Rock horned lizard


The rock horned lizard or Ditmars' horned lizard is a species of phrynosomatid lizard endemic to Sonora in northern Mexico, south of the Arizona border. Bearing the shortest horns of all the horned lizards, it lives in thorn-scrub and deciduous Sinaloan woodlands. The rock horned lizard was "lost" to science for about 65 years. It has a unique habitat preference and limited distribution. It also had a very imprecise holotype locality record which made it difficult to locate. An extraordinary effort by :fr:Vincent Daniel Roth|Vincent Roth based on a cross-correlational analysis of gut contents from only three specimens led to its rediscovery.

Etymology

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.

Description

The rock horned lizard has its occipital and temporal horns reduced to flaring expansions. It has a deep and narrow occipital notch and a high postorbital ridge. The mandibles of Phrynosoma ditmarsi feature a large vertical expansion. It has a bare tympanum in the anterior neck fold posterior to a vertical row of four spines. One row of the rock horned lizard's lateral abdominal fringe scales is surrounded by prominent scales.