Selvasaura almendarizae, Scarsbrook & Walton & Rawlence & Hitchmough, 2023

Scarsbrook, Lachie, Walton, Kerry, Rawlence, Nicolas J. & Hitchmough, Rodney A., 2021, Hoplodactylus tohu Scarsbrook & amp; Walton & amp; Rawlence & amp; Hitchmough 2023, n. sp., Journal of Herpetology 10 (3), pp. 385-395 : 385-395

SelƲasaura almendarizae sp. nov.

Figs. 1–7

Unnamed clade 3 ( Torres-Carvajal et al., 2016) in part.

SelƲasaura sp. ( Moravec et al., 2018) in part.

Proposed standard English name: Almendáriz’s Microtegus

Proposed standard Spanish name: Microtegúes de Almendáriz

Holotype.— QCAZ 12798 ( Figs. 1 , 2 ), adult male, Ecuador, Provincia Napo, Wildsumaco Wildlife Sanctuary , 0 ° 41 ′ 17.17 ′′ S, 77 ° 36 ′ 1.45 ′′ W, WGS84, 1,350 m, 22 July 2014, collected by J. Camper.

Paratypes (2).— ECUADOR: Provincia Napo: QCAZ 5073 , adult male, same collection data as holotype except 0 ° 40 ′ 46.96 ′′ S, 77 ° 36 ′ 2.81 ′′ W, 1,250 m, 30 July 2012 . Provincia Pastaza: QCAZ 9140 , adult male, Zanjarajuno Ecological Center , 1 ° 22 ′ 19.08 ′′ S, 77 ° 51 ′ 57.99 ′′ W, 940 m, 20 March 2008, collected by P. Rivera, L. Coloma, and S. Ron.

Diagnosis.—The new species belongs to SelƲasaura as defined by Moravec et al. (2018). However, in the absence of morphological synapomorphies defining SelƲasaura , the new species is assigned to SelƲasaura based on phylogenetic evidence ( Fig. 8 ; see also Moravec et al., 2018). SelƲasaura almendarizae sp. nov. differs from S. braƲa ( Table 1 ) in having more femoral pores in males (9– 12 vs. 7–9, respectively), fewer gular collar scales (7–9 vs. 9–11), fewer transverse rows of dorsals (25–32 vs. 33–36), fewer scales around midbody (29–32 vs. 32–34), and fewer lateral scale rows (5 vs. 6–7). The new taxon can be further distinguished from S. braƲa and other Cercosaurinae species in having a unilobed hemipenis, which among microteiids has been reported only in a few species within Gymnophthalminae ( Calyptommatus sp. , Nothobachia ablephara , and Scriptosaura catimbau ) and Alopoglossidae ( Alopoglossus breƲifrontalis , Alopoglossus festae , Alopoglossus kugleri , Alopoglossus myersi , and Alopoglossus plicatus ; Nunes, 2011; Hernández Morales et al., 2020).

Characterization.—(1) Three to four supraoculars, anteriormost larger than posterior one; (2) two prefrontals; (3) 9–12 femoral pores in males (females unknown); (4) lower eyelid scale single and transparent; (5) scales on dorsal surface striated; (6) five rows of lateral scales at midbody; (7) 25–32 dorsal scales between occipital and posterior margin of hindlimb; (8) lateral body fold present; (9) keeled ventrolateral scales on each side absent; (10) dorsum brown with a conspicuous, cream or gray vertebral stripe with wavy borders and scattered black marks along sides, extending from interparietal or postparietal to tip of tail; (11) white labial stripe present, with black outline on dorsal border and brown flecks or brown transversal bars on supralabials; (12) flanks of body grayish brown, turning cream on ventrolateral region; (13) white stripe along forelimb absent; (14) adult males with a longitudinal row of ocelli (black thick outline and white center) extending from above forelimb insertion posteriorly along flanks.

Description of Holotype.—Adult male (QCAZ 12798); SVL 39.54 mm; TL 73.04 mm; HL 9.65 mm; HW 5.3 mm; HD 3.92 mm; EN 3.38 mm; FLL 13.31 mm; HLL 18.61 mm; AGD 19.11 mm.

