Sceloporus scalaris scalaris Wiegmann
Sceloporus scalaris Wiegmann, Isis von Oken, 21:370, 1828.—México. Type locality restricted to México, Distrito Federal, by Smith and Taylor (1950b:137).
Sceloporus scalaris scalaris, Smith, Occ. Pap. Mus. Zool. Univ. Michigan, 361:2, December 15, 1937.
Carapan (2); Cherán; Ciudad Hidalgo; Huingo (3); Jacona (3); Jiquilpan (2); Lago de Camécuaro (2); Lago de Chapala; Lago de Cuitzeo (5); Morelia (4); Pátzcuaro (4); Queréndaro; Quiroga; Tacícuaro (5); Tarécuaro; Zacapu (4); Zamora (4); Zinapécuaro (11).
This small terrestrial species does not seem to be abundant anywhere in the state. It sometimes is found in open pine, oak, or pine-oak forest, but usually it is observed in areas supporting bunch grass. In such places the lizards sun and forage on the open ground and quickly take refuge in the large clumps of grass. Altitudinally, the species ranges from 1550 to 2300 meters. Although Sceloporus scalaris scalaris has been found in association with S. dugesi intermedius, S. spinosus, and S. torquatus, it does not seem to form any close ecological association with any of these species. In the pine forests of the Cordillera Volcánica S. s. scalaris is replaced by Sceloporus aeneus aeneus, another small terrestrial species that occurs in great abundance throughout the coniferous forests of the Cordillera Volcánica.
Sceloporus siniferus siniferus Cope
Sceloporus siniferus Cope, Proc. Amer. Philos. Soc., 11:159, 1869.—Pacific side of the Isthmus of Tehuantepec. Type locality restricted to Tehuantepec, Oaxaca, México, by Smith and Taylor (1950b:134).
Sceloporus siniferus siniferus, Smith and Taylor, Bull. U. S. Natl. Mus., 199:134, October 26, 1950.
Twenty-six km. S of Arteaga; Barranca de Bejuco (2); Coahuayana; El Ticuiz (2); La Mira; La Orilla (2); La Placita (9); Maruata; Ojos de Agua de San Telmo; Ostula (4); Playa Azul (6); Pómaro (2); Puerto de las Higuerita; Santa Ana (3).
This small terrestrial species inhabits the dense arid tropical scrub forest on the coast and lower foothills of the Sierra de Coalcomán to elevations of about 150 meters. It also occurs in the lower Balsas Valley, but it has not been found in the scrub forest of the broad Tepalcatepec Valley. Perhaps the large number of Sceloporus siniferus on the coastal lowlands is responsible for the small number there of S. pyrocephalus, another terrestrial species of about the same size. The latter is abundant in the Tepalcatepec Valley, where S. siniferus siniferus has not been found. Sceloporus siniferus siniferus is a fast runner and difficult to collect; consequently, the small number of specimens available is not indicative of its abundance.