Strophurus congoo, Vanderduys, Eric, 2016

Vanderduys, Eric, 2016, A new species of gecko (Squamata: Diplodactylidae: Strophurus) from north Queensland, Australia, Zootaxa 4117 (3), pp. 341-358 : 343-353

Strophurus congoo sp. nov.

Congoo gecko

( Figures 2–7 , 9 (left))

Material examined. Holotype: QMJ93409, female, 17 km southeast of Petford, north Queensland, Australia (145o0'00 E, 17o30'00" S), collected by E. Vanderduys and A. Reside, 1 November 2013. Paratypes: Collection locations as above. QMJ88502, female collected by E. Vanderduys, 4 May 2009; QMJ93406, male; QMJ93407, male; QMJ93408, female; QMJ93411, male; all collected by E. Vanderduys and A. Reside, 1 November 2013.

Diagnosis. The new species belongs to the family Diplodactylidae (as defined by Han et al. 2004), and conforms to the genus Strophurus as defined by Greer (1989) in having caudal glands and a conspicuous mouth colour. The new species also conforms in all respects to diagnostic features presented in comprehensive identification guides to Australian reptiles ( Wilson & Swan 2013; Cogger 2014) and its antipredator strategies conform with those presented in Melville et al. (2004 as subgenus Strophurus ). There is also strong support for Strophurus congoo sp. nov. falling within Strophurus based on genetic data (Oliver, pers. comm.). The presence of precloacal pores in males and the same genetic data suggest Strophurus congoo sp. nov. is a member of the S. ciliaris group ( S. krisalys , S. ciliaris , S. wellingtonae (Storr) , S. taenicauda (De Vis) , S. williamsi , S. intermedius , S. rankini , S. spinigerus (Gray)) .

Strophurus congoo sp. nov. is a small (maximum SVL 49.1 mm), short-tailed (TL/SVL 0.45–0.56), faintly patterned or immaculate gecko from northeast Queensland, Australia. Strophurus congoo sp. nov. is readily distinguished from all other Strophurus by the combination of the following characters: its lack of enlarged tubercles, its generally dull pattern, with a scattering of dark grey spots, each occupying a single scale at most, and sometimes a very faint indication of slightly darker brown dorsal reticulations, and often faint longitudinal stripes along the tail. Ventral surface is demarcated from dorsal surface along the lower sides, the ventral surface being paler than the dorsal, usually with scattered darker spots, each occupying a single scale. The colour of the ventral surface of the tail is more strongly demarcated from the dorsal tail surface colour than on the body. Eye colour is cream with a pale brown to orange reticulum through the iris. The mouth lining is pale blue–purple.

Description. Holotype: detailed morphometric and scalation data are presented in Table 1. Scalation: rostral bordered above by 3 scales (two large nasals and one granular internasal scale); enlarged supraciliaries only on upper, posterior edge of eyes; nares not in contact with rostral; supralabials and infralabials progressively smaller posteriorly. General head scalation of small circular to oblong granular scales, forming hexagramic patterns with neighbouring tiny scales; each larger granular scale is bordered by six approximately equal sized neighbours and six tiny intergranules. The mental scale is an isosceles trapezoid, 1.7 times wider than deep, bordered posteriorly by three granular scales.

Head wide, long and distinct from the neck. Snout long, rounded when viewed from above, slightly angular at the level of the nares when viewed from the side. Eyes large with vertical pupil. Ear opening diagonally elliptic on both sides. Trunk slender and approximately half the snout-vent length. General body, limb and tail scalation is similar to general head scalation, with granular scales larger ventrally than laterally and dorsally, but otherwise approximately equal in size throughout. Forelimbs and hindlimbs are moderately long relative to body length. Tail original, almost cylindrical in cross-section, unbroken and approximately half the length of the head and body. There is a median cluster of enlarged precloacal scales between the two hind limbs and a median cluster of enlarged scales posterior to cloaca at the base of the tail. Precloacal pores and cloacal spurs absent.

Colour in life ( Figure 2 ): Dorsal colour pale grey with numerous darker spots peppering the background colour; these spots no larger than the scales on which they sit. Very faint dorsolateral stripes present on either side of the trunk, paler than the background colour, continuing over the hips and onto the tail. A distinct colour demarcation at lower lateral surface, with belly pale cream, peppered with darker spots as on the dorsal surface, and very obscure, rough-edged longitudinal stripes. Eye colour cream with brown reticulations. Tail colouration as for body, including the dorsoventral colour demarcation. Mouth lining dark blue, tongue maroon to almost black.

