Potamites ecpleopus (COPE, 1875)
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|Higher Taxa||Gymnophthalmidae (Cercosaurinae), Sauria, Gymnophthalmoidea, Squamata (lizards)|
|Common Names||E: Common Stream Lizard|
|Synonym||Neusticurus ecpleopus COPE 1876: 161|
Neusticurus bicarinatus — GUICHENOT 1855: 30
Neusticurus ecpleopus — O’SHAUGHNESSY 1879: 295
Neusticurus ecpleopus — WERNER 1910: 28
Neusticurus tuberculatus SHREVE 1935: 209
Neusticurus ecpleopus — UZZELL 1966: 290
Neusticurus ecpleopus — PETERS et al. 1970: 207
Neusticurus ecpleopus — DUELLMAN 1978: 218
Neusticurus ecpleopus — AVILA-PIRES 1995: 427
Neusticurus ecpleopus — DIRKSEN & DE LA RIVA 1999
Neusticurus ocellatus — DIRKSEN & DE LA RIVA 1999
Neusticurus ecpleopus — CASTOE et al. 2004
Potamites ecpleopus — DOAN & CASTOE 2005
Neusticurus ecpleopus — COSTA-PRUDENTE et al. 2013
Neusticurus ecpleopus — MORATO et al. 2014
Potamipes ecpleopus — VAZ-SILVA et al. 2015 (in error)
Potamites ecpleopus — DIAGO-TORO et al. 2021
|Distribution||S Colombia, Ecuador, Bolivia (Bolivia, La Paz, Santa Cruz), Brazil (Amazonas, S Para, Acre), N Peru|
Type locality: Peru; according to UZZELL (1966) probably in drainage of Río Huallega, between Rioja, Moyobamba, Balsaspuerto, and exit of Huallaga into Amazon basin.
|Types||Type: unlocated (fide TORRES-CARVAJAL 2001), lost fide UZZELL 1966|
Holotype: MCZ 37711 [tuberculatus]
|Diagnosis||Diagnosis. Neusticurus with short snout, tympanum superficial, lower eyelid with an undivided sernitransparent disc. Back with six longitudinal rows of tubercles, 28-40 (34.1 ± 2.1) in a paravertebral row. Flanks with prominent, trihedral tubercles surrounded by distinctly smaller scales. Ventrals in 18-23 (21.3 ± 1.0) transverse rows. Tail moderately compressed, with a double dorsal crest formed by two continuous rows of tubercles. Two transverse rows of scales on underside of tail correspond to two transverse rows on the sides; no distinct verticils.|
Description. Gymnophthalmid with maximum SVL in males of 84 mm (MPEG 14206), in females of 71 mm (MPEG 13092). Head 0.21-0.28 (0.24 ± 0.02, n= 57) times SVL, 1.3-1.7 (1.52 ± 0.09, n= 57) times as long as wide, 1.0-1.4 (1.19 ± 0.07, n= 56) times as wide as high. Snout blunt, rising gently toward top of head; supratemporal and gular regions in adult males distinctly swollen. Neck slightly narrower than head and body. Body cylindrical. Limbs well developed, forelimbs 0.26-0.37 (0.32 ± 0.02, n= 47) times SVL, hind limbs 0.43-0.57 (0.50 ± 0.03, n= 45) times. Tail moderately compressed, tapering gradually toward tip, 1.4-1.8 (1.64 ± 0.11, n= 44) times SVL.
Tongue lanceolate, covered with imbricate, scale-like papillae, with a smooth, bifid tip. Anterior teeth conical and very small, progressively enlarging posteriad and changing into bicuspid and tricuspid.
