Buthidae C.L. Koch, 1837

Soleglad, Michael E. & Fet, Victor, 2003, High-level systematics and phylogeny of the extant scorpions (Scorpiones: Orthosterni), Euscorpius 2003 (11), pp. 1-175 : 89-90

Family Buthidae C.L. Koch, 1837

Type Genus. Buthus Leach, 1815 .

Synonyms.

Androctonides C.L. Koch, 1837; type genus

Androctonus Ehrenberg, 1828 .

Available names of family-level groups. (STATUS

UNCLEAR):

Isometrini Kraepelin, 1891; type genus Iso-

metrus Ehrenberg, 1828 (see also Fet &

Messing (in press) on a junior homomym

Isometrinae, Crinoidea , Echinodermata).

Babycurini Pocock, 1896; type genus

Babycurus Karsch, 1886 .

Ananterinae Pocock, 1900; type genus Anan-

teris Thorell, 1891.

Tityinae Kraepelin, 1905; type genus Tityus

C.L. Koch, 1836.

Orthochirinae Birula, 1917; type genus

Orthochirus Karsch, 1892 .

Charminae Birula, 1917; type genus Charmus

Karsch, 1879.

Uroplectaria Pavlovsky, 1924; type genus

Uroplectes Peters, 1861 .

Rhopalurusinae Bücherl, 1969 (original spell-

ing Rhopalurinae, a junior homonym of

Rhopaluridae, Mesozoa ; see Fet et al.,

2003b); type genus Rhopalurus Thorell,

1876.

Akentrobuthinae Lamoral, 1976; type genus

Akentrobuthus Lamoral, 1976 (see comments

under family Microcharmidae ).

Composition. The family Buthidae includes 80 extant genera ( Table 9; Fet & Lowe, 2000; for additional genera described and synonymies made since 1998, see Lourenço, 1999a, 1999b, 2000b, 2000c, 2001a, 2001d; Fet et al., 2001 a; Kovařík, 2001; Gantenbein et al., 2003).

Distribution. All continents except Antarctica. Some of the New World genera include extinct Tertiary species (amber of the Dominican Republic and Mexico). In addition, five fossil Tertiary genera of Buthidae (all from the Eocene/Oligocene Baltic amber, ca. 65 Mya) have been described: Palaeolychas , Palaeotityobuthus , Palaeoprotobuthus , Palaeoakentrobuthus , and Palaeoananteris (Lourenço & Weitschat, 1996, 2000, 2001); and a subfossil genus Palaeogrosphus was described from the copal of Madagascar (Lourenço, 2000c).

Taxonomic history. This family was early recognized as a separate lineage from all other extant scorpions ( Peters, 1861); this division was maintained by all later taxonomists ( Thorell, 1876a; Pocock, 1893; Kraepelin, 1899, 1905; Birula, 1917a, 1917b). Buthidae were considered a sister group of all other extant families by Lamoral (1980) and Sissom (1990). It is the only family of scorpions that has medical importance due to its potent, mammal-specific neurotoxins, and many aspects of buthid biology have been extensively studied. However, the comment by Stockwell (1989: 182) that the family Buthidae “is surprisingly poorly studied with regard to suprageneric phylogenetic relationships” is still valid.

Biogeographic history. This extremely diverse family could have been established in Permian/Triassic within Pangea, judging from its modern worldwide distribution. Sissom (1990) followed Lamoral (1980) in assuming Laurasian origin of “protobuthoids”, spreading to Gondwanaland in Pangean times before the two masses split. However, there is certainly no evidence that buthid ancestors originated in the northern part of Pangea; this notion is probably a remnant of simplistic views of early scorpion geographers, including Kraepelin (1905) and Birula (1917a, 1917b) who derived buthids from non-orthostern Carboniferous taxa, which they superficially resemble. Statement by Lourenço & Sissom (2000: 122) that “during Pangean times…the protobuthids were the dominant fauna” certainly is not based on any known facts.

There are a number of widespread buthid genera as well as genera endemic to certain biogeographic regions. While extensive radiation is currently exhibited by buthids on all continents (especially in deserts and tropics of Asia, Africa, and the Americas), there is number of endemic genera. It could be possible to trace Gondwanaland relationships between African, Asian, and South American genera of Buthidae . For example, Grosphus and Tityobuthus are endemic to Madagascar (Lourenço, 1996a, 1996d), and Ananteris is found in both Africa and South America (Lourenço, 1993, 1996d), suggesting a Gondwanaland connection; Lourenço (1996b) considered Ananteris a close relative of Tityobuthus . The preliminary phylogeny (see discussion below) suggests that the New World Buthidae could form a separate lineage together with certain Old World genera; especially intriguing in our preliminary DNA phylogeny (Fet et al., 2003a) is connection between the Madagascan Grosphus and the New World Buthidae ( Centruroides and Rhopalurus ), which again could indicate Gondwanaland relationships. Fet et al. (2003a) emphasized that the extensive radiation of Buthidae could parallel evolution of unique mammal-specific neurotoxic venom in this family.

Diagnosis. See parvorder Buthida .

Discussion. Subfamilies are currently not recognized in Buthidae ; for detailed taxonomic history of this issue see Fet & Lowe (2000: 54–55). Analysis of subfamilial and tribal division of Buthidae is beyond the scope of our present paper. The complexity of this family clearly requires further division, and already early authors introduced subfamilies (Kraepelin, 1905; Birula, 1917a, 1917b) and even tribes ( Pavlovsky, 1924). Most of subfamily names have not been formally synonymized, and the issue has been controversial (Froy, 2002) but not yet approached with modern methods of classification. There are indications that at least two major groups exist within this family, which might correspond to two trichobothrial configurations— “alpha ” and “beta” patterns on the pedipalp femur discovered by Vachon (1975), and discussed further in this paper. The most recent key of buthid genera ( Sissom, 1990: 93– 100) suggested that the “beta” pattern is present almost exclusively in the Old World genera. At the same time, “alpha ” pattern is found in all other New World genera (all of which also share a loss of tibial spurs; Sissom, 1990: 89) and a number of the Old World genera (mainly Afrotropical). Toxicologists routinely discuss profound differences in venom structure and function between Buthidae of the Old World (such as Androctonus , Leiurus and Mesobuthus ; all “beta” pattern), and the New World ( Centruroides , Tityus ; all “alpha ” pattern) (Loret & Hammock, 2001; Froy & Gurevitz, 2003). The preliminary DNA phylogeny (Fet et al., 2003a) appears to agree with a possible division into at least two subfamilies; in addition, tribal division could become necessary. If subfamilies will be introduced, the nominotypical subfamily Buthinae will likely incorporate most Old World genera with “beta” configuration. We should also note that the current genus-level diversity in Buthidae is much higher in the Old World (71 genera) than in the New World (10 genera), although species-level diversity is in fact higher in the New World. To some extent it could be an artifact of “splitting” tendencies of buthid taxonomists who worked in the Old World (Fet & Lowe, 2000; Fet et al., 2003a), and to the absence of modern revisions of the largest New World buthid genera such as Centruroides (ca. 50 species) and Tityus (ca. 120 species). On the other hand, it is clear that evolutionary radiation of Buthidae in the deserts of Asia and Africa is unrivalled by that in the New World where most desert niches are occupied by Vaejovidae or Bothriuridae ( Nenilin & Fet, 1992) .