Ameiva Meyer

Harvey, Michael B., Ugueto, Gabriel N. & Gutberlet, Ronald L., 2012, 3459, Zootaxa 3459, pp. 1-156 : 80-88

Ameiva Meyer

Figure 58–59

Ameiua Meyer 1795: 27. Type species Ameiua americana Meyer by subsequent designation (see remarks). [Original spelling emended by Bechstein 1800]

Cnemidotus Wagler 1828: 860 . Type species Lacerta ameiva Linnaeus.

Pachylobronchus Wagler 1833: 891 . Type species Lacerta ameiva Linnaeus.

Pholidoscelis Fitzinger 1843: 20 . Type species Ameiva major Duméril and Bibron by original designation.

Tiaporus Cope 1892: 132 . Type species Tiaporus fuliginosus Cope by monotypy.

Diagnosis.—From all other Teiinae , Ameiva can be distinguished by the combination of the following characters: first supraciliary short, third or fourth supraciliary usually elongate (except in A. wetmorei ), five regular parietals (except in A.wetmorei ), the prefrontal separated from the nasal, small numerous scales at the heel (except in A. lineolata series), homogeneous manual subdigital lamellae, smooth ventrals and subcaudals, and males lacking preanal spurs.

Content.— Twenty-five named species, each assigned herein to one of five species groups.

Definition.—Small to large lizards reaching 243 ( Ameiva praesignis ) mm SVL; tail 1.9–2.6X as long as body; posterior maxillary and dentary teeth longitudinally compressed, tricuspid; pupil reniform.

Prefrontal usually separated from nasal and contacting (except in Ameiva lineolata Series) first supraciliary; frontal entire (transversely divided in A. bifrontata complex and in few specimens of A. ameiva ), lacking longitudinal ridge (except A. bifrontata complex); posterior suture of frontal usually contacting third supraocular in most species, frequently or usually contacting second supraocular in A. ameiva complex, A. dorsalis , and A. fuscata ; scales of frontoparietal region smooth, outwardly convex to flat (key-hole shaped depression absent); frontoparietals paired; parietals consisting of five regular scales (three in A. wetmorei ); interparietal entire, variable in size; medial pair of enlarged occipitals usually absent; occipitals usually larger than first row of dorsals; supratemporals slightly to moderately enlarged, separated from parietals by one or more scales (except in A. lineolata series).

Rostral groove usually present; nostril oval and oriented anteroventrally, its position relative to nasal suture varying among species groups; loreal single; supraoculars eight (rarely 6, 7, 9, or 10); first supraocular entire, larger than fourth supraocular (except Ameiva maynardi ), and usually broadly contacting second supraocular; circumorbital semicircles consisting of 2–40 small scales, their anterior extent varying among species; supraciliaries 11–18, separated from supraoculars by 1–3 rows of 17–81 granular scales; first supraciliary small, second and third enlarged and subequal in size or third greatly enlarged (first and second supraciliaries subequal and longer than rest in A. wetmorei ); angulate keel extending from first subocular to elongate subocular below eye; suboculars usually four; first subocular usually contacting first supraciliary, usually contacting supralabials in most Caribbean species or usually separated from supralabials by anterior expansion of second supralabial in A. ameiva , A. bifrontata , and A. parecis Groups ; scales in front of auditory meatus variable in size; auricular flap and preauricular fold absent.

Supralabials 11–17; first supralabial smaller than or subequal to second, its ventral margin curved in Ameiva ameiva Group and A. lineolata Series, toothy in other groups; infralabials 10–15; first pair of chinshields broadly contacting infralabials (frequently partially to completely separated by small granular scales in A. auberi , A. dorsalis , and A. exsul ) and usually forming a medial suture greater than or equal to half their length in all species except A. dorsalis Group where variable in length in several species; interangular sulcus absent; anterior gulars 18–55; gular patch absent; posterior gulars 7–29; intertympanic sulcus absent; larger anterior gulars undergoing sharp transition to smaller posterior gulars at intertympanic crease except in A. lineolata Series, A. auberi , and A. dorsalis ; mesoptychials not to moderately enlarged, not forming differentiated transverse row; gular fold lacking serrated edge.

Dorsals smooth; scales on flank subequal to middorsals, not projecting laterally, supported by small apical granules; scales on rump much smaller than proximal subcaudals; scales of chest large and flat; pectoral sulcus present in Ameiva erythrocephala Group and some specimens of A. bifrontata Group, absent in other groups; ventrals smooth, in 29–37 transverse and 8–20 longitudinal rows; lateral-most ventrals often gradually decreasing in size on flanks; preanals 4–17 (generally highest counts in A. erythrocephala Group); preanal plate present, bordered by subtriangular scales; preanals one-half as large to slightly larger than scale anterior to them; preanal spurs, postcloacal buttons, and postanal plates absent; scales on dorsolateral edge of tail like those on top and sides, denticulate edge and dorsolateral crests absent; caudal annuli complete; proximal subcaudals smooth.

