A phylogenetic analysis of the ancient Asian scorpion family Pseudochactidae

 

As previously mentioned, the ancient, relictual Asian scorpion family Pseudochactidae Gromov, 1998 is probably one of the most interesting scorpion families in the world. It consist of both of extinct and extant taxa, and the latter is often labeled as "living fossils" due to their unique morphology. 

In a recent article, Lorenzo Prendini and co-workers present a new phylogenetic analysis of the genus with new information about the phylogeny and taxonomy of this fascinating family and its evolution. 

Abstract:
The ancient, relictual Asian scorpion family Pseudochactidae Gromov, 1998, has a disjunct distribution. Five genera and seven species of living pseudochactids are assigned to one epigean subfamily, Pseudochactinae Gromov, 1998, from Central Asia and southern China, and two hypogean subfamilies, Troglokhammouaninae Prendini et al., 2021, and Vietbocapinae Lourenço, 2012, from caves of the Khammouan-Phong Nha-Kẻ Bàng Karst in the northern Annamite (Trường Sơn) Mountains of Laos and Vietnam. The extinct subfamily Chaerilobuthinae Lourenço and Beigel, 2011, comprises one genus and 15 species, hypothesized to be endogean, from mid-Cretaceous Burmese amber. The discovery and uncertainty regarding the phylogenetic placement of Qianxie solegladi Tang, 2022, from South China, together with the discovery that the Cretaceous amber Chaerilobuthinae, from the Burma Terrane, is the sister group of the extant pseudochactid subfamily Vietbocapinae provided an opportunity to revisit the phylogeny and biogeography of Pseudochactidae, and their adaptation to subterranean habitats in Southeast Asia. In the present contribution, pseudochactid phylogeny is reanalyzed using three mitochondrial markers (12S rDNA, 16S rDNA, Cytochrome c Oxidase Subunit I), three nuclear markers (18S rDNA, 28S rDNA, Internal Transcribed Spacer) and 143 morphological characters, for all extant pseudochactid taxa and seven exemplar species of the extinct Chaerilobuthinae. Divergence time and ancestral range estimation are conducted and the evolution of troglomorphic characters investigated to reassess how this lineage of “living fossils” dispersed and diversified. Recent changes to the systematics of Pseudochactidae are confirmed. The four subfamilies, genera, and species were monophyletic with high support and the following scheme of relationships: (Pseudochactinae (Troglokhammouaninae (Chaerilobuthinae + Vietbocapinae))). Phylogenetic analyses, reinforced by a multivariate morphometric analysis and pairwise genetic distances, confirm the validity of the monotypic, epigean Chinese genus, Qianxie Tang, 2022, which formed a monophyletic group with the epigean Central Asian genus, Pseudochactas Gromov, 1998, rather than the hypogean Southeast Asian genus, Troglokhammouanus Lourenço, 2007. Qianxie solegladi is transferred to Pseudochactinae. A revised time tree of Pseudochactidae suggests that the Burmese Chaerilobuthinae diverged from the Indochinese subfamilies, Troglokhammouaninae and Vietbocapinae, in the Early Cretaceous (ca. 117 Ma), consistent with Early Devonian rifting of the Burma Terrane.

Reference:
Prendini L, Xuan Q, Du SE, Wang C-BE, Ehrenthal VL, Loria SF. Phylogeny and divergence time estimation of relictual Asian scorpion family suggests Early Cretaceous connections between Burma Terrane and Eurasia, and corrects placement of Chinese taxon. American Museum Novitates. 2026(4051):1–55. [Open Access]

Family Pseudochactidae 

A new fossil species described from Early Cretaceous amber from Myanmar and some taxonomical decisions

 

Wilson Lourenco and  Jürgen Velten have recently published an article where they describe a new fossil species from Early Cretaceous amber from Myanmar (Burma).

Serratochaerilobuthus barbarae Lourenco & Velten, 2025

A few weeks ago, Xuan et al, 2025 published a study reviewing the taxa in the fossil family Chaerilobuthidae and decided to change status of this family to subfamily (Chaerilobuthinae) and placed it in the extant family Pseudochactidae Gromov, 1998. The two extinct genera Chaeriloiurus Lourenço, 2020 and Serratochaerilobuthus Lourenço, 2024, were synonymized with Chaerilobuthus Lourenço and Beigel, 201.

