Added December 15 2024.

Abronia: Arboreal Alligator Lizards

Anguids

Introduction

The genus Abronia was first described by Gray in 1873, but for a few decades afterwards its species were generally assigned to Gerrhonotus instead.

Abronia differs from other gerrhonotine lizards (Coloptychon, Gerrhonotus, Barisia, Elgaria, and Mesaspis) in the combination of having: (1) the fifth row of temporal scales absent (except, probably anomalously, on one side of one specimen of A. salvadorensis) (present in all other genera); (2) large, well-clawed limbs (smaller limbs in all other genera); and (3) a reduced lateral fold (much better developed in all other genera), particularly between the anterior limb and ear [Campbell and Frost].

Abronia is generally found in S Mexico and Guatemala, with a few further to the south as far as Costa Rica and Panama. As their common name suggests, they are largely arboreal, associated with areas such as dry-oak forests at higher altitudes.

Further information on the remaining species will be added over time.

NOTE: The area “Nuclear Central America” refers to an area “defined as comprising the eastern portion of the Sierra Madre del Sur, its ancient geanticline and the flanking geosynclinal portion of the Gulf Coast and Caribbean em- bayments, with Southeastern Mexico, Guatemala, Belize, Honduras, and Nicaragua making up the principal land area” [from “Nuclear Central America, Hub of Antillean Transverse Belt” by G L Vinson and J H Brineman, January 01 1963].

	QUICK INDEX
A. antauges, Mount Orizaba Alligator Lizard	A. anzuetoi, Anzuetoi Arboreal Alligator Lizard	A. aurita, Cope's Arboreal Alligator Lizard
A. bogerti, Bogert's Arboreal Alligator Lizard	A. campbelli, Campbell's Arboreal Alligator Lizard	A. chiszari, Chiszar's Arboreal Alligator Lizard
A. cuchumatanus, Cuchumatanes Alligator Lizard	A. cuezpali	A. cunemica, Coapilla Arboreal Alligator Lizard
A. deppei, Deppe's Arboreal Alligator Lizard	A. fimbriata	A. frosti, Frost's Arboreal Alligator Lizard
A. fuscolabialis, Mount Zempoaltepec Arboreal Alligator Lizard	A. gadovii, Gadow's Alligator Lizard	A. gaiophantasma, Brilliant Arboreal Alligator Lizard
A. graminea, Sierra de Tehuacan Arboreal Alligator Lizard, Terrestrial Arboreal Alligator Lizard	A. juarezi, Sierra Juarez Alligator Lizard	A. leurolepis, Flat-scaled Arboreal Alligator Lizard, Smoothback Arboreal Alligator lizard
A. lythrochila, Red-lipped Arboreal Alligator Lizard	A. martindelcampoi, Martín del Campo’s Arboreal Alligator Lizard	A. matudai, Matuda's Arboreal Alligator Lizard
A. meledona	A. mitchelli, Mitchell's Arboreal Alligator Lizard	A. mixteca, Mixtecan Arboreal Alligator Lizard
A. montecristoi, Monte Cristo Arboreal Alligator Lizard	A. monticola, Montane Alligator Lizard	A. moreletii, Morelet's Alligator Lizard
A. morenica, Sierra Morena Arboreal Alligator Lizard	A. oaxacae, Oaxacan Arboreal Alligator Lizard	A. ochoterenai, Ochoterena’s Arboreal Alligator Lizard, Northern Chiapas Arboreal Alligator Lizard
A. ornelasi, Ornelas’s Arboreal Alligator Lizard, Cerro Baul Alligator Lizard	A. ramirezi, Ramirez's Alligator Lizard	A. reidi, Reid's Arboreal Alligator Lizard
A. salvadorensis, Salvador Arboreal Alligator Lizard	A. smithi, Smith's Arboreal Alligator Lizard	A. taeniata, Banded Arboreal Alligator Lizard, Bromeliad Arboreal Alligator Lizard
A. vasconcelosii, Bocourt's Arboreal Alligator Lizard	A. viridiflava, Dwarf Alligator Lizard	A. zongolica

