Research Article |
Corresponding author: Pablo J. Venegas ( pvenegas@corbidi.org ) Academic editor: Alexander Haas
© 2020 Pablo J. Venegas, Luis A. García-Ayachi, Juan C. Chávez-Arribasplata, Germán Chávez, Iván Wong, Antonio García-Bravo.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Venegas PJ, García-Ayachi LA, Chávez-Arribasplata JC, Chávez G, Wong I, García-Bravo A (2020) Four new species of Stenocercus Duméril & Bibron, 1837 (Squamata, Iguania) from the Department of Amazonas in northeastern Peru. Evolutionary Systematics 4(2): 79-108. https://doi.org/10.3897/evolsyst.4.57578
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The tropical Andes are known to be the richest and most diverse place on earth. This mountainous region covers almost one third of the Peruvian territory, and its herpetofauna remains poorly known. The lizard genus Stenocercus Duméril & Bibron, 1837 contains 69 species and most of them occur in the tropical Andes, although some exist as high as 4000 m a.s.l. The examination of newly collected material from the Andes of northern Peru in the Department of Amazonas reveals four new species of Stenocercus which we describe below. Of these four new species, three inhabit the ecoregion of Peruvian Yungas at elevations of 1460 to 2370 m a.s.l., and one the Marañón dry forest ecoregion at elevations of 1340 to 1470 m a.s.l. Additionally, we provide new data about coloration, natural history and distribution of the poorly known S. aculeatus O’Shaughnessy, 1879; and discuss the identity of some populations of S. prionotus Cadle, 2001 and S. scapularis Boulenger, 1901.
Andes, herpetofauna, Marañón dry forests, montane forest, morphology, Peruvian Yungas
With the creation of conservation biology, at the end of the seventies, as a new field of research, new and striking terms such as “biodiversity” or “hotspots” were coined to highlight the importance of biological diversity and areas with a high species richness and endemism, respectively. The tropical Andes, a name currently applied to the hotspot that encompasses the Andean mountains between Venezuela and Bolivia, are known to be the most diverse region on earth (
New species of reptiles and amphibians are frequently discovered in the Peruvian Andes especially when remote regions are surveyed (e.g.
Currently the tropical Andes faces many threats and the most important by far are human activities including mining, logging, construction, agriculture and cattle ranching (
Lizards of the Stenocercus clade are one of the most geographically and ecologically widespread taxa currently ranked as a genus in South America (
In order to contribute to the knowledge of the scarcely known herpetofauna of the Peruvian Andes, we conducted several herpetological surveys of the montane environments of the Andes of northern Peru, especially in the Department of Amazonas. In this paper, we describe four new species of Stenocercus from that department and present new data regarding taxonomy, natural history, and distribution of S. aculeatus O’Shaughnessy, 1879. This contribution increases the number of Stenocercus species known from Peru to 47.
This study was carried out in accordance with the guidelines for use of live amphibians and reptiles in field research (
Lizards were captured by hand or noosing with a fishing rod. Coordinates and elevation were taken with a GPS (Garmin, WGS84). All collected specimens were euthanized with T61, fixed in 10% formalin for 48 hours and permanently stored in 70% ethanol. Voucher specimens were deposited at the herpetological collection of the Centro de Ornitología y Biodiversidad (
Measurements of snout-vent length (SVL) and tail length (TL) were taken with a ruler and recorded to the nearest 1 mm. All other measurements were made with digital calipers and recorded to the nearest 0.1 mm. Sex was determined by noting the presence of hemipenes and dimorphic phenotypic characters such as height of the vertebral crest and the ventral pattern. Data on scutellation of all species of Stenocercus compared herein was taken from
The taxonomic conclusions of this study are based on the observation of morphological features and color patterns as evidence to infer the existence of species (
Holotype:
PERU • ♂, adult; Amazonas Department, Bongará Province, Florida District, Huembo; 5°51.47’S, 77°58.75’W; 2090 m a.s.l.; 09 Dec. 2019; P.J. Venegas and L.A. García-Ayachi leg.;
Paratypes:
PERU • 1 ♂, 1 ♀, adults, collected with the holotype;
Stenocercus catherineae sp. nov. preserved holotype, adult male, SVL 82 mm (
Dorsolateral and ventral views of Stenocercus catherineae sp. nov. in life: (A, B) holotype, adult male, SVL 82 mm (
Stenocercus catherineae sp. nov. differs from other species of Stenocercus except for S. aculeatus, S. angulifer Werner, 1901, S. huancabambae Cadle, 1991, S. philmayi sp. nov., S. prionotus Cadle, 2001, and S. scapularis Boulenger, 1901 by having: (1) projecting-angulate temporals, (2) laterally oriented nostrils; (3) dorsal and lateral scales of body similar in size, and (3) scales on posterior surface of thighs keeled and imbricate.