Lourenco and Velten do not accept the results of this study.

In addition, the  authors also elevate Pseudochactidae Gromov, 1998, to superfamily status as Pseudochactoidea Gromov, 1998. Likewise, they raise Vietbocapinae Lourenco, 2012, to family rank as Vietbocapidae Lourenco, 2012. The authors also synonymize Troglokhammouaninae with Pseudochactidae Gromov, 1998, and the genus Aemngvantom Prendini, Ehrenthal & Loria, 2021 with Vietbocap Lourenco & Pham, 2010. 

These major taxonomical decisions seem to be made mainly because Lourenco and Velten disagree with several previous works  (e.g. Prendini et al, 2021). The problem is that the authors do not present any real and thorough justifications or analysis themselves to justify the proposed decisions. The studies they criticize have thorough morphological and phylogenetical analysis to back up their claims. 

I do not have the competence to tell who is correct, but I feel that basically just saying "we disagree" is not enough to justify such major taxonomical decisions. Because of this I have chosen not to accept the taxonomical decisions in the Lourenco and Velten article in The Scorpion Files until justification based on morphological, phylogenetical and/or genetical analysis are provided. 

This is a decision I reluctantly take after consulting with a few others in the scorpion community and I understand if some of you do not support this.

Abstract:
A new species is described for the genus Serratochaerilobuthus Lourenço, 2024. The description of this new species brings further evidence for the validity of the genus and confirms the family Chaerilobuthidae as one of the most speciose groups among those known from Early Cretaceous Burmite.

Reference:
Lourenco WR, Velten J. Description of a second species for the genus Serratochaerilobuthus Lourenço, 2024 (Scorpiones: Chaerilobuthidae). Faunitaxys. 2025;13(10):1-6. [Open Access]

Family Pseudochactidae

Extinct family Chaerilobuthidae from Mid-Cretaceous Burmese amber with 16 species are now a part of the extant family Pseudochactidae

 

In a recent article, Qiang Xuan and co-workers have analyzed the taxa in the extinct family Chaerilobuthidae Lourenço and Beigel, 2011. This family originally consisted of 3 genera and 16 species. All taxa are based on fossil specimens found in Mid-Cretaceous Burmese amber.

The authors conclude that the family Chaerilobuthidae should change status to subfamily (Chaerilobuthinae) and placed in the extant family Pseudochactidae Gromov, 1998. The two extinct genera Chaeriloiurus Lourenço, 2020 and Serratochaerilobuthus Lourenço, 2024, are synonymized with Chaerilobuthus Lourenço and Beigel, 2011 which contains 16 species (all extinct).

Chaerilobuthinae with its taxa is now listed in The Scorpion Files for Pseudochactidae, but are not included in the count of number of taxa which only includes extant taxa.

Abstract:
The extinct scorpion family Chaerilobuthidae Lourenço and Beigel, 2011, endemic to Burmese amber, was initially established due to its unique pedipalp trichobothrial pattern related to the Type A and Type B patterns of families Buthidae C.L. Koch, 1837 and Chaerilidae Pocock, 1893, respectively. The present contribution describes 11 new specimens, representing seven species of Chaerilobuthidae from Mid-Cretaceous Burmese amber, revealing their morphology using various imaging technologies. A revised diagnosis of Chaerilobuthus Lourenço and Beigel, 2011 is provided based on new morphological characters of the carapace, ocelli, chelicera, pedipalp trichobothria, coxapophyses, and leg tarsi. The other two genera of Chaerilobuthidae, Chaeriloiurus Lourenço, 2020 and Serratochaerilobuthus Lourenço, 2024, are synonymized with Chaerilobuthus based on a reassessment of their morphological characters and morphometric analysis, creating Chaerilobuthus brigittemuellerae (Lourenço and Velten, 2020), comb. nov. and Chaerilobuthus schmidti (Lourenço and Velten, 2024), comb. nov.. The systematic position of Chaerilobuthidae is clarified based on phylogenetic analyses of an updated morphological character matrix for Pseudochactidae Gromov, 1998, an extant family in Asia. Phylogenetic analysis placed Chaerilobuthidae sister to the pseudochactid subfamily Vietbocapinae Lourenço, 2012, justifying its transfer to Pseudochactidae, as Chaerilobuthinae Lourenço and Beigel, 2011, stat. nov.. This discovery confirms that Pseudochactidae date back 100 Mya and contributes to understanding the origin and evolutionary history of this relictual family.