Colour in preservative ( Figure 3 ): All dorsal surfaces are medium grey with very faint darker mottling. A sparse peppering of dark spots, which are both darker and more numerous on the head than the rest of the body and are generally smaller than the scales they occupy, although some are single scale in size. Ventral surface is cream to very pale tan with a moderately distinct demarcation between ventral and dorsal colour along the lower flank. Same dorsal/ventral colour demarcation present on tail. Small dark spots are present on ventral surfaces as on the dorsal surfaces.

Paratypes: see Table 1. The three males had 5–7 precloacal pores (mean 6.0). One male (QMJ93411) had a regenerating tail so tail measurements are not included for this individual.

Colour in life ( Figures 4–6 ): Dorsal colour cream, pale tan to dark grey, usually with numerous darker spots peppering the background colour, each spot no larger than the scale on which it sits. Usually a distinct colour demarcation with paler belly at lower lateral surface. Along the demarcation line, one individual (QMJ88502; Figure 4 (a)) had an irregular line of darker scales. Belly cream to white and immaculate or peppered with darker spots as on dorsal surface, and sometimes with obscure, rough-edged longitudinal stripes of either a very pale grey or very pale brown ( Figure 5 ). Colour on tail and limbs as for the body, including the dorso-ventral colour demarcation. Often a faint cream stripe on the upper lateral surface of tail. The newly regenerating tail of QMJ93411 was a dull grey brown, similar to the ground colour of the rest of the body, lacking in any indication of the pale upper lateral stripe seen in some other individuals. Eye colour is cream with reddish-brown reticulations; mouth lining pale to dark blue, and tongue is pale blue, pale purple or brown to deep maroon or almost black ( Figure 6 ).

Variation. An adult male that was seen but not collected was consistent with the colour in life of the paratypes. A juvenile seen but not collected was immaculate except for very faint dorsal spots and very indistinct colour demarcation between upper and lower surfaces. Evidence of internal tail glands, a characteristic unique to Strophurus ( Greer 1989) among Australian geckoes, is visible as transverse rows of slightly raised scales on the dorsal surfaces of the tails of two preserved specimens. These raised scales border the presumptive fracture planes in the skin from which tail secretions are ejected. Similar transverse rows of raised scales were clearly visible on the juvenile ( Figure 7 ).

Etymology. Strophurus congoo sp. nov. is named in honour of Mr Tom Congoo , Bar-Barrum elder, and his family, who hold native title claim over the area where Strophurus congoo sp. nov. was first discovered. The specific epithet is used as a noun in apposition. Mr Congoo readily allowed our original survey team (EV plus former CSIRO staff members Nick Colman and Genevieve Perkins) to survey the area.

Comparison with other Strophurus . Strophurus congoo sp. nov. is readily distinguished from all other Strophurus as follows. It differs from from the "spiny-tailed" and "thorn-tailed" geckos ( Wilson & Swan 2013) S. assimilis (Storr) , S. ciliaris , S. intermedius , S. krisalys , S. rankini , S. spinigerus , S. strophurus (Dumeril & Bibron) , S. wellingtonae and S. williamsi , in having no enlarged tubercles or spines on either the dorsal body or caudal surfaces; the dorsal and lateral body scales in Strophurus congoo sp. nov. are homogenous in size throughout. In S. rankini the dorsal and caudal tubercles may be reduced to the point of being almost indiscernible or only slightly enlarged ( Storr et al. 1990; Wilson & Swan 2013; Cogger 2014) and sparse ( Storr 1979), but they are present, in contrast to Strophurus congoo sp. nov. It further differs from the above species in its small size (maximum SVL 49.1 mm) as compared to S. assimilis (78.0), S. ciliaris (89.0), S. intermedius (63.6), S. krisalys (76.0), S. rankini (63.0), S. spinigerus (74.0), S. strophurus (70.0), S. wellingtonae (85.0) and S. williamsi (66.6). The tail is generally shorter in Strophurus congoo sp. nov. (maximum TL/SVL 0.56) than in the above species, though there is overlap in TL/SVL ratios with some. Minimum TL/SVL ratios for those species are as follows: S. assimilis (0.55), S. ciliaris (0.53), S. intermedius (0.52), S. krisalys (0.59), S. rankini (0.60), S. spinigerus (0.70), S. strophurus (0.60), S. wellingtonae (0.59) and S. williamsi (0.43). See Table 2 for comparative mean and range values.

