Phrynocephalus persicus, commonly known as the Persian toad-headed agama, is a small diurnal desert lizard of the family Agamidae. It is the westernmost representative of the Central Asian genus of toad-headed agamas Phrynocephalus and is only known from deserts and semideserts of Iran and possibly Azerbaijan. Taxonomy Phylogeny within the genus Phrynocephalus is not well understood yet. There is a lack of data and controversy between opinions regarding both phylogenetic relationships and species vs. subspecies status of the different forms Phrynocephalus helioscopus and Phrynocephalus persicus, also called the "helioscopus-persicus complex". There is an ongoing scientific debate about the phylogeny and the taxonomic format of Phrynocephalus persicus. Recent studies suggest existence of at least two distinct subspecies: the Persian toad-headed agama (Phrynocephalus persicus persicus De Filippi, 1863) from northern and central Iran, and Horvath's toad-headed agama (Phrynocephalus persicus horvathi Mehely, 1894) from Armenia, Azerbaijan, NW Iran and NE Turkey. The IUCN considers P. persicus and P. horvathi as two distinct species, and classifies the Phrynocephalus persicus as Vulnerable, while Phrynocephalus horvathi is Critically Endangered. This usage has been followed here. Proposed subspecies P. persicus persicus Solovyova et al. (2011) P. persicus horvathi Solovyova et al. (2011) P. helioscopus horvathi Méhely (1894) P. helioscopus var. horvathi Méhely (1894) P. horvathi Rostombekov (1938) Description The snout-vent length of the body and weight ranges between 2.3 cm and 0.4 g in newborns and 7 cm and 7.8 g in adults. There is a sexual dimorphism in morphology (size, color) and behavior. Females are slightly larger than males. P. persicus appears to have a shorter tail compared to P. horvathi. Like its relatives, the species does not have visible ear-drums. Head and body are wide and covered with small scales. There is no large shield on the head as in Lacertidae lizards. Coloration is cryptic and usually corresponds to the color of the surrounding substrate, which makes the lizard almost invisible. Scales of different size, shape and color associated to create a mosaic pattern, which serves as camouflage allowing the lizard to blend in with a sandy substrate. Accumulations of conical scales create more or less symmetrically distributed dark spots of the color pattern. The dorsal pattern consists of transverse series of dark dots which form pronounced dark areas on the shoulders and the lumbar region of the body. The center of the back may carry 1–3 latitudinally spread groups of dark spots, or may