Phymaturus tenebrosus, Lobo & Quinteros, 2005

Lobo, Four New Species From Rgentina Fernando & Quinteros, Sebastián, 2005, A Morphology-Based Phylogeny Of Phymaturus (Iguania: Liolaemidae) With The Description Of Four New Species From Argentina, Papéis Avulsos de Zoologia (São Paulo) 45 (13), pp. 143-177 : 153-165

Phymaturus tenebrosus sp. nov.

Holotype: MCN 1271. 20 km south of Cerro Alto , National Road Nº 40, Rio Negro, Argentina. C. Abdala, F. Lobo, I. Martínez Oliver, and S. Quinteros, collectors.

Paratypes: MCN 1264-1270, 1272-73. Same data as holotype.

Diagnosis: Phymaturus tenebrosus belongs to the patagonicus group (sensu Etheridge, 1995) because it has flat imbricate superciliaries, non-rugose dorsal scales on tail, subocular usually not fragmented, and subocular-supralabials separated by one scale row. The new species is distinguishible from all other species of the genus by its dorsal pattern: black in most specimens, some with very fine, sparse white spots (e.g., holotype). This melanissm is dark brown in some specimens. The morphologically most similar species to P. tenebrosus are P. zapalensis and the recently described P. calcogaster , from which this new species can be readily distinguished. Phymaturus zapalensis has a more dense pattern of dorsal spots and very often a pattern of reticulation/ occellation and obvious sexual dimorphism (females with variegated pattern) and P. calcogaster , which was described solely from the male holotype ( Scolaro & Cei, 2003), which has a peculiar pattern not seen in P. tenebrosus : dorsum with larger and homogeneous white spots arranged in trasverse rows, a subocular fragmented into five scales ( P. tenebrosus usually lacks subocular fragmentation), and the throat of P. calcogaster is variegated.

Description of holotype – Male. SVL 87.2 mm. Head length 16.2 mm. Head width 15.5 mm. Head height (at parietal) 9.2 mm. Axilla-groin 46.5 mm (53.3% of Snout-vent length). Tail length (complete, not regenerated) 81.1 mm (0.93 times SVL). Body moderately wide, trunk width: 33.3 mm (0.38% of SVL). Twenty-two smooth dorsal head scales. Seven, four, and seven scale organs in each postrostral. Nasal bordered by eight scales, not in contact with rostral. Canthal separated from nasal by two scales. Loreal region flat. Eight enlarged supralabial scales with seventh upturned posteriorly but not contacting subocular. Seven enlarged infralabials. Auditory meatus oval with five projecting scales on the anterior margin. Auricular scale absent. Nine convex, juxtaposed temporals. Rostral undivided. Mental subpentagonal, in contact with four scales. Interparietal bordered by seven scales. Frontal region without an azygous scale. Supraorbital semicircles incomplete posteriorly. No distinctly enlarged supraoculars. Nine imbricate flat superciliaries. Subocular unfragmented, separated from supralabials by one row of lorilabials. Nine lorilabials, the eight to ninth contacting subocular. Preocular separated from lorilabial row by two scales. Scales of throat round, flat, and juxtaposed. Eighty-one gulars between auditory meata. Lateral nuchal folds well developed, with granular scales over longitudinal fold. Antehumeral pocket well developed. Eighty-one scales between auditory meatus and shoulder. In ventral view, gular fold not well developed and posterior gular folds present with their anterior margins with enlarged scales on their borders. Dorsal scales round, smooth, juxtaposed. Thirty-nine dorsal scales along midline of the trunk in a distance equivalent to head length. Scales around midbody: 202. Mid-dorsal scales not enlarged in comparison to those on flanks. Ventral scales larger than dorsals. Ventral scales between mental and precloacal pores: 170. Nine precloacal pores. Brachial and antebrachial scales smooth with rounded posterior margins. Supracarpals laminar, round, smooth. Subdigital lamellae of fingers with 3-5 keels (more conspicuous in proximal lamellae). Number of subdigital lamellae of fingers I: 11; II: 16; III: 22; IV: 24; V: 15. Claws moderately long. Supradigital lamellae convex, imbricate. Infracarpals and infratarsals with round margins and 2-3 obtuse keels. Supracarpals and supratarsals smooth, with round posterior margins. Subdigital lamellae of toes I: 13; II: 17; III: 18; IV: 23; V: 21.

