Stabilizing a chaotic taxonomy: redescription and redefinition of the genera Lasiodorides Schmidt & Bischoff, 1997 and Thrixopelma Schmidt, 1994 (Araneae: Theraphosidae)

The genera Lasiodorides Schmidt &
Bischoff, 1997 and Thrixopelma Schmidt, 1994 are preliminarily revised, and their taxonomy stabilized. Both sexes of Lasiodorides polycuspulatus Schmidt &
Bischoff, 1997, and the male of Lasiodorides striatus (Schmidt &
Antonelli, 1996) are redescribed, and the genus Lasiodorides is rediagnosed. Lasiodorides rolinae Tesmoingt, 1999 is proposed as a junior synonym of L. polycuspulatus syn. nov., based on colouration and spermathecal morphology. Lasiodorides remotus Schmidt, 2007 is proposed as a junior synonym of L. polycuspulatus syn. nov., based on spermathecal morphology. Thrixopelma aymara (Chamberlin, 1916) and Thrixopelma lagunas Schmidt &
Rudloff, 2010 are redescribed. Thrixopelma ockerti Schmidt, 1994 is illustrated from the syntype series and redescribed based on a non-type female from Iquitos, Peru, held in the collections of the Museo de Historia Natural, Universidad Nacional Mayor de San Marcos, Lima, Peru. Thrixopelma longicolli (Schmidt, 2003) comb. nov. is newly transferred from Lasiodorides to Thrixopelma based on palpal bulb morphology, and the holotype male is redescribed. The inherent problems of the paratype exuviae of this taxon are also discussed. Thrixopelma peruvianum (Schmidt, 2007) comb. nov. is newly transferred from Euathlus Ausserer, 1875 following examination of the holotype female exuvia and a conspecific non-type female exuvia. Thrixopelma cyaneolum Schmidt, Friebolin &
Friebolin, 2005 is discussed ad illustrated from the syntype female exuviae. Thrixopelma pruriens Schmidt, 1998 is discussed and illustrated from the holotype female exuvia, and the problematic non-type material discussed. Finally, we argue that future designation of exuviae as type specimens of novel theraphosid spiders should be considered an unacceptable practice in arachnology.