Dorsal and lateral head scales smooth, juxtaposed; rostral subrectangular, 1.43 times wider than high; frontonasal pentagonal, laterally in contact with nasal, smaller than frontal; prefrontals hexagonal, longer than wide, with medial suture, laterally in contact with nasal, loreal, and first superciliary; frontal hexagonal, longer than wide, wider anteriorly, in contact with prefrontals and supraoculars I and II; frontoparietals pentagonal, longer than wide, wider posteriorly, each in lateral contact with supraoculars II and III; interparietal heptagonal, lateral borders parallel to each other; parietals slightly shorter than interparietal, polygonal, positioned anterolaterally to interparietal, each in lateral contact with supraocular III and dorsalmost postocular; postparietals three, medial scale smaller than laterals; supralabials seven, fourth slightly longer and below center of eye; infralabials seven, fourth below center of eye; temporal enlarged, juxtaposed, smooth, polygonal; one enlarged, smooth supratemporal; nasal divided above and below nostril, subtriangular, wider than long, in contact with rostral anteriorly, supralabials I and II ventrally, frontonasal and prefrontals dorsally, loreal posterodorsally and frenocular posteroventrally; loreal rectangular; frenocular trapezoidal, in contact with nasal, separating loreal from supralabials; supraoculars three, first one largest; 4/5 (right/left) superciliaries, first one enlarged, extending onto dorsal surface and in contact with loreal; palpebral disk single, transparent; three suboculars, third one largest; three postoculars of similar size; ear opening round, without denticulate margins; tympanum recessed into a shallow auditory meatus; mental 1.27 times wider than long; postmental pentagonal, wider than long, followed posteriorly by four pairs of genials, anterior two in contact medially, posterior two separated by postgenials; all genials in contact with infralabials; gulars imbricate, smooth, in nine rows; gular fold complete; posterior row of gulars (collar) with nine scales that are similar to each other in size medially and become smaller laterally.

Scales on nape wider than those of dorsals; scales on sides of neck small and granular; dorsal scales elongated, imbricate, arranged in transverse rows; scales on dorsal surface of neck striated; 28 dorsals between occiput and posterior margin of hindlimbs; 16 dorsal scale rows in a transverse line at midbody; ventrolateral scales smooth; dorsals separated from ventrals by five rows of small scales at level of 13th row of ventrals; lateral body fold present; ventrals smooth, wider than long, arranged in 23 transverse rows between collar fold and preanals; 10 ventral scale rows in a transverse line at midbody; subcaudals smooth; limbs overlapping when adpressed against body; axillary region with granular scales; scales on dorsal surface of forelimb smooth, imbricate; scales on ventral surface of forelimb granular; 3 thick, smooth thenar scales; supradigitals 4/4 (right/left) on finger I, 6/6 on II, 8/8 on III, 9/9 on IV, 6/6 on V; supradigitals 4/4 on toe I, 7/7 on II, 9/9 on III, 11/12 on IV, 9/8 on V; subdigital lamellae of forelimb single, 6/7 on finger I, 12/11 on II, 14/13 on III, 14/12 on IV, 11/10 on V; subdigital lamellae on toe I single, divided on toes II-V from half-length to base, 6/- on toe I, 11/11 on II, 15/16 on III, 20/20 on IV, 14/13 on V; groin region with small, imbricate scales; scales on dorsal surface of hindlimbs smooth, imbricate; scales on ventral surface of hindlimbs smooth; scales on posterior surface of hindlimbs granular; 12/11 femoral pores on each leg; preanal pores absent; cloacal plate with four scales, bordered by four scales anteriorly, of which the two medial-most are enlarged.

Cranial Osteology of Holotype.—The skull of SelƲasaura almendarizae sp. nov. ( Figs. 3 , 4 ) is depressed (skull height = 46% of skull length) and moderately long (skull width = 51% of skull length). Marginal teeth are present on the maxillary arcade (i.e., premaxilla and maxillae) and palatal teeth are absent. The opisthotics-exoccipitals and parasphenoid-basisphenoid are indistinguishably fused and, therefore, are described as single units, namely, otoccipitals and parabasisphenoid, respectively. The mandible is dentigerous and V-shaped in dorsal and ventral profiles, and its greatest width is approximately 13% of its total length ( Fig. 5 ). Each mandibular ramus increases slightly in height posteriorly and has approximately the same width throughout its length. The rami meet anteriorly forming the mandibular symphysis.