Stenocercus aculeatus, S. angulifer, S. prionotus, and S. scapularis can be easily distinguished from S. catherineae sp. nov. by having strongly keeled ventrals, whereas in the new species ventrals are feebly to moderately keeled. Stenocercus aculeatus, S. angulifer and S. scapularis also have a dorsolateral crest (absent in S. catherineae sp. nov.); and S. prionotus lacks a postfemoral mite pocket (present in S. catherineae sp. nov.). Stenocercus catherineae sp. nov. differs from S. philmayi sp. nov. by having smaller dorsal scales with 43 to 53 vertebrals and 46 to 59 scales around midbody versus 32 to 38 vertebrals and 34 to 45 scales around midbody in S. philmayi sp. nov. The gular region in adult males of S. catherineae sp. nov. is black, whereas in S. philmayi sp. nov. it is cream.
The new species is most similar to S. huancabambae (Fig.
At the locality of Cuispes, and probably also in Huembo, S. catherineae sp. nov. and S. flagracanthus sp. nov. exist in sympatry; however, both species are strikingly different. S. flagracanthus sp. nov. has a relatively short tail armed with projecting spines, whereas S. catherineae sp. nov. has a long tail, compressed laterally, and a projecting vertebral crest.
Lateral view of the postfemoral mite pocket in three species of Stenocercus: (A) S. catherineae sp. nov. (
Dorsolateral and ventral views of adult males of three species of Stenocercus: (A, B) S. huancabambae, (C, D) S. aculeatus, (E, F) S. prionotus from northern-central Peru, and (G, H) S. prionotus from southern Peru. Photographs by: (A-D) Pablo J. Venegas, (E) Andy Barboza, (F) Diego Vasquez, and (G, H) German Chávez.
(1) Maximum SVL in males 83 mm (n = 3); (2) SVL in females 75 mm (n = 2); (3) vertebrals 43–53; (4) paravertebrals 62–73; (5) scales around midbody 46–59; (6) supraoculars 4; (7) internasals 4–6; (8) postrostrals 2–4; (9) loreals 5–6; (10) gulars 22–26; (11) subdigitals on Finger IV 18–21; (12) subdigitals on Toe IV 25–30; (13) posthumeral mite pocket present as a deep depression with a wide opening [Type 3 of
Adult male (Fig.
(Fig.
(Fig.
Measurement and scutellation characters of Stenocercus catherineae sp. nov. are presented in Table
Sexual dimorphism is evident in adult individuals. In two adult female paratypes (Fig.
Variation in scutellation and sexual dimorphism in snout-vent length (mm) of Stenocercus aculeatus, S. catherineae sp. nov., S. dracopennatus sp. nov., S. philmayi sp. nov., and their most similar species S. angulifer and S. huancabambae. Range followed by mean ± standard deviation is given for quantitative characters if applicable.
