I Have Discovered the Culprit!

The mystery of the reptile formerly, if briefly, known as Phillips' Yellow-Headed Lizard has been solved. It appears that a young male Agama Lizard maliciously masqueraded as a new species in order to play a joke on the new guy in town.

There are a number of species of Agamas. The one in my guide book described the heads of males as bright orange or orange-red, but this youngster had different shadings. It was this difference in head colouring that was obviously the reason I mistook him for a new species.