Enlarged scales of brachium connected by continuous band of subtriangular plates on dorsal surface of arm of Ameiva lineolata Series, separated by small granular scales in all other species; preaxial brachial scales 1–2X as wide as long (except in A. corvina , A. erythrocephala , and A. pluvianotata where scales are not enlarged, longer than wide), usually not extending beyond middle of arm; postaxial brachial scales variable in size, both extending to or beyond center of arm; antebrachial scales enlarged and smooth, separated from brachial scales by large gap on proximal antebrachium in A. erythrocephala Group and A. dorsalis , narrowly separated from or in continuous row with preaxial brachial scales in all other species; postaxial antebrachial scales slightly enlarged to granular; subdigital lamellae of hand homogeneous in size, entire (except A. lineolata with scattered divided subdigital lamellae, not restricted to phalangeal articulations), 13–22 (counts lower in A. ameiva Group than in other groups) under fourth finger.

Prefemorals 4–14; femoral and abdominal pores 22–78 (higher in Ameiva erythrocephala Group than other species) in continuous row on each side (abdominal pores not separated from femoral pores by gap); each compound pore-bearing scale consisting of partially fused prefemoral or abdominal scale and 2–6 granular scales; 4–26 (usually higher in A. dorsalis Group than in other species) scales separating right and left pore rows; scales at heel relatively small and numerous (except A. lineolata and holotype of A. wetmorei , both with three relatively large subequal scales); tibiotarsal shields absent; tibiotarsal spurs absent in most species (two rows of about eight total spurs with elongate mucrons present in A. dorsalis and some populations of A. auberi ); lamellae under fourth toe 29–46; distal lamellae of fourth toe smooth in most species (keeled in A. plei ); scales between subdigital and supradigital lamellae of toes small and mostly restricted to phalangeal articulations in most Caribbean species, keeled and separating lamellae in A. fuscata and the A. ameiva and A. bifrontata Groups ; noticeably enlarged postaxial scales between fourth and fifth toe absent; fifth toe well-developed in Caribbean species, reduced in some A. griswoldi and all specimens of the A. ameiva and A. bifrontata Groups.

β- keratin containing layers of dorsal scales folded into macrohoneycomb; dorsal and caudal scales with one subterminal lenticular scale organ; ventrals lacking scale organs; generation glands present in most Caribbean species and the A. bifrontata Group, absent in A. fuscata , A. pluvianotata , and the species of the A. ameiva Group. Snout of adults usually red or with reddish cast except few species with snout of same color as dorsal head scales ( Ameiva ameiva , A. atrigularis , A. dorsalis , A. lineolata , A. pantherina , A. parecis , A. praesignis , A. wetmorei ). In juveniles (characters of juvenile coloration of A. corvina , A. maynardi , and A. pluvianotata unknown), light vertebral stripe absent (most species), or solid and straight ( A. auberi species complex, A. bifrontata species complex, at least some subspecies of A. chrysolaema , A. wetmorei ), or split and straight ( A. lineolata ), or widening substantially on the posterior body ( A. dorsalis ), or straight but breaking into spots posteriorly ( A. plei ), or present only from mid-dorsum to sacrum ( A. praesignis ); light paravertebral stripes absent (most species), or present and straight (at least some subspecies of A. chrysolaema , A. lineolata ), or broken into spots ( A. plei ), or absent ( A. abaetensis ); dark dorsolateral field absent (most species), solid (at least some subspecies of A. chrysolaema , A. exsul , A. lineolata ), or completely broken into blotches ( A. bifrontata species complex, A. parecis , A. plei ); dorsolateral light stripe solid and extending to tail (most species), or fading towards sacrum ( A. ameiva Group, A. fuscata , A. griswoldi , A. wetmorei ), or broken ( A. dorsalis ), or absent ( A. pluvianotata ); dark lateral field solid (most species), or solid anteriorly and breaking into spots posteriorly ( A. bifrontata divisa and other members of the bifrontata complex not currently assigned to a particular subspecies), or completely broken into blotches (most taxa of the A. bifrontata complex, A. dorsalis , A. exsul , A. griswoldi , A. parecis ); upper lateral light stripe solid and extending to groin (most species), or broken to groin (some taxa of the A. bifrontata complex, A. dorsalis , A. exsul ), or extending above the leg as either a broken or continuous stripe ( A. wetmorei ), or absent ( A. pluvianotata ); lower lateral light stripe absent (most species), or solid and extending to groin ( A. lineolata , A. wetmorei ), or broken ( A. exsul ); thighs lacking light spots (most species), or with light spots ( A. chrysolaema complex, A. exsul , A. griswoldi , A. lineolata , A. plei , A. wetmorei ). In adult males, turquoise ventrolateral spots present (most species), absent in A. lineolata and A. wetmorei ; venter immaculate to finely spotted, except in some specimens of A. praesignis from Venezuelan and Colombian Llanos with moderately large black blotches; juvenile dorsal color pattern present in adult males with only slight modification in most species, but some species undergo considerable ontogenetic changes ( A. ameiva , A. atrigularis , A. exsul , A. fuscata , A. griswoldi , A. pantherina , A. parecis , A. plei , A. praesignis ).

