Lygosoma quadrupes (LINNAEUS, 1766)
Can you confirm these amateur observations of Lygosoma quadrupes?
|Higher Taxa||Scincidae, Lygosominae (Lygosomini), Scincoidea, Sauria, Squamata (lizards)|
|Common Names||E: Short-limbed Supple Skink, Linnaeus' Writhing Skink|
G: Asiatischer Schlankskink
|Synonym||Anguis quadrupes LINNAEUS 1766: 390|
Lacerta serpens BLOCH 1776
Lacerta abdominalis THUNBERG 1787
Chalcida serpens — MEYER 1795: 31
Scincus brachypus SCHNEIDER 1799: 192 (or 1801)
Seps pentadactylus DAUDIN 1802
Mabuya serpens — FITZINGER 1826
Lygosoma serpens — HARDWICKKE & GRAY 1827
Podophis quadrupes — WIEGMANN 1834
Lygosoma abdominalis GRAY 1839: 332
Lygosoma brachypoda DUMÉRIL & BIBRON 1839: 721
Podophis chalcides GRAY 1845
Lygosoma brachypoda — GRAVENHORST 1851: 367
Eumeces chalcides — GÜNTHER 1864
Eumeces chalcides — LEIDY 1884: 66 (?)
Lygosoma chalcides — BOULENGER 1887: 340
Lygosoma chalcides — TAYLOR 1922: 233
Lygosoma quadrupes — COCHRAN 1930
Lygosoma quadrupes — SMITH 1935: 290
Lygosoma quadrupes — TAYLOR 1963: 1049
Lygosoma quadrupes — GREER 1970
Lygosoma quadrupes — BROWN & ALCALA 1980: 108
Gongylus brachypoda — FRANK & RAMUS 1995: 187
Lygosoma quadrupes — MANTHEY & GROSSMANN 1997: 267
Lygosoma quadrupes — COX et al. 1998: 115
Lygosoma quadrupes — GAULKE 1999
Lygosoma quadrupes — ZIEGLER et al. 2007
Lygosoma quadrupes — KOCH 2012
Lygosoma quadrupes — SILER et al. 2018
Lygosoma quadrupes — FREITAS et al. 2019
|Distribution||Indonesia (restricted to Java by Siler et al. 2018)|
Type locality: Java.
|Reproduction||oviparous (not imputed, fide Zimin et al. 2022)|
|Types||Holotype: unlocated; no depository indicated by Linnaeus. Catalogues of Linnaean types in the Stockholm and Uppsala collections do not list this species (Lonnberg, 1896; Andersson, 1899, 1900), and Das (2012) was similarly unable to identify any type specimen. Siler et al. (2018) erroneously list ZMB 1276 as a syntype.|
Syntype: ZMB 1276 (see Bauer & Günther, 2006). Bloch (1776) redescribed this species based on two specimens and provided illustrations of both. Investigation by Bauer and Günther (2006) revealed that only a single syntype of this species remains (ZMB 1276) which was the larger of the two specimens illustrated in Bloch’s (1776) redescription and that the missing syntype may have been lost or destroyed prior to the receipt of these specimens to ZMB (Siler et al. 2018). [Lacerta serpens]
|Diagnosis||Diagnosis (genus): Lygosoma can be identified by the following combination of characters: (1) body size small to large (SVL 49–168 mm); (2) trunk moderately elongate to elongate (AGD 58–93% SVL); (3) digits short (FinIIILam 4–9, ToeIVLam 5–13); (4) MBSRC 25–38; (5) PVSRC 84–123; (6) lower eyelid scaly; (7) supranasal scales in contact medially or not in contact medially, usually fully or partially fused with nasals; (8) prefrontals not in contact medially; (9) frontoparietal single or paired; (10) parietals in contact medially posterior to interparietal; (11) enlarged nuchal scales present or absent; and (12) palatine bones with posteriomedially projecting processes, pterygoids emarginated along posterior edge [Freitas et al. 2019].|
Diagnosis (genus): Lygosoma species are characterized by the following features: oblong head with scaly or transparent movable lower eyelid, elongated snout with fusion or presence of supranasals, single or paired frontoparietals, elongated body with snout to vent length from 41 to 170 mm, short reduced limbs, relatively long tail, smooth or keeled subcycloid scales, and outer precloacals overlapping the inner precloacals (Taylor 1963; Greer 1977; Lim 1998; Das 2010) [GEISSLER et al. 2012].