Variation: Based on 16 adult specimens (12 females and 4 males from both known localities). SVL 85.0- 107.5 mm (x = 94.8; SD = 6.4). Head length 0.15-0.19% (x = 0.17; SD = 0.01) of SVL. Tail length 1.00-1.41 (x = 1.21; SD = 0.18) times SVL. Scales around midbody 171-236 (x = 199.2; SD = 20.2). Dorsal head scales 16-25 (x = 20.2; SD = 2.18). Ventrals 149-185 (x = 171.4; SD = 14.15). Precloacal pores in males 7-9 (x = 8.5; SD = 1.0). Scales surrounding interparietal 5-8 (x = 6.9; SD = 0.9). Scales of neck along longitudinal fold from posterior border of auditory meatus to shoulder 58-88 (x = 70.9; SD = 8.3). Gulars 65-100 (x = 77.8; SD = 9.3). Scales between rostral and frontal 6-11 (x = 8.7; SD = 1.3). Dorsal and flank pattern in most specimens black, in some specimens with small and scacerly distributed white spots.Some specimens brown morph with conspicuous black spots on flanks (similar to that exhibited by specimens of P. zapalensis ). Not all specimens have strong ventral coloration (orange in brown individuals, yet mustard or dark gray in black specimens), suggesting that this coloration may be related to season or physiological conditions.

Color of holotype in alcohol ( Figure 2C and D ): Dorsal background with black spots and small white markings that are smaller and more densely distributed middorsally. This pattern extends over the head and dorsal surfaces of the limbs. The tail is patternless. General coloration of ventral surfaces (throat, limbs, and tail) gray, with slight yellow color in the posterior region of abdomen continuous over the cloaca and thighs.

Color in life: See Figure 4 . Dorsum black scattered with small white spots. Margins of ventral region gray and central areas of chest, abdomen, ventral surfaces of thighs and cloaca mustard. Females can exhibit their bellies light gray to orange.

Etymology: The epithet tenebrosus Latin word that means “dark, gloomy” in reference to the dark dorsal coloration of this new species.

Distribution ( Figure 5 ): This new species is known to be found between Bariloche and Pilcaniyeu northward to 20 km south of Cerro Alto (National Road Nº 40), Rio Negro, Argentina.

II – Other terminal taxa included in the analysis

Because its distribution (too far from type locality) and some meristic characters we analyzed as terminal taxon: Phymaturus cf. punae (Road to Laguna Brava, La Rioja province). Around 40% of specimens of cf. punae examinated have their rostral scale divided like Phymaturus punae (San Guillermo, San Juan), number of scales around midbody are fewer in Phymaturus punae (x = 179.6; SD = 10.9; 168.0-196) than in Phymaturus cf. punae (x = 205.8; SD = 13.7; 188.0-234.0).

Phymaturus cf. antofagastensis (SC) , from Cuesta de Randolfo and Sierra de Calalaste: according to Pereyra (1991) the type locality of Phymaturus antofagastensis is Los Nacimientos near Paso San Francisco. Both terminals (Paso San Francisco and Randolfo-Calalaste) have enlarged scales in the central area of chest, as described in the original description ( Pereyra, 1985). Specimens from Cuesta de Randolfo and Sierra de Calalaste exhibit an undivided rostral and a homogeneous dense “spray” dorsal pattern of coloration ( Figure 12C ), whereas most specimens from Paso San Francisco have a divided rostral scale and an “aggregate dorsal” pattern of coloration ( Figure 12D ).

Phymaturus cf. palluma (CH) : (Chillán, Chile): lizards from this population, as in P. cf. dorsimaculatus (Copahue, Neuquén province), have ringed tails but they lack the reticulate pattern typical of other Phymaturus . Females from this locality have immaculate throats, whereas all other P. cf. palluma have spotted or black throats. Specimens from this population also have lorilabials occasionally in contact with the subocular, which never occurs in other P. cf. palluma , and members of this population have fewer scales in contact with the nasal than in all other populations.