Scientific Name	Common Name	Distribution	Size	Notes
Abronia
A. antauges	Mount Orizaba Alligator Lizard	Mexico (Veracruz)	SVL approx 7 cm, TL approx 15 cm	Description: head-shields smooth; four pairs of shields between the rostral and the frontal, the two anterior very small; the second pair sometimes separated; nasal separated from the rostral; two superposed postnasals; one loreal; two or three outer supraoculars; ten upper labials. Sides of neck covered with granular scales. Lateral fold strong, extending on the neck. Dorsal scales in fourteen longitudinal series, the median smooth or obtusely keeled, the laterals smooth; fifty transverse series. Ventral scales nearly the same size as dorsals, in twelve longitudinal series. Tail subquadrangular at the base; upper caudal scales more strongly keeled than the dorsals. Coloration: bronzy green above; head spotted with black; three longitudinal bands on the back; flanks and sides of neck with a black network enclosing greenish-white dots; a whitish streak on the side of the head; lower surfaces dark green with numerous small angular yellowish-white spots, or lighter with small greenish-black spots. [SOURCE: Boulenger]
A. anzuetoi	Anzuetoi Arboreal Alligator Lizard	Guatemala		Diagnosis: a species of Abronia having: (1) distinctive spinelike supra-auricular scales in subadults and adults; (2) unexpanded supranasals; (3) a median frontonasal scale; (4) posterior internasals relatively small, although about twice the length of anterior internasals; (5) discrete canthals; (6) two or three primary temporals, the lower two contacting the postoculars; (7) usually no parietal-median supraocular contact; (8) a single occipital; (9) posterolateral head scales not knoblike; (10) anterior superciliary contacting cantholoreal, similar in length to other scales in series; (11) posterior subocular broadly separated from the lower primary temporal by the penultimate supralabial, which is the posteriormost scale in this series to reach the orbit; (12) at least three rows of granular preauriculars; (13) postmental divided; (14) posterior infralabial elongate, often about twice as long as preceding infralabials; (15) six longitudinal nuchal scale rows; (16) 27-28 dorsal transverse scale rows; (17) 14 dorsal longitudinal scale rows arranged parallel to ventrolateral fold; (18) 14 ventral longitudinal scale rows; (19) adults dark green or dark blue-green; and (20) juvenile pattern unknown. This species differs from all other species of Abronia that have spinelike supra-auricular scales, except A. aurita, A. gaiophantasma, A. lythrochila, and some A. matudai, in having 14 longitudinal ventral scale rows. Abronia anzuetoi differs from all other species of Abronia, except A. aurita, A. graminea, and A. smithi, in having a distinctly yellow circumorbital region. Abronia anzuetoi differs from A. aurita in coloration (dark emerald green or dark blue green versus a paler green with yellow and/or orange markings), in having relatively longer posterior internasals, and possibly in being of a larger body size (maximum known SVL 135 mm versus 125 mm). Abronia anzuetoi differs from A. gaiophantasma in having more numerous postoccipital rows between the occipital and first nuchal row (two or three versus one), expansion of the posterior infralabial, and in a green coloration with yellow eye region (versus a brown dorsum and circumorbital region not yellow), and from A. lythrochila in having a divided postmental (usually single in A. lythrochila), and in a green dorsal coloration with yellow orbit (color variable in A. lythrochila, but often brownish or with numerous black markings, never with yellow orbit). [SOURCE: Campbell ad Frost]
A. aurita	Cope's Arboreal Alligator Lizard	Guatemala, poss. SE Mexico	SVL 12.5 cm	Description: distinguished from A. vasconcelosii in having three pairs of shields between the rostral and the frontal instead of four. Dorsal scales strongly but finely keeled, in sixteeen longitudinal and twenty-six transverse series. Coloration: pea-green, more or less shaded with yellow; the rugosities of the scales everywhere black; blackish-green shades form indistinct Vs directed backwards on the middle of the back; eyelids and auricular process yellow; below yellowish, with dirty green shades. [SOURCE: Boulenger]
A. bogerti	Bogert's Arboreal Alligator Lizard	Mexico (Oaxaca)
A. campbelli	Campbell's Arboreal Alligator Lizard	Guatemala
A. chiszari	Chiszar's Arboreal Alligator Lizard	Mexico (Veracruz)
A. cuchumatanus	Cuchumatanes Alligator Lizard	Guatemala
A. cuetzpali		Mexico (Oaxaca)
A. cunemica	Coapilla Arboreal Alligator Lizard	Mexico (Chiapas)