Reference:
Xuan Q, Prendini L, Engel MS, Cai C, Huang D. Extinct scorpion family Chaerilobuthidae from Mid-Cretaceous Burmese amber reinterpreted as subfamily of extant family Pseudochactidae (Chelicerata: Scorpiones). Zoological Journal of the Linnean Society. 2025;203(1):zlae169. [Subscription required for full text]

Thanks to Gerard for informing me about this article!

Family Pseudochachtidae

A new genus and species in the enigmatic family Pseudochactidae from China

 

The family Pseudochactidae Gromov, 1998 consisted for many year of only one genus and one species. In recent years a few more genera and species have been described, many from isolated areas. Victoria Tang has now described a new genus and species from the Yunnan Province of China, greatly increasing the distribution of this family.

Qianxie Tang, 2022

Qianxie solegladi Tang, 2022

The new species seems to be found only above ground and it exhibits no troglomorphism, which is different from its presumed sister genus, Troglokhammouanus Lourenço, 2007.

Abstract:
A new monotypic genus belonging to the basal scorpion family Pseudochactidae Gromov, 1998, Qianxie solegladi gen et. sp. n., is described from Yunnan Province of China. The family is recorded from China for the first time, vastly extending its known geographic range. The new genus shares morphological characters with both Pseudochactas Gromov, 1998 and Troglokhammouanus Lourenço, 2007. It differs from Pseudochactas and is similar to Troglokhammouanus in the shapes of anterior and posterolateral carapace margins, form of the circumocular sutures, distance between median ocelli, development of dorsoventral projection of patella, length of tarsal spinules, recurvature of the lateral margins and concavity of the surface of the sternum. It is similar to Pseudochactas in the degree of carapace granulation, pedipalp manus carination, secondary accessory and retroventral carinae of the chela manus, numbers of lamellae and teeth on the pectines, development of the median lateral carinae of metasomal segments III–IV and ventromedian carina of metasomal segment V. The new genus is hypothesized to be more closely related to Troglokhammouanus than to Pseudochactas and is placed in the subfamily Troglokhammouaninae.

References:
Tang V. A new scorpion genus and species from China, Qianxie solegladi gen. et sp. n. (Scorpiones: Pseudochactidae). Euscorpius. 2022(351):1-19. [Open Access]

Family Pseudochactidae

A review of the enigmatic family Pseudochactidae and troglobitism/troglomorphism in scorpions

 

Most scorpion researchers agree that the most remarkable scorpion discovery in the last century was the discovery of the very special scorpion Pseudochactas ovchinnikovi Gromov, 1998 in a remote, mountainous region of southeastern Uzbekistan and southwestern Tajikistan. This species "gave birth" to the family Pseudochactidae. Later one more species in the genus was discovered and the family was further increased two more genera with a few more species. Most of the latter are cavernicolous (found in caves), but not all of them have troglomorphisms like reduced eyes and pigmentation. All of the species in the family are rare and have a relictual distribution.

Lorenzo Prendini and co-workers have now conducted a thorough review of the family Pseudochactidae. Based on morphological and phylogenetical analysis they have concluded the following:

New subfamily:

 Troglokhammouaninae Prendini, Ehrenthal & Loria, 2021.

New genus:

Aemngvantom  Prendini, Ehrenthal & Loria, 2021.

New species:

Aemngvantom thamnongpaseuam Prendini, Ehrenthal & Loria, 2021.

New combination:

Aemngvantom lao (Lourenço, 2012).

Synonymizations:

Troglokhammouanus louisanneorum Lourenço, 2017 is synonymized with  Troglokhammouanus steineri Lourenço, 2007.