Dermatocranium: The premaxilla forms the anteromedial margin of the snout and the medial margin of each fenestra exonarina. It bears a broad posterodorsally oriented nasal process, which extends and tapers between the anterior half of the nasals, and a broader anterior alveolar portion. The premaxilla articulates with the maxillae anterolaterally and the nasals posteriorly. The tapered posterior end of the nasal process articulates with the anteromedial margins of the nasals. In ventral view, the premaxilla bears a chevron-shaped medial ridge pointing forward and extending halfway the length of the premaxilla. The ventral surface of the premaxilla lacks posteroventral extensions at its articulation with the maxilla. Anteroventrally, the alveolar portion of the premaxilla bears 10 conical teeth.

The septomaxillae are dorsoventrally compressed and lie anteromedially within the nasal capsules, lateral to the nasal septum. They form the floor of the anteromedial portion of the nasal cavity and the roof of the cavum containing the vomeronasal organ. The septomaxillae are oriented anteroventrally and articulate with the maxillae anterolaterally and the vomers ventrally.

The maxillae occupy most of the anterolateral aspect of the skull between the orbits and the snout. In lateral aspect, each maxilla extends approximately 38% the length of the skull. Each maxilla bears 14 laterally compressed teeth on a well-developed alveolar shelf. Maxillary dentition is heterodont, with conical anterior teeth and larger, tricuspid (lateral cusps much smaller than the medial one) posterior teeth. In an anterior-to-posterior sequence in lateral view, the maxilla articulates with the premaxilla, nasal, prefrontal, jugal, and ectopterygoid. The preorbital facial process of each maxilla forms the lateral rim of the fenestra exonarina. There are three anterior inferior alveolar foramina on the pars facialis of the maxilla. The posterior half of the pars facialis of each maxilla extends to a point posterior to the center of the orbit and overlaps the jugal. The part of the maxilla bearing the last four teeth forms part of the floor of the orbit, as well as the anterolateral rim of the inferior orbital fenestra. The maxillae articulate with the jugals posterodorsally and ectopterygoids posteroventrally. In ventral view, the anterior half of each maxillary alveolar shelf is expanded medially and overlaps the corresponding vomer laterally; this expansion makes the medial borders of the shelves parallel to each other. Posteriorly, each alveolar shelf bears a triangular medial process that overlaps the anterolateral aspect of each palatine. In posterior view, the dorsal aspect of each maxilla is notched at a point about halfway its length to form the floor of the maxillopalatine foramen.

The nasals form most of the roof of the nasal capsules. They articulate with the nasal process of the premaxilla anteriorly and overlap the frontal posteriorly. The internasal suture represents approximately half the length of each nasal. In an anterior-to-posterior sequence, the lateral margin of each nasal articulates with the maxilla, prefrontal, and frontal, respectively. The nasalprefrontal articulation is interrupted posteriorly by the slender anterolateral processes of the frontal. Anteriorly, the nasal forms the posterodorsal rim of the fenestra exonarina. The prefrontals form the anterodorsal rims of the orbits. Each prefrontal articulates with the nasal and frontal dorsally and with the maxilla anteriorly, ventrolaterally, and ventrally. In posterior view, the ventral margin of each prefrontal is notched to form the roof of the maxillopalatine foramen. The lacrimals are absent.

The frontal lies between the orbits, is longer than wide, and forms most of the dorsal orbital margin. Anteriorly, the frontal is W-shaped in dorsal view because it is partially overlapped by the nasals. In ventral view, the anterolateral processes are shorter than the anteromedial process. The anterolateral processes articulate with the dorsal margin of the prefrontals. The transverse posterior margin of the frontal lies posterior to the orbits and articulates with the anterior margin of the parietal. Posterolaterally, the frontal articulates with the anterior third of the anterior process of the postfrontal. In ventral view, the cristae cranii are strongly developed and meet anteriorly to form a tubular structure.

The parietal forms most of the posterior surface of the skull table. Laterally, the parietal extends ventrally and forms the medial rim of the supratemporal fossae. Posteriorly, the corpus of the parietal bears a pair of long supratemporal processes that are laterally overlapped by the supratemporals, which are laterally compressed and extend anteriorly less than half the length of the supratemporal fossa. The distal end of each supratemporal process approaches the paraoccipital process of the otoccipital. Medially, the posteroventral surface of the parietal bears the parietal fossa.