A. deppei	Deppe's Arboreal Alligator Lizard	Mexico (Guerrero, Mexico, Morelos)		Description: head very distinct from neck; head-shields smooth; a pair of small shields behind the rostral; five preefrontals, the central a little smaller and completely enclosed between the others; nasal separated from the rostral; a small supranasal; two small superposed postnasals and two loreals, second largest; four small outer supraoculars; frontal touching the interparietal; ten upper labials, last two much larger than the others, and than the temporals. Sides of neck covered with granular scales. Lateral fold feeble, commencing in advance of the arm. Nuchal scales in six longitudinal series. Dorsal scales in ten or eleven longitudinal series (thirteen or fourteen in the middle of the body), oblique, much larger than ventrals, smooth; twenty-seven transverse series. Ventrals in thirteen or fourteen longitudinal series. Limbs short. Tail a little longer than head and body; caudal scales smooth. Coloration: dark brown above, with yellow spots forming transverse bands on the body, limbs, and tail; lips and lower surfaces yellowish white. [SOURCE: Boulenger]
A. fimbriata		NE Guatemala	TL approx 28.5 cm, SVL 11 cm	Description: head-shields slightly rugose; four pairs of shields between the rostral and the frontal; nasal separated from the rostral; two small superposed postnasals; two loreals, second largest; five large inner and three small outer supraoculars; nine upper labials; a series of long pointed projecting scales above the ear. Sides of neck with granular scales. Lateral fold pretty well marked though not very deep, commencing in advance of the arm. Dorsal scales obtusely keeled, in fourteen longitudinal and thirty transverse series; ventrals smaller, in fourteen longitudinal series. Tail cylindrical, a little depressed at the base, one third longer than head and body. Coloration: greenish grey above, usually with angular brown cross bands edged posteriorly with black ; the projecting scales above the ear yellow; lower surfaces yellow, nearly all the ventral scales with a brown dot. [SOURCE: Boulenger]
A. frosti	Frost's Arboreal Alligator Lizard	NW Guatemala
A. fuscolabialis	Mount Zempoaltepec Arboreal Alligator Lizard	Mexico (Oaxaca)
A. gadovii	Gadow's Alligator Lizard	Mexico (Guerrero)
A. gaiophantasma	Brilliant Arboreal Alligator Lizard	NE Guatemala		Diagnosis: (1) supra-auricular scales of subadults and adults spinelike; (2) supranasals relatively small and unexpanded, not in contact at the dorsal midline; (3) frontonasal scale present, not contacting frontal; (4) posterior internasals relatively small, only slightly larger than the anterior intemasals; (5) canthals discrete; (6) three or four anterior temporals per side, usually the lower two (rarely one) contacting the postoculars; (7) parietal not in contact with median supraoculars; (8) usually a single occipital; (9) posterolateral head scales not knoblike; (10) anterior superciliary contacting cantholoreal, similar in length to other scales in series; (11) posterior subocular broadly separated from the lower primary temporal by the penultimate supralabial, the posteriormost scale in this series to reach the orbit; (12) two or occasionally three incomplete rows of subimbricate preauricular scales; (13) postmental single or divided; (14) posteriormost infralabial not elongate; (15) six longitudinal nuchal scale rows; (16) 28-30 dorsal transverse scale rows; (17) 12 dorsal longitudinal scale rows, arranged parallel to ventrolateral fold; (18) 14-16 ventral longitudinal scale rows; (19) adults tan, brown, grey-brown, or reddish brown; (20) juveniles and subadults with dark brown crossbands. This species differs from other species of Abronia occurring east of the Isthmus of Tehuantepec in having 12 (versus 14 or more) dorsal longitudinal scale rows. Abronia gaiophantasma differs from all Nuclear Central American species, except A. salvadorensis, A. matudai females, and some individuals of A. lythrochila in having an essentially brown dorsal coloration, with or without dark crossbands. Abronia gaiophantasma differs from A. salvadorensis in lacking a fourth row of temporal scales, having distinct supra-auricular spines; from A. matudai in having unexpanded supranasals, in usually having 3-4 anterior temporals (versus usually 2), in having 14-16 ventral longitudinal scale rows (versus 12), in having distinct supraauricular spinelike scales, and in lacking contact between the parietals and the median supraoculars; and from A. lythrochila in having smaller lateral neck scales, having larger scales in the temporal region, lacking multiple rows of granular preauriculars, and lacking red pigment on the upper edge of the infralabials. [SOURCE: Campbell and Frost]