Vietbocap thienduongensis Lourenço and Pham, 2012 is synonymized with Vietbocap canhi Lourenço & Pham, 2010.

Vietbocap aurantiacus Lourenço et al., 2018 is synonymized with Vietbocap canhi Lourenço & Pham, 2010.

Vietbocap Vietbocap quinquemilia Lourenço et al., 2018 is synonymized with Vietbocap canhi Lourenço & Pham, 2010.

The family consists now of three subfamilies, four genera and six species. The article has revised descriptions of all species, pictures and habitat information with conservation status. An identification key for the family is also provided.

The article also provide a review of the global diversity of cavernicolous, troglomorphic and troglobitic scorpions and an ecological key to the classification of this kind of scorpions is also presented. 

Abstract:
The first integrative systematic revision of the relictual Asian scorpion family Pseudochactidae Gromov, 1998, making use of an unprecedented collection of material acquired during several expeditions to most of the type localities, is presented. The subfamilies, genera and species of Pseudochactidae are revised based on a phylogenetic analysis of 140 morphological characters and 8608 nucleotide base pairs of concatenated DNA sequence from two nuclear and three mitochondrial gene loci, and a multivariate statistical analysis of 22 ratios and 8 counts for 60 specimens. Three subfamilies, four genera and six species are recognized in the family. Troglokhammouaninae, subfam. nov., is created to restore the monophyly of the nominotypical subfamily Pseudochactinae Gromov, 1998. Aemngvantom, gen. nov., is created to accommodate Aemngvantom lao (Lourenço, 2012), comb. nov., and Aemngvantom thamnongpaseuam gen. et sp. nov. Four new synonyms are presented: Troglokhammouanus louisanneorum Lourenço, 2017 = Troglokhammouanus steineri Lourenço, 2007, syn. nov.; Vietbocap thienduongensis Lourenço and Pham, 2012 = Vietbocap canhi Lourenço and Pham, 2010, syn. nov.; Vietbocap aurantiacus Lourenço et al., 2018 = V. canhi, syn. nov.; Vietbocap quinquemilia Lourenço et al., 2018 = V. canhi, syn. nov. Revised diagnoses of the subfamilies, genera and species, with comparative images, a key and distribution maps are provided, along with a summary of available data on ecology and conservation status, where applicable. Among the Southeast Asian pseudochactids, all of which appear to be obligately cavernicolous, the three species of Vietbocapinae Lourenço, 2012, are highly troglomorphic whereas the sole species of Troglokhammouaninae is barely so. Applying recently revised definitions of the Schiner-Racovitza system for the classification of subterranean organisms, only Vietbocapinae can be considered troglobitic. The global diversity of cavernicolous, troglomorphic and troglobitic scorpions is similarly revisited and a key to ecological classification of cavernicolous and troglomorphic scorpions presented. The world totals of troglomorphic vs. troglobitic scorpions are currently 58 vs. 28 species, in 29 vs. 17 genera and 15 vs. 13 families, respectively.

Reference:
Prendini L, Ehrenthal VL, Loria SF. Systematics of the relictual Asian scorpion family Pseudochactidae Gromov, 1998, with a review of cavernicolous, troglobitic, and troglomorphic scorpions. Bulletin of the American Museum of Natural History. 2021(453):1-149. [Open Access]

Thanks to Matt Simon for informing me about this article!

Family Pseudochactidae

Two new, troglobitc species discovered 3000-5000 meters inside a cave system in Vietnam

The family Pseudochactidae Gromov, 1998 contains several enigmatic genera and species, many of them troglobites living in cave systems in Asia. In a recent article, Wilson Lourenco and co-workers present the discovery of two new, troglobitic species in the genus Vietbocap Lourenço & Pham, 2010 from the Thien Duong cave in Vietnam.

Vietbocap aurantiacus Lourenço, Pham, Tran & Tran, 2018

Vietbocap quinquemilia Lourenço, Pham, Tran & Tran, 2018

The two species were discovered 3000-5000 meters inside the cave system. This is a new record of distance from a cave entrance for scorpions.

