Teiidae, Gray, 1827

Harvey, Michael B., Ugueto, Gabriel N. & Gutberlet, Ronald L., 2012, 3459, Zootaxa 3459, pp. 1-156 : 142-144

Key to Genera and Species Groups of Extant Teiidae

Based on characters described in this study, we present the following key to teiid genera and species groups. Wherever possible, we relied on highly conservative characters, although a few characters in the key show low levels of polymorphism. Nonetheless, each couplet contains several characters, so that users of the key will not be led astray by specimens having rare character states, missing body parts, or aberrations.

1 Femoral and abdominal pores absent; loreals three or more; 2–3 complete rows of lorilabials separating suboculars from supralabials; prefrontals heavily fractured; vertical fold of skin in front of auditory meatus ( Callopistinae )....... Callopistes

- Femoral and abdominal pores present; loreals 1–2; one or more suboculars contacting supralabials; prefrontals usually entire; skin in front of auditory meatus without vertical fold......................................................... 2

2 Complete caudal annuli alternating with annuli divided dorsally; gap of granular scales separating femoral from abdominal pores; circumorbital scales absent or reduced to 1–3/1–3 circumorbitals at posterior border of fourth supraocular ( Tupinambinae )....................................................................................... 3

- Caudal annuli complete; femoral and abdominal pores continuous; circumorbital scales present ( Teiinae )................ 6

3 Pupil round; loreals two; large scale inserted between first subocular, supralabials and posterior loreal; complete row of lateral supraocular granules; supraciliaries 23–28 (count combined from both sides); chinshields usually separated from infralabials by row of granular sublabials; intertympanic sulcus incomplete medially or absent; longitudinal rows of ventrals 30–39; proximal subcaudals keeled............................................................................. 4

- Pupil reniform; loreal single; first subocular contacting supralabials or rarely separated from them by anterior expansion of second subocular; lateral supraocular granules absent; supraciliaries 14–19 (count combined from both sides); chinshields usually in contact with infralabials; intertympanic sulcus complete medially; longitudinal rows of ventral 20–28; proximal subcaudals smooth..................................................................................... 5

4 Ventrals keeled and with subterminal lenticular scale organs positioned atop keel; interangular sulcus complete, containing small granular scales; tail laterally compressed with large scales on dorsolateral edge forming prominent crests; dorsals heterogeneous, consisting of large keeled scales surrounded by smaller scales............................... Dracaena

- Ventrals smooth, lacking lenticular scale organs; interangular sulcus absent; tail cylindrical without dorsolateral crests; dorsals flat and mostly smooth (may be keeled on neck and posterior body), separated by small granular scales........... Salvator

5 Fifth toe elongate, extending beyond free proximal phalangeal articulation of Toe IV; tail laterally compressed; eight rows of enlarged, keeled scales forming accessory crests at base of tail in addition to pair of dorsolateral crests extending length of tail.......................................................................................... Crocodilurus

- Fifth toe moderate, not extending beyond free proximal phalangeal articulation of Toe IV; tail cylindrical; accessory and dorsolateral crests absent from tail............................................................... Tupinambis

6 Posterior maxillary and mandibular teeth oriented transversely and bicuspid....................................... 7

- Posterior maxillary and mandibular teeth oriented longitudinally and tricuspid..................................... 8

7 Frontoparietals fused; fifth toe reduced but with three free phalanges; distal digital lamellae under fourth toe sharply keeled; hemipenis lacking apical basin.................................................................... Dicrodon

- Frontoparietals paired; fifth toe vestigial, reduced to small nub; distal digital lamellae under fourth toe weakly keeled or smooth; hemipenis with apical basin.................................................................. Teius

8 Suboculars not keeled or with short keel restricted to first and second subocular; dorsals apparently lacking subterminal lenticular scale organs; ventrals keeled; antebrachials small and keeled; scales separating digital lamellae continuing as row of enlarged scales between fourth and fifth toe; hemipenis with relatively long papillae between lobes; apical hemipenial awns absent ( Kentropyx )..................................................................................... 9