Strophurus taenicauda , although most closely related to the spiny-tailed Strophurus ( Kluge 1967; Brown et al. 2012; Oliver, pers. comm.), has no enlarged dorsal spines or tubercles. Strophurus congoo sp. nov. differs from S. taenicauda in smaller maximum size (e.g. SVL 69.3–73.2 mm), usually shorter tail (range TL/SVL 0.54–0.84) (measurements from Brown et al. 2012) different eye colour (orange to red in S. t. taenicauda and S. t. triaureus Brown, Worthington Wilmer & Macdonald; cream to pale yellow with prominent pale flecks around the pupil in S. t. albiocularis Brown, Worthington Wilmer & Macdonald), lacking gold–orange dorsal tail stripe and pattern of starkly contrasting black spots and patches on a white to pale grey ground colour

2014). R anđ L = right anđ left hanđ siđe, respectively.

QM No Holotype QMJ88502 QMJ93406 QMJ93407 QMJ93408 QMJ93411 Mean

QMJ93409 (Stanđarđ đeviation)

SVL 49.1 44.0 44.7 44.3 48.0 46.0

25.8 23.7 25.2 22.6 21.8 NA

/SVL 0.53 0.54 0.56 0.51 0.45 NA 0.52 (0.041)

HW 9.0 8.2 8.6 8.0 9.6 7.5

HW/SVL 0.18 0.19 0.19 0.18 0.20 0.16 0.18 (0.013) 6.4 5.3 5.7 5.4 5.9 5.3

/HW 0.71 0.65 0.66 0.68 0.61 0.71 0.70 (0.037) 12.0 11.6 11.2 12.0 11.8 11.6

/SVL 0.24 0.26 0.25 0.27 0.25 0.25 0.25 (0.010) 4.4 4.0 3.9 4.0 3.8 3.9

/HL 0.37 0.34 0.35 0.33 0.32 0.34 0.34 (0.015) 1.9 1.3 1.9 1.5 1.7 2.1

EYE 2.7 2.4 2.5 2.8 2.7 2.9

/EYE 1.63 1.67 1.56 1.43 1.41 1.34 1.51 (0.131)

EYE/HL 0.23 0.21 0.22 0.23 0.23 0.25 0.23 (0.014) 23.6 22.2 21.3 21.6 22.1 23.2

/SVL 0.48 0.50 0.48 0.49 0.46 0.50 0.49 (0.017)

Forearm 7.6 7.1 7.2 7.2 7.6 7.2

Forearm/SVL 0.15 0.16 0.16 0.16 0.16 0.16 0.16 (0.003)

Tibia 8.1 8.1 8.1 8.5 8.4 8.2

Tibia/SVL 0.17 0.18 0.18 0.19 0.18 0.18 0.18 (0.008)

TW 3.5 3.4 3 2.6 3.5 NA

3.3 3.1 2.6 3 3.4 NA

……continued on the next page shallow trapezoiđ trapezoiđ shallow trapezoiđ trapezoiđ trapezoiđ trapezoiđ

Male/Female F F M M F M

unđiviđeđ lamellae counteđ unđer the 4th toe rather than 3rđ toe as in Oliver & Parkin (2014), because previous authors have generally useđ 4th toe lamellae in đescriptions,

( Ogilby 1892; Sađlier et al. 2005; Smith 1995; Stirling & Zietz 1893; Storr 1978; 1983; 1988a; b).

Mođal values are given for meristic counts

measurements of specimens listeđ in Appenđix 1: Material Examineđ plus sixteen S. williamsi inđiviđuals measuređ in the fielđ near Townsville.

Where Strophurus congoo sp. nov. and S. williamsi are sympatric, the dorsal tubercles of S. williamsi tend to be reduced. Nevertheless, the two species are readily distinguished by the following features of S. williamsi (see description of Strophurus congoo sp. nov. for comparison): enlarged orange tubercles on the body and tail, dorsal pattern obvious, and usually including a broad darker, zigzag pattern longitudinally ( Figure 8 ), more prominent patterning on belly, often including broad, irregular brown reticulations, and iris white, with dark reticulations and a distinct orange border ( Figure 9 ).

