Stenocercus Duméril and Bibron

Torres-Carvajal, Omar, 2007, A TAXONOMIC REVISION OF SOUTH AMERICAN STENOCERCUS (SQUAMATA: IGUANIA) LIZARDS, Herpetological Monographs 21 (1), pp. 76-178 : 79-166

Stenocercus Duméril and Bibron

Stenocercus Duméril and Bibron, 1837 (4): 349.

Type species (by monotypy): Stenocercus roseiventris Duméril and Bibron, 1837 .

Trachycyclus Duméril and Bibron, 1837 (4): 355. Type species (by monotypy): Trachycyclus marmoratus Duméril and Bibron, 1837 .

Proctotretus Duméril and Bibron, 1837 (4): 266. Type species (subsequent designation by Fitzinger, 1843): Proctotretus pectinatus Duméril and Bibron, 1837 .

Heterotropis (Trachycyclus) Fitzinger, 1843: 71 . Type species (by monotypy): Trachycyclus marmoratus Duméril and Bibron, 1837 .

Steironotus (Stenocercus) Fitzinger, 1843:71 . Type species (by monotypy): Stenocercus roseiventris Duméril and Bibron, 1837 .

Scelotrema Tschudi, 1845:154 . Type species: none designated.

Ptygoderus Gray, 1845:216. Type species (by monotypy): Proctotretus pectinatus Duméril and Bibron, 1837 .

Ophryoessoides Duméril, in Duméril and Duméril, 1851:66. Type species (by monotypy): Ophryoessoides tricristatus Duméril , in Duméril and Duméril, 1851.

Brachysaurus Hallowell, 1856:232. Type species (by monotypy): Brachysaurus erythrogaster Hallowell, 1856 .

Saccodeira Girard, 1857:197 . Type species (by monotypy): Saccodeira ornatissima Girard, 1857 .

Microphractus Günther, 1859 a:90 . Type species (by monotypy): Microphractus humeralis Günther, 1859 .

Scartiscus Cope, 1862:182 . Type species (by monotypy): Scartiscus caducus Cope, 1862 .

Tropidocephalus Müller, 1880:45 . Type species (by monotypy): Tropidocephalus azureus Müller, 1880 .

Diagnosis.— Stenocercus can be distinguished from other iguanian genera by the following combination of characters ( Arnold, 1984; Boulenger, 1885 a; Frost and Etheridge, 1989; Frost, 1992; Frost et al., 2001 b): (1) maxillae do not articulate anteromedially posterior to palatal portion of premaxilla; (2) premaxillary spine not overlapped by nasals; (3) nasal concha fused to roof of nasal chamber; (4) jugal and squamosal not broadly juxtaposed; (5) parietal roof trapezoidal in shape; (6) parietal foramen in frontoparietal suture or absent; (7) supratemporal overlaps lateral aspect of supratemporal process of parietal; (8) nuchal endolymphatic sacs do not penetrate nuchal musculature; (9) labial blade of coronoid poorly developed or absent; (10) anterior surangular foramen dorsal to posteriormost extent of dentary; (11) marginal teeth pleurodont; (12) palatine teeth absent; (13) posterior coracoid fenestra present; (14) anterior process of interclavicle poorly developed or absent; (15) posterior process of interclavicle anterior to contact with sternum long; (16) sternal ribs three; (17) interparietal scale not enlarged; (18) gular scales imbricate posteriorly; (19) gular fold incomplete medially; (20) femoral pores absent; (21) preanal pores absent; (22) hemipenes weakly bilobate, with distinctly divided sulci; (23) hemipenial sheath musculature extensive; (24) hemipenial dorsal accessory muscle absent; (25) colic septa absent.

KEY TO THE SPECIES OF STENOCERCUS

1. Scales on posterior surface of thighs granular _ _ _ _ 2

Scales on posterior surface of thighs flat, smooth or keeled, imbricate _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 28

2. Vertebral scales similar in size to adjacent paravertebral scales _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3

Some or all vertebral scales larger than adjacent paravertebral scales, forming distinct middorsal row _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 13

3. Caudal whorls per autotomic segment two; caudal scales moderately to strongly mucronate _ _ 4

Caudal whorls per autotomic segment three; caudal scales not mucronate _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 6

4. Caudal scales strongly spinose _ _ _ _ _ _ _ _ _ S. eunetopsis

Caudal scales mucronate but not strongly spinose _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 5

5. Scales around midbody 51–66; tail length 59–67% of total length _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. cupreus

Scales around midbody 85–111; tail length 0.53–0.61 of total length _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. empetrus

6. Mite pocket underneath oblique neck fold deep _ _ 7

If present, mite pocket underneath oblique neck fold shallow _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 8

7. Lateral and dorsal nuchals similar in size; venter of adult males generally uniform in color _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. latebrosus

Lateral nuchals less than half the size of dorsal nuchals; venter of adult males with scattered black dots _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. ornatissimus

