Uma thurmanae, Derycke & Gottscho & Mulcahy & Queiroz, 2020

Derycke, Elizabeth G., Gottscho, Andrew D., Mulcahy, Daniel G. & Queiroz, Kevin De, 2020, A new cryptic species of fringe-toed lizards from southwestern Arizona with a revised taxonomy of the Uma notata species complex (Squamata: Phrynosomatidae), Zootaxa 4778 (1), pp. 67-100 : 81-87

Uma thurmanae sp. nov.

Mohawk Dunes Fringe-toed Lizards

Figs 5–8

Holotype. Adult female ( USNM 590033 ; Figs 5–6 ) collected on 29 March 2015 by A. D. Gottscho at 17:28 hours. Type locality: the north end of the Mohawk Dunes (~ 2.2 km south of Interstate 8), Yuma County, Arizona, United States of America (32°41.698 N; 113° 48.935 W; WGS-84 datum). Deposited at the National Museum of Natural History , Smithsonian Institution, Washington, DC, USA.

Paratypes. USNM 590034 adult female , USNM 590035 adult male , USNM 590036 adult male , USNM 590037 juvenile female , USNM 590038 adult female , USNM 590039 juvenile female , USNM 590040 adult male , USNM 590041 adult male , USNM 590042 juvenile female , USNM 590043 adult male. Collected 25 and 26 March 2016 by A.D. Gottscho, J. Rabbers, and S. Harrington from Mohawk Dunes, Yuma County, AZ, USA. Deposited at the National Museum of Natural History , Washington , DC, USA .

Diagnosis. Uma thurmanae is a morphologically cryptic species that doesn’t exhibit any known fixed morphological differences from other species in the complex, but it can be distinguished from those other species both by statistical differences in morphological characters ( Table 5, Fig. 3 ) and in multivariate morphospace ( Fig. 4 ). It can also be distinguished from all other members of the U. notata complex by nucleotide substitutions in three mtDNA loci ( Table 8).

Description of holotype. Adult female; SVL= 68 mm; tail length= 77 mm; head width= 12 mm; head length= 15 mm; head height= 8 mm. Scalation: dorsal head scales smooth, slightly raised; parietal eye present, centrally located in a circular interparietal scale; enlarged post-parietal scales present with three scales separating post-parietal scales from inter-parietal scale; five enlarged anterior auricular scales; four superciliaries; 12 lower festoons; three suboculars, with the third being substantially larger and more elongated than the first two; five enlarged anterior auricular scales; two canthals; four internasal scales; supralabials elongated, and strongly keeled, increasing in size posteriorly; eight from rostral scale to a point below middle of eye; 11 infralabials from mental scale to a point below middle of eye, 15 to corner of mouth; rostral single; five postrostrals, four in broad contact with the rostral scale, one in narrow contact; one mental; one postmental one; gular scales extend between anteriormost sublabial scales to contact postmental scale; gular region covered in small scales varying in shape from hexagonal to rectangular to rhombic to almost round; gular fold present, with enlarged scales; dorsal body scales small, flat, granular, uniform, with no middoral row of enlarged scales; ventral scales larger than dorsal scales, smooth, flat, and uniform; dorsal limb scales slightly larger than dorsal trunk scales; ventral limb scales smaller, more rounded than ventral body scales; anterior scales on front limbs enlarged and strongly keeled; anterior and posterior lateral scales on hind limbs weakly keeled and enlarged; 27 femoral pores on each hind leg in one row; fringes present on all digits, both anteriorly and posteriorly, but appearing smaller and more symmetrical on digits I, II, and V versus larger and more asymmetrical, with the fringes on the posterior edge larger than those on the anterior edge, on digits III and IV; largest fringe scales on the posterior edge of pedal digit IV; 31 fringe scales on left pedal digit IV, 30 on right pedal digit IV. Tail flattened ventrally, with whorls of enlarged scales; four rows of smaller scales separate the eighth and ninth whorls of enlarged scales ventrally.

Position Uma sp. Rest of U. notata complex

20 T C

23 C T

89 A C

122 C A/G

203 T C

218 A G

383 G A

455 T C

485 G A

615 C T

773 C A

920 G A

962 C T

975 T C

1016 C T

Coloration and pattern (in life). Dorsum with an ocellated pattern. The individual ocelli are roughly circular beige markings, each with a rusty central spot and radiating lines, surrounded by black. The lateral ocelli are aligned in rows so that their black borders form broken black longitudinal lines between the rows of ocelli. Underside of torso cream-colored and unblemished except for two black ventrolateral blotches slightly anterior to the midpoint between axilla and groin. Gular region marked by five black diagonal lines oriented anterolateral to posteromedial. Limbs lighter in coloration, consisting of a light-colored background with dark brown and gray spots. Eight black markings present ventrally on the tail, beginning 17.65 mm posterior to the cloaca as a small cluster of black dots in the center of the tail, and increasing in length and width posteriorly. In preservative, dorsal coloration is yellowed, with muted contrast between ocelli and background.

