Flat-tailed Horned Lizard

Appearance

The Flat-tailed Horned Lizard is named for Colonel George A. M'Call, who collected the first specimen in California in the 19th century. The species occupies a small range in the Sonoran Desert of southeastern California, southwestern Arizona, and extreme northern Mexico in the Baja California and Sonora states. Over time, horned lizard populations have adapted to climate, food, and predators, causing them to in some ways be distinct from one another.

⟶ "A medium-sized flat-bodied lizard with a wide oval-shaped body and scattered enlarged pointed scales on the upper body and tail. The back skin is smooth with small spines. 8 horns extend from the back of the head. The two central horns are long, slender and sharp. Long and narrow spines on the lower jaw and two rows of fringe scales on the sides of the body, the bottom row scales smaller than the upper."

Naming

This lizard is threatened by development, agriculture, and other man-made intrusions into their small range. The majority of their remaining habitat in the US is administered by the Bureau of Land Management. The species frequently coexists with sources of natural gas, oil, geothermal energy, and minerals which can found in its habitat. In 1982, the US Fish and Wildlife Service declared ''P. mcallii'' as a Candidate 2 Category for the list of threatened and endangered species due to concerns over potential threats to their habitat which could further diminish the population. ''P. mcallii'' has also been given special status in both California and Arizona, which prevents their collection.

Experiments have been conducted to investigate the "fluctuations in populations of flat-tailed horned lizards, ''Phrynosoma mcallii'', in the Coachella Valley, California. This species has the smallest range of any horned lizard in the United States. In parts of its range, there are potentially conflicting activities, such as suburban development, agriculture, off-road recreation, and activities along the international border."

"Between 1978 and 1980 the Bureau of Land Management supported investigations of the status of ''P. mcallii'' in California. The purpose of this work was to determine the local distribution and relative abundance of ''P. mcallii'', to correlate these parameters with various habitat attributes, and to gather information on the structure of the populations and mobility and food habits of individual lizards."

The study also looked at the flat-tailed horned lizard's distribution and abundance throughout Arizona. The species was found to be restricted to an area of desert, 650–700 km2 in size, in the southwestern corner of the state. The species was most abundant in places with the Western whiptail , nests of the black harvester ant , galleta grass and sandy soils.