S. aculeatus | S. angulifer | S. catherineae | S. dracopennatus | S. huancabambae | S. philmayi | |||
Character |
|
|
n = 5 | n = 38 | n = 6 | n = 3 | n = 32 | n = 8 |
Scales around midbody | 41 | 37 | 32–37 | 38–50 | 46–59 | 39–45 | 37–53 | 34–45 |
35.00 ± 2.00 | 42.10 ± 2.37 | 53.00 ± 5.44 | 41.33 ± 3.21 | 43.94 ± 3.20 | 41.00 ± 3.70 | |||
Vertebrals | 37 | 38 | 31–39 | 37–47 | 43–53 | 38–40 | 37–51 | 32–38 |
35.20 ± 3.27 | 41.63 ± 2.25 | 47.33 ± 4.76 | 39.33 ± 1.15 | 43.39 ± 3.40 | 35.88 ± 1.96 | |||
Paravertebrals | 50 | 53 | 41–48 | 37–57 | 62–73 | 53–57 | 48–64 | 49–59 |
45.20 ± 2.95 | 50.42 ± 3.81 | 68.33 ± 4.37 | 54.67 ± 2.08 | 56.31 ± 3.74 | 55.14 ± 3.48 | |||
Gulars | 20 | 18 | 15–18 | 16–20 | 22–26 | 19–20 | 18–28 | 20–24 |
16.60 ± 1.14 | 18.47 ± 0.76 | 24.33 ± 1.63 | 19.33 ± 0.58 | 20.93 ± 1.64 | 21.75 ± 1.75 | |||
Supraoculars | 5 | 4 | 4 | 4–5 | 4 | 4 | 3–6 | 4–5 |
4 | 4 | 4 | 4 | 4 | 5 | |||
Internasals | 5 | 4 | 4–5 | 4–8 | 4–6 | 4–5 | 4–7 | 3–5 |
4 | 6 | 4 | 5 | 6 | 4 | |||
Subdigitals Finger IV | 21 | 21 | 18–19 | 15–19 | 18–21 | 19–21 | 14–20 | 18–21 |
18.80 ± 0.45 | 17.28 ± 1.11 | 19.33 ± 1.21 | 20.00 ± 1.00 | 16.81 ± 1.41 | 19.25 ± 1.16 | |||
Subdigitals Toe IV | 31 | 27 | 23–27 | 19–25 | 25–30 | 26–28 | 20–28 | 28–31 |
25.00 ± 1.58 | 22.84 ± 1.44 | 27.50 ± 1.64 | 27.00 ± 1.00 | 24.62 ± 1.56 | 29.25 ± 1.16 | |||
Tail length/total length | 0.72 | 0.72 | 0.70 – 0.73 | 0.68–0.73 | 0.66–0.69 (n=5) | 0.69–0.73 | 0.67–0.70 | 0.67–0.72 (n=7) |
0.71 ± 0.02 | 0.70 ± 0.02 | 0.67 ± 0.01 | 0.71 ± 0.02 | 0.69 ± 0.01 | 0.71 ± 0.02 | |||
Maximun SVL males | 81 | 95 | 103 | 96 | 82 | 89 | 99 | 95 |
Maximun SVL females | unknown | unknown | 91 | 82 | 75 | unknown | 75 | 74 |
Stenocercus catherineae sp. nov. is only known from three proximate localities at Huembo and Cuispes in the northern extreme of the Cordillera Central at the Río Utcubamba basin in the Department of Amazonas, at elevations between 1466 to 2085 m a.s.l. (Fig.
Distribution map of S. catherineae sp. nov. (red triangles), S. dracopennatus sp. nov. (yellow star), and S. philmayi sp. nov. (blue squares), and the similar species: S. aculeatus (fuchsia diamonds), S. angulifer (blue diamonds), S. huancabambae (orange diamonds), S. prionotus (turquoise diamonds), and S. scapularis (red diamonds). Symbols with a dot in the middle correspond to type localities. White circles with a dot are important cities for reference.
At Cuispes only one individual was collected in the croplands close to the village. Other squamate reptiles collected with S. catherineae sp. nov. at Cuispes were Atractus sp. Wagler, 1828, Dipsas palmeri Boulenger, 1912, and S. flagracanthus sp. nov. At Cocachimba, the two specimens collected were found basking at 1000 hours on the base of rocky fences with bushes along a trail. An uncollected adult female was observed basking at 900 hours on a fallen wall of an abandoned house. The general landscape at Cocachimba is composed of croplands of corn, fruit and sugar cane bordered by rocky fences and some streams with narrow fringes of riverine forest or shrub vegetation. Other species of squamate reptiles collected with S. catherineae sp. nov. at Cocachimba were: Atractus sp., Chironius exoletus Linnaeus, 1758, Mastigodryas boddaerti Sentzen, 1796, and Petracola angustisoma Echevarría & Venegas, 2015.
