My daughter and I were in Caprock Canyons State Park up near Quitaque, Texas and we were treated to a sighting of this beautifully marked Collared Lizard, Crotaphytus collaris, sunning herself on a rock near the Wild Horse trailhead.
This beauty shows the fading breeding coloration that this species attains during the spring. The fact that her throat lacks the leopard spotting means she is female. Notice the black line over the back of her neck by which she earns her common name.
She sat patiently while we took her picture. You can see her ear openings here. Notice how large her jaw muscles are. She earns her meals by pouncing upon smaller lizards and insects, so a strong bite comes in handy.
This specimen was about 10 inches long from nose to tip of her long tail. You can see her long legs and feet are built for running. This member of the Iguanidae family can zip along on two feet when properly motivated. Sometimes people call this species the mountain boomer because of the startling speeds they attain. We were lucky that she was enjoying the sun-warmed rock while we took her picture and got more than an empty frame for you to see.