8. Lateral nuchals similar in size to dorsal nuchals _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. ivitus

Lateral nuchals less than half the size of dorsal nuchals _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 9

9. Dorsal head scales prominently keeled _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. orientalis

Dorsal head scales smooth _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 10

10. Scales around midbody fewer than 40; tail length at least 70% of total length _ _ _ _ _ S. modestus

Scales around midbody more than 40; tail length less than 70% of total length _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 11

11. Oblique neck fold absent; posthumeral mite pocket absent _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. melanopygus

Oblique neck fold present; posthumeral mite pocket present as one or more vertical folds or ridges _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 12

12. Antehumeral fold weakly developed; mite pockets underneath oblique and antehumeral neck folds absent; males with distinct black spots on venter _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. stigmosus

Antehumeral fold strongly developed; distinct mite pockets underneath oblique and antehumeral neck folds; ventral color pattern in males variable, but never with distinct black spots _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. chrysopygus

13. Caudal whorls per autotomic segment two _ _ _ _ _ _ 14

Caudal whorls per autotomic segment three _ _ _ _ 20

14. Dorsal scales on neck and body keeled and imbricate _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 15

Dorsal scales on neck and body granular _ _ _ _ _ _ _ _ _ 17

15. Adult males with black vertical bar anterior to each fore limb, sometimes forming antehumeral collar _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 16

Adult males lack antehumeral collar, scales around midbody 66–96 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. carrioni

16. Scales on flanks granular; scales around midbody 80–110 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. chlorostictus

Scales on flanks keeled and imbricate; scales around midbody 67–82 _ _ _ _ _ _ _ _ S. bolivarensis

17. Lateral nuchal scales less than half the size of dorsal nuchal scales _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. empetrus

Lateral and dorsal nuchal scales similar in size _ _ 18

18. Scales around midbody 79–102 _ _ _ _ _ _ _ _ _ _ S. simonsii

Scales around midbody generally more than 100 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 19

19. Adult males with complete black antehumeral collar followed anteriorly by two black transverse bars on the neck; caudal scales strongly spinose; tail length 47–54% of total length _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. torquatus

Color pattern in adult males not as described above; caudal scales moderately spinose; tail length 57–62% of total length _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. crassicaudatus

20. Antegular folds usually meet ventromedially forming continuous transverse fold_ _ _ _ _ _ _ _ _ 21

If present, antegular folds never meet ventromedially _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 26

21. Adult males with black transverse band on ventral surface of neck and lavender ventral background _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 22

Color pattern in adult males not as described above _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 23

22. Vertebrals fewer than 65 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. imitator

Vertebrals more than 65_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. praeornatus

23. Scales around midbody fewer than 65; scales on temporal region and flanks distinctly keeled and imbricate _ _ _ _ _ _ _ _ _ _ S. haenschi

Scales around midbody more than 65; scales on temporal region and flanks granular, or smooth or slightly keeled and imbricate _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 24

24. Lateral and dorsal nuchal scales granular and similar in size _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. humeralis

Lateral nuchal scales granular, less than half the size of keeled and subimbricate dorsal nuchal scales_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 25

25. Scales around midbody 74–88; black patch on shoulder in some males _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. varius

Scales around midbody 79–104; black patch on shoulder in males absent _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. boettgeri

26. Lateral and dorsal body scales similar in size; generally more than 90 scales around midbody _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. nubicola

Lateral body scales reduced in size, approximately half the size of dorsal scales; generally fewer than 90 scales around midbody _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 27

27. Postfemoral mite pocket deep _ _ _ _ _ _ _ _ _ _ _ S. variabilis

Postfemoral mite pocket absent _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. frittsi

28. Caudal fracture planes present _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 29

Caudal fracture planes absent _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 57

29. Caudal whorls per autotomic segment two _ _ _ _ _ _ 30

Caudal whorls per autotomic segment three or four _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 34

30. Caudal scales strongly spinose; preanals not projected _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 31

Caudal scales not spinose; preanals posteriorly projected, forming denticulate border _ _ _ _ _ 32

31. Vertebral crest conspicuous and continuous; lateral body scales approximately half the size of dorsal scales _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. roseiventris

Vertebral crest low and discontinuous; lateral and dorsal body scales similar in size _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. marmoratus

32. Ventral scales strongly keeled _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. azureus

Ventral scales smooth_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 33

33. Antehumeral fold present; four phalanges in Finger IV _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. pectinatus

Antehumeral fold absent; five phalanges in Finger IV _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. doellojuradoi

34. Caudal whorls per autotomic segment three _ _ _ _ 35

Caudal whorls per autotomic segment four _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. formosus

35. Nostrils lateral to canthal ridge _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 36

Nostrils medial to canthal ridge_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 40

36. Postfemoral mite pocket present _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 37

Postfemoral mite pocket absent_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 38

