Scorpionoidea Latreille, 1802

Soleglad, Michael E. & Fet, Victor, 2003, High-level systematics and phylogeny of the extant scorpions (Scorpiones: Orthosterni), Euscorpius 2003 (11), pp. 1-175 : 111-112

Superfamily Scorpionoidea Latreille, 1802

Type Genus. Scorpio Linnaeus, 1758 .

Synonyms.

Bothriuroidea Simon, 1880, new synonymy (valid as family name).

Composition. This superfamily includes four extant families: Bothriuridae , Liochelidae , Scorpionidae , and Urodacidae . We do not recognize a separate superfamily Bothriuroidea as proposed by Mello-Leitão (1945) and Lourenço (2000a); it is synonymized here with Scorpionoidea . With changes in rank of some taxa, our content of extant Scorpionoidea is the same as that of Stockwell (1989) and Prendini (2000). We also include here the fossil family Protoischnuridae following Carvalho & Lourenço (2001).

Distribution. Asia, Africa, Australia, Oceania, North America, Central and South America.

Taxonomic history. Stockwell (1989) included five families in Scorpionoidea : Bothriuridae , Diplocentridae , Ischnuridae , Scorpionidae , and Urodacidae ; his analysis clearly defined the basal position of Bothriuridae . Prendini (2000) provided a detailed morphological phylogenetic analysis of this superfamily, and justified existence of seven families ( Bothriuridae , Diplocentridae , Hemiscorpiidae , Heteroscorpionidae , Ischnuridae , Scorpionidae , and Urodacidae ).

Biogeographic history. The scorpionoids are found both in the New and the Old World. Our placement of Protoischnuridae (South America) (Carvalho & Lourenço, 2001) in this superfamily marks the oldest scorpionoid taxon as Lower Cretaceous (ca. 110 Mya). Final vicariant separation of South America and Africa took place 100 to 120 Mya (Hay et al., 1999). By this time, a scorpionoid family Protoischnuridae already existed in South America so it is conceivable that other scorpionoid families ( Bothriuridae , Liochelidae , Scorpionidae , and Urodacidae ) also already have diverged. All other available scorpionoid fossils (family Scorpionidae ) are Tertiary. One could interpret scorpionoids as a group which originated in Gondwanaland since its few representatives in the northern continents (North America, North Africa, Middle East) could be Tertiary migrants. Presence of Mioscorpio in Miocene of Europe sets the possible age bracket for such migrants. Further, the current distribution of scorpionoids could be due to differential extinction of a formerly widespread group ( Nenilin & Fet, 1992), and then one does not have to evoke Gondwanaland disjunctions with subsequent south-tonorth migrations to explain disjunct ranges of such groups as Diplocentrinae .

Diagnosis. Synapomorphies. Ventral surface of leg tarsus with pairs of large socketed setae; legs with one pedal spur (prolateral); paraxial organ with reflection of internobasal sperm duct; hemispermatophore capsule extremely well-developed; ventral denticle of cheliceral movable finger considerably longer than dorsal denticle; chelal finger outer denticles (OD) removed outward from median denticle (MD) row. Important Symplesiomorphies. Ventral edge of cheliceral movable finger smooth; median denticle (MD) row of chelal finger aligned in straight line; genital operculum of female generally fused; chela with “10-carinae” configuration.

Discussion. We confirm the phylogeny of Scorpionoidea as recently established by Prendini (2000) in his extensive cladistic analysis. The family Bothriuridae is a sister group to three other scorpionoid families. With the nomenclatural changes introduced here, the family Urodacidae ( Urodacinae + Heteroscorpionidae ) is the sister group to the clade including Liochelidae ( Liochelinae + Hemiscorpiinae ) and Scorpionidae ( Scorpioninae + Diplocentrinae ).