From the remaining Strophurus species, that lack enlarged spines or tubercles on the tail and/or dorsal body surface, Strophurus congoo sp. nov. most closely resembles the seven "striped" or "phasmid" geckos ( Wilson & Swan 2013; Oliver & Parkin 2014); S. jeanae , S. mcmillani , S. michaelseni , S. robinsoni , S. taeniatus , S. wilsoni Storr , and S. horneri Oliver & Parkin.

Male Strophurus congoo sp. nov. are differentiated from males of the phasmid geckos listed above as well as from their relative Strophurus elderi (Stirling & Zietz) in possessing precloacal pores. Male Strophurus congoo sp. nov. further differ from S. horneri , S. jeanae , S. mcmillani , S. michaelseni and S. taeniatus in lacking clear longitudinal stripes on the body and tail; at most Strophurus congoo sp. nov. has three faint, wavy, pale stripes along the original tail, commencing at or behind the hips and separated by slightly darker grey stripes. One of the pale tail stripes forms a rough mid-line 1–4 scales wide. This is bordered on either side by a darker stripe 2–5 scales wide, while the pale dorsolateral tail stripes are 1–4 scales wide. These do not form clear stripes as in the above species. When there is an indication of dorsal body pattern, it is in the form of very faint longitudinally arranged series of blotches, tending to join up, but not regular enough to be considered stripes. Male Strophurus congoo sp. nov. further differs from S. horneri , S. jeanae , S. mcmillani , and S. taeniatus in having a shorter tail with no apparent overlap in proportions with these species ( Table 2 ).

In its light blue–deep purple mouth lining, Strophurus congoo sp. nov. differs from S. mcmillani and S. michaelseni (pink–flesh-coloured), and from S. ciliaris , S. taeniatus and S. jeanae (yellow–orange). With the exception of S. michaelseni , eye colour in Strophurus congoo sp. nov. is similar to the phasmid geckos, that is, pale orange to dark brown reticulations on a cream to grey iris (deep orange to brown with darker reticulations in S. michaelseni ). Strophurus congoo sp. nov. differs from S. michaelseni in its slender build (robust in S. michaelseni ).

Strophurus congoo sp. nov. differs from S. elderi in colour and pattern. Strophurus elderi is dark grey–brown with dark-edged cream–white spots scattered over the dorsal surface, and associated with enlarged tubercles ( Cogger 2014). Strophurus elderi also has a stout tail and the mouth colour is pink to flesh coloured ( Greer 1989).

Distribution and habitat. All Strophurus congoo sp. nov. were found in close association with Triodia bitextura hummocks, the majority visible on the outside of the hummock and not more than 22 cm from the ground when first seen. Of the three individuals that were not in actual contact with Triodia bitextura when first observed, one was perched on a small stick that was leaning on a hummock while another, QMJ88502, was first observed crawling rapidly between two hummocks on a fallen stick. One juvenile ( Figure 7 ) was first observed on a small rock, with three small (diameter <20 cm) hummocks within 80 cm.

Strophurus congoo sp. nov. is known from a limited area of infertile granitic and rhyolite country in the Einasleigh Uplands bioregion within the northern Great Dividing Range, Queensland, Australia ( Figure 1 ). The area is in the seasonally dry tropics, a region characterised by marked seasonal differences with a distinct wet season usually from December–April, and mostly dry for the remainder of the year. All individuals of Strophurus congoo sp. nov. were located within open Eucalyptus spp. woodland with Triodia bitextura hummocks, with or without other grass species and the shrub Jacksonia thesioides and sedge Schoenus sparteus ground cover ( Figures 10 and 11 ).

