Phrynocephalus (Toad Headed Agamas) is the genus of Agamid lizards first described by Kaup in 1825. It includes over 40 species of small and medium sized lizards characteristic of arid regions of Central Asia and Iran with irradiation to Arabian Peninsula, India and western Part of Caspian Basin. The majority of toad headed agamas are oviparous; however, there are three Central-Asian viviparous species Phrynocephalus przewalskii Strauch, 1876, Phrynocephalus putjatai Bedriaga, 1909 and Phrynocephalus theobaldi Blyth, 1863, which are mainly linked with higher elevations.
Along with widespread species like Phrynocephalus helioscopus which is known from the norrthwestern Caspian Basin to eastern China the genus includes a number of endemic species/subspecies like (Ph. albolineatus Zhao, 1979 from N-Xinjiang (China); Phrynocephalus alticola Peters, 1984 from Jammu and Kashmir (India); Phrynocephalus horvathi from the Atropatan biogeographic province (Armenia, Azerbaijan, Turkey, northwest Iran); Ph. lidskii Bedriaga, 1909 from northernTibet; Ph. persicus Eichvald. 1863 (Iran), etc.).
History of study
Being the one of the most complex systematic groups Phrynocephalus have been a subject of study by many systematics (Ananjeva, 1987; Arnold, 1999; Bedriaga, 1909; Carevskij, 1929; Anderson, 1999; Zhao and Alder, 1993; Pang et al. 2008; Melnikov et al 2008) and ecologists (Darevsky, 1957; Rogovin et al. 2000; Semenov and Borkin, 1985; Tadevosyan, 2006, 2007) from Eurpope, Russia, China, Canada and US. There are numerous contra-versions about taxonomy of this group.
Range and behavior
In general if one considers morphology, natural history, behavior, diet, home range, and ecological niche Phrynocephalus is homological to North American Phrynosoma and Australian Moloch. Many species of Phrynocephalus have small home ranges, and they usually form a kind of colonies, so it is usual to encounter several specimens within some hundred square meters. Individual lizards communicate with each-other using a wide arsenal of attractive behavioral elements including but not limited to tail movements, turning upside down, attacking, The complete arsenal of behavioral reactions depends on species, as well as on the sex, age, individual physiological conditions and environmental temperature range. Some species can live live up to ten years (e.g. Phrynocephalus mystaceus), however many species live only two to three years and reach maturity at eight to sixteen months. The number of offspring usually does not exceed a range of two to six, implying that lizards of this genus must achieve a relatively high population density to survive. Many lizards die due to predation by birds, small mammals, snakes and other larger lizards, even more die due to overgrazing and man-made habitat destruction.
Different species of Phrynocephalus are under protection in a number of countries. For example, protection is afforded to the taxon Phrynocephalus helioscopus horvathis at Goravan Sands Reservation in Armenia, Azerbaijan, Uzbekstan; protection is given to Phrynocephalus theobaldi at the region of Karakoram-West Tibetian Plateau alpine steppe; and protection is afforded P. versicolor at the Great lakes basin desert steppe region (Mongolia).
- Pang, J., Wang, Y., Zhong, Y., Rus Hoelzel, A., Papenfuss, T.J., Zeng, X., Ananjeva, N and Zhang, Y. 2003. A phylogeny of Chinese species in the genus Phrynocephalus (Agamidae) inferred from mitochondrial DNA sequences. Mol. Phylogen. Evol. 27: 398-409.
- Rogovin, K.A., Semenov, D.V., Shenbrot, G.I. 2000. Lizards of the Northern Mongolian Deserts: Densities and Community Structure. Asiatic Herpetological Research 9: 1-9.
- Wang Y, & Fu, J. 2004. Cladogenesis and Vicariance Patterns in the Toad-Headed Lizard Phrynocephalkus versicolor Species Complex. Copeia 2004, 2: 199-206.
- Tadevosyan, T.L. 2006. Habitat Suitability for Reptiles in the Goravan Sands Sanctuary, Armenia. Herp. Cons. Bio. 1 (1): 39-45.
- Tadevosyan, T.L. 2007. The role of vegetation in microhabitat selection of syntopic lizards, Phrynocephalus persicus, Eremias pleskey, and Eremias Strauchi from Armenia. Amphibia-Reptilia 28, (3): 444-448.