Christinus marmoratus (GRAY, 1845)
Can you confirm these amateur observations of Christinus marmoratus?
|Higher Taxa||Gekkonidae, Gekkota, Sauria, Squamata (lizards: geckos)|
|Common Names||E: Marbled Southern Gecko, Marbled Gecko|
|Synonym||Phyllodactylus porphyreus DUMÉRIL & BIBRON 1836 (partim)|
Phyllodactylus Peronii FITZINGER 1843: 95
Diplodactylus marmoratus GRAY 1845
Goniodactylus australis GRAY 1845
Gonatodes australis — BOULENGER 1885: 72 (?)
Phyllodactylus marmoratus — BOULENGER 1885: 88
Phyllodactylus macrodactylus BOULENGER 1885: 89
Phyllodactylus affinis — BOULENGER 1885: 89
Phyllodactylus marmoratus — LUCAS & FROST 1894: 28
Phyllodactylus marmoratus — LOVERIDGE 1934
Phyllodactylus marmoratus — BUSTARD 1965
Phyllodactylus marmoratus — COGGER 1983
Christinus marmoratus — WELLS & WELLINGTON 1984
Christinus biggsae WELLS & WELLINGTON 1985: 10
Phyllodactylus marmoratus marmoratus — STORR 1987
Christinus marmoratus marmoratus — RÖSLER 2000: 62
Christinus marmoratus macrodactylus — RÖSLER 2000: 62
Christinus marmoratus — COGGER 2000: 208
Christinus marmoratus — WILSON & SWAN 2010: 60
Christinus marmoratus — HEINICKE et al. 2014
|Distribution||Australia (New South Wales, South Australia, Victoria, Western Australia)|
Type locality: restricted to West- and South Australia (Kangaroo Island, Swan River, Freemantle, Champion Bay, Houtman’s Abrolhos, Norfolk Island, Aneitum).
Type locality: “Australia” and “Houtman’s Abrollos” [GRAY 1845].
Type locality: Australia [macrodactylus].
|Types||Lectotype: BMNH xxi.9.a. Designated by Wells & Wellington (1985) (marmoratus)|
Syntypes: MNHN 6734, 6734A [Peronii]
Holotype: BMNH 220.127.116.11 [affinis]
Holotype: BMNH xxii.86a [australis]
Syntypes: BMNH 18.104.22.168 [macrodactylus]
Holotype: AMS 116977 [biggsae]
|Diagnosis||Definition (genus). Christinus is distinguishable from all other geckos based on the following combination of characters: size large (70–80 mm max. SVL), with a moderately proportioned head, cylindrical body, and round, tapering tail. Digits are free and bear a single pair of dilated terminal adhesive pads (‘leaf toes’); claws are present on all digits. Dorsal scalation consists of small, smooth granules. Preanal pores are absent; 3–4 cloacal spurs are present. The eye bears a vertical pupil with crenate margins. The skull displays no co-ossification with the overlying skin. Nasals are fused; frontal single; parietal paired; stapes imperforate; 14 scleral ossicles; 12-13 premaxillary and between 30 and 39 dentary tooth loci; hyoid with second ceratobranchial cartilages. There are 27–28 presacral vertebrae and one pair of cloacal bones. The phalangeal formula is 2-3-4-5-3 (manus)/2-3-4-5-4 (pes); paraphalangeal elements are absent.|
Four cranial osteological apomorphies were found for Christinus marmoratus: lateral vertex of the postorbitofrontal located anterior to the frontoparietal suture (95-00, Fig. 28); length of the exposed portion of the frontal shorter than the width of the frontoparietal suture (127-20, Fig. 28); number of premaxillary tooth loci 12 or 13 (368-00).
Christinus has more presacral vertebrae than any other genus of leaf-toed gecko. It can be distinguished from all other Australian leaf-toed gecko genera (which belong to the family Diplodactylidae) based on possession of enlarged scales on the dorsal surface of the broadened terminal adhesive pads, as well as all traits that distinguish gekkonids from diplodactylids (including L-shaped meatal closure muscles, hard-shelled eggs, and a single centre of ossification in the premaxilla; Kluge, 1987) [HEINICKE et al. 2014]
Diagnosis (Christinus): The genus Christinus Is characterised by the following: Round rostral and mental, with postmentals enlarged; enlarged lablals; no preanal pores; digits lay flat, long and thin, somewhat depressed; distal expansion of digits form distinct pads; apical sub-digital lamellae as large pair; sub-digital lamellae enlarged but smaller than apical; digits have dorsal scales which are larger distally than at base; all digits possess retractile claws which fit into a groove in the apical lamellae; dorsal scales small, smooth and homogeneous; clutch size two, but practices communal egg-laying behaviour; size up to 80 mm SVL. A relictual group of endemics confined to southern Australia and the Lord Howe and Norfolk Island groups. A colour plate of Christinus marmoratus is in Cogger, (1983, pI. 85) and a plate of Christinus guentheri can be found in Cogger, Sadlier and Cameron, (1983) [from WELLS & WELLINGTON 1984].
Description: Grey or brown above, with a complex series of fine blackish markings which tend to form transverse, light-centred bars, but which, almost as often, form a fine reticulated pattern, especially on the head, neck, flanks and limbs. Whitish below. Scales on the back small, but normally fewer than 10 scales in the middle of the back in a distance equal to the diameter of the eye. Fingers and toes long and slender, the width of the distal expansion of the fourth toe at least twice the maximum diameter of the ear-opening. Body slender, only slightly depressed. 70 mm (snout-vent). [...] Digits relatively shorter than in alexanderi; usually 8-9 subdigital lamellae under the fourth toe; nostril facing laterally; rostral in narrow or point contact with nostril; two or more internasal scales, all in contact with rostral.” (modified after Cogger 2014: 346, 348)
|Comment||Karyotype: Christinus marmoratus marmoratus is a composite of two chromosomally distinct, but morphologically very similar taxa.|
Type species: Diplodactylus marmoratus GRAY 1845 is the type species of the genus Christinus WELLS & WELLINGTON 1994: 75. See comments in Bauer 1994 for a discussion of nomenclatorial issues.
Subspecies: Christinus marmoratus macrodactylus is not recognized as subspecies any more (Glenn Shea, pers. comm. Feb 2019).
|Etymology||Named after the marmorated color pattern of this species.|
The genus was named for Miss Christine Biggs of London.