Zebra-tailed Lizard (Callisaurus draconoides)
This lizard (photographed in Lower Hot Springs Canyon in September 2004) has a distribution throughout southern Arizona and northwestward into eastern California and Nevada. Its appearance is similar to our Greater Earless Lizard -- one difference being
(as emphasized here at left) that the black crossbars on the ventral side of the Zebra tail extend over the dorsal part of the zebra-tail as well [see Stebbins Plate 22, which illustrates the difference clearly, though Stebbins does not specifically mention this distinction], and the location of the black belly markings and blue coloration (on the male) midway between the front and hind legs [rather than closer to the hind legs, as in the Greater Earless]. The Zebra-tailed also has external ear openings, which the Greater Earless lacks. We can't see this in these photos.
Both of these lizards are very fast runners, and they occupy similar habitats, though the Greater Earless's is more restricted in its elevation range.