Plica rayi, Murphy, John C. & Jowers, Michael J., 2013

Murphy, John C. & Jowers, Michael J., 2013, Treerunners, cryptic lizards of the Plica plica group (Squamata, Sauria, Tropiduridae) of northern South America, ZooKeys 355, pp. 49-77 : 63-66

Plica rayi sp. n. Ray’s TreerunnerFigs 8e, 9e, 10

Plica plica - Etheridge 1970: 242 (in part).

Holotype.

FMNH 177926 a male. Collected by Gary Myers in 1962. Venezuela, Amazonas, Puerto Ayacucho (~ 05°39'N, 67°38'W), on the Orinoco River.

Other material.

Colombia– Vichada, Puerto Carreno, (~ 6°08'N, 67°26'W) MCZ 150179-81; Venezuela - Puerto Ayacucho FMNH 177924-34, MCZ58335-36, 160222-24.

Diagnosis.

A Plica with greatly reduce mucronate scales, the two clusters on the neck reduced to small knobs; in overall appearance this lizard has a smooth external texture; 182-202 scales around mid-body (more than any other Plica species); seven subocular plates; scales on snout juxtaposed and flat; nasal scales separated from rostral by a single scale; spiny scales around auditory meatus greatly reduced or completely absent; lamella under fourth toe 36-45 (more than any other Plica species). Males have a well-developed dorsal crest that extends onto the tail; females have this crest greatly reduced. Plica caribeana sp. n. has 125 or fewer scales around mid-body and imbricate, keeled scales on the snout. Plica kathleenae sp. n. has 158 scales at mid-body and imbricate scales on the snout. Plica medemi sp. n. has 145 scale rows at mid-body and well developed spines on the anterior margin of the auditory meatus. Plica plica has 140 or fewer scales around mid-body; keeled, imbricated scales on the snout, and has well developed spiny scales. The two tepui associated species ( Plica lumaria and Plica pansticta ) have fewer scale rows around the body (141-164), imbricate scales on the snout and fewer lamellae on the toes.

Description of holotype.

FMNH 177926, male, 103 mm SVL, 175 mm tail. Rostral broader than tall, with small asperities, makes contact with five post-rostral scales; nasals small, separated from upper labials by one scale, separated from each other by five scales; scales on snout, juxtaposed, flat with round asperities; canthal single, makes contact with three loreals, separated by seven inter-canthal scales; circumorbital scales weakly keeled, well developed, nine on each side, and maintain their size posteriorly; occipitoparietal broader than long, in direct contact with circumorbital scales; upper labials 4/4, fourth is the longest; lower labials five, bordered by four rows of slightly enlarged scales below; loreals in 8/9 rows between canthal and upper labials, scales weakly keeled; dorsal crest on nape and extends to about mid-tail, scales relatively small, largest spines close to occipital region; dorsolateral fold well developed on anterior body extends passed thigh, ventrolateral fold barely discernible in preserved specimens; dorsal scales exceptionally small; scales around mid-body 190; ventrals 80; auditory meatus with small cluster of reduced spines on anterior margin, none on posterior margin; ventral flap has few spines on margin; two small tufts of spines on neck, reduced to almost smooth knobs, anterior tuft larger than posterior; gular fold complete; antegular fold incomplete; dewlap originates on the gular fold; mental rounded, in contact with four scales on posterior edge; scales on throat small, smooth, subtriangular; ventrals larger than dorsals, imbricate, smooth; fourth finger with 27 lamellae; fourth toe with 37 lamellae; feet about 35% of SVL; tail laterally compressed at base and along most of its length.

In alcohol, dark transverse bands on the snout and back of head, as well as a well-formed shoulder stripe that extends onto neck and throat. Dorsum brown gray with light spots; tail with alternating, indistinct dark and pale bands; forearms and lower legs also with indistinct bands; chin spotted, black gular center; venter of body and tail cream.

Variation.

Rostral may or may not have asperities; nasals separated from upper labials by one or two scales, separated from each other by 5-6 scales; circumorbital scales usually 8-9 (rarely 7 or 10), keeled, and may become slightly smaller posterior; loreal region has 7-9 rows between canthal and upper labials, scales weakly keeled; suboculars 4-5, usually four; mental rounded, in contact with 3-4 scales on posterior edge; lower labials 4-6, usually five; scales around mid-body 181-202; ventrals 80-93; fourth finger with 27-35 lamellae; fourth toe with 36-45 lamellae. Preserved specimens show poorly defined dorsal crests, males have greatly enlarged spines in the occipital region, these are barely discernible in females; dorsolateral and ventrolateral folds not obvious in preserved specimens; in life these folds are quite distinct based on Fig. 10.

Body and tail. Female’s SVL 66-106 (n=8, x=79.13, SD=17.21); undamaged tails 134-175 (n=4, x=148.50, SD=15.79). Male’s SVL 85-105 (n=3, x=96.00, SD=8.92), undamaged tails (n=1) 143 mm. Feet 35-39% of SVL; tail depressed at base, becomes more cylindrical distally. Individuals measured for this study ranged from 55-106 mm SVL, and had unbroken tails that were up to 2.1 times the SVL.

In alcohol, a uniform brown gray dorsum; dorsum has some traces of transverse bands, but white spots numerous on some individuals; tail with alternating, indistinct dark and pale bands; forearms and lower legs also with indistinct bands; chin spotted, black gular center; venter of body and tail cream.

In life breeding males have a red-orange face and throat with about five irregular black brown markings extending from the supraorbital crest to the upper labials and some extend onto the throat; crown and face otherwise brown. A black nape blotch extends from the dorsal crest onto the throat where it widens and contains some white pigment; the body is brown-black with indistinct white and black markings; limbs with indistinct bands. Females are brown black with the head slightly darker in color than the body, and a black gular blotch at the anterior edge of the dorsolateral fold; upper forelegs with light colored mottling, lower forelegs with indistinct bands.

Etymology.

This lizard is namedin honor of Ray Pawley, former Curator of Reptiles at Brookfield Zoo, for his lifelong interests and work on amphibians and reptiles. Suggested common name: Ray’s Treerunner.

Distribution.

Known from two localities along the Orinoco River:Puerto Ayacucho, Amazonas, Venezuela and Puerto Carreno, Vichada, Colombia. The distance between these two locations is about 65 km. They have also been observed at Tobogan de la Selva (~ 5°23'13"N, 67°37'0"W) and Raudal de Danto at Autana (4°48'N, 67°29'W, 89 m asl).

Ecology.

Plica rayi is associated with granitic rainforests. It is very abundant in rocky areas; tobogans are granite slabs used as refugia by the lizards. In May, coinciding with the initiation of rains, males have a bright red-orange head coloration not observed in other months (July, September, or December). At night they sleep vertically with the head facing the sky ( César Barrio-Amorós, personal communication).