Abstract:
Two new species of scorpion belonging to the family Pseudochactidae and to the genus Vietbocap are described based on specimens collected in the Thien Duong cave, which belongs to the Vom cave system, in the Phong Nha–Ke Bang National Park, Quang Binh Province, Vietnam. The previously described species from this cave, Vietbocap thienduongensis Lourenco & Pham, 2012 was collected in the initial section of the cave (1500 to 1800 m from the cave entrance) and proved to be a true troglobitic element. The diagnosis of this species, only known from males, is completed based on females collected at 750 m from the cave entrance. The two new species described here were collected respectively at 3000 and 5000 m from the cave entrance and are also true troglobitic elements, very similar to V. thienduongensis, but showing some clear morphological differences. This observed situation suggests a possible case of speciation within the cave system, the first one ever reported for scorpions. The population found at 5000 m from the entrance of the cave is a total new record of distance from a cave entrance for scorpions.

Reference:
Lourenco WR, Pham DS, Tran TH, Tran TH. The genus Vietbocap Lourenco & Pham, 2010 in the Thien Duong cave, Vietnam: A possible case of subterranean speciation in scorpions (Scorpiones: Pseudochactidae). C R Biol. 2018. [Subscription required for full text]

Family Pseudochactidae

A checklist of the scorpion fauna of Vietnam

Dinh-Sac Pham and co-workers have recently published an updated checklist of the scorpion fauna of Vietnam.

Abstract:
A faunistic inventory is proposed for the known Vietnamese scorpion species. The aim of this contribution is to bring an up-to-date checklist of all known species in Vietnam, prior to a more detailed study of the Vietnamese fauna to be performed by one of the authors (T.- H.T.) in the context of the preparation of a doctoral degree. Final taxonomic decisions should be taken at the end of the doctoral dissertation.

Reference:
Pham DS, Tran TH, Lourenco WR. Diversity and endemicity in the scorpion fauna of Vietnam. A preliminary synopsis. C R Biol. 2017;340(2):132-7. [Open Access]

A checklist of the scorpion fauna of Vietnam

The scorpion fauna of Vietnam has previously received little attention. Dinh-Sac Pham and co-workers have now published a checklist of the scorpion fauna of Vietnam based on the available literature. The aim of the study is to make ready for future taxonomic studies of the scorpions of Vietnam.

In the article the authors raise the subgenus Vietscorpiops (Lourenço and Pham, 2015) (Euscorpiidae) to genus status and the species Scorpiops dentidactylus Lourenço and Pham, 2015 is moved to the new genus (as Vietscorpiops dentidactylus (Lourenço and Pham, 2015) ).

Abstract:
A faunistic inventory is proposed for the known Vietnamese scorpion species. The aim of this contribution is to bring an up-to-date checklist of all known species in Vietnam, prior to a more detailed study of the Vietnamese fauna to be performed by one of the authors (T.- H.T.) in the context of the preparation of a doctoral degree. Final taxonomic decisions should be taken at the end of the doctoral dissertation.

Reference:
Pham DS, Tran TH, Lourenco WR. Diversity and endemicity in the scorpion fauna of Vietnam. A preliminary synopsis. C R Biol. 2016. [Open Access]

Family Euscorpiidae

A review of the scorpion biogeography of Southeast Asia

Wilson Lourenco has written a book chapter on the biogeography of scorpions of Southeast Asia in the book "Biodiversity, Biogeography and Nature Conservation in Wallacea and New Guinea, volume II". See abstract below for more details.

Abstract:
Biogeographic patterns observed among modern scorpions are the consequence of different major events which can be integrated in the schematic scales proposed by M. Udvardy. The distribution of the principal modern groups (i.e. families and genera) is derived from elements (protofamilies and protogenera of Pulmonate- Neoscorpionina) which originated in Pangea. The main factor in the phylogenetic/palaeobiogeographic scale was probably not the latitudinal and longitudinal overland migration (dispersion) of the ancestors Neoscorpionina, which followed the predominantly southward shift of the warm tropical belt, but a rather more passive vicariant process in association with dispersal in Haffer’s sense, in response to the progressive fragmentation of Pangea. This was followed by continental drift which led to the present configuration of the continents and climates. This suggestion seems to be in accordance with the very poor vagility observed in modern scorpions. On the millennial scale, Pleistocene and post-Pleistocene biogeography has been responsible for the regional level of the distribution pattern which, during its settlement, has led to the selection of some new specific lineages and to the extinction of others. On the secular scale, the ecological biogeography is a consequence of recent natural or anthropic events. This scale has been little used by scorpion biogeographers, mostly because of lack of data on scorpion life history strategies. In this chapter, examples from Southeast (and Wallacea) scorpions are proposed for and discussed in relation to the three biogeographic scales of Udvardy.

