Chaerilus tryznai Kovařík, 2000

Tang, Victoria, 2025, Current challenges and preliminary morphological reassessment of the genus Chaerilus Simon, 1877 in China (Scorpiones: Chaerilidae), Euscorpius 406, pp. 1-89 : 30

Chaerilus tryznai Kovařík, 2000

( Figures 44–51 ; Tables 1–2) http://zoobank.org/urn:lsid:zoobank.org:act:00E2C268-

AC3C-4B38-8801-9992CE905FDF

Chaerilus tryznai : Kovařík, 2000: 38, 41–42, 58, 65–66, 69, 72; Kovařík, 2001: 82; Soleglad & Fet, 2003: 7, 33; Yang, 2008: 8, 50, 76; Di et al., 2009: 131–133; Di, 2009: 98, 106–108, 196–198; Di & Zhu, 2009: 97–98, 101; Sun, 2010: 101, 108–109; Kovařík, 2012: 2, 13; Kovařík & Ojanguren-Affilastro, 2013: 132, 142; Di et al., 2013: 52 , 57–58, 88, 95; Di et al., 2014: 9, 14; Yin et al., 2015: 42, 46, 48, 49; Di et al., 2015: 111; Tang, 2022a: 55; Tang, 2022b: 3, 14; Tang, 2025: 16 .

Chaerilus triznai [ISS]: Zhu et al., 2008: 37–40, 44, 47–51.

TYPE MATERIAL ( Kovařík, 2000: 65). China, TibetAutonomous Region, Nyingchi City , Bomê County, 29°52'N 95°45'E, 1♂ 12♀, 1 juv. , FKCP.

OTHER MATERIAL. China, Tibet Autonomous Region, Nyingchi City, Mêdog County (incorrectly given as “Nêdong District, Shannan City” in Di (2009: 106) and Sun (2010: 108)), Hanmi Village, 29°02'N 95°03'E (extends to Arunachal Pradesh), 2♀, MHBU ( Zhu et al., 2008: 47); Nyingchi City, Bomê County, 4♀ (Di, 2009: 106). Two ♀ reported in Yin et al. (2015: 46).

MATERIAL EXAMINED (VT) [putative; misidentified as C. wrzecionkoi in Tang (2024b)]. China, Tibet Autonomous Region, Nyingchi City, Bomê County, Tramog Town , 29°51'32.5''N 95°46'03.4''E, 2859 m a. s. l., 27 th July 2023, 1♀, leg. Tongtong ( Figs. 44–51 ) .

DIAGNOSIS. TL ca. 32.3 mm for ♂ and 30.74–44 mm for ♀. General color blackish brown to black. Two pairs of lateral ocelli and one pair of median ocelli. Carapace and tergites granular; CAM straight; sternite III – VI smooth, VII granular and acarinate. Metasoma I – V with carinae 10-8-8-8-7. Male telson not strongly elongated. PTC 4 in ♂ and 3–4 in ♀. VADC of cheliceral movable/fixed fingers 6/4. Pedipalp chela slightly slender in ♂, ChL/W ca. 3.12 in ♂ and 2.6–2.91 in ♀; manus with D 1, D 3 – 5, and V 1 , 3 present and granular, E and I obsolete; DSC of movable finger 8, dorsal edge of movable finger straight .

CURRENT ASSESSMENT OF TAXONOMIC VALIDITY. Valid, but species characterization requires refinement.

REMARKS. This species was the first Chaerilus described from Tibet, on the basis of 1 adult male, 12 adult females, and 1 juvenile. It was contrasted only with C. assamensis given the unique count of finger denticle subrows (8) at the time. The single differential character utilized was the CAM shape (straight in C. tryznai , arched in C. assamensis ). After reviewing the original description of C. dibangvalleycus (presumed synonym of C. assamensis as per Kovařík & Ojanguren-Affilastro, 2013), the two species further differ in the VADC of cheliceral fixed finger, D 3 development, and sternite VII ( Table 1). However, those differences hold true only if C. dibangvalleycus is indeed synonymous with C. assamensis . Nevertheless, the opposite outcome does not logically negate the difference (based solely on the paper descriptions) between C. dibangvalleycus and C. tryznai . Yin et al. (2015: 46) studied two new female specimens (deposited in USTC, without collection details), increasing the upper TL bound to 44 mm while decreasing the lower ChL/W bound to 2.6. Additional comments for the interspecific difference are given under C. pseudoconchiformus and C. wrzecionkoi .

Zhu et al. (2008: 47–51) redescribed this species based on the same female from Hanmi Village, Mêdog ( Fig. 1 ), later reported in Di’s dissertation (2009: 106) who mistakenly stated that it was from Nêdong District (in Shannan City) despite providing the same coordinates; illustrations and measurements of the female are identical in Zhu et al. (2008: figs. 45–59, tab. 1) and Di (2009: figs. 48–50, tab. 5), and the former paper will be referenced to henceforth. Zhu et al. (op. cit.) also listed another female collected one day before from the same locality as the female examined, and the two records were followed by Di et al. (2013: 57). Di (2009: 106) further mentioned 4 females from Bomê without coordinates. All six females were fully documented in Sun’s dissertation (2010: 108), but Di et al. (2013: 57) excluded the four females from Bomê.

Not much useful information can be retrieved from the redescription as the key characters were generally identical with the original description. However, Zhu et al. (2008: 50) provided a ChL/W of 2.2 for the female they examined, but measurements from their table 1 would give a value of 2.083 (6.75/3.24). A crude measurement based on their figure 47 yields, on the other hand, a ChL/W of 2.54 (to derive width in pixels, a constraint rectangle was applied to the chela figure in situ, i.e., no rotation, and the length was obtained from the pixel distance between fingertip and the most proximal, angular granule on the external margin). This is closer to the original metrics (2.9), and even more so to the lower bound value (2.6) given in Yin et al. (2015: tab. 3).

DISTRIBUTION. Hanmi Village of Mêdog County, and Bomê County, 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 44–45. Adult female Chaerilus cf. tryznai, fresh specimen (now preserved in 75% ethanol), habitus in dorsal (44) and ventral (45) views, under white light; record included in the map.

Figures 46–51. Adult female Chaerilus cf. tryznai, carapace (46), pectines (47), sternite VII (48), and left chela (right chela movable finger broken) in dorsoexternal view (49) under white light, and left (50) and right (51) pedipalp movable fingers under UV light.