The species is endemic to the Mexican state of Sonora, in northern Mexico, south of the Arizona border.

An extraordinary effort by Vincent Roth based on a cross-correlational analysis of gut contents from only three specimens led to its rediscovery.

Its specific name, ditmarsi, is in honor of Raymond Lee Ditmars, the first curator of reptiles of the Bronx Zoo, and a pioneer in herpetology.

[2] The preferred natural habitat of P. ditmarsi is rocky areas in forest and shrubland.

It has a bare tympanum in the anterior neck fold posterior to a vertical row of four spines.