The female paratype (
The specific name is a noun in the genitive case and is a patronym for Catherine Dupont, a Peruvian veterinary specialist in One Health, who is actively working searching and monitoring viruses and other zoonotic pathogens. The specific name of this lizard is in recognition of her passion for the natural world and its creatures, and her selfless support of the herpetological division of
Holotype:
PERU • ♂, adult; Amazonas Department, Bongará Province, Yambrasbamba District, Yambrasbamba; 5°43.01’S, 77°58.61’W; 2370 m a.s.l.; 07 Sept. 2017; P.J. Venegas leg.;
Paratypes:
PERU • 2 ♂, adult and juvenile collected with the holotype;
Stenocercus dracopennatus sp. nov. differs from all species of Stenocercus, except for S. aculeatus, S. angulifer, S. prionotus, and S. scapularis, by having: (1) projecting angulate temporals, (2) laterally oriented nostrils, (3) dorsolateral crest (distinct on second half of body and base of tail in S. prionotus), (4) dorsal and lateral scales of body similar in size, (5) strongly keeled ventrals, and (6) scales on posterior surface of thighs keeled and imbricate.
However, S. dracopennatus sp. nov. can also be easily distinguished from S. prionotus (state of characters in parentheses) by having a low-lying vertebral crest (high and projected, Figs
Stenocercus dracopennatus sp. nov. can be readily distinguished from S. angulifer and S. aculeatus by having two canthals and a black patch covering the ventral surface of the neck (one canthal and a black patch extensively covering most of the gular region in the last two species, see Figs
(1) Maximum SVL in males 89 mm (n = 3); (2) SVL in females unknown; (3) vertebrals 38–40; (4) paravertebrals 53–57; (5) scales around midbody 39–45; (6) supraoculars 4; (7) internasals 4–5; (8) postrostrals 2–5; (9) loreals 4–5; (10) gulars 19–20; (11) subdigitals on Finger IV 19–21; (12) subdigitals on Toe IV 26–28; (13) posthumeral mite pocket present as a deep depression with a narrow opening [Type 3 of
Male (Fig.
(Fig.
(Fig.
Measurements and scutellation characters of Stenocercus dracopennatus sp. nov. are presented in Table
Stenocercus dracopennatus sp. nov. is only known from the type locality, a summit near Yambrasbamba village at 2370 m elevation, located on the eastern slope of the Cordillera de Colán, at the Río Chiriaco basin, Department of Amazonas, Peru (Fig.
The specific epithet “dracopennatus” is a noun derived from two words in Latin, “draco” that means dragon, the mythological being, and “pennatus” that means feathered. The specific name is a noun in apposition and refers to the similarity between lizards and dragons, which in both Western and Chinese cultures are beings similar to reptiles like crocodiles or serpents. Moreover, due to the big scales of this new species that give it the appearance of being covered by feathers, we decided to name S. dracopennatus sp. nov. for its resemblance to an imaginary feathered dragon.
Lateral view of head and posthumeral mite pockets of adult male Stenocercus for comparison: (A) S. dracopennatus sp. nov. (
Holotype:
PERU • ♂, adult; Amazonas Department, Bongará Province, Cuispes District, Cuispes village; 5°55.49’S, 77°56.94’W; 1850 m a.s.l.; 7 Mar. 2017; G. Chávez leg.; from farms adjacent to Cuispes village;
Paratypes:
PERU • 2 ♂, 1 ♀, adults; collected with the holotype;
Stenocercus flagracanthus sp. nov. differs from all other species of Stenocercus, except from S. arndti Venegas, Echevarria & Alvarez, 2014, S. bolivarensis Castro & Ayala, 1982, S. carrioni Parker, 1934, S. chlorostictus Cadle, 1991, S. crassicaudatus Tschudi, 1845, S. empetrus Fritts, 1972, S. eunetopsis Cadle, 1991, S. torquatus Boulenger, 1885, and S. simonsii Boulenger, 1899 by having granular scales on the posterior surface of the thighs, a relatively short tail, caudals spinose and two caudal whorls per autotomic segment. Among the aforementioned species, S. flagracanthus sp. nov., possesses caudal scales with the most strongly projected mucrons. This difference is evident comparing S. flagracanthus sp. nov. with S. carrioni, S. crassicaudatus, S. empetrus, S. eunetopsis, and S. simonsii, and to a lesser degree comparing it with S. arndti, S. chlorostictus and S. torquatus. Moreover, the size of mucrons along the second half of the tail in S. flagracanthus sp. nov., is clearly alternating, with large mucrons followed by small mucrons per each caudal whorl. In the other species, this character is indistinct or only possible to observe at the distal extreme, like in S. carrioni. With the goal of facilitating the distinction between S. flagracanthus sp. nov. and the aforementioned species, herein, we provide more differences.
