J. Martin Walker

Evidence for Specific Recognition of the San Esteban Whiptail Lizard (Cnemidophorus estebanensis)

The divergent whiptail lizard of Isla de San Esteban, Gulf of California, differs from Cnemidophorus tigris in more morphological characters than any other form of the complex. C. estebanensis, characterized by impressive differences in size, color pattern, and scutellation, is regarded herein as specifically distinct from C. tigris. The whiptail lizard of Isla Tiburon, with which C. estebanensis has sometimes been confused, is allocated to C. tigris gracilis instead of C. tigris aethiops, which is restricted to southern Sonora, Mexico. i i t e San Esteban hiptail sis)

Systematics of Cnemidophorus gularis. I. Reallocation of Populations Currently Allocated to Cnemidophorus gularis and Cnemidophorus scalaris in Coahuila, México@@@Systematics of Cnemidophorus gularis. I. Reallocation of Populations Currently Allocated to Cnemidophorus gularis and Cnemidophorus scalaris in Coahuila, Mexico

Cnemidophorus scalaris is currently defined as a biparental species with a range which includes most of the Mexican Plateau and a part of the Big Bend area of southern Texas. C. gularis replaces C. scalaris in Mexico east of the Mexican Plateau and in parts of Oklahoma, Texas and southeastern New Mexico. In Coahuila, Mexico, C. gularis is distributed westward from the vicinity of Monclova to the vicinity of Sacramento near the eastern edge of the intermontane Cuatro Cienegas Basin. Specimens from an area 3.2 km NNE to 11.7 km W Sacramento are intermediate in color and pattern, size and scutellation between C. gularis and the Cuatro Cienegas Basin endemic C. scalaris pallidus indicating extensive gene exchange between the two. To reflect this relationship, the appropriate nomenclatural combinations are C. gularis gularis and C. gularis pallidus. These subspecies are highly distinctive in color and pattern and maximum body size, but are similar in qualitative and quantitative features of scutellation. Specimens collected in Coahuila along Mexican Highway 30 from 8.8 to 20.0 km SW Cuatro Cienegas de Carranza to 33.6 km NW San Pedro de las Colonias, and specimens collected along Highway 54 from the vicinity of Castaiios to Cuesta la Muralla represent an unrecognized subspecies of C. gularis. Southern Coahuila, from the vicinity of Saltillo westward along Highway 40 to the vicinity of Zapata and Viesca, and adjacent parts of Zacatecas and Nuevo Le6n are inhabited by a distinctive color and pattern variant which previous workers have allocated to C. scalaris semifasciatus. Evidence presented in this report indicates that the nomenclatural combination C. gularis semifasciatus reflects the true systematic re

Systematics of the Santa Catalina Whiptail (Cnemidophorus catalinensis) with Reference to the Superspecies Cnemidophorus tigris

Astract: The teiid lizard Cnemidophorus catalinensis Van Denburgh and Slevin is endemic to Isla Santa Catalina in the southern region of the Gulf of California approximately 22.4 km E of Baja California Sur. Small mesoptychial scales, granular postantebrachial scales, 4-4 supraocular scales, and paired frontoparietal scales align the Santa Catalina whiptail with the tigris species group. Small maximum body size (maximum snout vent length 84 mm), a distinctive melanistic dorsal and ventral color pattern, and a distinctive ensemble of scutellation characters suggest that the potential for reproductive isolation has evolved. Cnemidophorus tigris is defined as a superspecies consisting of 15 continental and insular subspecies and seven allospecies. The Zoogeographie affinities of the Santa Catalina whiptail are with insular populations of Cnemidophorus in the northern Gulf region which were presumably derived from the Sonoran coast.