Rostral approximately rectangular, about twice as wide as high, just visible from above. Frontonasal mostly divided, but single i n most specimens from Benjamin Constant (Brazil, near the border with Peru and Colombia), and in occasional specimens from other localities. In a few specimens frontonasal partially divided, while RMNH 24599 presents a divided frontonasal with one of the parts still further (transversely) divided, resulting in three asymmetrical scales. A pair of prefrontals, irregularly pentagonal orhexagonal, slightly longer than wide. An azygous scale may occur between frontonasals and prefrontals (in MPEG 3579 and B M 1979.135 the two pairs of scales are completely separated by a large azygous scale). Frontal hexagonal, longer than wide, narrower posteriorly; laterally in contact with second, and mostly with first and third, supraoculars. A pair of irregularly pentagonal frontoparietals, longer than wide, forming a broad medial suture and laterally in contact with third and fourth supraoculars (in MPEG 13579 a small, elongate scale partially separates the two frontoparietals, and forms a short suture with interparietal). Interparietal relatively large, roughly oval to hexagonal, mostly angulate anteriorly, rounded posteriorly; bordered on each side by a subequal to smaller parietal, in a staggered position, slightly anterior to interparietal. The three scales form a round posterior margin which clearly delimits the dorsal head scales anteriorly of it from the occipital and supratemporal regions. Scales on occipital region very variable among specimens, convex, juxtaposed, heterogeneous in shape and size, mostly distinctly smaller than scales on anterior part of head, although a few enlarged scales may be present. Usually several medium-sized, elongate scales border the interparietal and are in contact with some larger, rounded to hexagonal scales; on sides of occipital region, scales form longitudinal rows, where scales within a row are subequal, but different rows have scales of different sizes; posteriorly the region is bordered by small scales. Four supraoculars, first distinctly smaller, second slightly larger than third and fourth; rarely one or a few small scales are present between two supraoculars, peripherally. Four or five, exceptionally six, supraciliaries, first longest. A few specimens show irregular grooves on some dorsal head scales, or splitting of small, extra scales, but head scutellation is mostly regular. Nasal undivided, nostril approximately in its centre or slightly anteriorly, directed lateroposteriorly. Loreal and frenocular relatively large, either loreal in contact with supralabials, thus separating nasal from frenocular, or these two latter scales in contact, separating loreal from supralabials. Continuous with frenocular there is a row of 4-7, exceptionally eight or nine, suboculars, of which median ones may be very small; in RMNH 24600 and K U 130249 the median scales completely disappear and the fourth supralabial borders on the small scales that fringe the lower eyelid. Two to four post-oculars, mostly in a regular row between posterior subocular and a slightly enlarged scale in posterior corner of supraocular area. Lower eyelid mostly with undivided semi-transparent disc; among 48 specimens, two had two palpebrals on both sides, two had one side undivided and the other side with two palpebrals, and another one had one side undivided and the other with three palpebrals. Five, exceptionally six, wide supralabials, one before last below centre of eye, followed by one or two post-supralabials. In most specimens supralabials widen slightly until fourth scale (below centre of eye), fifth supra-labial and postsupralabials decrease gradually in size. Temporal scales oval, convex, all smooth or part of them broadly keeled, heterogeneous in size. Largest temporal scales either mainly in upper and posterior areas, or they form oblique rows separated by small scales. Ear-opening large, round, oval, or horseshoe-shaped, with smooth margin; tympanum superficial.
Mental distinctly curved anteriorly, with convergent, short sides, and straight posterior margin. Followed posteriorly by an undivided, pentagonal post-mental, and four pairs of chinshields. First three pairs of chinshields in contact with infralabials; first, and in most cases second pair, in contact medially (exceptions only among Ecuadorian material, where six out of fifteen specimens have second pair narrowly separated). Fourth pair in some specimens in short contact with infralabials, in other instances scales so reduced that they may no longer be recognised as chinshields. Lateral to fourth pair of chinshields some elongate, convex scales. Scales posterior to chinshields convex, oval to elongate hexagonal, juxtaposed, in divergent rows. They form a narrow mid-ventral line of small scales, followed at both sides by medium-sized scales, laterally again becoming smaller and rounded. Chin delimited posteriorly by a transverse row of small scales. Four or five, exceptionally six, wide infralabials, one before last below, or ending below, centre of eye; followed by one or two, rarely three, mostly narrow and elongate post-infralabials. Gulars in 7-11 (9.3 ± 0.9, n= 87) transverse rows, anteriorly roundish, convex, with a slightly to distinctly wider median pair of scales; posterior two or three rows (including collar) with squarish, larger scales. Some lateral gular scales may be keeled or trihedral. Gular fold distinct, collar with 6-10 (8.2 ± 1.0, n= 57) scales.