Strophurus congoo sp. nov. were found within areas mapped (Accad et al. 2006; Sattler & Williams 1999) as Regional Ecosystems (RE) 9.12.7a ( Eucalyptus cullenii +/- Corymbia leichhardtii +/- C. erythrophloia woodland on acid and intermediate volcanic rocks [particularly rhyolite]), 9.12.2 ( Eucalyptus cullenii +/- Corymbia leichhardtii +/- C. erythrophloia woodland on acid and intermediate volcanic rocks and Eucalyptus portuensis (= E. acmenoides ), Corymbia citriodora , E. granitica or E. crebra , C. intermedia or C. clarksoniana mixed openforest on steep hills and ranges on acid and intermediate volcanics close to Wet Tropics boundary) and 9.12.27 ( Eucalyptus melanophloia and/or E. shirleyi +/- Corymbia erythrophloia low open-woodland on igneous rocks). The more detailed descriptions for these three Regional Ecosystems (not provided here) all mention presence of tussock forming grasses such as Themeda triandra , Heteropogon spp. (spear grasses) and Mnesithea rottboellioides (northern cane grass). However, none mention Triodia spp. which form a significant proportion of the ground cover in many areas. Regional Ecosystem 9.11.10 ( Eucalyptus cloeziana , Corymbia citriodora , E. portuensis and E. cullenii mixed open forest on steep dissected hills on highly metalliferous metamorphic rocks), which occurs nearby has a ground layer of " Themeda triandra … and occasionally Triodia " in the detailed description and some of the areas in which Strophurus congoo sp. nov. were found may be more correctly mapped as RE 9.11.10. I estimate area of occupancy for Strophurus congoo sp. nov. using these four listed Regional Ecosystems and excluding the area where my field observations indicate there is no Triodia present, to be approximately 35800 hectares ( Figure 1 ). This is likely an underestimate, but further field work is required to determine whether or not the true extent of occurrence and area of occupancy spread further than the area I have calculated.

Figures

FIGURE 1. Map of collection location of Strophurus congoo sp. nov. overlaid on Google Earth imagery. Hatched area is an estimated minimum area of occupancy, based on Regional Ecosystem classification and field observations of habitat type. Previous records from Atlas of Living Australia and my own records of Strophurus williamsi are also shown. Grey area in inset map is the Einasleigh Uplands bioregion, while stippling indicates the Great Dividing Range.

FIGURE 2. Holotype QMJ 93409 female Strophurus congoo sp. nov. in life, showing relatively unmarked dorsal surface with a faint peppering of dark spots.

FIGURE 3. Holotype QMJ 93409 female Strophurus congoo sp. nov. in preservative.

FIGURE 4. Strophurus congoo sp. nov. in life: (a) QMJ 88502, female, note clear demarcation between ventral and dorsolateral colour; (b) QMJ 93406, male; (c) QMJ 93407, male; (d) QMJ 93408, female, note clear pale stripe along tail.

FIGURE 5. Strophurus congoo sp. nov. in life: QMJ 93408, showing typical ventral pattern and ventrolateral colour demarcation.

FIGURE 6. Strophurus congoo sp. nov. QMJ 88502 (L) and QMJ 93406 (R), showing variation in mouth lining colour from dark to pale blue, tongue colour, and dark to pale dorsal head colouration.

FIGURE 7. Strophurus congoo sp. nov., juvenile, not collected, shown in situ as found. Locations of slightly raised transverse scale ridges indicating fracture planes are shown by arrows. From the tail base, only the 1 st, 3 rd, 5 th and 7 th glands are indicated to save cluttering the image.

FIGURE 8. Strophurus williamsi QMJ 88499, collected 275 m from Strophurus congoo sp. nov. QMJ 93411, showing obvious orange, enlarged tubercles, distinct dorsal pattern, and orange rim of iris which distinguish this species from Strophurus congoo sp. nov. where the two co-occur.

FIGURE 9. Strophurus congoo sp. nov. (QMJ 93411), left and sympatric Strophurus williamsi (QMJ 88499), showing differences in eye colour: cream with brown to orange reticulum and no orange border in Strophurus congoo sp. nov. versus iris white, with dark reticulations and distinct orange border in S. williamsi.

FIGURE 10. Habitat of Strophurus congoo sp. nov. dominated by Triodia bitextura and Schoenus sparteus on a rocky to gravelly substrate in mixed open Eucalyptus woodland.

FIGURE 11. Triodia bitextura habitat of Strophurus congoo sp. nov. Foreground arrow indicates position of capture of QMJ 93406; background arrow indicates capture location of Strophurus williamsi QMJ 93410 approximately 9 m away.