Systematics of Cnemidophorus gularis. II. Specific and Subspecific Identity of the Zacatecas Whiptail (Cnemidophorus gularis semiannulatus)

gularis and populations previously allocated to C. scalaris pallidus and C. scalaris semifasciatus are actually conspecific, with the appropriate nomenclatural combinations being C. g. gularis, C. g. pallidus and C. g. semifasciatus. Analyses of specimens from southern Durango, Zacatecas, Aguascalientes and San Luis Potosi provide additional evidence that all populations previously allocated to C. s. scalaris are actually conspecific with C. gularis. C. gularis scalaris is currently the only available name for what is actually a number of highly distinctive geographic variants which occur in parts of Chihuahua, Durango, Zacatecas, Aguascalientes, San Luis Potosi, Nuevo Leon, Tamaulipas, Queretaro, Guanajuato, Michoacan and Jalisco. Specific recognition is herein accorded to one of these geographic variants which occurs in most of Zacatecas and adjacent parts of southern Durango, extreme western San Luis Potosi and extreme northern Aguascalientes between elevations 1,981-2,819 m. C. gularis semiannulatus (n. ssp.) is characterized by a maximum snout vent length of about 104 mm, 84.4 granules around midbody, 197.0 granules from occiput to rump, 34.7 femoral pores, circumorbital scales which extend anteriorly to the middle of the third supraocular scales, plate-like postantebrachial scales, enlarged mesoptychial scales; juvenile pattern of six vivid stripes and numerous minute spots; adult pattern of sharply defined grayish to yellowish middorsal spots and/or bars, stripes absent (adult males) or occasionally fused with spots and bars (adult females); ventral pattern consisting of a vivid reddish-pink suffusion. Adults of both sexes of C. g. semiannulatus attain sexual maturity at a snout vent length of about 55 mm. Average clutch size based upon oviducal eggs and yolked ovarian follicles in 22 females was 4.68 (range 37).

Population Structure and Reproductive Characteristics in Cnemidophorus parvisocius (Lacertilia: Teiidae)

Cnemidophorus parvisocius Zweifel is one of the smallest and southernmost species of the sexlineatus species group in Mexico. It occupies the more xeric habitats in the remote Tomellin Canyon in southeastern Puebla and N-central Oaxaca between 518-1692 m elevation. Analysis of snout-vent length data for 457 adults of C. parvisocius revealed the presence of a small northern variant (females, X = 57.4 mm; males, X = 61.3 mm) and a larger southern variant (females, X = 60.3 mm; males, X = 65.5 mm). Males and females are reproductively mature by June following the year of their hatching. Analysis of three geographic samples revealed no variation in clutch size. Clutch size, based upon yolked follicles and oviducal eggs, varied from 1-4 (X = 1.77, 151/85). Cnemidophorus parvisocius has the smallest clutch size reported for a species of the sexlineatus group.

A Review of the San Pedro Nolasco Whiptail Lizard (Cnemidophorus bacatus Van Denburgh and Slevin)

Samples comprising 51, 52, and 24 specimens of Cnemidophorus bacatus, the endemic whiptail lizard of Isla San Pedro Nolasco, Gulf of California, were obtained in August 1964-1967. This species has been only briefly mentioned in the literature since it was originally described. Analysis of the new material supported the view that C. bacatus is one of the smallest species of the TIGRIS species group. This species is recognizable by a combination of 4-4 supraocular scales, granular postantebrachial scales, small mesoptychial scales, approximately 74 granules around midbody, 164 granules from the interparietal scale to the base of the tail, 37 femoral pores combined, 30 subdigital lamellae, 13 circumorbital scales, 13 lateral supraocular granules, and small body size. Juveniles have a blackish brown dorsum with a pattern of stripes and spots, and a slate black venter; whereas adult males and females have a dark brown ground color with a pattern of spots, and a black venter. The sex ratio of 124 sexable C. bacatus was 649 9 :60 8 8. The presence of recent hatchlings and gravid females in the population at the same time may indicate that C. bacatus produces a minimum of two clutches per year. Clutch size varies from one to three, average near two. Mean clutch size on the basis of yolked ovarian follicles was 1.89 (72/38); on the basis of oviducal eggs and corpora lutea, 1.70 (17/10); and on the basis of a combination of these methods, 1.85 (89/48).