Stenocercus flagracanthus sp. nov. differs from S. carrioni, S. chlorostictus and S. euneptopsis by having dorsal scales of the neck granular and not keeled (keeled and imbricate in the three former species). Stenocercus flagracanthus sp. nov. can be easily distinguished from S. crassicaudatus and S. empetrus by having a distinct black antehumeral collar (faint or absent in the remaining species). Stenocercus crassicaudatus, S. euneptopsis and S. simonsii have longer tails than S. flagracanthus sp. nov. with 57 to 62%, 64 to 66%, and 57 to 63% versus 50 to 54% of total length, respectively. Stenocercus flagracanthus sp. nov. also differs from S. crassicaudatus by having fewer scales around midbody with 96 to 104 (xˉ = 99.63) in the new species, and 97 to 121 (xˉ = 108.87) in S. crassicaudatus. Stenocercus flagracanthus sp. nov. differs from S. bolivarensis by having granular lateral body scales versus strongly keeled and imbricate lateral body scales (
Males of S. arndti are easily distinguished from S. flagracanthus sp. nov. by having a bold black transverse band at midbody that extends ventrolaterally (absent in S. flagracanthus sp. nov.). Stenocercus torquatus can be distinguished from S. flagracanthus sp. nov. by having black nuchal bands, absent in S. flagracanthus sp. nov. Moreover, Stenocercus torquatus has more scales around midbody than S. flagracanthus sp. nov. (120 to 137, xˉ = 116.96 versus 96 to 104, xˉ = 99.63, respectively). Stenocercus empetrus can be easily separated from S. flagracanthus sp. nov. by the ventral coloration, venter yellowish-orange with black reticulations in the former and whitish gray without reticulations in S. flagracanthus sp. nov.
Stenocercus roseiventris D’Orbigny in Duméril & Bibron, 1837 and S. marmoratus Duméril & Bibron, 1837 share with S. flagracanthus sp. nov. the presence of caudal scales with strongly projected mucrons but differ by having the scales on the dorsal surface of neck and posterior surface of thighs imbricate and keeled.
(1) Maximum SVL in males 76.8 mm (n = 5); (2) maximum SVL in females 68.3 mm (n = 1); (3) vertebrals 83–97; (4) paravertebrals 95–111; (5) scales around midbody 96–104 (6) supraoculars 4–6; (7) internasals 4–6; (8) postrostrals 4–5; (9) loreals 4–7; (10) gulars 55–62; (11) lamellae on Finger IV 26–29; (12) lamellae on Toe IV 30–33; (13) posthumeral mite pocket present as one or more vertical folds or ridges [Type 1 of
Male (Fig.
(Fig.
Dorsolateral and ventral views of Stenocercus flagracanthus sp. nov. in life: (A, B) holotype, adult male, SVL 75 mm (
(Fig.
Measurements, scutellation, and other morphological characters of Stenocercus flagracanthus sp. nov. are presented in Table
The adult male paratypes (n = 4) are identical to the holotype (Fig.