Phymaturus cf. palluma (EP) : (El Planchón and San Pedro, Chile): females can exhibit precloacal pores (not found in other P. cf. palluma ), temporal scales are protruded conical shaped not as in dorsimaculatus and P. cf. palluma (CH) , anterior gular fold present (absent in P. cf. palluma of Payunia), the lorilabials never contact the subocular (as in P. cf. palluma of Chillán), there are no enlarged scales on the margins of posterior gular fold as in P. cf. palluma (ME) . Specimens from El Planchón are quite similar of those from Maule ( MVZ 232506-07).

Phymaturus cf. palluma (ME) : differs from P. cf. palluma (PA) because adult specimens of the former have partially or completely black heads and neck foldings, sexual dimorphism in dorsal pattern, but never a divided rostral (which is common in P. cf. palluma PA ). This population differs also in similar way from P. cf. palluma (LB) because this last population lacks sexual dimorphism, and temporal scales in adult specimens are strongly projected (spinose).

Phymaturus cf. palluma (LB) (Laguna Blanca) : is smaller than P. verdugo : 86-110 mm, whereas in P. verdugo : 106-120 mm SVL. From P. dorsimaculatus sp. nov. because do not exhibit the same pattern of black transversal bars over theirs neck and shoulders and ringed pattern on tails (this last character discriminate it also from P. cf. palluma CH ). Does not exhibit sexual dimorphism in pattern like P. cf. palluma (ME) (with both states agregate and dense “spray” Figure 12 ). Is allopatrically distributed very far from the northern group of species ( P. punae , P. cf. punae LR , P. antofagastensis , and P. cf. antofagastensis SC ) and no individuals have a divided rostral.

Phymaturus cf. palluma (PA) (Payunia) : these lizards are morphologically similar to those here called “ Mendoza ” but the adult specimens lack the distinct black head and neck present in other forms of “palluma ”. This character discriminates this form from other members of the palluma group. It shares with northern species of the group the a divided rostral in many specimens.

Phymaturus cf. patagonicus (EC) (San Antonio del Cuy, Rio Negro): Phymaturus with a gray background coloration with white spots (like in P. patagonicus from Dolavon, Chubut province), spots are smaller and usually these lizards have a dark gray to black dorsolateral band. This dark band is also present in individuals of P. tenebrosus and most females of P. zapalensis ( Figure 12A ), but P. patagonicus (EC) lacks black and brown morphs and has a smaller body size.

2) Phylogenetic analysis of Phymaturus comparison of four matrices

The analysis applying the ANY INSTANCE coding method for binary polymorphic characters brought one most parsimonious tree of 522.48 steps (CI = 0.57; RI = 0.66) ( Figure 6 ). This topology recovered P. patagonicus as the most basal species of the genus, the patagonicus group is paraphyletic, P. payunae is the sister taxon of a subclade formed by P. somuncurensis , P. spectabilis , and P. spurcus , this group is related to another formed by P. indistinctus as the most basal species, P. cf. patagonicus (EC) , and P. nevadoi as sister taxon to the pair formed by P. zapalensis and P. tenebrosus . Phymaturus excelsus is related to the palluma group for which P. dorsimaculatus is the most basal species. The topology of the palluma group in this tree is unbalanced, with species subsequently related as follows: P. cf. palluma (CH) , P. cf. palluma (LB) , P. cf. palluma (ME) , P. cf. palluma (EP) , P. cf. palluma (PA) , P. punae , P. punae (LR) , P. cf. antofagastensis (SC) , P. antofagastensis , and P. mallimaccii . Jacknifing recovered four nodes with good support in the consensus tree: 52% for P. tenebrosus-P. zapalensis , 90% for P. spectabilis-P. spurcus , 94% for the palluma group, and 61% for the palluma group except P. dorsimaculatus and P. cf. palluma (CH) .

