Added 8 March 2015.

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Genus Plica - Tree Runners


Genus Plica - Tree Runners

A South American genus, not frequently seen in captivity. This may be due to lack of interest (at least in the UK) in iguanids from that region, and possibly also due to the preponderance of ants in the lizards' diets: however, Bosch and Werning claim that for at least one of the species, it is possible to keep them healthy with other arthropods, unlike some other ant-eating lizards.

Boulenger gives the characteristics of the genus as follows: tympanum distinct; body subcylindrical or depressed; slightly serrated dorsal ridge; dorsal scales small, imbricate, uniform; upper head-scales enlarged, occipital very large; neck strongly pleated below, the folds forming a pair of pouches on each side; no gular sac; digits compressed, bent at the articulations, with keeled lamellae below; no femoral or preanal pores; tail long, cylindrical or compressed; lateral teeth tricuspid, the anterior ones slightly enlarged and canine-like; pterygoid teeth present or absent; large sternal fontanelle; no abdominal ribs.

These species derive their common name from their usual arboreal habit, where they spend much of their lives on tree trunks.

For a long time the genus was confined to P. plica and P. umbra, with the further naming of P. lumaria in 1990, but in 2013 evidence was presented that P. plica actually represented a complex of species. As ever we are indebted to the Reptile Database for this information, and to the 2013 Murphy & Jowers paper (see Bibliography).

For husbandry details see Bosch and Werning.


P. caribeana, Caribbean Tree Runner

P. kathleenae, Kathleen's Tree Runner

P. lumaria

P. medemi, Medem's Tree Runner

P. pansticta

P. plica, Tree Runner

P. rayi, Ray's Tree Runner

P. umbra

Scientific Name

Common Name





P. caribeana

Caribbean Tree Runner

Venezuela, Trinidad & Tobago

Forest- and forest-edge species, interestingly often found in small colonies of 6-15 individuals (see Murphy & Jowers). Scalation details: scales on snout imbricate, keeled; dorsolateral and ventrolateral folds well developed; 1 longitudinal dewlap fold. Scale rows at midbody: 92-125, usually 110-125. Coloration: dorsal black and green transverse bands. [SOURCE: Murphy & Jowers, 2013]

P. kathleenae

Kathleen's Tree Runner


Known only from the Acarai Mountains. Scalation details: 6 suboculars; scales on snout mostly imbricate, slightly pyramidal with asperities; gular fold complete, antegular fold incomplete, with dewlap originating in space between the two folds; throat folds relatively small, not forming mite pockets as in other Scale rows at midbody: 158. Other: head proportionately longer than other Plica species.[SOURCE: Murphy & Jowers, 2013]

P. lumaria


S Venezuela


Scalation details: scales on snout smooth, imbricate; 1 scale between nasal and rostral [SOURCE: Murphy & Jowers, 2013].

P. medemi

Medem's Tree Runner


Scalation details: scales on snout juxtaposed, smooth and slightly domed; dorsolateral and ventrolateral folds well developed, extending to groin; entire anterior margin of ear lined with spiny scales; 41 lamellae on 4th toe. Coloration: green dorsum with black spots, no transverse bands; head orange. Scale rows at midbody: 145. [SOURCE: Murphy & Jowers, 2013]

P. pansticta


Scalation details: scales on snout smooth, imbricate; 1 scale between nasal and rostral [SOURCE: Murphy & Jowers, 2013].

P. plica

Tree Runner

Colombia, Ecuador, Venezuela, Guyana, Surinam, French Guyana, Trinidad, Brazil, Bolivia, N Peru


Scalation details: nostril latero-superior; supraciliary edge projecting, angular; upper head-scales imbricate, more or less distinctly keeled; row of large transverse supraoculars; occipital little broader than long, narrower than supraocular region; labials large, 4-5 supralabials, 5-6 infralabials; neck constricted, strongly pleated, pouched inferiorly; posterior gular fold continuous with a lateral fold curving above the shoulder and ending above the hind limb; sides of neck with groups of enlarged, spinose scales; small dorsal crest, highest on the nape; dorsal and lateral scales very small, strongly keeled; dorsolateral fold covered with small erect spinose scales; second more or less distinct fold on each side from axilla to groin; ventral scales slightly larger than dorsals, smooth. Scale rows at midbody: 126-140 [Murphy & Jowers]. Other: head large, snout short; body depressed; tail slender, slightly compressed, with serrated upper edge. Coloration: greyish-olive or greenish above, spotted or marbled with dark brown, forming more or less distinct crossbands on back and limbs; collar of black marblings; lower surfaces whitish; throat black. [SOURCE: Boulenger, Murphy & Jowers, Peters et al]

P. rayi

Ray's Tree Runner

Colombia, Venezuela

Scalation details: scales on snout juxtaposed, flat; nasals separated from rostral by single scale; 7 suboculars; spiny scales around ear great reduced or absent; greatly reduced mucronate scales, 2 clusters on neck reduced to small knobs; males with well-developed dorsal crest extending on to tail, females with greatly reduced crest; 36-45 subdigital lamellae on 4th toe. Scale rows at midbody: 182-202. [SOURCE: Murphy & Jowers, 2013]

P. umbra


Colombia, Ecuador, Venezuela, Guyana, Surinam, French Guyana, Brazil, Bolivia, N Peru


Scalation details: nostril small, turned upwards; upper head-scales usually with small granular asperities; anterior supraorbitals transversely dilated, forming 2 diverging series; row of large transverse supraoculars; occipital broader than long, as broad as or broader than supraocular region; labials large, 4-5 supralabials and 5-6 infralabials; ear-opening large, anterior border very slightly or not at all denticulated; strong oblique antehumeral fold; feeble longitudinal and strong transverse gular fold, latter forming small pouch on each side; sides of neck feebly pleated, without spines; dorsal crest most developed on nape, reduced to very slight ridge on back; dorsal scales as large as or a little larger than ventrals, rhomboidal, keeled, keels forming oblique lines; no enlarged spinose scales on sides of neck; ventrals rhomboidal, more or less distinctly keeled or shortly mucronate; size of scales very variable. Scale rows at midbody: Other: snout short and very broadly rounded; body not depressed; tail round or slightly compressed, slender. Coloration: reddish- or purplish-brown above, with more or less distinct blackish crossbands; broad black band on antehumeral fold, sometimes extending across the nape; frequently a large yellowish spot on the side of the neck in front of the black band; lower surfaces brownish or yellowish, uniform or clouded with brown [SOURCE: Boulenger, Peters et al]

P. u. umbra



Scalation details: vertebral scale row continuous from occiput to tail, forming denticulate crest on neck; 34-46 vertebral scales from occiput to anterior margin of thigh; 50-66 paravertebral scales from occiput to anterior margin of thigh; 46-56 scales around body; dorsal head scales swollen, with blunt, irregular keels and a pair of pyramidal parietal scales; all scales more sharply keeled and more strongly mucronate [SOURCE: Peters et al].

P. u. ochrocollaris




Scalation details: vertebral scales usually not distinguishable from adjacent scales on posterior back, forming less distinct crest; 48-58 vertebral scales; 68-81 paravertebral scales; 54-65 scales around body; dorsal head scales smooth or nearly so; all scales less sharply keeled and mucronate [SOURCE: Peters et al].


“Treerunners, cryptic lizards of the Plica plica group (Squamata, Sauria, Tropiduridae) of northern South America”, John C Murphy, Michael J Jowers, Zookeys 355:49-77 (25 November 2013).


The Murphy & Jowers article can be found here.

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