Chaerilus conchiformus Zhu, Han & Lourenço, 2008

Tang, Victoria, 2025, Current challenges and preliminary morphological reassessment of the genus Chaerilus Simon, 1877 in China (Scorpiones: Chaerilidae), Euscorpius 406, pp. 1-89 : 11-14

Chaerilus conchiformus Zhu, Han & Lourenço, 2008

( Figures 12–19 ; Tables 1–2) http://zoobank.org/urn:lsid:zoobank.org:act:5726EDCE-

209E-42B7-B2F8-4075F5D3F8D1

Chaerilus pictus (misidentification): Qi et al., 2005: 34–38; Yang, 2008: 18–19, 46–48, 76.

Chaerilus conchiformus : Zhu et al., 2008: 37–43 , 50; Di et al., 2009: 131–133; Di, 2009: 99–101, 189–193; Di & Zhu, 2009: 97, 101; Sun, 2010: 101–103; Kovařík, 2012: 2; Kovařík & Ojanguren-Affilastro, 2013: 131–132, 136; Di et al., 2013: 52 , 55, 57, 88, 95; Di et al., 2014: 4, 9, 14; Yin et al., 2015: 42–43, 46, 48–49; Di et al., 2015: 111; Tang, 2022a: 12, 21, 54–55; Tang, 2022b: 3, 14; Tang, 2023: 20; Tang, 2025: 13 , 16.

TYPE MATERIAL ( Zhu et al., 2008: 39) [lost]. China, Tibet Autonomous Region, Nyingchi City, Bayi District, Bayi Town , 29°41'N 94°21'E (type locality), 1♀ , MHBU; Nyingchi City, Bayi District , hill behind the Xizang Agricultural and Animal Husbandry University (specified in Di, 2009: 99), 1 juv. ♀ ; Nyingchi City, Bayi District, Baishuwang Town , 29°34'N 94°30'E, 6♀ , MHBU; Nyingchi City, Mainling City, Zhaxiraodeng Township (“ Pai Town ”?), 29°12'N 94°06' E, 1♂ , MHBU.

OTHER MATERIAL. China, Tibet Autonomous Region, Nyingchi City, Bayi District, Bayi Town, 1 juv., MHBU ( Qi et al., 2005: 34); Nyingchi City, Bayi District, Bayi Town, 29°41'N 94°21'E (= type locality), 1♂ 3♀, 1 juv. (Di, 2009: 99); Nyingchi City, Bayi District, Bayi Town, hillside north of Xizang Agricultural and Animal Husbandry University, 29°39'50.6''N 94°20'35.4''E (approximated), 2♀, 7 juvs (Di, 2009: 99); Nyingchi City, Mainling City, 1 juv. (Di, 2009: 99). One ♀ reported in Yin et al. (2015: 46).

MATERIAL EXAMINED (VT). China, Tibet Autonomous Region, Nyingchi City, Mainling City, Milin Town , 29°12'51.6''N 94°12'46.2''E, 2936 m a. s. l., 21 st November 2022, 1♂, leg. Yiyang Xu ( Figs. 12–19 ) .

DIAGNOSIS. TL ca. 43.47 mm for ♂ and 32–41.04 mm for ♀. General color reddish brown to dark brown. Two pairs of lateral ocelli and one pair of median ocelli. Carapace and tergites granular, stronger in ♀; CAM straight; sternite III – VI smooth, VII subgranular and tetracarinate. Metasoma I – V with carinae 10-10-8-8-7. Male telson not strongly elongated. PTC 5 in ♂ and 3–4 in ♀. VADC of cheliceral movable/fixed fingers 5–6/5–6 (8?). Pedipalp chela not strongly sexually dimorphic, rounded in both sexes, ChL/W ca. 1.77 in ♂ and 1.6–1.9 in ♀; manus with D 1, D 3 – 5, and V 1 , 3 present and granular, E and I obsolete; DSC of movable finger 7–8, dorsal edge of movable finger straight .