Hemipenis with pair of taβ- like and smooth apical awns; apical papillae and apical basin absent; asulcate expansion pleat vestigial in the Ameiva bifrontata Group, well-developed in other groups; asulcate expansion pleat interrupting about 11–24 distal laminae in Caribbean species and about 5–9 distal laminae in A. ameiva and A. bifrontata Groups ; discontinuous distal laminae approximately 4 in A. chrysolaema and species of the A. ameiva Group; 0–15 laminae proximal to expansion pleat in Caribbean species, 14–26 in the A. ameiva and A. bifrontata Groups ; basal papillae absent.

Etymology.— We do not know the derivation of Ameiva . Duméril and Bibron (1839) remark that the name had been used by earlier authors and was said to be a common name used somewhere in the New World as was the case with Teius .

Distribution.— The genus Ameiva occurs in eastern South America and the Caribbean Islands with one species ( Ameiva praesignis ) extending into northern Colombia, Panama, and extreme southern Costa Rica. Ameiva ameiva and A. praesignis have been introduced to South Florida ( Ugueto & Harvey 2011).

Interspecific Relationships.— In all of our analyses, Ameiva forms a monophyletic group containing four clades. We used suites of morphological characters ( Table 4) to define geographically and morphologically cohesive groups of species. Species groups are consistent with well-established biogeographic patterns and, except for the A. dorsalis Group, demonstrably monophyletic ( Fig. 60).

The West Indian Ameiva form a monophyletic group in all recent analyses of both morphological (this study) and molecular characters (Giugliano et al. 2009; Hower & Hedges 2003; Reeder et al. 2002). Unlike other Ameiva (characters in parentheses), the West Indian species share the narial suture positioned behind the nostril (passing through nostril or located in front of it), the first subocular usually contacting the supralabials (usually separated from supralabials), a long fifth toe (reduced), and supradigital and subdigital lamellae usually in contact along the postaxial margin of the toes (separated).

The West Indian Ameiva most likely evolved from a South American ancestor and are most closely related to the Ameiva bifrontata Group in all our trees. The West Indian species and the A. bifrontata Group (characters of A. ameiva Group in parentheses) share the frontal suture usually contacting the third supraocular (usually contacting second), “toothy” first supralabials (curved), presence of generation glands (absent), and a red or reddish snout (snout same color as rest of head). Moreover, some species in both groups have a pectoral sulcus. The red snout and pectoral sulcus occur in no other Teiidae . South American ancestry of the West Indian Ameiva contrasts with conclusions of recent molecular studies that found West Indian species to be related to Holcosus ( Hower & Hedges 2003, Giugliano 2009) or Aspidoscelis (Reeder et al. 2002) . We judge a South American origin and common ancestry with the A. bifrontata Group to be likely for three reasons: (1) most West Indian radiations of other groups of animals arose from ancestral species in northern South America, (2) alternative hypotheses require convergent evolution of two characters (the red snout and pectoral sulcus) unique to these lizards among Teiidae , and (3) alternative phylogenetic analyses (Giugliano 2009; Hower & Hedges 2003; Reeder et al. 2002) included fewer species of Ameiva .

Analyses of morphological (this study) and mtDNA ( Hower & Hedges 2003) both identified a Lesser Antillean clade ( Fig. 60) including Ameiva erythrocephala , A. fuscata , A. griswoldi , A. plei , and A. pluvianotata . We found A. corvina to be nested within this clade, and Hower and Hedges (2003) found A. corax to be nested within this clade. Both studies found A. auberi and A. dorsalis to be sister taxa, and distinctive tibiotarsal spurs in these two species support this conclusion. On the other hand, we found these species to be closely related to the Greater Antillean A. taeniura , whereas the molecular phylogeny placed these two species at the base of the Lesser Antillean radiation.

Both analyses found that Ameiva lineolata and A. maynardi are sister species. These two species share a suite of distinctive characteristics and are both relatively small. Perhaps because of their unusual traits, our analyses consistently placed these two species outside of Ameiva . However, they possess the diagnostic characters of our Ameiva dorsalis group; they are the closest relatives of A. taeniura in the molecular phylogeny ( Hower & Hedges 2003).