Runs made applying the FREQUENCY BINS coding method for binary polymorphic characters brought one shortest tree of 978.63 steps (CI = 0.49; RI = 0.58) ( Figure 6 ). In this analysis the patagonicus group is monophyletic with P. indistinctus as the most basal species, P. excelsus is the sister taxon to all remaining species, the subsequent node has P. spurcus as sister taxon to all the rest of the group. P. spectabilis , P. tenebrosus , and P. nevadoi are branching up the most terminal subclade formed by two groups, one formed by P. cf. patagonicus (EC) and P. patagonicus , and the other by P. somuncurensis sister taxon of the pair P. payunae- P. zapalensis . The palluma group is monophyletic with P. dorsimaculatus and P. cf. palluma (CH) as the most basal species of the group, two main subclades are formed in this hypothesis, one including P. cf. palluma (ME) sister taxon of the pair P. cf. palluma (PA) - P. cf. palluma (LB) , and the other group including all northern species plus P. cf. palluma (EP) . Phymaturus cf. punae (LR) is sister taxon of a clade formed by P. cf. antofagastensis (SC) , P. punae , and P. antofagastensis , whereas P. mallimaccii is related to P. cf. palluma (EP) . Jacknife values for this analysis include 99% for the palluma group, 53% all species of that group without P. dorsimaculatus , 53% for P. cf. palluma (PA) - P. cf. palluma (LB) , and 52% for a node formed by P. punae , P. antofagastensis , and P. cf. antofagastensis (SC) .

Phylogenetic analysis applying the SCALED coding method for binary polymorphic characters yielded one most parsimonious tree of 571.06 steps (CI = 0.56; RI = 0.65) ( Figure 7 ). In this analysis the patagonicus group is monophyletic, formed by two main groups, one including P. excelsus , P. indistinctus , and P. patagonicus , and the other with P. payunae as the basal species, with P. spectabilis-P. spurcus as sister taxon of a subclade formed by P. somuncurensis , P. cf. patagonicus (EC) , P. nevadoi , P. tenebrosus , and P. zapalensis . In the palluma group, P. cf. palluma (PA) , and P. cf. palluma (LB) are sister taxa and basal-most subclade in the group. Phymaturus dorsimaculatus and P. cf. palluma (CH) are sister taxa, related to a central and northern clade that includes P. mallimaccii related to the pair P. antofagastensis- P. cf. antofagastensis (SC) , and P. cf. palluma (EP) related to a group formed by P. cf. palluma (ME) , P. punae , and P. cf. punae (LR) . Jacknifing analysis of the consensus tree found support for six nodes, 64% for P. spurcus- P. spectabilis , 99% for the palluma group, 57% for all species of the palluma group except P. dorsimaculatus (not recovered in the shortest tree), 86% for P. cf. palluma (PA) - P. cf. palluma (LB) , 80% for the northern clade: P. mallimaccii , P. punae (LR) , P. punae , P. antofagastensis , and P. cf. antofagastensis (SC) ; P. cf. palluma (EP) and P. cf. palluma (ME) are not in this subclade in this consensus tree, 54% for P. punae , P. antofagastensis , and P. cf. antofagastensis (SC) (these two last taxa are related to P. mallimaccii in the shortest tree, Figure 7 ).

The analysis applying the MISSING coding method for binary polymorphic characters recovered two equally parsimonious trees of 489.59 steps (CI = 0.60; RI = 0.68). In Figure 7 we show one of these trees. In this analysis the patagonicus group is not monophyletic, common to these trees are the pair formed by tenebrosus and zapalensis , and the subclade including P. somuncurensis sister taxon of P. spurcus- P. spectabilis . Phymaturus dorsimaculatus and P. cf. palluma (CH) are the basal subgroup in the palluma group, P. cf. palluma (LB) is the most basal species of a big clade formed by all remaining species. Phymaturus cf. palluma (PA) and P. cf. palluma (ME) are related to a group including cf. palluma (EP) and all northern species; P. cf. punae (LR) is basal to a couple of sister taxa, one including P. punae and P. cf. antofagastensis (SC) and the other mallimaccii and antofagastensis . For this analysis Jacknifing reports eight nodes supported over 50% of frequency. The palluma group at 99%, P. cf. palluma (EP) plus all northern species: P. punae , P. punae (LR) , P. mallimaccii , P. antofagastensis , and P. cf. antofagastensis at 85%, all northern species at 83%, P. cf. palluma (LB) - P. cf. palluma (PA) at 81% (not found in both trees); the subclade formed by P. punae and P. antofagastensis (SC) at 79%, P. spurcus-P. spectabilis at 68%, all northern species without P. punae (LR) at 53% and a node not found in the two shortest trees formed by P. antofagastensis , P. punae , and P. cf. antofagastensis (SC) at 74%.

