The Amphibians and Reptiles of Michoacan, Mexico Part 10

Mus. Zool. Univ. Michigan, 548:1, November 9, 1953.--Eight kilometers south of Tecoman, Colima, Mexico.

Apatzingan (2); Coahuayana; La Placita; Punta San Juan de Lima.

These specimens have been discussed in detail by Mosimann and Rabb (1953). All are from the arid tropical scrub forest; those from the coastal regions were collected at elevations of less than 40 meters, and those from the Tepalcatepec Valley were collected at an elevation of 335 meters.

Crocodilia

~Crocodylus acutus acutus~ Cuvier

_Crocodylus acutus_ Cuvier, Ann. Mus. Hist. Nat. Paris, 10:55, 1807.--Santo Domingo.

_Crocodylus acutus acutus_, Muller and h.e.l.lmich, Ibero-Amerik. Stud., 13:128, 1940.

Boca de Apiza (2); Playa Azul (2).

The crocodile or "caiman" is abundant in the brackish lagoons along the cost of Michoacan; three large adults and several juveniles were observed at Estero Pichi at Playa Azul; others were seen at Mexiquillo and Maruata. Residents of the Balsas-Tepalcatepec Basin frequently have reported "caimanes" in the Rio Balsas and Rio Tepalcatepec, but the existence of the crocodile in these rivers has not been verified by specimens.

Sauria

~Phyllodactylus duellmani~ Dixon

_Phyllodactylus duellmani_ Dixon, Southwest Nat., 5:37, April 15, 1960.--Rancho El Espinal, Michoacan, Mexico.

Fourteen km. SSW of Apatzingan; Capirio; Cafradia (3); El Espinal (3).

This species is known only from the Tepalcatepec Valley, where it has been found in open arid situations from 180 to 500 meters. Specimens were found in the daytime in stumps, dead cacti, and the hollow branches of the legume, _Apoplanesia paniculata_. In life adults were pale gray or grayish tan above and creamy white below. A juvenile having a snout-vent length of 18 mm. had a pale orange tail with gray cross-bands. In the adults the tail was colored like the body. The specimen from 14 kilometers south-southwest of Apatzingan (KU 29764) and those from Cofradia (BMNH 1914.1.28.28-30) were not listed by Dixon (1960).

~Phyllodactylus h.o.m.olepidurus~ Smith

_Phyllodactylus h.o.m.olepidurus_ Smith, Univ. Kansas Sci.

Bull., 22:121, November 15, 1935.--Five miles southwest of Hermosillo, Sonora, Mexico.

El Ticuiz (2); La Placita; Ostula (2); Pomaro; San Pedro Naranjestila.

These specimens have been referred to _Phyllodactylus h.o.m.olepidurus_ by James R. Dixon (_in litt._), who is currently studying the American members of the genus. Geckos of this species have been found in tropical semi-deciduous forest in the coastal lowlands to elevations of 500 meters. Most specimens were found beneath the bark of standing dead trees or stumps. Two individuals from El Ticuiz (UMMZ 115102) in life were dark gray above with brownish tubercles; the belly was a dusty cream-color. Apparently this species does not enter the Tepalcatepec Valley, where _Phyllodactylus lanei_ is abundant.

~Phyllodactylus lanei~ Smith

_Phyllodactylus lanei_ Smith, Univ. Kansas Sci. Bull., 22:125, November 15, 1935.--Tierra Colorado, Guerrero, Mexico.

Apatzingan (13); 21 km. S of Arteaga: El Sabino (53); La Playa; Ostula (2); Rio Marquez, 10 km. S of Lombardia (8); 16 km. N of Tafetan.

This widespread species has been taken at elevations of less than 1100 meters in the Balsas-Tepalcatepec Basin, where it occurs in riparian situations in the foothills. Specimens have been collected in tropical semi-deciduous forest at Ostula and in oak forest south of Arteaga; both of these localities are on the Pacific slopes of the Sierra de Coalcoman, a region inhabited by _Phyllodactylus h.o.m.olepidurus_. Both species have been collected at Ostula.

