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False Scorpions - Suborder: Epiocheirata
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Recent taxonomic studies have seen some changes to the status of various group with the Pseudoscorpiones. For instance the Genus: Lechytia was raised to family status and later to lowered again to subfamily*, the Suborder Atoposphyronida** has been lowered to superfamily, and other rearrangements have been made as well. More than two-thirds of the nearly 4,200 species of Pseudoscorpions now reside in the Suborder: Epiocheirata. The suborder itself contains two superfamilies; one, the Feaelloidea is represented in Australia but not in our region. The other, the Chthonioidea, is represented in the Northern Rivers by species from three of its four*** families.
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Despite the large number of species worldwide, only eight species of Epiocheirata have so far been identified from the Northern Rivers region. As a a group of organisms Pseudoscorpions are not just neglected by the scientific community, the public in general is not overly perturbed by them either although it must be said that Australia is in the top five group of nations with regards to the number of species described. Despite that there is little doubt that more species remain to be discovered locally and that the overal diversity of Pseudoscorpions in Australia and, by inference, the Northern Rivers region as well, will expand over time.
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The species within the Suborder: Epiocheirata - which means 'gentle hand' - do not possess poison glands as opposed to the Iocheirata, who do. As this is not a feature that is obvious on sight, placing unknown specimens in either order is difficult without intimate knowledge of Pseudoscorpions and, without the means to make close-up observations. Diagnoses with in the order are made on the basis of a number of features which include but are not limited to: the presence of paired trichobotria (a pair of long setae, near the tip of the fixed 'finger' of the chela, that serve to detect airborne vibrations, air currents and electrical charge), the presence of coxal spines (spines on the 'hip' or first joint of the leg, visibly only from below) and, a longitudinal row of setae on each side of the male genital atrium (the internal chamber at the entrance to the male genitals).
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Superfamily: Chthonioidea
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* = The status of Lechytia as a subfamily or as a family remains an issue that is not fully agreed upon by taxonomists.
** = in 2019 M.Harvey reconsidered the position of the Superfamily:Feaeloidea and downgraded it to family status. It was then placed, together with the Family: Pseudogarypidae in a third suborder the Atoposphyronida, resurrecting the old name. iNaturalist does not reflect this change.
*** = Many consider the Family: Tridenchthoniidae to be a subfamily within the Chthoniidae. Its treatment here is in keeping with its status on 'iNaturalist' as of January 2024, which largely conforms to Harvey, (1992), despite the 'World Catalogue of Pseudoscorpiones' not listing it as a family.
** = in 2019 M.Harvey reconsidered the position of the Superfamily:Feaeloidea and downgraded it to family status. It was then placed, together with the Family: Pseudogarypidae in a third suborder the Atoposphyronida, resurrecting the old name. iNaturalist does not reflect this change.
*** = Many consider the Family: Tridenchthoniidae to be a subfamily within the Chthoniidae. Its treatment here is in keeping with its status on 'iNaturalist' as of January 2024, which largely conforms to Harvey, (1992), despite the 'World Catalogue of Pseudoscorpiones' not listing it as a family.
References and links:
> Benavides, L.R., Cosgrove, J.G., Harvey, M.S. and Giribet, G., (2019). 'Phylogenomic interrogation resolves the backbone of the Pseudoscorpiones tree of life.' Molecular Phylogenetics and Evolution, Volume 139, 2019. 106509, ISSN 1055-7903, https://doi.org/10.1016/j.ympev.2019.05.023.
> Harvey, M.S., (1992.) 'The phylogeny and classification of the Pseudoscorpionida (Chelicerata: Arachnida).' Invertebrate Systematics, 6 (6), 1373 – 1435
> Harvey, M.S., (2007). 'The smaller arachnid orders: Diversity, descriptions and distributions from Linnaeus to the present (1758 to 2007).' Zootaxa. 1668. 363–380. doi:10.11646/zootaxa.1668.1.19.
> Judson, M.L.I., (2018). 'Ontogeny and evolution of the duplex trichobothria of Pseudoscorpiones (Arachnida).' Zoologischer Anzeiger,Volume 273,2018,Pages 133-151. ISSN 0044-5231, https://doi.org/10.1016/j.jcz.2017.12.003.
> Murienne, J., Harvey, M.S. and Giribet, G., (2008). 'First molecular phylogeny of the major clades of Pseudoscorpiones (Arthropoda: Chelicerata).' Molecular Phylogenetics and Evolution, Volume 49, Issue 1, 2008, Pages 170-184, ISSN 1055-7903, https://doi.org/10.1016/j.ympev.2008.06.002.
> World Pseudoscorpiones Catalog (2022). World Pseudoscorpiones Catalog. Natural History Museum Bern, online at http://wac.nmbe.ch, accessed on 18/02/2024.
https://en.wikipedia.org/wiki/Glossary_of_spider_terms
https://en.wikipedia.org/wiki/Trichobothria
https://inaturalist.ala.org.au/taxa/372858-Epiocheirata
> Benavides, L.R., Cosgrove, J.G., Harvey, M.S. and Giribet, G., (2019). 'Phylogenomic interrogation resolves the backbone of the Pseudoscorpiones tree of life.' Molecular Phylogenetics and Evolution, Volume 139, 2019. 106509, ISSN 1055-7903, https://doi.org/10.1016/j.ympev.2019.05.023.
> Harvey, M.S., (1992.) 'The phylogeny and classification of the Pseudoscorpionida (Chelicerata: Arachnida).' Invertebrate Systematics, 6 (6), 1373 – 1435
> Harvey, M.S., (2007). 'The smaller arachnid orders: Diversity, descriptions and distributions from Linnaeus to the present (1758 to 2007).' Zootaxa. 1668. 363–380. doi:10.11646/zootaxa.1668.1.19.
> Judson, M.L.I., (2018). 'Ontogeny and evolution of the duplex trichobothria of Pseudoscorpiones (Arachnida).' Zoologischer Anzeiger,Volume 273,2018,Pages 133-151. ISSN 0044-5231, https://doi.org/10.1016/j.jcz.2017.12.003.
> Murienne, J., Harvey, M.S. and Giribet, G., (2008). 'First molecular phylogeny of the major clades of Pseudoscorpiones (Arthropoda: Chelicerata).' Molecular Phylogenetics and Evolution, Volume 49, Issue 1, 2008, Pages 170-184, ISSN 1055-7903, https://doi.org/10.1016/j.ympev.2008.06.002.
> World Pseudoscorpiones Catalog (2022). World Pseudoscorpiones Catalog. Natural History Museum Bern, online at http://wac.nmbe.ch, accessed on 18/02/2024.
https://en.wikipedia.org/wiki/Glossary_of_spider_terms
https://en.wikipedia.org/wiki/Trichobothria
https://inaturalist.ala.org.au/taxa/372858-Epiocheirata
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