CURRENT ASSESSMENT OF TAXONOMIC VALIDITY. Valid, but pending the designation of a neotype.

REMARKS. Qi et al. (2005: 34–38) misidentified 1 adult female and 2 juvenile Chaerilus from Bayi Town (in Bayi District) as C. pictus . The same adult female (17 th August 2002) was later used as the holotype for describing C. conchiformus ( Zhu et al., 2008: 38–39) , and one of the juveniles (6 th August 2003) was listed as a female paratype, while the other juvenile (sex not specified; 2 nd August 2002) was neglected from the type series. Qi et al. (2005: 34) used the name “Bayizhen town” for the origin of the adult female, which was changed to “Bayi Town” in Zhu et al. (2008: 39), in accordance with the two original juveniles. The Pinyin “zhèn” (Dz) is semantically synonymous with “town” in English, hence this name constitutes a tautological toponym. Zhu et al. (op. cit.) further listed 6 female paratypes (July 2006) from Baishuwang (“Cypress King”) Town (in Bayi District) and 1 male paratype (30 th July 2006) from “Pai Town” (in Mainling City). However, the coordinates they provided for “Pai Town” traces to Zhaxiraodeng Township (in Mainling City) according to Google Maps, located ca. 80 km southwest of Pai Town (29°30'16.0''N 94°51'03.9''E). Later, in Di’s (2009: 99) dissertation, a total of 1 male, 6 females, and 10 juveniles were reported from Bayi Town; also included was a juvenile (7 th August 2003) from Mainling City. Among the 17 specimens from Bayi, based on the collection date, one was the holotype female. The single male, 1 juvenile, and 3 females were collected by Z.-Y. Di on 12th July 2008, but they all share exactly the same coordinates with the holotype female (29°41'N 94°21'E). The name of their locality was given as “Dabaishu Scenic Spot” (k柏树Kã区), which is most likely what is now called “Baishuwang Scenic Spot” (柏树王ã区). In the remaining 11 specimens, the neglected juvenile (2 nd August 2002) reappeared. Finally, 2 females and 8 juveniles were collected near Xizang Agricultural and Animal Husbandry University by different collectors on two different dates. However, one of these juveniles appears to be the paratype female (6 th August 2003) chosen from Qi et al. (2005) by Zhu et al. (2008), given the identical date and collector. The other 9 new specimens were collected by Zhu et al. on 2 nd August 2006, with coordinates approximated above ( Fig. 1 ). Additional records are cited from iNaturalist as follows: Nyingchi City, Bayi District, Xianjin Town, 29°47'29.0''N 94°22'20.9''E (iNaturalist obs. ID = 196900795), 29°39'47.7''N 94°20'09.4''E (iNaturalist obs. ID = 248548420); Nyingchi City, Mainling City, Milin Town, 29°12'50.7''N 94°12'31.0''E (iNaturalist obs. ID = 142538526; same collector of the adult male examined herein).

While the materials reported for C. conchiformus are puzzling, this species is fairly distinctive within all Chinese congeners due to its strongly dilated and somewhat flattened pedipalp chelae in both sexes, dorsally adorned with conspicuous and subgranular carinae. The pedipalp feature alone renders it unique and easily recognizable. Nevertheless, confusions persist when comparing descriptions by Qi et al. (2005: 34) and Zhu et al. (2008: 39–40). All sternites were described as smooth in the earlier work, but Zhu et al. (2008) noticed the subgranular and tetracarinate sternite VII. Qi et al. (2005) documented 10 carinae on metasoma I–VI, with a pair of “lateral” (likely “median lateral”) carinae gradually fading out on segment II–IV. On the other hand, Zhu et al. (2008) described the metasoma carina formula as 10-10-8-8 for segment I–VI, mentioning the distal reduction of “lateral carinae” on segment II, yet without explaining the condition on III–IV. Qi et al. (2005) enumerated a VADC of 8 for both movable and fixed cheliceral fingers, a count decreased to 6 in Zhu et al. (2008), without providing any explanation. It is worth reiterating that both works, which M.-S. Zhu coauthored, were based on the very same female specimen.

