Hormuridae reinstalled after study on the evolution, biogeography and phylogeny of Indo-Pacific taxa

Indo-Pacific hormurid scorpion phylogeny from one of the two new studies on hormurid scorpions.

Lionel Monod and Lorenzo Prendini have recently published a major study on the evolution, biogeography and phylogeny of Indo-Pacific scorpions belonging to several genera previously placed in Hemiscorpiidae. This is a complicated study and I recommend to read the paper to get all details concerning the conclusions listed below.

Another paper by Monod, Harvey and Prendini on hormurid scorpions was published in the end of last year. This paper actually preceded the Monod & Prendini paper in content, and I have therefor not written about it until now, when the latter paper is published. In the first paper three new species of Hormurus are described and the evolution of burrowing behavior in the reinstalled family Hormuridae is discussed.

Main conclusions:

Family Hormuridae Laurie, 1896 is elevated to family rank after being a subfamily in Hemiscorpiidae.

The genera Hormiops Fage, 1933 and Hormurus Thorell, 1876, previously placed in synonymy with Liocheles Sundevall, 1833, are reinstated as valid genera. See Scorpion Files family page for list of species which are included in the reinstalled genera.

Genera Cheloctonus Pocock, 1892, Chiromachetes Pocock, 1899, Chiromachus Pocock, 1893, Hadogenes Kraepelin, 1894, Hormiops Fage, 1933, Hormurus Thorell, 1876, Iomachus Pocock, 1893, Liocheles Sundevall, 1833, Opisthacanthus Peters, 1861, Palaeocheloctonus Lourenco, 1996 and Tibetiomachus are included in Hormuridae.

The family Hemiscorpiidae includes now only the genus Hemiscorpius Peters, 1861.

Based on the conclusions in the current paper, I have chosen to reinstall the family Heteroscorpionidae Kraepelin, 1905 in The Scorpion Files and moved the genus Heteroscorpion Birula, 1903 from Hemiscorpiidae to Heteroscorpionidae. See familiy pages (links below) for more details.

The following new species are described from Australia:

Hormurus ischnoryctes Monod & Prendini, 2013
Hormurus macrochela Monod, 2013
Hormurus ochyroscapter Monod, 2013

Hormurus longimanus (Locket, 1995) is reinstated as the valid name for this species and the replacement name, Liocheles extensus Locket, 1997 is placed in synonymy.

Abstract 1:
Scorpions previously assigned to the genus Liocheles Sundevall, 1883, of the family Hormuridae Laurie, 1896, are widely distributed in the tropical forests of the Indo-Pacific region. Revisionary systematics of these poorly known scorpions has revealed a tremendous diversity of species. As part of an ongoing investigation, the first analysis of Indo-Pacific hormurid scorpion phylogeny based on morphological data scored for all currently recognized species of Hormiops Fage, 1933, Hormurus Thorell, 1876, and Liocheles, is presented. The taxonomy of these scorpions is reassessed and their biogeography reinterpreted in the light of the phylogeny. Phylogenetic, morphological, and distributional data support the revalidation of Hormiops and Hormurus, previously synonymized with Liocheles. The phylogeny indicates that the Australasian hormurids are more closely related to the Afrotropical and Neotropical hormurids than to the Indian hormurids, as previously proposed, refuting the “out-of-India” origin of Asian hormurids. A recent paleogeographical hypothesis, the “Eurogondwana model”, is supported instead. According to this hypothesis, hormurid scorpions colonized Laurasia from Africa via the Apulia microplate (Europa terrane) in the Cretaceous, subsequently colonized the Australo-Papuan archipelago in the early-mid Cenozoic, and then went extinct in the Northern Hemisphere during the second half of the Cenozoic. These results suggest that, contrary to the traditional paradigm, dispersal and extinction may affect spatial and temporal biotic distributions as much as vicariance, even in animals with limited vagility, such as scorpions.

Abstract 2:
Three new species from the semi-arid ecosystems of Queensland, Australia, are described in the present contribution: Hormurus ischnoryctes n. spec., Hormurus macrochela n. spec., Hormurus ochyroscapter n. spec. Additionally, the discovery of the first female specimens of Hormurus longimanus (Locket, 1995) from the Northern Territory of Australia, as well as additional diagnostic characters and locality records for this species, warranted its redescription. Hormurus longimanus (Locket, 1995) is reinstated as the valid name for this species and the replacement name, Liocheles extensus Locket, 1997 placed in synonymy. Unlike most species of Hormurus and of the closely related genera, Hormiops Fage, 1933 and Liocheles Sundevall, 1883, which inhabit humid tropical ecosystems (evergreen forests), the four Australian species treated here inhabit seasonally dry (monsoon) habitats, and two of these (H. ischnoryctes and H. ochyroscapter) are the first fossorial hormurids to be recorded in Australia, and the first fossorial species of Hormurus to be described. The four species treated here appear to be relicts of an old hygrophilous lineage that sustained a major adaptive radiation during the late Tertiary aridification of the continent. Endemism and conservation issues coneerning these phylogenetically valuable species are discussed in the context of high sensitivity to habitat disturbance and high risk of extinction of stenotopic species.

Reference 1:
Monod L, Prendini L. Evidence for Eurogondwana: The roles of dispersal, extinction and vicariance in the evolution and biogeography of Indo-Pacific Hormuridae (Scorpiones: Scorpionoidea). Cladistics. 2014;In Press. [Subscription required for full text]

Reference 2:
Monod L, Harvey MS, Prendini L. Stenotopic Hormurus Thorell, 1876 scorpions from the monsoon ecosystems of northern Australia, with a discussion on the evolution of burrowing behaviour in Hormuridae Laurie, 1896. Rev Suisse Zool. 2013 Jun;120(2):281-346.

Family Hormuridae
Family Hemiscorpiidae
Family Heteroscorpionidae