Anolis boulengerianus

Oca, Adrián Nieto-Montes De, Köhler, Gunther & Feria-Ortiz, Manuel, 2014, Anolis boulengerianus Thominot, 1887, a senior synonym of Anolis isthmicus Fitch, 1978 (Squamata: Dactyloidae), Zootaxa 3794 (1), pp. 125-133 : 130-132

Comparison of Anolis boulengerianus and A. isthmicus and taxonomic conclusions

A comparison of our Anolis boulengerianus and A. isthmicus samples is provided in Table 2 (also see Fig. 2 ). There were no obvious differences between these samples in any of the characters in the table, and we were unable to find any differences in any other characters examined. Thus, this comparison clearly demonstrates that A. boulengerianus represents the same taxonomic species that what is currently referred to as A. isthmicus . Because of the priority principle, A. isthmicus Fitch, 1978 becomes a junior synonym of A. boulengerianus Thominot, 1887 . Also, A. isthmicus and Anolis subocularis Davis, 1954 were classified in the A. subocularis species group by Savage and Guyer (1989). However, because A. isthmicus is a junior synonym of A. boulengerianus and this name is older than A. subocularis , the A. subocularis group becomes the A. boulengerianus group. We provide the following synonymy and diagnosis for A. boulengerianus :

......continued on the next page Anolis boulengerianus Thominot, 1887:182 ; three syntypes, MNHN 6554 and 1994.1670–71, from “Téhuantépec ( Mexique).”

Anolis isthmicus Fitch, 1978:2 ; holotype, KU 176034, from “ 19.5 km WNW Tehuantepec, Oaxaca, Mexico.” Liner (1994), Lieb (1981, 1995), Savage and Guyer (1989).

Anolis nebuloides: Guibé (1954; in part) , Brygoo (1989; in part).

Anolis nebulosus: Barbour (1934; in part) , Smith and Taylor (1950; in part).

Diagnosis. Anolis boulengerianus is a medium-sized species (SVL of largest male examined 60.0 mm, of largest female 51.4 mm) that belongs to an unnamed group of beta anoles that occur in Mexico west of the Isthmus of Tehuantepec (except for the Atlantic versant) and differ from all of the other species of beta anoles in the lepidosis of the supraocular region; namely, in the possession of a longitudinal series of much enlarged supraocular scales, each wider than long, which combined form a broadly oval supraocular disk surrounded by relatively small scales ( Fitch 1978; Figs. 1–2 ). The species in this unnamed group were classified in the A. gadovii , A. nebuloides , A. nebulosus , and A. boulengerianus species groups by Savage and Guyer (1989), although monophyly of these groups has not been investigated and the contents of some of them has been modified recently (Nieto-Montes de Oca et al., 2013).

Anolis boulengerianus may be distinguished from all of the species in the A. gadovii group ( A. dunni Smith, 1936 , A. gadovii Boulenger, 1905 , A. liogaster Boulenger, 1905 , A. omiltemanus Davis, 1954 , A. peucephilus Köhler et al., 2014 , and A. taylori Smith & Spieler, 1945 ) in having strongly keeled midventral scales (midventral scales smooth in the other species). In addition, A. boulengerianus may be distinguished from all of the species in the above Mexican unnamed group with distinctly keeled midventral scales (i.e., those in the A. boulengerianus , A. nebuloides , and A. nebulosus groups, respectively) as follows: from the species in the A. nebuloides group ( A. megapholidotus Smith, 1933 and A. nebuloides ) by having dorsal scales gradually decreasing in size laterally (dorsal scales abruptly decreasing in size laterally in A. megapholidotus and A. nebuloides ) and smaller, more numerous middorsal scales between the levels of the axilla and groin (52–75, x = 62.5, n = 21; versus 33–37, x = 35.0, n = 4, in the type series of A. nebuloides ; and 28–32, x = 30, n = 6, in A. megapholidotus ); from the species in the A. nebulosus group ( A. forbesi Smith & Van Gelder, 1955 , A. microlepidotus Davis, 1954 , A. nebulosus , and A. quercorum Fitch, 1978 ) by having a larger body size (maximum SVL = 60.0 mm; versus <53 mm in the other species [ Fitch 1978; Lieb 1981; Herrera-Flores 2011]) and longer limbs (tibia length / head length ratio 0.92–1.1, x = 0.99, n = 20; versus 0.67–0.76, x = 0.83, n = 23, in A. forbesi [ Herrera-Flores 2011]; adpressed hind limb reaching the eye or beyond in A. boulengerianus ; reaching the shoulder in A. microlepidotus , the ear in A. nebulosus , and beyond the ear, but failing to reach the eye, in A. quercorum ; Fitch 1978); and from the other species in the A. boulengerianus group ( A. subocularis ) by having more numerous middorsal and midventral scales between the levels of the axilla and groin (52–75, x = 62.5, n = 21 and 45–62, x = 50.5, n = 21 dorsals and ventrals, respectively; versus 40–55 and 30–42 dorsals and ventrals, respectively, in A. subocularis [ Fitch 1978]; also 36–51, x = 41.5–44.6, n = 15–18 and 32–44, x = 37.3–38.9, n = 15–18 dorsals and ventrals, respectively, in three samples of A. subocularis [ Feria-Ortiz 2001]).