A juvenile from 21 kilometers south of Arteaga (UMMZ 118933) had alternating black and white bands on the tail. In life most of the lizards are dull ashy gray or grayish tan above and white below.

According to Dixon (_in litt._), one specimen from Apatzingan (UMMZ 115102) resembles _Phyllodactylus magnus_ in scutellation, but it lacks the distinctive yellow venter of that species.

Apparently _Phyllodactylus lanei_ is restricted to rather mesic environments in the Balsas-Tepalcatepec Valley and surrounding foothills; in the more open arid environments on the floor of the valley it seems to be replaced by _Phyllodactylus duellmani_.

~Phyllodactylus paucituberculatus~ Dixon

_Phyllodactylus paucituberculatus_ Dixon, Southwest. Nat., 5:40, April 15, 1960.--Rio Cupat.i.tzio (= Rio Marquez), 6.5 miles south of Lombardia, Michoacan, Mexico.

Rio Marquez, 10 km. S of Lombardia (6).

Two of these specimens (UMMZ 112692-3) were discussed in detail by Dixon (1960:40) in his description of the species. On August 25, 1960, Dixon collected four additional specimens at the type locality, a conglomerate cliff along the Rio Marquez. These will be reported by him in his forthcoming study of the genus.

~Anolis dunni~ Smith

_Anolis dunni_ Smith, Copeia, no. 1:9, May 10, 1936.--Agua del Obispo, Guerrero, Mexico.

Arteaga (3); 19 km. S of Arteaga.

Three females from Arteaga (UMMZ 119075) have snout-vent lengths of 41, 41, and 44 mm. In life the pale grayish brown dorsum was marked with dark brown; the belly was white, and the throat was pale pink. All have a dark interorbital bar and dark vertical bars on the upper l.a.b.i.als. In two specimens there are only scattered dark flecks on the dorsum; in the third there is a dark pos...o...b..tal stripe, a dark lateral stripe, and four narrow transverse bands on the body. A male from 19 kilometers south of Arteaga (UMMZ 119076) having a snout-vent length of 49 mm. had in life a tan dorsum, a broad white stripe from the ear to the groin, scattered small white spots on the dorsum, and indistinct pale cream-colored spots on the posterior surfaces of the thighs. This male has the dark l.a.b.i.al bars, but lacks the dark interorbital bar, found in the females. The large rose-pink throat fan extends to about the middle of the belly. In all of the specimens the middorsal scales are keeled and much smaller than the smooth pavementlike or slightly imbricate ventrals. All have two gulars in contact with the mental, five scales between the nasals, five scales (not including the first l.a.b.i.als) in contact with the rostral, and four rows of loreals. In these characters these specimens agree well with _Anolis dunni_ from Guerrero, as diagnosed by Davis (1954b).

Previously _Anolis dunni_ has been reported only from the vicinity of Agua del Obispo, Guerrero, a locality situated at an elevation of about 900 meters in pine-oak forest in the Sierra del Sur. All known close relatives of _Anolis dunni_ occur only in Guerrero: _A. taylori_ Smith and Spieler from Acapulco, _A. gadowi_ Boulenger from Tierra Colorado, _A. liogaster_ Boulenger, and _A. omiltema.n.u.s_ Davis from Omiltemi. The present specimens from elevations of about 900 meters in riparian stream vegetation and oak forest represent the northern known limits of this group of _Anolis_.

~Anolis nebulosus~ (Wiegmann)

_Dactyloa nebulosa_ Wiegmann, Herpetologia Mexicana, p. 47, 1834.--Mexico. Type locality restricted to Mazatlan, Sinaloa, Mexico, by Smith and Taylor (1950b:66).

_Anolis nebulosas_, Bocourt, Mission Scientifique au Mexique et dan l'Amerique Centrale. Reptiles, livr. 2:77, 1873.