The postfrontals are small, flat, star-shaped bones that form part of the posterodorsal rims of the orbits. Each postfrontal has a long anterior process that articulates with the frontal anteromedially and three short posterior processes. The postfrontals articulate with the postorbitals laterally.

The postorbitals are long, flat, wider anteriorly and form the posterolateral margins of the skull along with the squamosals. The postorbitals lie ventral to the postfrontals, forming part of the posterodorsal rim of the orbits. The posterior end of each postfrontal articulates with the medial face of the squamosal.

The squamosals are slender and crescent-shaped and form the posterolateral rims of the supratemporal fossae and the posterior halves of the supratemporal arches. Posteriorly, the squamosal articulates dorsally with the posterior end of the supratemporal and ventrally with the cephalic condyle of the quadrate.

Jugals are broadly V-shaped and largely overlapped by the maxillae anterolaterally, forming the posteroventral rims of the orbits. Each jugal is composed of two elongate processes that enclose an obtuse angle, with the vertex lying approximately halfway between the anterior and posterior ends of the skull. The anterior or maxillary process articulates with the maxilla anteriorly, ventrally, and laterally and ectopterygoid posteromedially. The dorsal third of the posterior or temporal process of the jugal articulates with the postorbital.

Vomers are the most anterior elements of the palate and form the medial border of each fenestra vomeronasalis externa anteriorly and each fenestra exochoanalis posteriorly. The vomers are fused medially along the anterior two-thirds of their length; the anterior end is tapered and V-shaped and overlaps the posteroventral aspect of the premaxilla. Ventrally, the fused vomers bear two conspicuous ridges that are arched toward each other.

Palatines are medially separated by the anterior half of the pyriform space. Each palatine is widest anteriorly; the tapered posterior end contacts the pterygoid. Anteriorly, the palatines overlap the vomers dorsally, thereby lying in the most dorsal aspect of the palate. Ventrally, each palatine bears a deep concavity, which represents the choanal duct extending from the choanal opening anteriorly. A conspicuous pterygoid process descends ventrally and forms the anteromedial margin of the inferior orbital fenestra.

The ectopterygoids form the posterolateral rims of the inferior orbital fenestrae. Each ectopterygoid bears three processes, namely, anterior, lateral, and posterior processes. The anterior process overlaps the posterior end of the maxilla, whereas the lateral process contacts the jugal. The posterior process is forked and braces the distal end of the transverse process of the pterygoid.

The pterygoids are the largest and most posterior elements of the palate. They form the posteromedial rim of each inferior orbital fenestra and, together with the parabasisphenoid, the rim of the posterior half of the pyriform space. Anteriorly, each pterygoid bears a palatine process medially and a transverse process laterally. Each flat palatine process is overlapped dorsally by the pterygoid process of each palatine. Each transverse process extends laterally, and its distal end is embraced by the dorsal and ventral branches of the forked posterior process of the ectopterygoid. Posteriorly, each pterygoid bears the long, laterally compressed quadrate process, which constitutes about half the length of the bone. The quadrate process extends posterolaterally to reach the ventral portion of the medial aspect of the quadrate. The anteromedial aspect of each quadrate process contacts the distal end of the basipterygoid process of the parabasisphenoid. Dorsally, the proximal end of each quadrate process bears the columellar fossa, which receives the ventral end of each epipterygoid. There are 14 ossicles in each eye, but their margins are not well resolved in the CT scans.

The dentary is more than half the length of the lower jaw laterally and bears 17 teeth on a well-defined alveolar shelf. Mandibular dentition is heterodont, with small conical anterior teeth and larger, tricuspid (lateral cusps much smaller than the medial one) posterior teeth. Posteriorly, the dentary extends as much as the overlying coronoid. The posterior margin of the dentary articulates with several bones. In lateral view, it articulates with the surangular and is largely overlapped by the labial process of the coronoid. In lingual aspect, the dentary is bifurcate; the ventral splenial process and anteroventral portion of the dorsal coronoid process articulate with the splenial, whereas the posterior aspect of the dorsal coronoid process is overlapped by the anterior lingual process of the coronoid. The dorsolateral margin of the dentary, at its union with the coronoid, lies ventral to the dorsal margin of the surangular. Posteromedially, the dentary articulates with the anterodorsal margin of the angular. Laterally, the anterior half of the dentary bears four mental foramina, which lie in a longitudinal series halfway between the ventral and dorsal margins.

