ZOOLOGY OF CHORDATES: STUDY GUIDE - Zakharenko M.O. - 2015

CHAPTER 4. SUPERCLASS TETRAPODA. LOWER TERRESTRIAL VERTEBRATES

4.6. Identification Guide to Reptiles

1 [2] Body enclosed in a broad bony shell, covered dorsally with large horny plates or smooth Skin.

Order Turtles. Testudinata.

2 [1] Body covered with scales dorsally.

3 [4] Limbs present; if absent, movable eyelids are developed.

Suborder Lizards. Sauria.

4 [3] Limbs absent, movable eyelids absent.

Suborder Snakes. Serpentes or Ophidia.

Class="center">Identification key for lizards.

1 [4] Limbs absent.

2 [3] A large skin fold along the sides; scales rhomboid, with folds on the tail.

Sheltopusik (European Glass lizard) - Ophisauras apodus.

3 [2] No skin folds along the sides of the body; scales rounded, smooth.

Slow worm - Anguts fragilis.

4 [1] Limbs present.

5 [92] HEAD dorsally covered with large, evenly arranged shields.

6 [19] Scales fish-like, dorsal scales similar to ventral ones, femoral pores absent.

7 [14] Eyelids fused into a transparent fixed membrane covering the eye, making the lower eyelid appear externally absent.

8 [9] A single frontoparietal shield.

9 [8] Two frontoparietal shields.

10 [11] Row of supraciliary shields divided into two groups (interrupted). 26–28 scales around the mid-body.

11 [10] Row of supraciliary shields uninterrupted, intact, no more than 24 scales around the mid-body.

12 [13] Back adorned with numerous short, longitudinally aligned white dashes that sometimes almost merge into light longitudinal stripes.

13 [12] Back without small white streaks or stripes.

14 [7] Eyelids movable, well-defined.

15 [16] Around the middle of the body at least 32 scales.

16 [15.] Around the middle of the body no more than 30 scales.

17 [18] A row of sharply distinct, enlarged scales along the back.

19 [6] Scales not fish-like, dorsal scales sharply distinct from ventral ones, femoral pores usually present.

20 [21] Eyelid immobile, the upper fused with the lower, with a large transparent opening in the middle.

21 [20] Eyelids movable.

22 [25] Femoral pores absent, only inguinal pores present, i.e., a small number (1–3) of pores near the anal plate.

23 [24] 3 inguinal pores on each side of the anal plate.

24 [23] One inguinal pore on each side of the anal plate.

25 [22] Femoral pores present.

26 [57] Nostril touching the first supralabial scale or, if separated from it, by a very narrow suture; the nostril opening does not rise above the level of the surrounding scales; scales of the upper part of the head, including the frontal, without a groove.

27 [44] Postnasal scales 2–3.

28 [29] 5 supralabials anterior to the subocular scale.

29 [28] 4 or 3 supralabials anterior to the subocular scale.

30 [41] Rostral scale does not Touch the nostril.

31 [32] No granules between the supraciliaries and supraoculars, or at most one.

32 [31] Granules present between the supraciliaries and supraocular scales.

33 [36] Tail approximately twice as long as head and body combined, or longer.

34 [35] 17–21 scales along the midline of the throat to the collar; 40–56 scale rows around the midbody; 11–20 femoral pores; 2 rows of preanal scales.

35 [34] 15–17 scales along the midline of the throat to the collar; 37–40 scale rows around the midbody; 9–12 femoral pores; a single row of preanal scales.

36 [33] Tail slender, therefore twice as long as head and body combined.

37 [38] Supratemporal scales touch the tympanic scale.

Sand lizard – Lacerta agilis.

38 [37] Tympanic shield not touching the upper temporal shields, or entirely absent.

39 [40] 40-50 scale rows around the midbody; femoral pores averaging 16.

40 [39] 33-40 scale rows around the midbody.

41 [30] Internasal shield touches the nostril.

42 [43] Hind FOOT longer than the head, or if not longer, the tail is at least twice as long as the head and body combined.

Green lizard - Lacerta viridis.

43 [42] Hind foot equal to or shorter than the head; tail 1.5 to 2 times

longer than the head and body combined.

44 [27] A single postnasal shield.

45 [52] A stripe along the spine, sometimes covering the entire back, consisting of elongated keeled scales, thus making the dorsal scales clearly distinguishable from the lateral ones.