A. graminea	Sierra de Tehuacan Arboreal Alligator Lizard, Terrestrial Arboreal Alligator Lizard	Mexico (Veracruz, Puebla, Oaxaca)		Description: very closely allied to A. oaxaca, from which it differs in the following points: sides of neck covered with small equal subgranular scales; a slight fold from the ear to the fore limb. Lateral fold stronger, enclosing granular scales. Dorsal scales in twelve or thirteen longitudinal series, very indistinctly keeled. Ventrals in twelve longitudinal series; two ventral series correspond to one dorsal. Eleven upper labials, eleventh forming with the lower temporals an obliquely ascending series of five shields. Coloration: pea-green above, each transverse series of dorsal scales black at the base; lower surface of the head yellowish-white, of body pale green. [SOURCE: Boulenger]
A. juarezi	Sierra Juarez Alligator Lizard	Mexico (Oaxaca)
A. leurolepis	Flat-scaled Arboreal Alligator Lizard, Smoothback Arboreal Alligator lizard	Mexico (Chiapas)
A. lythrochila	Red-lipped Arboreal Alligator Lizard	Mexico (Chiapas), Guatemala
A. martindelcampoi	Martín del Campo’s Arboreal Alligator Lizard	Mexico (Guerrero)
A. matudai	Matuda's Arboreal Alligator Lizard	Mexico (Chiapas), Guatemala
A. meledona		SE Guatemala
A. mitchelli	Mitchell's Arboreal Alligator Lizard	Mexico (Oaxaca)		Description: the species differs from all other species of Abronia in possessing two occipitals and in having only one scale row between the occipitals and first transverse nuchal scale row. Abronia oaxacae and A. mixteca have three small occipitals while all other species have one. The supranasals are large, triangular and extend more than halfway between the anterior and posterior internasals. A canthal is present on both sides, distinguishing this species from all other species west of the Isthmus of Tehuantepec except for A. fuscolabialis and A. chiszari. There are four anterior temporals, the two lower ones in contact with the postoculars. Protuberant supra-auricular scales are absent. The lateral neck scales are relatively small and subgranular, approximately 11 scales occur in a vertical line extending from the outermost nuchal to the first large scale on the ventrolateral part of the neck. The postbrachials are slightly smaller than the lateral neck scales. The number of transverse dorsal scale rows is 34; only A. bogerti and A. chiszari, both with 39, and A. reidi and A. matudai, with 34-36, are known to have more. Sixteen longitudinal dorsal scale rows are present, a number equalled only in A. chiszari; all other species of Abronia possess 14 or fewer. The dorsal scales are arranged along the sides in oblique, rather than parallel, rows and, although slightly convex, are not keeled. The ventrolateral fold is well developed, with a series of two or three small to subgranular scales extending along the side; two or three small scales extend perpendicularly from the fold and lie between the transverse dorsal scale rows. The only other members of the genus having oblique scale rows are A. mixteca and A. deppei, but both of these species have poorly defined ventrolateral folds with virtually no subgranular scales between dorsals and ventrals. Osteoderms are present on the head, nape and dorsum to about midbody; they seem to be absent on the proximal portion of the tail. Several species to the east of the Isthmus of Tehuantepec exhibit the same osteodermal pattern on head and body, but these species also have osteoderms on the tail. Abronia deppei and A. mixteca lack osteoderms on the nape and dorsum, and in A. t. taeniata, they extend posteriorly for only several nuchal rows. Abronia mitchelli possesses 12 longitudinal ventral scale rows, as do A. t. taeniata, A. bogerti, A. chiszari and A. reidi. The number of dorsal scales between the hindlimbs is 10, a number equalled only by A. aurita. The colour in life was reported to be green with black markings
A. mixteca	Mixtecan Arboreal Alligator Lizard	Mexico (Guerrero, Oaxaca)
A. montecristoi	Monte Cristo Arboreal Alligator Lizard	Guatemala, El Salvador, Honduras
A. monticola	Montane Alligator Lizard	Costa Rica, Panama	SVL approx 6 cm, TL approx 14.5 cm	Found at higher altitudes (8,000 to 11,000 m): Slevin noted that the species was “confined to the highlands”. Description: prefrontal separated from the frontal by a pair of shields. Dorsal scales in fifteen longitudinal series, the three or four median rows keeled, the others smooth; forty-five transverse series. Otherwise as in G. moreletii. Coloration: upper surface and sides brown, the latter a little darker, and bounded above by a narrow black line; a somewhat irregular row of small black spots down the median dorsal line; below yellowish olive, the scales of the abdomen with black borders, those of the gular and thoracic regions with black centres. [SOURCE: Boulenger]