37. Postfemoral pocket deep; tail in adult males slightly compressed _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. aculeatus

Postfemoral pocket shallow; tail in adult males strongly compressed laterally _ _ _ S. angulifer

38. Posthumeral mite pocket covered by axillary flap; scales on dorsal aspect of thigh not projected _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 39

Posthumeral mite pocket not covered by axillary flap; dorsal aspect of thigh with one row of enlarged, projecting scales _ _ _ _ S. fimbriatus

39. Two projecting angulate temporals; vertebral crest strongly projected _ _ _ _ _ _ _ _ _ _ _ _ _ S. prionotus

Angulate temporals not projected; vertebral crest less projected_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. caducus

40. Longitudinal row of enlarged supraoculars occupying most of the supraocular region _ _ _ _ _ _ _ _ 41

Longitudinal row of enlarged supraoculars occupying most of the supraocular region absent _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 46

41. Postfemoral mite pocket present _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 42

Postfemoral mite pocket absent _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 45

42. Two or three dorsally-projected angulate temporals; one canthal _ _ _ _ _ _ _ _ _ _ _ _ _ S. huancabambae

Angulate temporals not projected; two canthals 43

43. Dorsal head scales smooth; ventral scales smooth and imbricate _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. puyango

Dorsal head scales keeled; ventral scales keeled and imbricate _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 44

44. Adult males with black blotch on ventral surface of neck; vertebral crest in males conspicuous but not strongly projected _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. limitaris

Adult males lack black blotch on ventral surface of neck; vertebral crest in males strongly projected _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. santander

45. Dorsal head scales keeled or wrinkled; ventral scales distinctly keeled in juveniles and adults _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. erythrogaster

Dorsal head scales smooth; ventral scales slightly keeled in juveniles, smooth in adults _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. iridescens

46. Postfemoral mite pocket absent _ _ _ _ _ S. apurimacus

Postfemoral mite pocket distinct, with vertical or posteroventrally oriented slitlike opening _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 47

47. Antehumeral fold present_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 48

Antehumeral fold absent _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 51

48. Oblique neck fold present_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. ochoai

Oblique neck fold absent _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 49

49. Posthumeral mite pocket shallow; males with black patches on ventral surface of thighs; maximum SVL approximately 80 mm in males and 65 mm in females _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. nigromaculatus

Posthumeral mite pocket deep; males without black patches on ventral surface of thighs; maximum SVL more than 80 mm in males and more than 65 mm in females _ _ _ _ _ _ 50

50. Posterodorsal head scales juxtaposed, protuberant, and wrinkled or multicarinate; black gular patch in adult males; parietal eye not visible through interparietal cornea _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. percultus

Posterodorsal head scales subimbricate with a central keel; gular region in adult males not black; parietal eye usually visible through interparietal cornea _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. ornatus

51. Posthumeral mite pocket deep with narrow opening; ventral aspect of hind limbs in adult males covered by black patch _ _ _ _ _ _ _ _ _ _ S. rhodomelas

Posthumeral mite pocket absent or shallow with wide opening; ventral aspect of hind limbs in adult males not covered by black patch _ _ 52

52. Posthumeral mite pocket absent _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 53

Posthumeral mite pocket shallow with wide opening _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 54

53. Ventral scales weakly keeled; tail in adult males strongly compressed; scales around midbody generally fewer than 60 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. trachycephalus

Ventral scales smooth; tail in adult males weakly compressed; scales around midbody more than 60 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. lache

54. Scales around midbody generally more than 60 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. guentheri

Scales around midbody generally fewer than 60 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 55

55. Black transverse band on ventral surface of neck in adult males generally present; venter extensively covered with black in some males _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. festae

Black transverse band on ventral surface of neck in adult males absent; longitudinal black midventral stripe usually present in adult males; venter not extensively covered with black _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 56

56. Black midventral stripe in most adult males; black blotches on gular region of juveniles and females _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. chota

Black midventral stripe in adult males absent; black blotches on gular region of juveniles and females absent _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. angel

57. Posthumeral and postfemoral mite pockets present _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. scapularis

Posthumeral and postfemoral mite pockets absent _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 58

58. Posterior supraciliaries enlarged, projected; head pyramidal in shape _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 59

Posterior supraciliaries not enlarged, not projected; head not pyramidal in shape _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. sinesaccus

59. Tail length 53–63% of total length _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 60

Tail length 44–52% of total length _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 61

60. Posterior supraciliaries distinctly pointed; two enlarged scales above tympanum; tibia about as long as thigh; scales around midbody more than 40 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. dumerilii

Posterior supraciliaries blunt; scales above tympanum not enlarged; tibia shorter than thigh; scales around midbody fewer than 40 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. tricristatus

61. Tail length at least 50% of total length; vertebral, paravertebral and lateral crests inconspicuous _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. quinarius

Tail length less than 50% of total length; vertebral, paravertebral, and lateral crests prominent _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ S. squarrosus