Phrynosoma ditmarsi STEJNEGER, 1906
Can you confirm these amateur observations of Phrynosoma ditmarsi?
|Higher Taxa||Phrynosomatidae, Phrynosomatinae, Phrynosomatini; Iguania, Sauria, Squamata (lizards)|
|Common Names||E: Rock Horned Lizard|
S: Camaleón de Roca
|Synonym||Phrynosoma ditmarsi STEJNEGER 1906|
Phrynosoma ditmarsi — SMITH & TAYLOR 1950: 104
Phrynosoma ditmarsi — LINER 1994
Phrynosoma ditmarsi — PIANKA & VITT 2003: 161
Phrynosoma hernandesi ditmarsi — KÖHLER 2021
Type locality: State of Sonora, not far from the boundary of Arizona.
|Reproduction||ovovivparous (Lambert & Wiens 2013).|
|Types||Holotype: USNM 36022|
|Diagnosis||Definition. Phrynosomadirmarsiisamoderatelysized(7690 mm SVL) viviparous homed lizard with a red, brown, gray, or yellow dorsal ground color and dark crossbands posteriorly. The venter is whitish, with strongly keeled scales. These lizards have a single row of lateral abdominal fringe scales which are bluntly pyramidal. The tail is short. The head is wider than long with a high postorbital ridge extending from the tip of the orbital boss to the outer enlarged temporals. A postocular boss is present as a broad pyramid in which three edges are formed by the continuation of the superciliary, supraocular, and orbitotemporal ridges. Occipital and temporal horns are reduced to rounded, flaring expansions on either side of the head, which has a deep and narrow occipital notch. The nares are in the line of the canthus rostralis. Postlabials are slightly enlarged, convex, and triangular; the keeled edge of the row is directed nearly horizontally. Mandibles are greatly expanded posteriorly, exceeding the diameter of the orbit. Five to eight rugose sublabials separate chinshields from infralabials, which increase in size and are keeled posteriorly. Gular scales are small and keeled. The tympanum is bare and resides in the anterior neck fold posterior to a vertical row of four small spines. Posterior and dorsal surfaces of the hind legs and tail have large, scattered, bluntly keeled scales, the larger scale bases surrounded by rosettes of smaller scales. Males have enlarged postanal scales (Hodges 1995).|
Diagnosis. Phrynosoma dirmarsi can be distinguished from all congeners by the combination of reduced occipital and temporal horns appearing as rounded, flaring expansions on either side of the head, a deep and narrow occipital notch, large vertical expansion of the mandibles, a high postorbital ridge, a single row of abdominal fringe scales, nares in the line of the canthus rostralis, and a bare tympanum in the anterior neck fold posterior to a vertical row of four spines (Hodges 1995).
Group: Belongs to the Tapaja clade fide LEACHE & MCGUIRE 2006.
Diet: With 11% of its diet being ants this species seems to be the least dependent and specialized on ants (Fabian 2014).
|Etymology||Named after Dr. Raymond Lee Ditmars (1876-1942), Curator of Reptiles at the Bronx Zoo, New York (1899-). Ditmars also worked in the Department of Entomology at the American Museum of Natural History (1893-1897) and as a reporter for the New York Times (1898).|