Tables

TABLE 2. Showing comparative size anđ tail length anđ heađ wiđth ratios of Strophurus congoo sp. nov. anđ all other Strophurus species. Unsourceđ đata are from

Species	SVL mean, range (n)	Mean TL/SVL mean, range (n)	HW/SVL mean, range (n)
Strophurus congoo sp. nov.	45.9, 43.2—49.1 (6)	0.52 (5), 0.45—0.56	0.18, 0.16—0.20 (6)
Strophurus assimilis	58.1, 26F78 (67) (Storr 1988a)	64.3, 0.55F0.73 (67) (Storr 1988a)
Strophurus ciliaris ciliaris	66.8, 35F86 (83) (Storr 1988a)	0.64, 0.53F0.74 (55) (Storr 1988a)
Strophurus ciliaris aberrans	70.3, 29F89 (253) (Storr 1988a)	0.66, 0.54F0.79 (184) (Storr 1988a)
Strophurus ciliaris 'population 7' (Sađlier et al. 2005) Strophurus elderi Strophurus intermedius Strophurus horneri (Oliver & Parkin 2014)	77.0 (Sađlier et al. 2005) 45F51 (Cogger 2014; Stirling & Zietz 1893; Wilson & Swan 2013) 55.1, 42.0F63.6 (14) 50.2, 41F58 (19) (Storr 1988a) 35.7	0.67, 0.60F0.72 (18) (Sađlier et al. 2005) ~0.55 (Cogger 2014) 0.61, 0.52F0.68 (7) 0.69, 0.58F0.66 (15) (Storr 1988a) 0.68	0.18, 0.17F0.21 (14) 0.16
Strophurus jeanae	40.9, 39.6F42.6 (4)	0.77, 0.63F0.88 (4)	0.13, 0.12F0.15 (4)
Strophurus krisalys Strophurus mcmillani	60.5, 33.9F76.0 (38) 47.5, 44.5F49.3 (3)	0.68, 0.59F0.80 (12) 0.67, 0.59F0.0.76 (28) (Sađlier et al. 2005) 0.64, 0.63F0.64 (2)	0.18, 0.16F0.19 (3)
Strophurus michaelseni	55, 48.3F63.3 (4)	0.51, 0.42F0.60 (2)	0.19, 0.19F0.22 (4)
Strophurus rankini Strophurus robinsoni	54.1, 43.1F60.9 (4) 56.1, 47F63 (11) (Storr 1979) 54.1 (1)	0.64, 0.60F0.70 (4) 0.64, 0.61F0.67 (7) (Storr 1979) 0.59 (1)	0.18, 0.18F0.19 (4) 0.17 (1)
Strophurus spinigerus spinigerus	57.0, 25F74 (345) (Storr 1988c)	0.68, 0.55F0.80 (Storr 1988c)
Strophurus spinigerus spinigerus	58.7, 31F71 (Storr 1988c)	0.67, 0.53F0.81 (Storr 1988c)
Strophurus strophurus	27F76 (Storr et al. 1990)	0.53F0.75 (Storr et al. 1990)
Strophurus taeniatus	41, 37.0F44.9 (12)	0.67, 0.58F0.74 (5)	0.14 (2)
Strophurus taenicauda S. t. taenicauda (Brown et al. 2012) S. t. albiocularis (Brown et al. 2012) S. t. triaureus (Brown et al. 2012) Strophurus wellingtonae Strophurus williamsi Strophurus wilsoni	75 (De Vis 1886) 61.5, 50.3F71.4 (21) 62.1, 52.2F69.3 (22) 64.6, 53.3F73.2 (9 68.2, 49F85 (62) (Storr 1988a) 52.5, 28.8F66.6 (90) 55.8, 44.0F64.8 (Kluge 1963) 47.5, 28F56 (6) (Storr 1983)	0.69, 0.59F0.84 0.68, 0.54F0.78 0.67, 0.59F0.72 0.69, 0.59F0.80 (44) (Storr 1988a) 0.72, 0.64F0.79 (15) (Sađlier et al. 2005) 0.59, 0.43F0.69 (61) 62.3, 50.8F71.0 (Kluge 1963) 0.48, 0.42F0.54 (6) (Storr 1983)	0.21 (De Vis 1886) 0.21, 0.17F0.31 0.19, 0.18F0.21 0.18, 0.17F0.21 0.18, 0.16F0.21 (90) 0.19, 0.18F0.20 (Kluge 1963)