Rock horned lizard

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

rock horned lizard
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Iguania
Family: Phrynosomatidae
Genus: Phrynosoma
P. ditmarsi
Binomial name
Phrynosoma ditmarsi
Stejneger, 1906

The rock horned lizard or Ditmars' horned lizard (Phrynosoma ditmarsi) 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 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 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.


  1. ^ Frost, D. R.; Hammerson, G. A.; Gadsden, H.; Sherbrooke, W. (2007). ""Phrynosoma ditmarsi "". The IUCN Red List of Threatened Species. doi:10.2305/IUCN.UK.2007.RLTS.T64074A12741807.en.
  2. ^ Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. pp. xiii + 296. ISBN 978-1-4214-0135-5. (Phrynosoma ditmarsi, p. 73).

Further reading[edit]

  • Lowe CH, Robinson MD, Roth VD (1971). "A Population of Phrynosoma ditmarsi from Sonora, Mexico". J. Arizona Acad. Sci. 6 (4): 275–277.
  • Stejneger L (1906). "A New Lizard of the Genus Phrynosoma, from Mexico". Proceedings of the United States National Museum 29: 565–567. (Phrynosoma ditmarsi, new species).

External links[edit]