Supported group common in all analysis (4) was the palluma group (94, and three 99%), P. cf. palluma (PA) - P. cf. palluma (LB) in three analysis (53, 81, 86%) (not supported in the any instance analysis). In three runs also is recovered the node P. spurcus-P. spectabilis (not in the frequency bins analysis; 52, 64, 68%). Phymaturus punae is related to antofagastensis and P. cf. antofagastensis (SC) in three jacknife consensus trees (missing, scaled and frequency) (74, 54 and 52%).The northern subclade formed by punae , punae (LR) , P. mallimaccii , P. antofagastensis , and P. cf. antofagastensis (SC) have support in the missing and scaled analysis (80-83%). Phymaturus dorsimaculatus is the most basal species in two of the jacknife consensus trees (frequency and scaled analysis) (53-57%).

Consensus tree and common apomorphies

In this study there are competing hypothesis that are shown in the four original topologies ( Figures 6 and 7 ). From these four original analysis we built a majority rule consensus tree shown in Figure 8 , because a majority rule tree can choose among hypothesis incongruent among the original runs observations on those contradictory relationships are given below.

Phymaturus somuncurensis is sister taxon of spurcus – spectabilis (Node 5) in the any instance and missing analysis, somuncurensis is related to the pair payunae – zapalensis in the frequency bins run while in the scaled analysis is basal to a group formed by other four species. Phymaturus cf. patagonicus (EC) is sister taxon of the group formed by nevadoi and the pair formed by zapalensis and tenebrosus (Node 6) in any instance and scaled runs, cf. patagonicus (EC) is sister taxon of patagonicus in the frequency bins analysis. Phymaturus dorsimaculatus is sister taxon of cf. palluma (CH) (Node 3) in scaled and missing runs, in the frequency bins run dorsimaculatus is the basal species of the palluma group not related to cf. palluma (CH) . Northern species (Node 12) are present in any instance and missing runs. Phymaturus mallimaccii is related to antofagastensis in the any instance and missing runs (Node 13); mallimaccii is related to antofagastensis and cf. antofagastensis (SC) in the scaled analysis and to cf. palluma (EP) in the frequency bins run.