Acahuato (3); Agua Cerca; Apatzingan (4); Araparicuaro (3); 29 km. S of Ario de Rosales (3); 20 km. S of Arteaga (2); Barranca de Bejuco; Cascada Tzararacua (5); Cerro Tancitaro (13); Cheran; Chupio (5); Coalcoman (10); Cofradia; Dos Aguas (10); 18 km. E of Dos Aguas (3); El Diezmo; El Sabino (43); El Ticuiz; Jiquilpan (2); La Orilla; La Placita; La Playa (3); Los Conejos (2); Los Pozos; Nogueleras (2); Ostula; 8 km. W of Patzcuaro (2); 8 km. NE of Patzcuaro; Playa Azul (3); Rio Cachan; Rio Marquez, 10 km. S of Lombardia; Rio Tepalcatepec, 27 km. S of Apatzingan; San Juan de Lima (6); San Pedro Naranjestila; Temazcal; Tuxpan (2); Tzitzio; Uruapan (74); 11 km. N of Uruapan (2); Volcan Jorullo; 16 km. E of Zacapu (2); 18 km. W of Zamora; Ziracuaretiro.

Even with the abundance of material the a.s.signment of a specific name to these anoles is only tentative, for definite determination between _Anolis nebulosus_ Wiegmann and _A. nebuloides_ Bocourt is uncertain.

Bocourt (1873:75) distinguished _A. nebuloides_ from _A. nebulosus_ by the following characters: (1) head scales keeled, not smooth; (2) snout narrower; (3) ear opening larger; (4) supraorbital semicircles separated by a row of small scales and not in contact; (5) dorsal scales larger and subequal in size to the belly scales. Boulenger (1885:77) used the same characters; Smith and Taylor (1950b:58) in their key to the Mexican species of _Anolis_ stated that the dorsal scales are slightly smaller than the ventrals in _A. nebulosus_ and markedly smaller in _A.

nebuloides_. Smith (_in litt._) stated that the characters of the relative sizes of the dorsal and ventral scales were incorrect in that key.

The application of the above criteria to specimens from Michoacan has not resulted in the recognition of two species. The majority of the specimens have the supraorbital semicircles separated by at least one small scale; the head scales, with the exception of those on the snout in a few individuals, are smooth; the dorsal scales are only slightly smaller than the ventrals. In other characters of scutellation the specimens are highly variable. The males in life have an orange throat fan. Anoles of this kind have been found in Michoacan, Colima, Jalisco, Nayarit, and southern Sinaloa. Near Oaxaca, Oaxaca, specimens were collected that superficially resemble those from Michoacan and farther north. These have low keels on the snout scales, dorsals somewhat larger than the ventrals, and a pink throat fan. In ten males from Oaxaca the size of the dorsal scales relative to that of the ventrals is 1.00:0.83; the same ratio for 25 males from Michoacan is 1.00:1.08. In both samples there are specimens in which the dorsal and ventral scales are about equal in size.

Investigations by Richard E. Etheridge on the osteology of _Anolis_, including those species here being considered, have revealed relatively constant differences in the parasternalia and in the caudal vertebrae.

The application of Etheridge's findings to anoline systematics must await the completion of his study.

The carination of the scales on the snout _versus_ smooth scales there seems to be the only significant character given by Bocourt that distinguishes _A. Nebuloides_ from _A. nebulosus_. The difference in the color of the throat fan, which is apparent only in living individuals, is more striking. Obviously more than one species is represented, as is borne out by the differences in the color of the throat fan and in the osteology, but there is uncertainty about the correct name for each species. On the strength of Bocourt's diagnosis of keeled snout scales in _A. nebuloides_, I am applying that name to the population in Oaxaca and _A. nebulosus_ to the specimens from Michoacan. As arranged here, the two species can be distinguished, as follows:

_A. nebulosus._--Dorsal scales only slightly smaller than the ventral scales; snout scales usually smooth; throat-fan bright orange in adult males.

_A. nebuloides._--Dorsal scales somewhat larger than the ventral scales; snout scales having a low keel; throat-fan pink in adult males.