The New Mexico Whiptail Lizard (Cnemidophorus neomexicanus) was designated the official state reptile of New Mexico in 2003. The New Mexico whiptail is a small lizard found primarily in the Rio Grande valley from northern New Mexico to northern Chihuahua, Mexico.

Whiptail lizards (named for their long, whiplike tails) are constantly in motion. They often run upright on their hind legs, giving them the appearance of miniature dinosaurs. Whiptail lizards swivel their heads frequently from side to side, taste the air with slender forked tongues, and use their pointed snouts to probe the ground (foraging for termites, spiders, and other ground-dwelling insects).

The whiptail lizards' alertness, speed, and agility help it outmaneuver predators such as thrashers, roadrunners, gila monsters, and snakes. These fascintating lizards can sprint up to fifteen miles per hour (as fast as a roadrunner). Whiptail lizards can also escape capture by sacrificing their tails (when grasped, their tail breaks easily along a fracture plane in the vertebrae). The disembodied tail wriggles violently, which startles and distracts the predator while the lizard dashes to safety.

The New Mexico Whiptail (as well as several other species of whiptail lizard living in the Southwest) play a part in one of the greatest mysteries of nature - they are all female! New Mexican whiptail lizards are actually a hybridization of the western whiptail (which lives in the desert) and the little striped whiptail (a grasslands lizard). Most products of crossbreeding (such as the mule) are usually sterile. But the New Mexico Whiptail reproduces by cloning - its eggs require no fertilization, and its offspring are exact and complete genetic duplicates of the mother.

Source:

Whiptail lizards: SouthernNewMexico.com
Unisexual Whiptail Lizards: American Museum of Natural History

Links:

State Reptiles & Amphibians - 50 States List