Variation in scutellation and sexual dimorphism in snout-vent length (mm) of Stenocercus flagracanthus sp. nov., and the similar species S. crassicaudatus and S. torquatus. Range followed by mean ± standard deviation is given for quantitative characters if applicable. Scale counts and measurements of S. crassicaudatus and S. torquatus were taken from
S. flagracanthus | S. crassicaudatus | S. torquatus | |
---|---|---|---|
Character | n = 8 | n = 31 | n = 46 |
Scales around midbody | 96–104 | 97–121 | 102–137 |
99.63 ± 2.88 | 108.87 ± 5.99 | 116.96 ± 8.21 | |
Vertebrals | 83–97 | 83–97 | 83–115 |
89.38 ± 5.21 | 89.80 ± 3.74 | 98.86 ± 7.94 | |
Paravertebrals | 95–111 | 107–166 | 103–151 |
100.13 ± 5.41 | 126.67 ± 12.21 | 124.05 ± 12.17 | |
Gulars | 55–62 | 44–55 | 47–67 |
57.50 ± 2.20 | 49.57 ± 2.73 | 54.09 ± 4.58 | |
Supraoculars | 4–6 | 6–8 | 6–8 |
5 | 6 | 7 | |
Internasals | 4–6 | 4–7 | 4–6 |
5 | 6 | 4 | |
Subdigitals Finger IV | 26–29 | 23–32 | 22–29 |
27.38 ± 1.19 | 28.53 ± 1.80 | 25.76 ± 1.49 | |
Subdigitals Toe IV | 30–33 | 26–38 | 26–32 |
31.28 ± 1.06 | 33.00 ± 2.86 | 28.96 ± 1.55 | |
Tail length/total length | 0.51–0.54 (n = 7) | 0.57–0.62 | 0.47–0.54 |
0.52 ± 0.01 | 0.59 ± 0.01 | 0.51 ± 0.02 | |
Maximun SVL males | 77 | 95 | 84 |
Maximun SVL females | 68 | 85 | 74 |
Stenocercus flagracanthus sp. nov. is only known from two close localities, Cuispes village and Canta Gallo, both on the Amazon versant of the extreme northern portion of the central Andes in the Río Utcubamba basin (Department of Amazonas), at elevations of 1720 and 1880 m (Fig.
Distribution map of Stenocercus flagracanthus sp. nov. (red square) and its most similar species: S. arndti (red circles), S. carrioni (blue triangles), S. chlorostictus (blue crosses), S. crassicaudatus (red triangles), S. empetrus (yellow diamonds), S. eunetopsis (green square), S. torquatus (green triangles), and S. simonsii (yellow triangles). Symbol with a dot in the middle corresponds to type locality. White circles with a dot are important cities for reference.
The single female paratype collected during the rainy season (March 2017) had 2 well-developed follicles, one each in the left and right ovary. The sizes of these follicles are 18.65 × 9.80 mm and 18.88 × 10.25 mm; their volumes were 937.8 mm³ and 1038.6 mm³, respectively. Stenocercus flagracanthus sp. nov. was found sympatric with S. catherineae sp. nov., Dipsas palmeri, Atractus sp. and Chironius exoletus.
The specific epithet “flagracanthus” is a noun in apposition derived from the Latin words “flagrum” (= whip, derived from “flagellum”) and the Greek “acanthos” (= spine or thorn). It refers to the spiny tail of this new species of lizard that resembles the ancient Roman torture tool, the “flagrum”, a whip-like instrument with accessories for inflicting damage.
Holotype:
PERU • ♂, adult; Amazonas Department, Luya Province, Pisuquía District, Las Corontas; 6°28.54’S, 78°8.77’W; 1340 m a.s.l.; 15 Dec. 2019; I. Wong and A. García-Bravo leg.;
Paratypes:
PERU • 1 ♀, adult, 1 juvenile; collected with the holotype;
Stenocercus philmayi sp. nov. differs from other species of Stenocercus except for S. aculeatus, S. angulifer, S. catherineae sp. nov., S. dracopennatus sp. nov., S. huancabambae, S. prionotus, and S. scapularis by having: (1) projecting-angulate temporals, (2) laterally oriented nostrils; (3) dorsal and lateral scales of body similar in size, and (3) scales on posterior surface of thighs keeled and imbricate. Stenocercus aculeatus, S. angulifer and S. scapularis differs from S. philmayi sp. nov. by having a dorsolateral crest (absent in S. philmayi sp. nov.). Stenocercus prionotus and S. philmayi sp. nov. share a prominent vertebral crest, however the former lacks a postfemoral mite pocket (present in S. philmayi sp. nov.). Adult males of S. aculeatus and S. angulifer can be easily distinguished from S. philmayi sp. nov. by having the gular region covered by a black patch (absent in the new species) and fewer gulars (15 to 18 in S. aculeatus and 16 to 20 in S. angulifer versus 20 to 24 in S. philmayi sp. nov.). The new species differs from S. scapularis by having fewer scales around midbody (34 to 45 in S. philmayi sp. nov. versus 52 to 70 in S. scapularis according with
The new species shares the presence of two canthals with the geographically close S. catherineae sp. nov. and S. dracopennatus sp. nov. (all from the northern extreme of the central Andes in the Department of Amazonas). However, S. philmayi sp. nov. possesses conspicuously larger dorsal scales than S. catherineae sp. nov., resulting in 32 to 38 vertebrals and 34 to 45 scales around midbody (43 to 53 vertebrals and 46 to 59 scales around midbody in S. catherineae sp. nov.). Adult males of S. catherineae sp. nov. have a black patch covering most of the gular region (Fig.