Diagnosis (species). Lygosoma quadrupes can be distinguished from congeners by the following combination of morphological characters: 1) body size small (SVL 66.8–78.3 mm); 2) limb length short; 3) supralabials 6 or 7; 4) infralabials 5 or 6; 5) superciliaries 7; 6) supraoculars 4; 7) Finger III lamellae 5 or 6; 8) Toe IV lamellae 6 or 7; 9) midbody scale rows 25 or 26; 10) axilla– groin scale rows 99–101; 11) paravertebral scale rows 117–121; and 12) single, enlarged, fused frontoparietal (Tables 2, 3 in Siler et al. 2018).
Comparisons.—Lygosoma quadrupes is phenotypically most similar to Lygosoma siamensis and L. tabonorum but can be distinguished from both by having longer relative forelimbs (FLL 4.7–5.9% SVL vs. 2.3–4.9% [L. siamensis], 3.3–4.6% [L. tabonorum]), a tendency toward longer relative hind limbs (HLL 6.6–9.7% SVL vs. 4.0–8.0% [L. siamensis], 5.1–6.8% [L. tabonorum]), and a greater number of axilla–groin scale rows (99–101 vs. 88–98 [L. siamensis], 83–90 [L. tabonorum]). Additionally, L. quadrupes differs from L. tabonorum by having a greater number of paravertebral scale rows (117–121 vs. 106–111) and superciliaries (7 vs. 5 or 6) (Tables 2, 3).
Compared with all other small, slender species recognized to occur in Southeast Asia (L. albopunctatum, L. anguinum, L. bowringii, L. frontoparietale, L. herberti, L. lineolatum, L. popae, and L. veunsaiensis), L. quadrupes can be distinguished from L. albopunctatum, L. anguinum, L. bowringii, L. frontoparietale, L. herberti, L. lineolatum, L. popae, and L. veunsaiensis by having a larger body size (SVL 66.8–78.3 mm vs. ?64.0 mm), longer axilla–groin distance (AGD 47.9–61.0 mm vs. ?42.0 mm), and a greater number of axilla–groin (99–101 vs. ?76) and paraver- tebral (117–121 vs. ?99) scale rows; from L. albopunctatum, L. frontoparietale, L. lineolatum, and L. popae by having a longer tail length (TL; 54.0–71.8 mm vs. ?54.0 mm); from L. anguinum, L. frontoparietale, L. lineolatum, and L. popae by having longer forelimbs (3.9–4.4 mm vs. ?4.3 mm); from L. albopunctatum by having a greater number of midbody scale rows (25 or 26 vs. 14); from L. frontoparietale by having fewer midbody scale rows (25 or 26 vs. 28 or 29); from L. albopunctatum, L. bowringii, L. frontoparietale, L. herberti, and L. samajaya by having fewer Finger III lamellae (5 or 6 vs. >7); and from L. albopunctatum, L. anguinum, L. bowringii, L. frontoparietale, L. herberti, L. popae, and L. samajaya by having fewer Toe IV lamellae (6 or 7 vs. >8); and from L. samajaya by having a longer axilla-groin distance (AGD 47.9–61.0 mm vs. ?43.4 mm), shorter forelimbs (3.9–4.4 mm vs. ‡13.2 mm), and a greater number of paravertebral scale rows (117–121 vs. ?61) (Tables 2 and 3).
