18 June, 2008

A phylogenetic review of the genus Hadurus and synonymization of Hoffmannihadrurus with Hadurus

Oscar Francke and Lorenzo Prendini have recently published a paper where they review the taxonomic history of the North American genus Hadrurus Thorell, 1876 and re-evaluate the phylogenetic relationships among the genus' species. In the same paper they also propose a synonymization of Hoffmannihadrurus Fet & Soleglad 2004 with Hadrurus. This means that the following names are valid for the two species previously included in Hoffmannihadrurus:

Hadrurus aztecus Pocock, 1902
Hadrurus gertschi Soleglad, 1976

Here is the abstract of the paper:

The ‘giant hairy scorpions’, genus Hadrurus Thorell, are the largest and most conspicuous scorpions in North America, but their systematics has long been confused. A new genus, Hoffmannihadrurus Fet et al. was recently created to accommodate the two species endemic to mainland Mexico, Hadrurus aztecus Pocock and Hadrurus gertschi Soleglad. In the present contribution, we review the taxonomic history of Hadrurus, re-evaluate the phylogenetic relationships among its component species with an analysis based on morphological characters and a taxon sample representing the known morphological variation, and assess the validity of the new genus. Seven independent analyses of the morphological character matrix, under weighting regimes that minimised length as well as those that maximised fit, each located a single most parsimonious tree with the following scheme of relationships: (Iurus ((Caraboctonus + Hadruroides) (H. aztecus ((H. gertschi + H. pinteri) (H. concolorous + H. hirsutus)) ((H. obscurus + H. spadix) (H. a. arizonensis (H. a. austrinus + H. a. pallidus)))))). This topology supports the monophyly of Caraboctoninae, Caraboctonini, Hadrurini, the ‘arizonensis’ subgroup, H. arizonensis and H. concolorous. It does not support the monophyly of Hoffmannihadrurus, Hadrurus, the ‘aztecus’ group, the ‘hirsutus’ group, and the ‘hirsutus’ subgroup, all of which were rendered paraphyletic by the grouping of H. gertschi with H. pinteri, rather than with H. aztecus. The results unequivocally demonstrate that the creation of a new genus for the mainland Mexican species was unfounded. We therefore propose the following new synonymy: Hoffmannihadrurus Fet et al., 2004 = Hadrurus Thorell, 1876, syn. nov.

Did you know that in Mexico the large Hadrurus are known as "Matacaballos", which actually means "Horse killers". Fortunately, studies have shown that the venom of these impressing scorpions has low toxicity against mammals.

Reference:
Francke OF, Prendini L. Phylogeny and classification of the gigant hairy scorpions, Hadrurus Thorell (Iuridae Thorell): a reappraisal. Systematics and Biodiversity. 2008;6(2):205-23. [Subscription required for fulltext]

Family Caraboctonidae

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