(1) Maximum SVL in males 95 mm (n = 4); (2) SVL in females 74 mm (n = 1); (3) vertebrals 32–38; (4) paravertebrals 49–59; (5) scales around midbody 34–45; (6) supraoculars 4–5; (7) internasals 3–5; (8) postrostrals 2–4; (9) loreals 4–6; (10) gulars 20–24; (11) subdigitals on Finger IV 18–21; (12) subdigitals on Toe IV 28–31; (13) posthumeral mite pocket present as a deep depression with a narrow opening [Type 3 of
Male (Fig.
(Fig.
Dorsolateral and ventral views of Stenocercus philmayi sp. nov. in life: (A, B) holotype, adult male, SVL 95 mm (
(Fig.
Measurements and scutellation of Stenocercus philmayi sp. nov. are presented in Table
Sexual dimorphism is evident in adults. Dorsal coloration in a single female paratype (
Stenocercus philmayi sp. nov. is only known from Las Corontas in the northern portion of the central Andes at elevations of 1340–1470 m within the Río Marañón basin (Fig.
The single female paratype collected during the rainy season (December 2019) had 2 eggs, one in the left and one in the right ovary. The sizes of these follicles are 19.71 × 9.44 mm and 19.81 × 8.40 mm; their volumes were 919.6 mm³ and 731.8 mm³, respectively.
The specific epithet philmayi is a noun in the genitive case and is a patronym for Philip May (1946–2017), an American lichenologist and philanthropist, who was passionate about protecting biological diversity. During his life-time, his generous support of Nature and Culture International was instrumental to the protection of endangered ecosystems and endemic species in the Amazonas, Cajamarca, and La Libertad departments of Peru. Even after his death in 2018, his generosity has continued to protect Latin America’s biodiversity through charitable bequests. This new species was discovered in one of the departments that May supported during his life, and naming it after him, honors May’s enduring legacy as a champion of biodiversity.
An elusive species represented by five specimens in museum collections (
Collecting specimens in the Andes of northern Peru for almost two decades, we acquired only two specimens of S. aculeatus in two locations of Abra Patricia at elevations of 1700 and 1990 m, just at the limits of the departments of Amazonas and San Martín (Fig.
Abra Patricia is the pass between the Río Chiriaco and Río Mayo basins located in the Peruvian Yungas, according to
One specimen (
The second individual (Fig.
Stenocercus aculeatus preserved specimen, adult male, SVL 80 mm (
Coloration in life of adult males (
Observations on the taxonomy and distribution of Stenocercus aculeatus, S. prionotus and S. scapularis.
Stenocercus aculeatus was a species briefly described in the past that generated confusion with other taxa, such as S. angulifer, due to the lack of specimens available in museum collections and the lack of data about its coloration in life (
The type locality of S. aculeatus, Moyobamba, at an elevation of 723 m (
The geographical distribution of S. aculeatus still seems peculiar with a gap of approximately 276 km to the northernmost locality in Zamora in southern Ecuador (
In the process of diagnosing the new species described herein, we examined the morphology and distribution of S. prionotus and S. scapularis, both from the Peruvian Amazon foothills, and adjacent Amazon lowlands, including Bolivia for S. prionotus (
The sympatric relationships between species such as S. aculeatus, S. prionotus and S. scapularis were discussed by
Dorsolateral and ventral views of Stenocercus scapularis in life: (A, B, E) adult female (
Distributional patterns and morphological affinities between S. aculeatus, S. catherineae sp. nov., S. dracopennatus sp. nov., S. huancabambae, and S. philmayi sp. nov.