Variation. Paratypes are similar to the holotype in coloration and pattern. Adult males were identified as specimens with SVL ≥ 65 mm and the presence of enlarged postanal scales; adult females were identified as specimens with SVL ≥ 60 mm and no enlarged postanal scales ( Norris 1958). For adults of both sexes combined, rostral width averaged 1.69 mm (range 1.34 to 1.89); mental width 0.55 mm (0.35–0.73); head length 16.90 mm (14.66–18.54); head width 13.51 mm (12.00–15.53); head depth 9.75 mm (7.89–12.11). Body width averaged 26.77 mm (23.16– 31.32); ventrolateral blotch width 4.28 mm (3.27–5.59); femur length 18.57 mm (16.00–21.05); length of pedal digit IV 16.00 mm (13.80–18.19); tail length 81.02 mm (67.65–93.16); tail base width 14.72 mm (12.96–17.39). Postrostral scales had a median of four (range 4–5); one mental scale; one postmental scale; postmental scale came in contact with gular scales in all but two specimens (USNM 590036 and USNM 590040). Infralabial scales had a median of 11 scales (range 10–11); eight supralabial scales per side except in USNM 590043 (seven scales) and USNM 590041 (nine scales); four internasal scales (3–6); four supercilliaries (4–5); 12 festoons on lower eyelid (11–14); five enlarged anterior auricular scales (5–6); 27 femoral pores (25–30); 30 fringe scales on posterior edge of pedal digit IV (25–33). USNM 590035 had one enlarged post-anal scale on the right. Dorsum ocelli had black borders and rusty central spots, with the background coloration ranging from off-white to slate gray. Limbs usually lighter in coloration than dorsum, with grey or light brown spotting. Ventral coloration ranged from cream to tawny. Ventrolateral markings ranged from a clustering of small black dots to solid black blotches. Gular markings ranged from five to six pairs of black diagonal lines. Black ventral tail markings ranged from six to eight. Juveniles duller than adults in dorsal coloration.

Distribution. Uma thurmanae is only known from the Mohawk Dunes, Yuma County, Arizona, USA (Figs. 1,7). The type material comes from the northern, central, and southern parts of the main dune system. The distance between our northernmost and southernmost samples is ~ 24 km. Nearly all of the probable range of U. thurmanae falls within the boundaries of the Barry M. Goldwater Range operated by the U.S. Marine Corps, although the holotype was collected on land administered by the Bureau of Land Management on the northernmost extent of the Mohawk Dunes abutting Interstate 8 (north of the Range). While this manuscript was in preparation additional individuals of what are likely members of U. thurmanae were observed east of the Mohawk Mountains near Dateland, Yuma County, Arizona (D. Leavitt, Arizona Dept. Game and Fish, pers. comm.). Examination of satellite imagery reveals that likely habitat for this species may extend east of the mountains through a pass in the southern end of the range (~ 32° 31’ N, ~ 113° 35’ W). Further work is needed to assess the distributional limits of this species. For this to occur, researchers would need to secure special use permits from the U.S. Air Force and/or Marine Corps to access restricted areas on this active range. Even if the range includes Dateland, U. thurmanae is endemic to Yuma County, Arizona.

Natural History. Uma thurmanae is a lowland, arenicolous, diurnal, insectivorous species specialized for life in windblown sand ( Fig. 8 ) much like other members of the Uma clade. Its natural history is presumed to be like that of other members of the U. notata complex ( Stebbins 1944; Norris 1958; Mayhew 1966; Stebbins 2003). U. thurmanae (under the name U. rufopunctata ) was the subject of an ecological study conducted at the Barry M. Goldwater Range ( Bagne & Finch 2012). The study used a System for Assessing Vulnerability of Species (SAVS; Bagne et al. 2011) to evaluate the various wildlife species found within the bombing range in terms of their resilience or vulnerability to both climate change and military activity in order to propose efficient management strategies. Of the 23 categories for which a species could possibly be impacted by through climate change, Uma thurmanae had an overall vulnerability score of 5.2, the fourth highest score of the 15 species evaluated. The most threatening impacts of both climate change and military activity are burrows collapsing from military vehicular activity, decrease in vegetative shade, and inhibited egg development from lack of moist sand.

Etymology. The specific name thurmanae honors Uma Karuna Thurman (born April 29, 1970), an American actress and pop icon, for her philanthropic contributions and outreach promoting wildlife conservation and human rights.

Figures

FIGURE 3. Box-and-whisker plots for discrete morphological characters that exhibited significant pairwise differences between OTUs. See Appendix 2 for details of how the characters were measured. SPLB=Supralabial Scales; SPCIL=Supraciliary Scales; INS=Internasal Scales; FP=Femoral Pores.

FIGURE 4. Locations of Uma specimens in the morphospace defined by the first two axes of a Discriminant Function Analysis of morphological characters. Top: when specimens with broken tails are included and TL excluded (n=57), U. inornata can still be distinguished from other OTUs, but U. notata overlaps considerably with U. rufopunctata and U. cowlesi overlaps considerably with U. sp. Bottom: analysis of only the specimens with intact tails such that tail length (TL) could be measured (n=32) allows each OTU to be distinguished.

FIGURE 5. (A) Dorsal and (B) ventral view of the adult female holotype (USNM 590033) of Uma thurmanae. Photographs by E. Langan and J. Poindexter.

FIGURE 6. Holotype (USNM 590033) of Uma thurmanae showing (A) dorsal and (B) ventral head; (C) dorsal right hindfoot and (D) dorsal right forefoot showing toe fringes. Photographs by E. Langan and J. Poindexter.

FIGURE 7. Satellite map of collecting localities for the type series of Uma thurmanae. Locations where specimens were collected, denoted by red stars, lie along the Mohawk Dunes, a long strip running northwest to southeast. The lizards are isolated in this dune system by the parallel Mohawk Mountains to the east, the Gila River and Interstate-8 to the north, and alluvial fans to the west and south, ultimately resulting in speciation. Source: “Mohawk Dunes,” 32° 34’ N, 113° 38’ W, Google Earth. Imagery date: May 29, 2016. Accessed: July 3, 2018.

FIGURE 8. (A) An individual of U. thurmanae in its natural habitat. (B) Sand dune habitat of U. thurmanae (camera pointed east with the Mohawk Dunes in the midground and the Mohawk Mountains in the background). Photographs by A. Gottscho.