Iurida Soleglad & Fet, 2003

Soleglad, Michael E. & Fet, Victor, 2003, High-level systematics and phylogeny of the extant scorpions (Scorpiones: Orthosterni), Euscorpius 2003 (11), pp. 1-175 : 92

Parvorder Iurida Soleglad & Fet , new parvorder

Composition. This parvorder, established here, includes three superfamilies ( Chactoidea , Iuroidea , and Scorpionoidea ) and 10 families. It corresponds to orthobothriotaxy “ Type C” ( Vachon, 1974; Soleglad & Fet, 2001).

Distribution. All continents except Antarctica.

Biogeographic history. Our phylogenetic analysis demonstrates the relationship between three superfamilies of this parvorder as ( Iuroidea , ( Scorpionoidea , Chactoidea )). Since already the oldest of superfamilies, Iuroidea , has a disjunct modern distribution between the New World and the Mediterranean, representatives of the parvorder Iurida should clearly have been present in the times of Pangea, which marks the possible upper age (Triassic) of the youngest node in the phylogeny of extant scorpions at the parvorder level (split of parvorder Iurida , the most derived of four scorpion parvorders). The oldest known fossils of Iurida are Cretaceous (families Protoischnuridae and Palaeoeuscorpiidae ). All three superfamilies of Iurida exhibit worldwide distribution, variously disjunct at the level of families, tribes, and sometimes even genera.

Diagnosis. Scorpions in the parvorder Iurida can be distinguished by the following characters: Synapomorphies. Orthobothriotaxy type C; ventral surface of cheliceral fixed finger without denticles; sternum type 2; hemispermatophore is lamelliform; pedipalp patella with “5-carinae” configuration; three lateral eyes present. Important Symplesiomorphies. None.

Discussion. The phylogeny of the parvorder Iurida , as established here, supports the topology ( Iuroidea , ( Scorpionoidea , Chactoidea )). This conflicts with the interpretation of Stockwell (1989) who included Iuridae (=current Iuroidea ) in his Vaejovoidea .

Characters used to define the superfamilies of parvorder Iurida are cheliceral dentition, leg pedal spurs, leg tarsus armature, and the paraxial organ.