Our analysis and that of Hower and Hedges differ in placement of A. chrysolaema and A. exsul . These large Greater Antillean species were placed at the base of the Lesser Antillean clade in our ordered analysis and at the base of a Greater Antillean clade in the molecular analysis. On the other hand, in our unordered analysis, A. chrysolaema moved to the base of the Greater Antillean clade, whereas A. exsul moved deeper into the Lesser Antillean clade as the sister species of A. griswoldi . Both species lack most defining characters of the Lesser Antillean clade such as short parietals, frequent longitudinal division of the interparietal, and a wide gap between the enlarged brachials and antebrachials. Nonetheless, A. chrysolaema is the only Greater Antillean species with a pectoral sulcus, whereas this trait is always present in the Lesser Antillean species.

In summary, the Lesser Antillean Ameiva share distinctive derived traits, many found in no other Teiidae , and clearly form a monophyletic group. Uncertainty persists regarding the interrelationships of the Greater Antillean species, because they lack distinctive morphological traits. Although morphological and molecular data sets agree on many points, further study is required to resolve persisting uncertainty about the relationships of Greater Antillean Ameiva .

Much of the diversity within the Ameiva bifrontata and A. ameiva Groups has not been adequately described. Ugueto and Harvey (2011) recently reviewed the A. ameiva Group in Venezuela and showed that some subspecies of A. ameiva are full, evolutionary species. In this analysis, we found that A. praesignis is the sister taxon of A. ameiva and A. atrigularis is the sister taxon of the recently described A. pantherina .

Ruthven (1924) thought a new taxon from Peru was a subspecies of Ameiva bifrontata , because it has a transversely divided frontal and similar habitus. Nonetheless, Ugueto and Harvey (2011) showed that the interparietal is frequently divided in some populations of upper Amazonian A. ameiva . Known only from the Peruvian Andes, A. bifrontata concolor is distantly allopatric from all other populations of A. bifrontata , which are restricted to a few southern Caribbean islands and northern Venezuela and Colombia.

As part of our ongoing revisions of species in this genus, we examined the type series of Ameiva bifrontata concolor (Appendix) . These lizards differ substantially from other populations of A. bifrontata . Perhaps not surprisingly, the phylogenetic analysis assigned this taxon to the A. ameiva Group when all characters were included in both the ordered and unordered analyses, but placed A. b. concolor at the base of the A. bifrontata Group when meristic characters were excluded. Striking morphological differences between A. b. concolor and other A. bifrontata , the results of the phylogenetic analysis, and the wide geographic hiatus between A. b. concolor and other A. bifrontata convince us that A. b. concolor is a full species, and we here formally recognize it as Ameiva concolor Ruthven. A complete redescription of the species will be published elsewhere.

Remarks.— In our taxonomy, we chose the oldest species name as the group or series name in accordance with well-established precedent. Hower and Hedges (2003) named four species groups without following this convention. Their plei Group is essentially equivalent to our Ameiva erythrocephala Group, whereas the other groups recognized by them ( auberi , exsul , and lineolata Groups ) together comprise our A. dorsalis Group.

Regarding the generic synonymy, two issues require comment. Meyer (1795) proposed Ameiua to accommodate fourteen species listed by Gmelin (1789), including several species no longer included in this genus such as Lacerta Teguixin Linnaeus (= Tupinambis teguixin ). Meyer further proposed Ameiua americana as a replacement name for Lacerta ameiva Linnaeus and this name was listed as the type species of Ameiva by Peters and Donoso-Barros (1970).

Earlier synonymies of Ameiva (e.g., Peters & Donoso-Barros 1970) have included Amieva , with the “i" and “e” interposed, based on Gray (1840). If available, Gray’s name could be used as a subgenus or genus for lizards here placed in the Ameiva dorsalis Group. This name would be pronounced differently than Ameiva and, therefore, could not be considered a secondary homonym. Amieva was clearly a misspelling and not proposed as a new name. We suspect that Peters and Donoso-Barros (1970) concluded otherwise, because Gray did not place an author after Amieva , and, following the practices of the day, this omission usually meant that the author intended to formally name a new genus. We interpret “ Amieva ” to be an incorrect subsequent spelling of Ameiva , because, when discussing A. trilineata, Gray (1840, p. 115) mentions, “this species differs from all the other species of the genus that we have in the British Museum in colour…” Gray (1840) misspelled other genera, notably Anolis , which he twice misspelled “ Anolius ” on page 110 only to correctly spell the genus again on page 112. As for Amieva he does not list the author of Anolis on p. 112 even though he does so for other genera of this section such as “ Chamaeleolis, Cocteau ” on p. 111. As an incorrect subsequent spelling not in prevailing usage, Gray’s name is removed from the synonymy of Ameiva and is not available for the species of the Ameiva dorsalis Group.