The coronoid lies immediately behind the mandibular tooth row. Its dorsal process is nearly as high as the maximum height of the dentary. Ventrolaterally, the labial process of the coronoid overlaps the dentary posterior to the tooth row. The coronoid articulates posteriorly with the surangular. In medial aspect, the coronoid bears two processes. The anterior lingual process articulates with the dentary anteriorly, splenial ventrally, and prearticular posteriorly. The posterior lingual process overlaps the anteromedial portion of the prearticular. The base of the lingual bifurcation of the coronoid is wide and dorsally concave.

The surangular occupies the posterior half of the mandible and forms the dorsal portion of the lower jaw between the coronoid and articular. It bears a large anterolateral foramen immediately posterior to the articulation with the coronoid and a smaller posterolateral foramen. In lateral aspect, the surangular tapers anteriorly between the coronoid dorsally and dentary ventrally. The ventrolateral border of the surangular articulates anteriorly with the dentary and behind it with the angular. Medially, the surangular bears three large foramina longitudinally aligned along the adductor fossa, followed posteriorly by three much smaller foramina. The surangular is fused with the articular/prearticular complex. The prearticular forms the posterior end of each mandibular ramus and lies mostly on the ventral and lingual aspects of the mandible.

Posteriorly, the prearticular bears the retroarticular process posteriorly and a short, semicircular angular process medially. The latter extends anteriorly as a prominent longitudinal crest, of which the anterior end is overlapped by the posteromedial process of the coronoid. In dorsal view, the retroarticular process is defined by two rounded crests that converge posteriorly, namely, the tympanic crest laterally and the medial crest medially. The medial crest bears the chorda tympani foramen at the medial side of its proximal end. Anterior to the angular and retroarticular processes, the dorsal aspect of the prearticular is fused with the overlying articular.

The angular is a small, slender bone that lies along the ventral surface of each mandibular ramus. Posteriorly, it articulates with the surangular laterally and prearticular medially. Anteriorly, each angular articulates with the dentary laterally and the splenial medially. Each angular is pierced by a small posterior mylohyoid foramen at the level of the anterior end of the adductor fossa.

The splenial lies on the medial aspect of the mandible. Its anterior end and most of its ventral margin articulate with the dentary; it articulates with the angular posteroventrally. Dorsally, the splenial articulates with the anteromedial process of the coronoid anteriorly and the prearticular posteriorly. The anterior end of the splenial is pierced by a large anterior inferior alveolar foramen, followed ventrally by a much smaller anterior mylohyoid foramen.

Neurocranium: The basioccipital lies between the otic capsules and forms the posterior floor of the braincase and the medial portion of the occipital condyle. Its anterior margin articulates broadly with the parabasisphenoid and bears a broad rectangular notch medially. The basioccipital articulates with the prootic anterolaterally and the otoccipital posterolaterally. On each side, the basioccipital has a short, wide ventrolateral process, dorsal to which the foramen rotundum opens.

The supraoccipital forms the posterior roof of the braincase. Its anteriorly concave posterior margin forms the dorsal rim of the foramen magnum. The V-shaped lateral border of the supraoccipital articulates with the prootic anteriorly and the otoccipital posteriorly. The anterodorsal margin of the supraoccipital is separated from the parietal by a gap and bears the processus ascendens medially, which is directed toward the parietal fossa of the parietal. On each side of this process, the dorsal surface of the supraoccipital bears a shallow depression.

Except for its short anteromedial cultriform process, the parasphenoid is fused with the basisphenoid to form the parabasisphenoid, which constitutes the anterior floor of the braincase. It articulates with the basioccipital posteriorly and the prootic posterodorsally. In ventral view, the medial portion of the posterior margin of the parabasisphenoid projects posteriorly as a rectangle that fits into the anteromedial notch of the basioccipital. Anteriorly, the parabasisphenoid bears two ventrolaterally oriented basipterygoid processes, which have expanded distal ends that articulate with the quadrate processes of each pterygoid. Dorsal to each basipterygoid process, the parabasisphenoid bears a short dorsolateral alar process, which articulates with the anteroventral process of the prootic. The posterior aspect of the parabasisphenoid is pierced on each side by the entrance to the Vidian canal and bears a short crista anterior to it, which corresponds to an anterior extension of the crista prootica. The thin and short cultriform process extends anteriorly to a point posterior to the posterior ends of the dentaries.