46 [49] Several granules between the supraocular and supraciliary shields.

47 [48] Internasal typically not touching the nostril; 37-40 scale rows around the midbody; 15-18 scales along the midline of the throat to the collar; 9-13 femoral pores.

48 [47] Internasal touching the nostril; 43-49 scale rows around the midbody; 20-25 scales along the midline of the throat to the collar; 14-17 femoral pores.

49 [46] No granules, or only a single one, between the supraocular and supraciliary shields.

50 [51] 26-38 scale rows around the midbody; 7-13 femoral pores; never green in coloration; males with a bright orange belly.

Viviparous lizard - Zootoca vivipara.

Identification key to snakes

1 [2] Eyes appear as small dark spots visible through the skin; lower surface of the body covered with scales similar to those on the back; tail extremely short, its length not exceeding its width.

2 [1] Eyes well developed; lower surface of the body covered with transversely elongated ventral shields; tail length many times greater than its width.

3 [6] A deep pit located between THE EYE AND the nostril, usually larger in size than the nostril.

6 [3] No pit between the eyes and nostrils.

7 [14] Ventral shields cover far from the entire width of the lower body surface; at least 35 scales around the midbody; submandibular shields absent; small claw-like vestigial hind limbs on the sides of the cloaca (examine with a magnifying glass).

14 [7] Ventral shields cover the entire lower surface of the body; no more than 33 scales around the midbody; submandibular shields developed; no traces of limbs on the sides of the cloaca.

15 [24] Upper surface of the head covered with numerous small scales similar to body scales, with only the supraocular shields potentially standing out by their larger size.

24 [15] Shields covering the upper head differ sharply in size and shape from the body scales.

25 [30] The upper surface of the snout across the line connecting the anterior edges of the eyes is covered with small, irregularly shaped shields; the shield bounding the nostril anteriorly does not touch the intermaxillary and is separated from it by a special shield (nasointermaxillary); the height of the nasal shield is greater than or equal to its length.

26 [27] The nostril is pierced in the middle of the nasal shield; the lateral edge of the snout is blunt.

Common European viper - Vipera berus.

27 [26] The nostril is pierced in the lower part of the nasal shield; the lateral edge of the snout is sharp.

28 [29] The greatest width of the head is equal to (or almost equal to) the distance from the tip of the snout to the angle of the Mouth; the intermaxillary shield touches two apical shields on the upper region of the snout; a wide, black, sometimes broken into separate transversely elongated spots, zigzag dorsal stripe merges with the black head; large, transverse black spots on the sides of the body, often merging with each other; the body between the stripes ranges from yellowish-gray to brick-red in color (black specimens also occur).

29 [28] The greatest width of the head is less than the distance from the tip of the snout to the angle of the mouth; the intermaxillary shield touches one apical shield on the upper surface of the head; a zigzag stripe along the spine of brownish tones and usually with black edges; the head, as a rule, is not black; the spots on the sides of the body are small; the main body color is brownish-gray tones.

Steppe viper - Vipera renardi

30 [25] The upper part of the snout across the line connecting the anterior edges of the eyes is covered with large, more or less symmetrically arranged internasal and prefrontal shields; the nasal shield is in contact with the intermaxillary, and the length of the nasal shield (or shields) significantly exceeds its height.

31 [32] Large venomous fangs are located in the anterior part of the upper jaw; the nasal shield touches the preocular and the large third supralabial.

32 [31] There are no venomous or large fangs in the anterior part of the upper jaw; a loreal shield is present in the vast majority of species.

33 [44] 15 scale rows around the middle of the body.

44 [33] 17 or more scale rows around the middle of the body.

45 [58]. 17 scale rows around the middle of the body.

48 [51] The nostril is pierced in a single shield; 7 supralabials; one temporal shield in the first row; the eye touches the third and fourth supralabial shields.

51 [48] The nostril is between two nasal shields; 8 (very rarely 7) or more supralabials; at least 2 temporal shields in the first row.

52 [55] A small subocular shield is located below the preocular; the upper surface of the snout is flat or slightly convex; the width of the head fits into its length less than twice.

53 [54] There is a single loreal shield; small scales are present between the posterior chin shields.

Caspian whipsnake - Dolichophis caspius.

54 [53] There is more than one loreal shield; there are no small scales between the posterior chin shields.

55 [52] There is no subocular shield below the preoculars; the upper surface of the snout is strongly concave or features a longitudinal groove.