- Prominent subocular keel extending to elongate subocular below eye; dorsals with single subterminal lenticular scale organs; ventrals smooth; at least some antebrachials enlarged and plate-like; when present, scales separating digital lamellae not continuing as row between fourth and fifth toes; apex of hemipenis with smooth awns or awns ornamented with short papillae ................................................................................................... 11

9 At midbody, scales on flanks small, strongly differentiated from enlarged dorsal scales............ Kentropyx striata Group

- At midbody scales on flanks gradually increasing in size to middorsal line; no sharp demarcation between scales on flanks and middorsals......................................................................................... 10

10 Scales on rump much smaller than proximal caudals; prefemorals 13–19; femoral and abdominal pores (both sides combined) 27–43; subarticular lamellae of hands usually entire; scales between pedal lamellae large and denticulate; lower lateral stripe broken or absent................................................................ Kentropyx calcarata Group

- Scales on rump slightly smaller than proximal caudals; prefemorals 10–13; femoral and abdominal pores 28 or fewer; subarticular lamellae of hands usually divided; scales between pedal lamellae moderate and serrate; lower lateral stripe solid to groin.......................................................................... Kentropyx paulensis Group

11 Subtriangular auricular flap partially covering external auditory meatus; suboculars 2–3; second pair of chinshields in medial contact; preanal plate single, subtriangular, larger than scale in front of it; single row of 3–4 poorly developed tibiotarsal spurs consisting of large triangular scales with raised and pointed distal ends..................................... Aurivela

- External auditory meatus not partially covered by auricular flap; suboculars 4 or more; second pair of chinshields separated medially; preanals usually paired or in transverse row; if present, tibiotarsal spurs well-developed and in two rows....... 12

12 Dorsolateral row of scales at base of tail serrate; subarticular lamellae of hand noticeably enlarged; distal subdigital lamellae of fourth toe sharply keeled; postanal plates usually present in males.............................................. 13

- Dorsolateral scales at base of tail like adjacent scales, not serrated; subdigital lamellae of hand homogeneous or with divided subarticular lamellae (basal subarticular lamellae enlarged in some Aspidoscelis ); distal subdigital lamellae of fourth toe smooth or weakly keeled; postanal plates absent except in Aspidoscelis .......................................... 15

13 Cephalic roofing scales fractured and heavily keeled; key-hole shaped depression in frontoparietal region; longitudinal ventral rows 6; scale surfaces covered in short aligned microridges........................... Holcosus septemlineatus Group

- Cephalic roofing scales smooth, mostly entire; scales in frontoparietal region flat or outwardly convex (i.e., key-hole shaped depression absent); longitudinal ventral rows 8; scale surfaces covered in macrohoneycomb......................... 14

14. Frontal replaced by irregular, keeled scales, three subequal shields at heel....................... Holcosus orcesi Group

- Frontal entire, one very wide ventral and one wide postaxial shield at heel.................... Holcosus undulatus Group

15 First supralabial subequal or longer than second; single pair of preanal spurs in males; continuous row of large keeled scales separating digital lamellae on Toes 2–5; subarticular lamellae of hand divided ( Cnemidophorus )..................... 16

- First supralabial subequal or smaller than second; preanal spurs absent, except for Medopheos with 5–6 pairs; digital lamellae of toes in contact between some phalangeal articulations, separated by continuous row of scales in some Ameiva ; subarticular lamellae of hand entire............................................................................... 19

16 Interparietal usually partially or completely divided longitudinally; first subocular usually separated from supralabials by anterior expansion of second subocular; ventrals in 10–12 longitudinal rows; postaxial brachials barely enlarged, restricted to patch near elbow; enlarged antebrachials separated from brachials by large gap of distinctly smaller scales.............. 17

- Interparietal usually entire; first subocular usually contacting supralabials; ventrals in 8 longitudinal rows; postaxial brachials enlarged, extending beyond center of arm; enlarged antebrachials in contact or only narrowly separated from brachials.... 18