The otoccipitals form the posterolateral walls of the braincase, lateral margins of the foramen magnum, and lateral portions of the occipital condyle. They meet the prootics anteriorly (suture not visible), supraoccipital dorsally, and basioccipital ventrally. Each otoccipital bears a short lateral paraoccipital process. Two foramina pierce the posterior surface of each otoccipital lateral to the occipital condyle; they are the dorsal hypoglossal foramen ventrally and the vagal foramen dorsally. Anterior to the paraoccipital process, each otoccipital has a deep concavity that corresponds to the posterior portion of the jugular recess. The fenestra ovalis lies mostly in the otoccipital and receives the footplate of the stapes; it lies between the jugular recess and the foramen rotundum. The anterior margin of the fenestra ovalis is formed by the posteroventral margin of the prootic. The crista interfenestralis separates the fenestra ovalis from the foramen rotundum.

The prootics form the anterolateral walls of the braincase. Each prootic bears a large anterodorsally oriented alar process, which articulates with the lateral margin of the supraoccipital posteriorly. The anterior margin of the alar process forms the crista alaris, ventral to which the prootic bears a lateral bulge that corresponds to the acoustic recess medially. The anteroventral process of the prootic articulates with the parabasisphenoid anteriorly and the basioccipital ventrally. The anteroventral process bears ventrally a large cavity that corresponds to the anterior portion of the jugular recess. Ventrolaterally, each prootic bears a conspicuous crista prootica, which constitutes the lateral wall of the jugular recess. The distinct trigeminal notch on the anteroventral aspect of the prootic is formed by the dorsal margin of the anteroventral process and the ventral margin of the alar process. Posteriorly, the prootic overlaps the anterior surface of the paraoccipital process of the otoccipital and forms the anterior margin of the fenestra ovalis. The boomerang-shaped orbitosphenoids lie immediately anterior to the cultriform process and form the lateral margins of the optic foramen.

Splanchnocranium: The quadrates lie on the posterolateral corners of the skull, articulating with and supporting the lower jaw. Ventrally, each quadrate bears a large transverse condyle that articulates with the glenoid fossa of the articular. A prominent crest extends posterodorsally from the transverse condyle to the cephalic condyle that forms the posterodorsal end of each quadrate. The cephalic condyle articulates with the posterior end of the supratemporal, the posterior end of the squamosal, and the distal end of the paraoccipital process of the otoccipital. Each quadrate is divided into a wide, anterolaterally concave lateral half bearing the tympanic crest along its lateral margin and a short medial half bearing the medial crest along its medial margin. The tympanic crest is notched close to its dorsal end. The medial half of each quadrate is in close contact with the quadrate process of the pterygoid ventromedially.

The rod-shaped epipterygoids form a pair of vertical braces between the palate and the skull table. The ventral end of each epipterygoid inserts into the columellar fossa of the quadrate process of the corresponding pterygoid, whereas the dorsal end surpasses the ventral tip of the ventrolateral extension of the parietal laterally in close distance but without contacting it.

Each thin cylindrical stapes lies anteroventral to the paraoccipital process of the otoccipital and bears an expanded proximal end forming an elongated footplate that attaches to the membrane covering the fenestra ovalis. The articular bone lies on the dorsal aspect of the posterior portion of each mandibular ramus between the proximal portions of both the retroarticular and angular processes of the prearticular, with which it is fused. It is also fused anteriorly with the surangular. It bears a pair of dorsal concavities, the medial and lateral portions of the glenoid fossa, which form the articular facet of the lower jaw.