A. moreletii	Morelet's Alligator Lizard	S Mexico, Guatemala, El Salvador, Nicaragua, Honduras	SVL approx 9.5 cm, TL approx 18.5 cm	Description: head-shields smooth; a large prefrontal, sometimes single and forming a suture with the whole anterior border of the frontal, sometimes divided into three, the median or larger shield forming only a short suture with the frontal; two pairs of small shields between the prsefrontal and the rostral ; nasal separated from the rostral ; a supranasal ; two superposed postnasals; one loreal and a large oanthal descending between the latter shield and the preocular; three outer supraoculars; ten or eleven upper labials. A rather narrow granular zone along the side of the neck. Lateral fold strong, extending on the neck. Dorsal scales in eighteen or twenty longitudinal series, the six median strongly keeled, the others smooth or indistinctly keeled; fifty-two to fifty-four transverse series; ventrals larger than dorsals, in twelve longitudinal series. The adpressed fore limb reaches the eye; the length of the hind limb equals half or three fifths the distance from axil to groin. Tail subquadrangular at the base; upper caudal scales strongly keeled. Coloration: olive-brown above, back uniform or blaok-spotted, sides spotted with black and greenish white; lower surfaces greenish white, uniform or with scattered blackish dots. [SOURCE: Boulenger]
A. m. moreleti
A. m. rafaeli		Mexico, Guatemala
A. m. salvadorensis		El Salvador, Nicaragua, Honduras
A. m. temporalis		S Mexico (Chiapas)
A. morenica	Sierra Morena Arboreal Alligator Lizard	Mexico (Chiapas)
A. oaxacae	Oaxacan Arboreal Alligator Lizard	Mexico (Oaxaca)
A. ochoterenai	Ochoterena’s Arboreal Alligator Lizard, Northern Chiapas Arboreal Alligator Lizard	Mexico (Chiapas), Guatemala
A. ornelasi	Ornelas’s Arboreal Alligator Lizard, Cerro Baul Alligator Lizard	Mexico (Oaxaca)
A. ramirezi	Ramirez's Alligator Lizard	Mexico (Chiapas)
A. reidi	Reid's Arboreal Alligator Lizard	Mexico (Veracruz)
A. salvadorensis	Salvador Arboreal Alligator Lizard	El Salvador, Honduras
A. smithi	Smith's Arboreal Alligator Lizard	Mexico (Chiapas)
A. taeniata	Banded Arboreal Alligator Lizard, Bromeliad Arboreal Alligator Lizard	E Mexico	TL approx 21.5 cm, SL approx. 8.5 cm	Description: closely allied to A.deppii. A small shield on each side between the anterior loreal and the central prsefrontal. Dorsal scales a little smaller, less oblique, obtusely keeled; they form fourteen longitudinal series, and twenty-eight or twenty-nine transverse series. Ventrals in twelve longitudinal series. Limbs a little longer. Coloration: light green above, with transverse brown bands on the body and tail; an oblique black band on tbe temple; lower parts yellow. [SOURCE: Boulenger]
A. vasconcelosii	Bocourt's Arboreal Alligator Lizard	Guatemala	TL 14.5 cm, SL approx 5.5 cm	Description: head-shields smooth; a pair of small shields behind the rostral and seven preefrontals, the two anterior in contact, the median separating the two other pairs and touching the frontal; nasal separated from the rostral; a small supranasal; two small superposed postnasals; two loreals, second largest; three small outer supraoculars; ten upper labials; a series of short, obtusely conical, projecting scales above the ear. Sides of neck covered with granular scales. Lateral fold pretty well marked though not very deep, commencing in advance of the arm. Dorsal scales obtusely keeled, of the flanks smooth, in twelve or thirteen longitudinal and twentyseven transverse series; ventrals smaller, in fourteen longitudinal series. Tail moderately long, a little depressed at the base. Coloration: bright green above, with broad angular blackish cross bands ; the projecting scales above the ear pale yellow ; lower surfaces greenish yellow, throat and breast black-dotted. [SOURCE: Boulenger]
A. viridiflava	Dwarf Alligator Lizard	Mexico (Oaxaca)	SVL approx 6.5 cm, TL 13.5 cm	Description: head-scales smooth; five prefrontals, central largest and in contact with the frontal; a pair of small shields between the rostral and the prerontals; nasal in contact with the rostral on one side; a supranasal; two superposed postnasals; one loreal; two outer supraoculars; ten upper labials. Sides of neck granular. Lateral fold strong, extending on the neck. Nuchal scales in eight longitudinal rows. Dorsal scales in fourteen longitudinal rows, the laterals smooth, the others ohtusely keeled, and forty-seven transverse rows; ventrals nearly as large as dorsals, in twelve longitudinal rows. The adpressed fore limb reaches the posterior border of the eye; the length of the hind limb equals two thirds the distance from axil to groin. Upper caudal scales more strongly keeled than dorsals. Coloration: olive above, with a black vertebral line; sides and lower surfaces black, spotted with greenish white. [SOURCE: Boulenger]
A. zongolica		Mexico (Veracruz)

Bibliography

“Anguid lizards of the gens Abronia: revisionary notes, descriptions of four new species, a phylogenetic analysis, and key”, Jonathan A Campbell and Darrel R Frost, Bulletin of the American Museum of Natural History, Number 216, New York, September 3 1993.