Reference:
Lourenco WR. Biogeography of Southeast Asia (and Wallacea) scorpions, a review. In: Telnov D, editor. Biodiversity, Biogeography and Nature Conservation in Wallacea and New Guinea, volume II. Riga: Entomological Society of Latvia; 2014. p. 27-46.

Thanks to professor Lourenco for sending me this paper!

Scorpions in the family Chaerilidae do not fluorescence under UV light

Scorpions fluorescence when they are exposed to ultraviolet light (in the range 320 - 400 nm). Several authors have discussed possible functions for this phenomena or if it has no function at all (previous blog posts on fluorescence).

Wilson Lourenco now reports that species in the family Chaerilidae do not fluorescence when exposed to UV light (Nine species were tested). This surprise finding is very interesting in the quest for any function of the fluorescence in scorpions. Interestingly, professor Lourenco also tested four species in the enigmatic family Pseudochactidae and they all did fluorescence. Pseudochactidae is considered to be the oldest and most primitive scorpion family and the presence of fluorescence may indicate that this is an early adaption in scorpions.

Abstract:
The fluorescence of scorpions in ultraviolet light, a well-known phenomenon, was discovered more than 60 years ago. Its possible function remains, however, a matter of discussion. Even during very recent studies, no conclusion has been reached. As suggested in these recent publications, the lack of or reduction of fluorescence could be a useful tool to explain the phenomenon. It is suggested here that, in at least some species of the family Chaerilidae Simon, this phenomenon is absent. This new discovery may initiate important comparative eco-physiological studies.

Reference:
Lourenço WR. Fluorescence in scorpions under UV light; can haerilids be a possible exception? Comptes Rendus - Biologies. 2012;335:731-4. [Subscritpion required for full text]

Thanks to professor Wilson Lourenco for sending me his paper!

A new species of Pseudochactas from Afghanistan

Photo: Michael Misch (C)

The discovery of the enigmatic Pseudochactas ovchinnikovi Gromov, 1998 from Central Asia and a new family, Pseudochactidae, was undoubtedly one of the most important discoveries in scorpion systematics in recent times. Now a second species of this genus has been described from south-central Afghanistan.

Pseudochactas mischi Soleglad, Kovarik & Fet, 2012 (Pseudochactidae)

The new species is named after Michael Misch, who collected the name species in Afghanistan and made it available to the authors of this paper. Congratulations, Michael, and thanks for your contributions to The Scorpion Files!

Abstract:
A new species of the rare genus Pseudochactas Gromov, 1998 is described from south-central Afghanistan. The species, P. mischi, sp. nov., is compared in detail to its northern sister species P. ovchinnikovi Gromov, 1998, known from Uzbekistan and Tajikistan. P. mischi, sp. nov. is a smaller, lighter colored species and has a considerably more robust metasoma, telson, and pedipalp chelae. Biogeographical observations on the genus Pseudochactas are provided.

Reference:
Soleglad, ME, Kovarik F & Fet, V. (2012). A new species of Pseudochactas from Afghanistan (Scorpiones: Pseudochactidae). Boletin de la SEA, (50):89-98.

Thanks to Michael Soleglad for sending me this paper!

Family Pseudochactidae

A new troglobitic Vietbocap species described from caves in Laos

Vietnam and Laos have cave system with enigmatic scorpion fauna with cave adaptions (troglobites). Previously, two species have been described in the genus Vietbocap Lourenco & Pham, 2010 (Pseudochactidae). In a forthcoming paper Wilson Lourenco describes a new species from the Tham Nam Lot cave in Laos.

