Phrynosoma douglasii (BELL, 1829)
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Phrynosoma douglasii
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| Higher Taxa | Phrynosomatidae, Phrynosomatinae, Phrynosomatini; Iguania, Sauria, Squamata (lizards) |
| Subspecies | |
| Common Names | E: Pigmy Short-horned Lizard G: Zwerg-Kurzhorn-Krötenechse douglasii: Pigmy Short-horned Lizard |
| Synonym | Agama Douglassii BELL 1829: 105 Phrynosoma Douglassi — WAGLER 1830: 146 Tapaya Douglassi GIRARD 1858: 398 Phrynosoma ornatissima — COPE 1871: 305 Phrynosoma Douglassi subsp. ornatissima COPE 1878: 49 PhrjTiosoma douglassi pygmaea YARROW 1882: 443 Phrynosoma Douglassi — GENTRY 1885: 140 Phrynosoma douglassii — BOULENGER 1885: 240 Phrynosoma douglassii — STEBBINS 1985: 141 Phrynosoma douglassii — LINER 1994 Phrynosoma douglasii — COLLINS & TAGGART 2009 Phrynosoma (Tapaja) douglasii — CROTHER et al. 2012 Phrynosoma douglasii — MONTANUCCI 2015: 45 |
| Distribution | Canada (SC British Columbia), USA (Washington, Oregon, N California, Idaho, Montana, Wyoming, W North Dakota, W South Dakota, W Nebraska, N California, N Nevada, Utah, Colorado, Arizona, New Mexico, W Texas), Mexico (Chihuahua) |
| Reproduction | viviparous |
| Types | Holotype: MCZ 5951; also given as MCZ 5952 or 5953 or BMNH 1946.8.10.52-53 Holotype: USNM 23993 [brachycercum] Syntypes: USNM 9199, 10918, 11473 [Phrynosoma douglassi pygmaea] |
| Diagnosis | Diagnosis. Phrynosoma douglasii can be distinguished from other members of the species complex by the following combination of adult characters: (1) snout short, 44.6% ± 1.04 (36.6–49%) of orbit to rostral scale distance; (2) rostrofrontal profile strongly rounded or angular with a steep, nearly vertical, incline; (3) frontal rim not elevated, or only slightly elevated above the occipital shelf; (4) enlarged frontal rim scales 0.66 ± 0.21 (0–2) / 0.73 ± 0.20 (0–2); (5) temporal shelf short, 7.4% ± 0.86 (2.0–19.5%) in males, 10.3% ± 0.66 (1.9–17.5%) in females; (6) temporal shelf surface moderately to strongly convex (rounded); (7) cephalic horns very short, third temporal horn length 8.0% ± 0.13 (4.6–10.6%); (8) cephalic horns directed upward (ca. 45°) to vertical; (9) tympanum elliptic, typically narrow, or small and rounded; (10) tympanum exposed, or partly or entirely concealed by granular scales; (11) tail moderately short 214% ± 5.36 (158–255%) in males, 167% ± 4.14 (123–225%) in females; (12) dorsal spots small to moderately large, wedge-shaped, slightly rounded, or forming transverse bands; (13) light-colored borders of dorsal spots confined to posterior edges; (14) dorsolateral white spots absent; (15) gular area with gray to charcoal suffusion or flecks (melanin-dispersed phase); (16) abdomen with scattered melanistic flecks or a gray suffusion, no melanistic spots (melanin-dispersed phase); (17) melanistic subcaudal bands absent (melanin-dispersed phase). From Montanucci 2015: 46. Comparisons. Phrynosoma douglasii can be distinguished from all other members of the species complex by its minute occipital and temporal horns (TH significantly shorter than in all other taxa, Table 3), the absence or weak development of the frontal rim (except P. brevirostris and P. diminutum sp. nov.), a low number of enlarged frontal rim scales, a short temporal shelf with a convex or strongly rounded surface, a narrow, elliptic tympanum, reduced to a small, rounded disc in some specimens, and usually concealed by scales. It is further distinguished from P. h. hernandesi and P. h. ornatum by its small adult size, vertical orientation of the occipital and temporal horns, a rounded or angular and steeply inclined rostrofrontal profile, and the absence of melanistic abdominal spots and melanistic subcaudal bands (melanin-dispersed phase). P. douglasii can be further distinguished from P. ornatissimum and its subspecies by its smaller adult size, pale gray to charcoal suffusion on the gular area (melanin-dispersed phase), absence of dorsolateral white spots and absence of a discrete yellow and/or white line along the medial border of each dorsal spot (except P. o. brachycercum). In southern Oregon, southwestern Idaho, and northern Nevada, where P. douglasii may occur in proximity to P. h. ornatum, the two taxa may be distinguished by the usual presence of red pigment on the temporal shelf and horns as well as red pigment on the gular area and above the lateral fringe scales of the latter species. In addition, P. douglasii may have a dark, transverse band across the frontal area of the head, which is lacking in P. h. ornatum. In southwestern Montana, this trait will also help distinguish P. douglasii from P. brevirostris. From Montanucci 2015: 46. |
| Comment | Subspecies: The former subspecies Phrynosoma douglassii hernandesi (Girard, 1858) has been elevated to species status by Zamudio et al. 1997. The subspecies P. d. brevirostre, ornatissimum, and P. d. ornatum have been synonymized with P. hernandesi following Zamudio et al. 1997. Phrynosoma douglassii brachycercum has been assigned to Phrynosoma ornatissimum by Montanucci 2015. Habitat: montane Group: Belongs to the Tapaja clade fide LEACHE & MCGUIRE 2006. Distribution: see map in Montanucci 2015: 24 (Fig. 6). Not in Sonora fide Lemos-Espinal et al. 2019. Not in Durango fide Lemos-Espinal (2018). Not listed for Mexico by Liner 2007. Also in S Alberta and S Sasketchewan [fide BOULENGER 1887] but not reported from there in the more recent literature. Publication date: some sources say 1828, but the cover page on the journal says 1829. |
| Etymology | Named after David Douglas (1799-1834), a botanist and traveler who collected in North America (1823-1834) and Hawaii (1834) for the Royal Horticultural Society, London. Agama Douglassii is the original spelling, and Bell repeatedly referred to “Mr. Douglass” although his correct name was “Douglas”. |
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