The palluma group (Node 1) is supported by the following common apomorphies (all runs) characters 5 (number of ventral scales), character 7 (number of gulars), character 11 (number of upper ciliars), character 13 (supralabial upturned), character 18 (preocular scale separation from lorilabial row) and character 26 (superciliary scales shape subcuadrangular not imbricated). The patagonicus group (Node 2) is not monophyletic in all runs and had no support as the palluma group, in those topologies where it is found monophyletic common apomorphies involves changes in characters 4 (number of dorsal scales in a head-length), 21 (males trunk length/snout vent length ratio), 28 (number of pterigoid teeth) 119 (lorilabials-subocular scale separation) and 149 (number of scleral ossicles). Evidence for the sister taxa relationship between dorsimaculatus and cf. palluma (CH) (Node 3) are changes on characters 10 (number of superciliaries) and 14 (subocular fragmentation, Figure 9 ). Character changes supporting Node 4 are related to characters 8 (number of scales in contact to interparietal), 13 (number of supralabial upturned), 16 (scales in contact to mental, Figure 9 ) and 130 (dorsal pattern of tails, Figure 10 ). Node 5 includes somuncurensis , spectabilis and spurcus , and changes are on characters 7 (number of gulars), 109 (male/female SVL ratio) and 151 (lacrimal foramina opening). Node 6 (within patagonicus group) is supported by changes on characters 6 (number of scales on the lateral wall of neck, between earing and shoulder) and 23 (males tibia length ( SVL ratio). Node 7 (within the palluma group) is supported by the following changes, characters 9 (number of infralabials), 17 (number of scale organs on posrostrals), 18 (number of scales separating preocular from lorilabial row), 19 (maximun SVL found), 109 (male/female SVL ratio) and 128 (throat of males pattern). Characters supporting the relationship between spurcus and spectabilis (Node 8) are 14 (subocular fragmentation, Figure 9 ), 19 (maximun SVL found) and 110 (males trunk length/ SVL ratio). Node 9 exhibit changes on characters 10 (number of superciliaries), 13 (number of supralabial upturned), 15 (scales in contact to nasal) and 18 (number of scales separating preocular from the lorilabial row). Phymaturus cf. palluma (EP) is related to the northern subclade in Node 10: characters 0 (number of dorsal head scales), 7 (number of gulars), 8 (number of scales in contact with interparietal), 17 (number of scale organs on posrostrals) and 18 (number of scales separating preocular from the lorilabial row). Phymaturus tenebrosus is sister taxon of zapalensis at Node 11, character 21 (males trunk length/SVL ratio). The northern Argentina subclade is supported by characters 6 (number of scales on the lateral wall of neck, between earing and shoulder) and 12 (number of scales between frontal and rostral). Phymaturus antofagastensis and mallimaccii are sister taxa at Node 13, characters 19 (maximun SVL found) and 110 (males trunk length/ SVL ratio).

Search of additional topologies

Analyzing with the range method of TNT for continuous characters we had an unique shortest tree for three analysis (any instance, frequency bins. and scaled analysis) while running with the missing coding method for binary polymorphic characters we had two topologies. Continuous characters ranges were entered with three decimals, so length measures of trees are given with three decimals, this fact make less expectable reaching more than one topology for the same run. For this reason we wanted to know how many other topologies are close to the shortest one for each analysis, and look if exist a tree or/and trees repeated among these four different analysis. We made a search looking for suboptimal trees up to one step longer having a total of 383 topologies (any instance-analysis: 57 trees, scaled-analysis: 199, frequency bins-analysis: 29 and missing-analysis: 98). In this analysis we got three topologies repeated in two of the four runs (tree 13 of any instance-analysis = tree 369 of the missing-analysis; tree 50 of any instance-analysis = tree 84 of the scaled-analysis and tree 177 of the scaled-analysis = tree 296 of the missing-analysis) and two trees were recovered in three of the four analysis: tree 18 of any instance-analysis = tree 82 of the scaled-analysis = tree 295 of the missing-analysis; and tree 54 of the any instance-analysis = tree 176 of the scaled-analysis = tree 294 of the missing-analysis. Trees 18 and 54 repeated in three of the four analysis differs between them in the arrengement of the patagonicus group. The palluma group in these trees show the same topology obtained in the missing-analysis, for the patagonicus group recover the following topologies: (((((((( tenebrosus zapalensis ) nevadoi ) (( spurcus spectabilis ) somuncurensis )) payunae ) cf. patagonicus EC ) patagonicus ) indistinctus ) excelsus ); and the other differing only in the position of payunae , here as follows: ((( tenebrosus zapalensis ) nevadoi ) ((( spectabilis spurcus ) somuncurensis ) payunae )). Terminal arrengements of the patagonicus group are the same recovered in the majority rule consensus tree and in other topologies see Figures 6 to 8.