56 [57] A single loreal shield; the eyes touch three supralabial shields; longitudinal dark stripes are usually present on the upper side of the body.

57 [56] At least 2 loreal shields; the eyes touch the 2nd supralabial shield; there are no longitudinal dark stripes on the body.

58 [45] 19 or more scale rows around the middle of the body.

59 [64] The pupil is vertical; the anal plate is undivided.

60 [61] The supralabials are separated from the eye by shields and do not touch it; the nail-shaped internasal shield projects strongly forward; usually one prefrontal; the nostrils are in the form of an oblique slit.

61 [60] At least 2 upper labial scales touch the eye; the internasal scale is neither nail-shaped nor protruding forward; 2 prefrontal scales; nostrils shaped as more or less round openings.

62 [63] A single longitudinal row of noticeably enlarged scales along the spine; posterior chin shields well developed; loreal scale does not touch the eye and is separated from it by the preocular.

63 [62] Scales along the spine not enlarged; posterior chin shields not developed; loreal scale touches the eye.

64 [59] Pupil round; anal plate usually divided.

65 [82] 19 scale rows around the midbody.

66 [73] Scales strongly keeled.

67 [68] Suture between the rostral and internasal scales shorter than the suture between the rostral and the first upper labial; usually 8 upper labials.

Dice snake - Natrix tessellata.

68 [67] Suture between the rostral and internasal scales not shorter than the suture between the rostral and the first upper labial; usually 7 upper labials.

69 [70] 2 preoculars; live specimens are dark olive (dark green) in color with transverse black bands or spots, with brick-red spaces between them on the anterior part of the body; a slanted black stripe under the eye, significantly wider than the black stripes along the sutures between the upper labial scales; in the temporal region, an even wider black stripe usually extends from the posterior margin of the supraocular to the corner of the mouth.

70 [69] Usually 1 preocular scale; body coloration otherwise; no wide black slanted stripes under the eye or in the temporal region (though sutures between upper labials are black in most cases).

71 [72] Ventral scales not exceeding 152.

72 [71] Ventral scales at least 153.

Grass snake - Natrix natrix.

73 [66] Scales smooth.

74 [75] No subocular scale beneath the preoculars; 7 upper labials; rostral strongly wedged between the internasals.

Smooth snake - Coronella austriaca.

Identification key to turtles

1 [2] Shell enclosing the animal's body covered with skin dorsally; tip of the snout extended into a soft nasal proboscis.

2 [1] Shell enclosing the animal's body covered with horny scutes dorsally; tip of the snout lacking a nasal proboscis.

3 [6] Hind limbs columnar; no webbing between digits; head covered with scales dorsally.

4 [5] 5 claws on the forelimbs.

Spur-thighed tortoise - Testudo graeca.

5 [4] 4 claws on the forelimbs.

Russian tortoise - Testudo horsfieldii.

6 [3] Hind limbs not pillar-like; webbing present between the toes; no dorsal shield scales on the head.

7 [8] Plastron immovably joined to the carapace; light longitudinal stripes along the neck.

Caspian turtle - Mauremys caspica.

8 [7] Plastron movably joined to the carapace; no light longitudinal stripes along the neck (neck spotted with light dots).

European pond turtle - Emys orbicularis

Review Questions

1. General characteristics of reptiles.

2. Structure of reptile skin

3. Skeleton of reptiles.

7. Digestive System of reptiles.

5. Respiratory system of reptiles.

6. Excretory system of reptiles.

7. Circulatory system OF reptiles.

8. Nervous system of reptiles.

9. Reproductive System of reptiles.

10. Reproduction and development of reptiles.

13. Significance of Reptiles in nature and human life.

14. Classification of reptiles.

15. Characteristics of anamniotes and amniotes.

16. Systematics of reptiles.

17. Ecological groups of reptiles.

18. Feeding habits of reptiles.

19. Distribution of reptiles across the globe.

20. Giants and pygmies among reptiles.

21. Reptiles of the Red Data Book of Ukraine.

22. Formation and types of eggs in reptiles.

23. Venomous snakes.

24. Reptiles of Ukraine.

25. Features of the circulatory system in crocodilians.

26. Predatory reptiles.

27. Viviparity in reptiles.

28. Decorative reptiles.

30. The Role of reptiles in nature and human life.

31. Legless lizards of Ukraine.