Perplexity extends to the measurement of this same specimen—all values are virtually different. Zhu et al. (2008) claimed that TL in C. conchiformus is 32–41.04 mm in females and 43.47 mm in male. They wrote in their table caption that the metrics pertained to the holotype female (also noted within the table), yet it is apparent that those values correspond to the paratype male. The TL was given as 43.47 mm (≠ 39.89 mm in Qi et al.) and the PTC was given as 5/5, contradicting with their female description (3/4, op. cit.: 39) but instead matching that of the male (op. cit.: 42). Amusingly, in Di’s (2009: 151) dissertation, his table 5 listed the male paratype as the holotype, while the largest female (41 mm) was degraded to the paratype. In this case, FL/CaL is less than 1 for male C. conchiformus (4.5/5.3), and so is the female (3.6/4.95). In the dichotomous keys provided by Di et al. (2009: 132), the lower bound of ChL/W of C. conchiformus was declined to 1.6, a value recycled in Di et al. (2013: 88) and Di et al. (2014: 14). This appears to be derived from the “ paratype female” measured in Di’s dissertation (7.7/4.8). In the original description, both holotype female and the single male were given a ChL/W of 1.8; calculation from the table 1 in Zhu et al. (2008) yields a ChL/W of 1.77. This suggests that either the value attributed to the female was erroneous, or this female was not the “ paratype female” studied by Di (indeed, 41≠ 39.89, unless one admits the mensurational inconsistency). These confusions were long overlooked, as the data were all concealed in their Chinese dissertations, which had never been published. In Yin et al. (2015: 46), measurement based on a new female specimen (deposited in USTC, without collection details) increased the upper bound to 1.9 for ChL/W of C. conchiformus . The authors provided a range of 1.6–1.9 for female C. conchiformus in their dichotomous keys (op. cit.: 49), yet listing the value as 1.8–1.9 in their table 3 (op. cit.: 48), while considering the ChL/W of males unknown. Yin et al. (op. cit.) recorded their new female with a DSC of 7 in table 2, which was then increased to 8 in table 3. This is because they used two different meristics—RN (“number of granule rows on the movable finger of the pedipalp”) in table 2, and RF (“row number of denticles on the fixed and movable fingers of the chelae”) in table 3 (but why adopting both “granule” and “denticle”?)—since the target finger considered differed. Clearly, RF represents a larger set ({fixed DSC, movable DSC}) than RN ({movable DSC}), yet the authors entirely ignored their count for the movable finger.

DISTRIBUTION. Bayi District and Mainling City, in Nyingchi City.

Figures

Figure 1. Map showing the known distribution of Chinese Chaerilus species. Black lines represent China national border, downloaded from GitCode. Yellow lines represent county-level division in Nyingchi and Shannan cities, downloaded from Tianditu. Red dash lines represent disputed area (Arunachal Pradesh), downloaded from Natural Earth. The locality of C. pseudoconchiformus is represented by the examined adult pair. Localities of C. conchiformus include those of an examined specimen, iNaturalist observations, and published records (see text). Localities of other species include those of iNaturalist observations and published records only (see text). Insets: left above corner, closeup of type locality of C. herta sp. n.; right bottom corner, localities of the studied C. cf. tryznai (white cross) and C. cf. wrzecionkoi (white triangle).

Figures 12–13. Adult male Chaerilus conchiformus, fresh specimen (now preserved in 75% ethanol), habitus in dorsal (12) and ventral (13) views, under white light; record included in the map.

Figures 14–19. Adult male Chaerilus conchiformus, carapace (14), pectines (15), sternite VII (16), and right chela in dorsoexternal view (17) under white light, and left (18) and right (19) pedipalp movable fingers under UV light.