Nape with granular scales separating longitudinal rows of trihedral or sharkfin-like tubercles; frequently there is an enlarged pair of occipital scales which may form the beginning of a row of tubercles. Two or three rows of tubercles on nape converge to each paravertebral row of body tubercles, or there is a short pair of paravertebral rows on nape, the members of which converge, and the paravertebral body rows diverge anteriorly, continuing on nape as a row parallel to the paravertebral one. Two other rows on nape at each side are continuous with the dorsolateral body rows. Sides of neck similar to nape, but tubercles may become conical and in some specimens more irregularly distributed. Body with six dorsal rows of tubercles: two para-vertebral rows and, on each side, two contiguous dorsolateral rows. Between the paravertebral rows, and the paravertebral and dorsolateral rows, small, flat, irregular, imbricate scales. Body tubercles larger than those on nape and mostly with an elevated median keel rising from a flat base. Twenty-eight to 40 (34.1 ± 2.1, n= 79) tubercles in a paravertebral row, from nape to base of tail. Flanks with medium-sized to small, trihedral tubercles, and small, flat, imbricate scales, forming distinct transverse bands. Ventrals mostly quadrangular, slightly imbricate, in eight longitudinal and 18-23 (21.3 ± 1.0, n= 87) transverse rows; the two medial rows at each side of midventral line with smooth scales, third row with smooth to broadly keeled scales, fourth (lateral) row with keeled and in some specimens convex scales. Minimum number of scales around midbody 33-50 (40.1 ± 3.9, n= 57). Preanal plate most commonly with two (occasionally one or four) anterior, and three (occasionally four) posterior scales (plus small lateral scales), of which either all three posterior scales reach the anterior ones, or the median posterior one is enclosed by the two lateral scales. Preanal and femoral pores present, forming a continuous row at each side; total number 16-48 in males, 4-29 in females. Pores between two or three scales, one of which usually larger than the others.
Tail dorsally with a double crest of tubercles, which are a continuation of the para-vertebral rows of dorsal tubercles; anteriorly both rows are separated by small scales similar to the small dorsals, distally the two crests touch each other. Sides of tail with elongate, keeled scales, in longitudinal and transverse rows. Scales in upper row, which is a continuation of the upper dorsolateral row of tubercles on body, more sharply keeled and usually forming a lateral row of tubercles; scales in lower lateral rows less prominent. Underside of tail with two rows of smooth scales. One ventral scale corresponds to one lateral row, and one dorsal tubercle; in a few specimens one ventral corresponds, at least in part of tail, to two lateral rows, of which the anterior row is formed by small scales which are only present in part of its height.
Dorsal aspect of upper arms with rhomboid to hexagonal, imbricate, strongly keeled scales, in longitudinal rows; ventral aspect with small, trihedral to conical scales. Forearms with rhomboid to hexagonal, imbricate, strongly keeled scales on dorsal aspect, scales slightly smaller and not in longitudinal rows on posterior and ventral aspects, and anterior aspect with a row of large, trapezoidal scales, mostly separated from ventral scales by a narrow band of small scales. Thighs with an antero-ventral row of trapezoidal scales; dorsally to it two rows of rhomboid to hexagonal, keeled scales, followed on dorsal aspect of thigh by small, flat scales intermixed with prominent tubercles; these extend slightly onto posterior aspect of thigh, which toward pores is covered by granular scales. Ventral aspect of thighs with smooth scales, smaller toward pores. Lower legs with dorsal and posterior aspects covered by tubercles interspersed among small, flat scales; a row of trapezoidal scales on its anterior aspect, followed ventrally by two or three other rows of scales, first row of hexagonal, smooth scales, second and third (when present) of rhomboid scales; scales of row bordering the tuberculate area keeled. Subdigital lamellae under fingers single, smooth; under toes partially divided (proximally), the inner half lamellae under base of first to fourth toe moderately tuberculate; 11-16 (14.0 ± 1.2, n= 110, 56 specimens) lamellae under fourth finger, 20-27 (23.0 ± 1.4, n= 111, 57 specimens) under the fourth toe (Avila-Pires 1995).
