I think one of us might have stepped on this little dude. Nice camo!
The Roundtail Horned Lizard (Phrynosoma modestum) is one of the smaller species of horned lizard. Their specific epithet is from the Latin word modestum meaning modest or calm. They are found in the United States, in western Texas, New Mexico and eastern Arizona, and three states in Mexico where they are referred to as "tapayaxtin".