostomopsidae (Nematoda, Enoplida): state of the art, list of valid species and dichotomous keys Author De Souza, João V. 0009-0009-4985-086X https: // orcid. org / 0009 - 0009 - 4985 - 086 X Author Maria, Tatiana F. 0000-0002-7553-2031 https: // orcid. org / 0000 - 0002 - 7553 - 2031 text Zootaxa 2023 2023-11-03 5361 4 463 496 https://www.mapress.com/zt/article/download/zootaxa.5361.4.2/52207 journal article 10.11646/zootaxa.5361.4.2 1175-5326 10152589 DAB237DC-1444-4007-BCCA-CB92CBE66617 Genus Parasaveljevia Wieser, 1953 The genus Parasaveljevia was erected by Wieser (1953) with the description of Parasaveljevia lupata Wieser, 1953 and Parasaveljevia cirrifera Wieser, 1953 ; it also accommodates Parasaveljevia clavicauda ( Filipjev, 1927 ) Wieser, 1953 (type species) previously described as Saveljevia . Wieser (1953) suggested that the genus Parasaveljevia may be identical to Hyptiolaimus , but this could not be proved. Wieser (1953) elaborated a key to separate the three species into two groups based on the size of the cephalic setae and the presence or absence of cirri and denticles. Later, P. clavicauda and P. lupata were considered species inquirendae because only females and juveniles were known ( Pastor et al. 2015 ). Then, P. cirrifera was designated as type species and two new species were described Parasaveljevia limitense Pastor, Russo & Vilares, 2015 and P. uncinoa . Both species resemble P. cirrifera , but they differ from it by cephalic sensilla and cephalic capsule length, respectively. An identification key for the three valid species of Parasaveljevia was provided by Pastor et al. (2015) , separating the three valid species according to their size and position of the cephalic setae, the position of the apical organ or cirri, and the size of the tail in relation to the anal body diameter. In the mentioned taxonomic key, authors used the term “lateral cephalic setae” to differentiate species; however, this setae position is not expected to occur because amphids are placed in the lateral position of the third ring of sensory organs. Then, these lateral setae are maybe lateral subcephalic setae that migrate to the cephalic setae circle. These authors also suggested that Oxyonchus striatus might belong to Parasaveljevia but paratypes must be checked and compared to confirm this supposition. Diagnosis from Pastor et al. (2015) : Lips high. All anterior sensillae setose. Asymmetric spoon like mandibles, ventrosublateral mandibles wider and broader than dorsal mandible. Teeth unequal, dorsal tooth small or reduced and two large ventrosublateral teeth extending beyond anterior end of mandibles. Base of ventrosublateral-dorsal teeth near or at the level of the mandibular ring. Presence of well-developed posterior processes for muscle insertion inside cephalic capsule. Short cephalic capsule. Cirri-shaped cephalic organs present. Denticles on mandibular plates present. Marine