17 Lateral supraocular granules in 2.5-3 rows; proximal subcaudals smooth; preaxial brachials barely enlarged, restricted to patch near elbow; femoral pores 57–86; flank spots in adult males large...................... Cnemidophorus murinus Group

- Lateral supraocular granules in single row; proximal subcaudals keeled; preaxial brachials moderately enlarged and extending beyond center of arm; femoral pores 49–58; flank spots in adult males small................ Cnemidophorus vanzoi Group

18 Proximal subcaudals keeled; scales on dorsal surface of brachium subtriangular; dorsal stripes of juveniles complete or broken in few places; ventral surfaces of adult males pale, never black....................... Cnemidophorus lemniscatus Group

- Proximal subcaudals smooth; scales on dorsal surface of brachium granular; dorsal stripes of juveniles broken into spots; ventral surfaces of adult males black............................................ Cnemidophorus nigricolor Group

19 First supraciliary as long or longer than second (except in Ameivula abaetensis , A. littoralis , and A. venetacauda where first supraciliary is divided); nasal usually in contact with prefrontal; postanal plates absent; small teiids less than 75 mm SVL from south and east of Amazonia............................................................................ 20

- First supraciliary shorter than second; third, fourth, or second and third supraciliaries enlarged; nasal usually separated from prefrontal in South American species (usually in contact in North American species); postanal plates present in males or absent; small to very large teiids from North America, the Caribbean, and South America........................... 21

20 Tail usually relatively short (1.5–2.1 times as long as SVL); parietals usually three; first supralabial usually subequal to second, its ventral margin straight to curved; three scales at heel; when adpressed, claw of Toe V passing skin between Toes III and IV........................................................................................... Contomastix

- Tail long (2.1–2.3 times as long as SVL); parietals usually five; first supralabial shorter than second, its ventral margin “toothy;” scales at heel small and numerous; Toe V reduced............................................. Ameivula

21 Nasal usually in contact with prefrontal; parietals usually three; postanal plates present in males.............. Aspidoscelis

- Nasal usually separate from prefrontal; parietals usually five; postanal plates absent................................ 22

22 Ventrals in 8 longitudinal rows at midbody; 5–6 pairs of preanal spurs in males; three relatively large, subequal scales at heel; western Ecuador and Peru....................................................................... Medopheos

- Ventrals in 10–20 longitudinal rows at midbody (8 in few Caribbean species); preanal spurs absent; scales at heel relatively small and numerous; Neotropical but absent from western Ecuador and Peru ( Ameiva ).............................. 23

23 Frontal transversely divided; nasal suture in front of nostril; frontal ridge well developed......... Ameiva bifrontata Group

- Frontal usually entire; nostril in front of nasal suture or suture passing through nostril; frontal ridge absent or poorly developed ................................................................................................... 24

24 Nasal suture passing through nostril; ventral margin of first supralabial curved; fifth toe reduced (=when adpressed, not surpassing skin between Toes 3 and 4); pedal lamellae separated by continuous row of granular scales along postaxial edge of digits; black edged ocelli on flanks....................................................... Ameiva ameiva Group

- Nostril in front of nasal suture (except in A. wetmorei ); ventral margin of first supralabial toothy (except in A. lineolata series); fifth toe long (except in some specimens of A. griswoldi ); pedal lamellae in contact at least distally (except in A. fuscata and some A. chrysolaema ); black edged ocelli absent (except in A. fuscata ).......................................... 25

25 Interparietal usually entire; parietals long; pectoral sulcus absent; enlarged brachials usually narrowly separated from antebrachials (except in A. dorsalis ); femoral and anal pores 20–48............................ Ameiva dorsalis Group

- Interparietal frequently divided longitudinally; parietals short and square; pectoral sulcus present; enlarged brachials separated from antebrachials by four or more rows of small scales; femoral and anal pores 39–78....... Ameiva erythrocephala Group