Color of Holotype.—Based on photographs of a freshly killed specimen, the dorsal surface of head, body, and limbs is light brown with dark-brown or black spots; light-brown vertebral stripe (~2 dorsal scales wide) extending from occiput to tail, finely bordered laterally by dark brown; faint tan dorsolateral line extending on each side from supratympanic scales to shoulder; narrow yellowish cream stripe from mouth commissure, through ventral border of tympanum, to forelimb insertion, and extending posteriorly as a ventrolateral band that fades away before reaching hindlimb; sides of neck and flanks light brown; one conspicuous ocellus with thick black border and cream center above forelimb insertion, followed by 3/2 (right/left) ocelli on flanks posteriorly; tail orange ventrally and reddish brown laterally; throat light olive green with brass tint and dispersed black dots; venter olive green with dark marks within each scale.

In preservative, dorsal surface of head and body gray, limbs whitish brown with scattered black markings, dorsal surface of tail light brown; vertebral stripe light gray becoming light brown toward the tail, bordered laterally by scattered black marks; flanks light gray with bronze-brown tint, ocelli on shoulders and flanks as described above; throat and belly creamy white with black spots; ventral surfaces of limbs and tail yellowish white ( Fig. 1 ).

Color in Life of Paratype QCAZ 9140.—Dorsal surface of head, body, and limbs light brown with dark-brown spots; cream vertebral stripe extending from occiput to tail, bordered laterally by fine dark brown; nearly inconspicuous tan dorsolateral line extending on each side from supratympanic scales to hindlimbs; narrow white stripe bordered by dark brown dorsally extending from below orbit to forelimb insertion; sides of neck and flanks light brown; nine ocelli-like spots along flanks, from neck to hindlimb insertion; tail flanks light brown with orange tint; throat creamy white; chest and belly creamy white with light green tint, and fine dark-green and cream spots on individual scales; ventral surface of forelimbs light brown; ventral surface of hindlimbs and cloacal plate yellowish white; ventral surface of tail creamy white, with scattered orange marks; iris orange ( Fig. 6 ).

Hemipenis of Paratype QCAZ 5073.—Organ partially everted and partially expanded, 4–5 mm long (~four subcaudals); organ unilobed, partially damaged during eversion; sulcus spermaticus broad and shallow throughout the hemipenial body, originating at the base of the hemipenis, and extending in a straight line until it divides into 2 branches at the distal 3rd of the organ; sulcal branches separated by fleshy fold; hemipenial body with 14 pairs of chevron-shaped flounces, separated by a longitudinal nude area on asulcate face (except first, proximalmost flounce), with vertices directed proximally on the lateral aspects of the body; flounces ornamented with calcified spicules ( Fig. 7 ).

Other Variation.—Variation in lepidosis and measurements in SelƲasaura almendarizae sp. nov. is presented in Table 1 .

Etymology.—The specific name is a noun in the genitive case and is a patronym for Ana Almendáriz, former curator of Herpetology in the Museo de Historia Natural Gustavo Orcés at Escuela Politécnica Nacional del Ecuador. Ana Almendáriz is an Ecuadorian herpetologist who has made important contributions to the study of amphibians and reptiles from Ecuador including more than a dozen species descriptions. For more than three decades, she also has trained many young herpetologists.

Distribution and Natural History.— SelƲasaura almendarizae sp. nov. is known from three localities along the northeastern slopes of the Andes of Ecuador at elevations between 950-1,350 m ( Fig. 9 ). This distribution range corresponds to Napo and Pastaza provinces in Ecuador. All specimens were found active during the day. Paratype QCAZ 9140 was found on mainland forest, on a leaf 100 cm above the ground, close to a stream. The new species occurs in Eastern Montane and Eastern Foothill forests ( Fig. 10 ), with annual mean temperatures of 7.2–21.9 ° C and 20– 23.9 ° C, respectively ( Ron, 2017). The type locality of S. almendarizae sp. nov. is part of Wildsumaco Wildlife Sanctuary, a 500-ha private reserve located near the Gran Sumaco Biosphere Reserve. The other two localities where this species has been recorded ( Fig. 9 ) also lie within protected areas, indicating that at least some populations of S. almendarizae sp. nov. are protected.