The interspecific phylogenetic relationships in Stenocercus are complex and morphologically heterogeneous. However, we discuss some conjectures originating on the basis of the morphological resemblance and the geographical proximity between S. aculeatus, S. catherineae sp. nov., S. dracopennatus sp. nov., S. huancabambae, and S. philmayi sp. nov. These five species are structurally similar (see Table
Although these species apparently possess allopatric distributions, they are distinguished externally by sexually dimorphic characters (e.g. height of crest, marks on flanks and ventral coloration on gular region and neck; see
We suggest that these specific distinctions shown by males, are due to the abundance of closely related species in the same region –the northern portion of the central Andes– likely with contact zones. Morphological resemblance and particular distinctions concerning features related to inter-sexual selection in this assemblage of lizards are a result of close phylogenetic relationships owing to a recent process of vicariance driven by constant geological changes in the formation of a complex landscape like the Huancabamba Deflection and the central Andes (
We describe four new species of Stenocercus only known either from a single locality or up to a maximum of three localities. Stenocercus catherineae sp. nov. is known from three geographically proximate localities in the Río Utcubamba basin. This species was abundant in the type locality, where several individuals were found basking close to a trail on a slope of second growth vegetation along the Río Chido, a tributary of the Río Utcubamba. The general landscape at the type locality is strongly impacted by agriculture and cattle ranching with some scattered patches of forest. The same degree of fragmentation is observed in the locality of Cocachimba where several individuals of S. catherineae sp. nov. were observed in bushes and on rocky fences delimiting croplands. However, at the locality of Cuispes only one individual of S. catherineae sp. nov. was collected whereas several individuals of S. flagracanthus sp. nov. were observed. The latter species is known from two close localities, both in the Río Utcubamba basin. However, all individuals observed were found in croplands and were using human construction as refuges (e.g. houses, rocky fences and piles of firewood).
Stenocercus philmayi sp. nov. is known only from its type locality and an unconfirmed locality (see Fig.
Stenocercus catherineae sp. nov., S. flagracanthus sp. nov., and S. philmayi sp. nov. inhabit croplands and use human-made buildings as refuges, as is well known for other species of Stenocercus (
The primary research was made possible with the support of the Critical Ecosystem Partnership Fund (CEPF) (project number CEPF-109938) through the Fondo de Promoción de las Áreas Naturales Protegidas del Perú (PROFONANPE). However, the development of our CEPF project would not have been possible without the logistic support of Odile Sanchez and Claudia Zarate from PROFONANPE. Our field work was also supported by the Global Genome Initiative (GGBN-GGI). The expeditions where Stenocercus catherineae sp. nov. was discovered were funded by APECO under the research grant “Carlos Ponce del Prado Award (XI edition)”. The expeditions to Cuispes and Las Corontas were funded by Nature and Culture International. We thank David Boyd and Angel Portocarrero ARA-Amazonas for their logistic support during the search for S. philmayi sp. nov. in Las Corontas. We are indebted to William W. Lamar for review and comments on an early version of this manuscript.
Material examined.
Stenocercus aculeatus – PERÚ: Amazonas: Bongará: Abra Patricia,
Stenocercus arndti – PERÚ: Cajamarca: Chota: Quebrada Checos,
Stenocercus carrioni – ECUADOR: Loja: Celica, Huajala
Stenocercus chlorostictus – PERÚ: Piura: Ayabaca: Caserio de toronche – Comunidad de Olleros,
Stenocercus crassicaudatus – PERÚ: Cusco: Urubamba: Machu Picchu,
Stenocercus empetrus – PERÚ: La Libertad: Huamachuco MUSM 8658, 8675, 8677–8680; Santiago de Chuco: Shulgomopampa,
Stenocercus eunetopsis – PERU: Cajamarca: Santa Cruz, Udima, MUSM 4018, 4022–4029.
Stenocercus huancabambae – PERÚ: Amazonas: Bagua: Chonza Alta (Bagua Chica),
Stenocercus prionotus – PERÚ: Huánuco: Huánuco: Dos Aguas,
Stenocercus scapularis – PERÚ: Cusco: La Convención: Echarati,
Stenocercus simonsii – ECUADOR: Azuay: Giron, sendero El Salado,
Stenocercus torquatus – PERÚ: Junín: Alto Yurinaqui, MUSM 8617–8619, Satipo: San Antonio,