On the Identity of the Genus <I>Crassolabium</I> Yeates, 1967 (Dorylaimida: Qudsianematidae)

  • Reyes Pena-Santiago
  • Marcel Ciobanu
Keywords: Crassolabium australe, Crassolabium robustum, morphology, synonymy, taxonomy, Thonus.


The identity and taxonomy of the genus Crassolabium are discussed based on examination of material of C. australe, its type species and its comparison with Iberian species of close genera. The existence of refractive masses (thickenings) at the inner core of lateral lips, the most distinctive diagnostic feature of Crassolabium, is considered to be of minor taxonomical significance because of its interspecific and even intraspecific variability. It is concluded that Crassolabium and Thonus are identical, and a reversal of precedence among both genera is suggested. Crassolabium australe is re-described, and some comments are provided on C. robustum, the second species in the genus.