Phylogenetic Relationships.—Data partitions and evolution models are presented in Table 2 . BI and ML analyses resulted in similar topologies, with only minor discrepancies among poorly supported nodes ( Fig. 8 ; Supplementary Tree Files 1, 2). Monophyly of SelƲasaura is strongly supported (PP = 1, BS = 92). The sister taxon of SelƲasaura is a clade (PP = 0.9, BS = 86) composed of Potamites and Dendrosauridion ; however, this relationship is better supported by BI than ML analysis (PP = 0.96 and BS = 49, respectively). The ML analysis placed the new species as a sister to all other congenerics with low support, whereas relationships among species of SelƲasaura were not resolved by the Bayesian analysis. Both BI and ML analyses maximally support the monophyly of S. almendarizae sp. nov., S. braƲa , and an undescribed species of SelƲasaura from Peru. Mean genetic distances between S. almendarizae sp. nov. and S. braƲa are 0.07 (12S) and 0.05 (16S).

Figures

FIG. 1. Holotype (QCAZ 12798; SVL = 39.54 mm) of SelƲasaura almendarizae sp. nov. in dorsal (top) and ventral (bottom) views. Photographs by J. Carrión.

FIG. 2. Head of the holotype (QCAZ 12798) of SelƲasaura almendarizae sp. nov. in dorsal (top), lateral (middle), and ventral (bottom) views. Individual scales were traced for clarity. Photographs by J. Carrión.

FIG. 3. Skull of the holotype of SelƲasaura almendarizae sp. nov. (QCAZ 12798) in (A) dorsal, (B) lateral, (C) ventral, (D) anterior, and (E) posterior views. Abbreviations: boc, basioccipital; ecp, ectopterygoid; epp, epipterygoid; f, frontal; j, jugal; m, maxilla; n, nasal; os, orbitosphenoid; otoc, otoccipital; pa, parietal; pbas, parabasisphenoid; pal, palatine; pm, premaxilla; po, prootic; porb, postorbital; posf, postfrontal; pref, prefrontal; pt, pterygoid; q, quadrate; sm, septomaxilla; soc, supraoccipital; sq, squamosal; sta, stapes; sut, supratemporal; v, vomer. Images by C. Koch. Scale bars correspond to left and right images, respectively.

FIG. 4. Skull of the holotype of SelƲasaura almendarizae sp. nov. (QCAZ 12798) in ventral view after sequential removal of (A) maxillae, pterygoids, quadrates, parabasisphenoid, and basioccipital; and (B) vomers, palatines, jugals, ectopterygoids, orbitosphenoids, epipterygoids, otoccipitals, prootics, and stapes. Abbreviations are the same as those in Fig. 3. Images by C. Koch.

FIG. 5. Mandible of the holotype of SelƲasaura almendarizae sp. nov. (QCAZ 12798) in (A) dorsal, (B) ventral, (C) lateral, and (D) medial views. Abbreviations: an, angular; arpre, articular/prearticular complex (fused with surangular); co, coronoid; d, dentary; rp, retroarticular process; san, surangular; sp, splenial. Images by C. Koch.

FIG. 6. Specimens of SelƲasaura almendarizae sp. nov. in life. (A, B) paratype QCAZ 9140, SVL = 39.73 mm; (C, D) uncollected specimens from Bigal River Biological Reserve, Napo Province (see map in Fig. 9). Photographs by S. R. Ron (A, B), A. Anker (C), and T. Garcia (D).

FIG. 7. Hemipenis of SelƲasaura almendarizae sp. nov. (QCAZ 5073, paratype) in sulcate (left), lateral (middle), and asulcate (right) views. Photographs by P. M. S. Nunes.

FIG. 8. Phylogeny of Cercosaurinae. Maximum likelihood tree obtained under a RAxML analysis of 147 taxa and 1,949 aligned base pairs of mitochondrial and nuclear DNA. Bootstrap support values/ posterior probabilities are indicated next to branches. Except for SelƲasaura, clades ranked as genera were collapsed into triangles if two or more species were included. Outgroup taxa are not shown. Bayesian and RAxML tree files are provided as Supplementary Tree Files 1, 2.

FIG. 9. Distribution of SelƲasaura almendarizae sp. nov. in Ecuador. Arrow points at type locality. The northernmost locality is based on the photographs presented in Fig. 6C,D.

FIG. 10. Habitat of the type locality of SelƲasaura almendarizae sp. nov. at Wildsumaco Wildlife Sanctuary, Napo Province, Ecuador. Photograph by J. D. Camper.