From larger species recognized to occur in Southeast Asia (L. angeli, L. bampfyldei, L. boehmei, L. corpulentum, L. haroldyoungi, L. isodactylum, L. kinabatanganensis, L. koratense, L. opisthorhodum, L. peninsulare, L. punctatum, and L. schneideri), L. quadrupes differs from L. boehmei, L. corpulentum, and L. koratense by having a smaller body size (SVL 66.8–78.3 mm vs. 86.0 mm [L. boehmei], 97.8–168.0 mm [L. corpulentum], 101.0–106.0 mm [L. koratense]) and shorter tail length (TL 54.0–71.8 mm vs 91.0 mm [L. boehmei], 97.6–159.8 mm [L. corpulentum], 93.0–95.0 mm [L. koratense]); from L. bampfyldei, L. haroldyoungii, L. isodactylum, L. kinabatanganensis, L. opisthorhodum, L. peninsulare, L. punctata, and L. schneideri by having a smaller body size (SVL 66.8–78.3 mm vs. 110.0–119.0 mm [L. bampfyldei], 114.8–148.0 mm [L. haroldyoungi], 82.5–117.0 mm [L. isodactylum], 141.0 mm [L. kinabatanganensis], 93.0 mm [L. opisthorhodum], 119.0 mm [l. peninsulare], 85.0 mm [L. punctata], 129.0 mm [L. schneideri]); from L. boehmei, L. corpulentum, L. haroldyoungi, L. herberti, L. isodactylum, and L. koratense, L. quadrupes differs by having a shorter head length (HL 4.4–5.6 mm vs. 12.3 mm [L. boehmei], 16.9–30.3 mm [L. corpulentum], 15.2–18.1 mm [L. haroldyoungi], 6.8–8.8 mm [L. herberti] 11.7–14.0 mm [L. isodactylum], 18.0–19.0 mm [L. koratense]) and shorter head width (HW 4.6–5.2 mm vs. 10.5 mm [L. boehmei], 12.0–21.8 mm [L. corpulentum], 9.5–12.0 mm [L. haroldyoungi], 7.5–8.4 [L. herberti], 7.7–9.0 mm [L. isodactylum], 13.0 mm [L. koratense]); from L. boehmei, L. corpulentum, L. isodactylum, and L. koratense by having fewer midbody (25 or 26 vs. 32 [L. boehmei], 36–40 [L. corpulentum], 30– 34 [L. isodactylum], 32–34 [L. koratense]) and a greater number of paravertebral scale rows (117–121 vs. 66 [L. boehmei], 78–86 [L. corpulentum], 88–98 [L. isodactylum], 63 [L. koratense]); from L. angeli by having fewer midbody scale rows (25 or 26 vs. 30); and from L. punctata by having a greater number of paravertebral scale rows (117–121 vs. 62–76); and from L. boehmei and L. koratense by having fewer infralabials (5 or 6 vs. 7 [L. boehmei], 7 [L. koratense]).
|Comment||Synonymy after SMITH 1935. The name Podophis has been also suggested for an extinct snake, Podophis descouensi RAGE & ESCUILLIÉ 2000. Later this name was replaced by Eupodophis descouensi RAGE & ESCUILLIÉ 2002.|
Lygosoma (Siaphos) lacertosum from Werner 1917 cannot be assigned to any known species given that the type specimen has been lost (J. Hallermann, pers. comm. 20 Dec 2013).
Phylogenetics: The genus Lygosoma s.s. is not monophyletic, with the African genera Mochlus and Lepidothyris nested in Lygosoma s.s.
Type Species: Anguis quadrupes LINNAEUS 1766 is the type species of the genus Lygosoma HARDWICKKE & GRAY 1827. Lygosoma is also the type genus of the (sub-) family Lygosominae (or Lygosomidae). Note that the correct group name is actually Lygosomatinae (-idae), following Article 29 of the Code. However, prevailing usage dictates that the incorrect but established form of the family group name be used (Allen et al. 2017).
Lygosoma is also the type genus of the family Lygosomidae Hedges & Conn 2012: 28 and the subfamily Lygosominae Gray 1845 in which Shea 2021 included the tribus Lygosomini Gray 1845, Ateuchosaurini Hedges 2014 (here: Ateuchosaurinae), Tiliquini Gray 1845 (here: Egerniinae), Eugongylini Welch 1982 (here: Eugongylinae), Ristellini Hedges 2014 (here: Ristellinae), Sphenomorphini Welch 1982 (here: Sphenomorphinae), and Mabuyini Mittleman 1952 (here: Mabuyinae).
The generic assignments to Lygosominae in this database follows Hedges 2014.
Key: Geissler et al. 2011 provide a key to the Lygosoma of Indochina.
Distribution: reports from Cambodia, Laos, West Malaysia, Thailand, and Vietnam represent L. siamensis SILER et al. 2018.
Habitat: forested habitats at lower elevations (Siler et al. 2018)
Limb morphology: Reduced limbs.
|Etymology||Named after the fact that this species has 4 reduced limbs (Latin pes = foot), which is misleading as all species have 4 limbs. However, in the past the genus also included limb-reduced species, now assigned to other genera (e.g. Anomalopus or Lerista).|
Lygosoma means ‘writhing body’ in Greek (lygos = writhe, soma = body). Genus names ending in -soma are feminine (Böhme & Denzer 2019). However, Ganesh 2017 claims that Lygosoma is neuter, without further explanation.