Geographic distribution: Slopes and foothills on Pacific versant of the Isthmus of Tehuantepec in southeastern Oaxaca, Mexico.

Figures

FIGURE 1. Head of a syntype of Anolis boulengerianus (MNHN 6554) in lateral (top), dorsal (middle), and ventral (bottom) view. Scale bar = 5 mm.

FIGURE 2. Head in dorsal view of (top) a syntype of Anolis boulengerianus (MNHN 6554) and (bottom) a specimen from the general region from where the type series of A. isthmicus was collected (MZFC 19453). Scale bar = 5 mm and 1 mm, respectively.

Tables

TABLE 2. Selected characters examined in samples of Anolis boulengerianus Thominot, 1887 and A. isthmicus Fitch, 1978 (see text for details). For meristic characters, the numbers in parentheses are ranges. For qualitative characters, the numbers in parentheses are percentages of specimens exhibiting character states. Sample sizes for the A. boulengerianus and A. isthmicus samples = 10 and 11, respectively, unless noted otherwise. Meristic bilateral characters were counted on the right side.

Character	Anolis boulengerianus	Anolis isthmicus
Dorsal head scales relief	Supraorbital semicircles slightly elevated; remaining scales flat	Supraorbital semicircles slightly elevated; remaining scales flat
Dorsal head scales surface	Usually weakly keeled on internasal area and sides of snout; smooth on rest of head (occasionally most scales on head keeled)	Weakly keeled on internasal area and sides of snout; smooth on rest of head
Postrostrals (including prenasals)	x = 5.7 (5–6)	x = 5.8 (5–7)
Prenasal	Moderately enlarged, in contact with rostral and first supralabial	Moderately enlarged, in contact with rostral and first supralabial
Scales bewteen circumnasals	x = 7.0 (6–8), n = 9	x = 6.7 (6–7)
Contact between supraorbital semicircles	In contact (80.0%) or narrowly separated by one small scale row (20.0%)	In contact (27.3%) or narrowly separated by one small scale row (72.7%)
Circumorbital scale row	One row of small scales (incomplete in some specimens)	One row of small scales (incomplete in some specimens)
Enlarged supraoculars	x = 3.0 (3–3)	x = 3.3 (3–4), one scale split into two in five specimens
Enlarged superciliaries	x = 2.0 (2–2)	x = 2.3 (2–3)
Scale rows between supraorbital semicircles and interparietal	x = 3.4 (1–3)	x = 3.4 (0–3)
Scales along canthus rostralis (to first supralabial)	x = 6.8 (6–8)	x = 7.2 (6–9)
Loreal rows below second canthals	x = 5.7 (5–7)	x = 5.2 (4–6)
Suboculars-supralabials contact	In broad contact	In broad contact
Postmentals	x = 4.2 (4–5)	x = 4.3 (4–6)
Anterior extension of lateral gular rows	First or second infralabial	First or second infralabial
Dorsal scale surface	Keeled	Keeled
Middorsal scales between levels of axilla and groin	x = 60.9 (54–69)	x = 63.8 (52–75)
Longitudinal rows of enlarged dorsal scales	x = 15.7 (14–20)	x = 16.7 (10–22)
Dorsal-lateral scales size transition	Gradual	Gradual