The Flat-tailed Horned lizard (Phrynosoma mcallii) is named for Colonel George A. M'Call. M'Call collected the first specimen in California in the 19th century. They occupy a small range in the Sonoran Desert of southwestern California, southwestern Arizona, and extreme northern Mexico. They are threatened by development, agriculture, and other man-made intrusions into their small range. The majority of their remaining habitat in the U.S.A. is administered by the Bureau of Land Management (BLM).