Colour in life: of MPEG 14206 (male) Prout's brown (121 A) with black and lighter spots on back, spectrum yellow (55) and yellow-green (58) spots on labials and flanks; a white, black bordered ocellus at each side; belly salmon (106), darker posteriorly. In MPEG 14247 (c?), five ocelli are present on one side, six on the other, first ocelli of each side with white centre, remaining ones with greenish centres; on ventral surface, head and gular region light yellow-green (58) with grey spots, belly with the two medial rows burnt-orange (116), toward the sides becoming close to cinnamon-rufous (40). RMNH 24611 (female) with dorsal surface of head raw-umber (223), back warm sepia (221A), flanks sepia (119) with a white, black bordered ocellus; on ventral surface, head glaucous (80) and white, gular region brown and white, belly white with an orange tinge; tail warm sepia (221A) and sepia (119), underside dark greyish-brown; iris brown. In RMNH 24613, a juvenile, head, flanks and limbs sepia (119), back and dorsal surface of tail drab (27); ventral region sepia and white under head, belly and limbs, sepia under tail (Avila-Pires 1995).
Color in preservative: basic colour brown, the tonality varying among specimens, mostly mottled with dark, or dark and light, flecks (uniformly ferruginous in RMNH 24594). Head dorsally similar in colour to back, or uniformly dark. Sides of head usually with a light band from suboculars to chinshields, which in some specimens extends as an oblique line toward gulars, and other transverse light bands from supralabials to chinshields. Back and flanks with similar basic colour, or dorsal area lighter. The three smaller specimens examined (RMNH 24596, RMNH 24613, RMNH 24592) are drab dorsally and dark brown on flanks (body and tail; head completely dark brown in the former two, lighter dorsally in RMNH 24592). All other juveniles have darker dorsal regions, but still distinctly lighter than flanks, while in adults such a distinction may or may not be evident, suggesting ontogenetic variation. A white, black bordered ocellus above or slightly posterior to level of forelimbs is present in almost all specimens, although it may be less conspicuous in females; it is absent in RMNH 24594. Other ocelli may be present along flanks, one anterior to arm level, and up to six posteriorly, usually becoming less defined posteriad. Other specimens present light, dark-surrounded spots, like suffused ocelli, or else no trace of ocellus, except for the one above the arm. Ventrally, head either cream with light grey to black spots and bands, or predominantly to totally grey, bluish-grey, or (in some Ecuadorian males) blue. Belly in most specimens predominantly cream, ventrolaterally with conspicuous black, or diffused grey, irregular spots, which in some specimens occur also medially. Some specimens with predominantly black or dark brown venter; in RMNH 24594 belly is deep orange, with darker spots. Limbs dorsally uniformly or mottled brown; a pattern more or less resembling ocelli may be present, especially on hind limbs; ventral surface similar to belly. Tail pattern dorsally similar to dorsal pattern of body, ventrally usually from lightly to heavily spotted at base, darkening distally; base (ventrally) homogeneously cream in MPEG 14023; underside of tail mostly uniformly bluish-grey in RMNH 24611 (Avila-Pires 1995).
See also description in Werner 1910: 28
|Comment||Synonymy after PETERS et al. 1970. Neusticurus ocellatus SINITSIN 1930 has been considered as a synonym of Neusticurus ecpleopus.|
Type species: Neusticurus ecpleopus COPE 1876: 161 is the type species of the genus Neusticurus COPE 1876.
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