Vietbocap lao Lourenco, 2012

A new subfamily, Vietbocapinae Lourenco, 2012 is suggested to accommodate the species in the genus Vietbocap.

Abstract:
A new species of scorpion belonging to the family Pseudochactidae and the genus Vietbocap is described from the Tham Nam Lot cave, located in the Laotian part of the Khammouan-Ke Bang karst in Southeast Asia. Like the previously described species of the genus, Vietbocap lao sp. n. is a true troglobiont, but presents an even greater degree of adaptation to cave life, with a total lack of pigmentation and a very weak sclerotization of the tegument. This is the third troglobitic element known for the family Pseudochactidae. It represents the fifth known species of pseudochactid, four of which are from the Khammouan-Ke Bang karst system. Taking into account some marked differences between Vietbocap and the other two pseudochactid genera, a new subfamily, Vietbocapinae subfam. n., is proposed to accommodate this genus.

Reference:
Wilson R L. The genus Vietbocap Lourenço & Pham, 2010 (Scorpiones: Pseudochactidae); proposition of a new subfamily and description of a new species from Laos. Comptes Rendus Biologies. 2012. 335:232-237. [Subscription required for full text]

Thanks to professor Lourenco for informing me about this paper!

Family Pseudochactidae

A new troglobitic, cave-dwelling scorpion from Vietnam

Wilson Lourenco and Din-Sac Pham have discovered another fantastic cave-dwelling scorpion from Vietnam belonging to the enigmatic family Pseudochactidae.

Vietbocap thienduongensis Lourenco & Pham, 2012

The new species is a true troglobite (e.g. lacking eyes and pigmentation among other traits) and was collected 2200 meters from the cave entrance of the Thien Duong cave (Vom cave system in the Phong Nha - Ke Bang National Park). This is actually a new distance record from a cave entrance for a scorpion!

Interestingly, this cave is totally isolated from the cave where Vietbocap canhi Lourenço & Pham, 2010 was discovered.

Abstract:
A second species of scorpion belonging to the family Pseudochactidae and to the genus Vietbocap is described from two specimens collected in the Thien Duong cave, which belongs to the Vom cave system, in the Phong Nha - Ke Bang National Park, Quang Binh Province, Vietnam. Like the previously described species of Vietbocap, the new species is also a true troglobitic element, the second known for the family Pseudochactidae. This represents the fourth known record of a pseudochactid, and the second from Vietnam.

Reference:
Lourenço WR, Pham D-S. A second species of Vietbocap Lourenço & Pham, 2010 (Scorpiones: Pseudochactidae) from Vietnam. Comptes Rendus Biologies. 2012;335(1):80-5. [Subscription required for fulltext]

Thanks to Gerard Dupre for informing me about this paper!

Family Pseudochactidae

A remarkable new genus and species of Pseudochactidae from Vietnam

New scorpion taxa are discovered regularly, but sometimes really fantastic discoveries are made. This is one of them! Lourenco & Pham have recently described a remarkable new troglobitic genus and species from the Tien Son Cave in Vietnam. The new taxa belongs to the enigmatic family Pseudochactidae Gromov, 1998, which now has three genera with three species from Tajikistan, Uzbekistan, Laos and Vietnam. There is not a consensus within the scorpion community on the phylogenetic position of this family, but there is an agreement that this family has a basal status among recent scorpions.

Vietbocap Lourenco & Pham, 2010
Vietbocap canhi Lourenco & Pham, 2010

This is the first true troglobite (loss of eyes and pigmentation and living in caves) reported for this family.

Abstract:
A new genus and species of scorpion belonging to the family Pseudochactidae are described based on four specimens collected in the Tien Son cave at the Phong Nha - Ke Bang National Park, Quang Binh Province, Vietnam. The new species represents a true troglobitic element, the first one known for the family Pseudochactidae. This represents the third known record of a pseudochactid, and the first from Vietnam.

Reference:
Lourenco WR, Pham D-S. A remarkable new cave scorpion of the family Pseudochactidae Gromov (Chelicerata, Scorpiones) from Vietnam. ZooKeys. 2010;71:1-13. [Free fulltext, but article not available online yet]

Thanks to Gerard Dupre for sending me this paper!

Family Pseudochactidae