3) Observations on the ontogenetic shift of morphological characters

A sample of 15 juvenile Phymaturus cf. palluma (PA) , presumably in their first range from 65.6-83.0 mm SVL allowed us to make observations on their dimorphic differentiation. Dissection of these specimens were disected to determine sex for all but two individuals. SVL X = 75.2 (SD = 4.8; range = 69.3-80.5) for males, and X = 75.0 (SD = 4.8; range = 67.3-83.1) for females. All specimens have the same dorsal pattern as adults, three of five males have their abdominal region variegated as do two of eight females. All male juveniles lack precloacal pores, but four of them (4/5) have a row of slightly modified scales suggesting the development of precloacal pores. All male juveniles have 2-3 enlarged scales on the base of the tail adjacent to the posterior margin of the cloacal apperture as can be seen in most adult males of the palluma group. This character is more obvious than the presence or absence of precloacal pores and be used to sex very early stages of neonate and new-born specimens without the need for dissections. Two individuals of undetermined sex were among the smallest examined: 66.1 and 65.6 mm SVL ( SDSU 1955 and 1961, respectively), both lack enlarged scales on the base of the tail and no traces of precloacal pores .

Four embryos taken from two gravid dissected females of P. dorsimaculatus exhibit the following differences in comparison to adults of their species: more, smallerscales on the dorsum and flanks, counting dorsal scales in a head length (moving with the caliper a head length on the midle of the back) in these embryos are 46-60 (36-44 in adults), fewer scale organs on the postrostrals 2-3 in two embryos but not fomed in the other two (X = 2.20; SD = 0.45) than in adults (X = 3.4; SD = 1.27); temporals are flat and forming a pavement in embryos, whereas in adults these become more prominent and, in some specimens, conical; dorsal scales of the tail are smooth, whereas in adults these are rugose (as for members of the palluma group). All other characters of squamation and those referred to dorsal, ventral, and tail pattern are the same as the adults. Almost the same differences were observed between juvenile and adult P. cf. palluma (CH) : more, smaller scales in the dorsum of body (39-42 in juvenile versus 32 in both adult females), temporals flat in juveniles vs. conical to spiny in adults, and dorsal scales of the tail are smooth in juveniles, whereas these are conspicuously rugose in adults. There was no distinction in the number of scale organs on the postrostrals as was detected between embryos and adults of P. dorsimaculatus . Later conditions of characters (exhibited by adults) described here having change from embryo-juvenileadult specimens like the number of dorsal body scales (in a head length), shape of the temporals, and dorsal tail rugosity are present only in species belonging to the palluma group. In species of the “patagonicus ” group, those earlier stages (greater number of dorsal scales, temporals flat, tail scales smooth) for all Phymaturus species are present also in adults, and because this condition is the same in adults of Ctenoblepharys and Liolaemus , we assume that terminal additions on the ontogeny of those characters happened in the common ancestor of the palluma group.

4) Biogeography of Phymaturus

Taking into account endemism areas described for this southern region of South America ( Flores & Roig-Juñent, 2001; Roig-Juñent & Flores, 2001; Roig-Juñent et al., 2002) terminals of our analysis are distributed as it follows: patagonicus , somuncurensis and cf. patagonicus (EC) in Monte Austral ( MAUS); indistinctus , spectabilis , spurcus and excelsus in Patagonia Central ( PCEN); tenebrosus in two areas Patagonia Central y Patagonia Occidental ( POCC); cf. palluma (LB) cf. palluma (PA) , nevadoi , payunae and zapalensis in Payunia ( PAY); cf. palluma (ME) , cf. palluma (EP) and cf. palluma (CH) in Cordillera Andina and Valle Central ( CAVC); dorsimaculatus in Patagonia Occidental; punae , mallimaccii , cf. punae (LR) , antofagastensis and cf. antofagastensis (SC) should be assignated to areas called Prepuna ( PREP) and Puna (PUNA) for the last two species. Curiously this subclade of northern populations of Phymaturus is distributed exclusively in the transitional Puna subdistrict delimited by Martínez Carretero (1995) that occupies western region of Catamarca, La Rioja and northwestern San Juan. Spliting this group in two areas in any further biogeographic analysis (like Fitch optimization, DIVA, etc.) can carry to make extra assumptions of historical events (vicariance, extinctions or/and dispersals). Delimitation of areas among members of the northern subclade of the palluma group between Prepuna and Puna it is not enough explicit and assigning one or other area to these taxa becomes problematic. In cladistic biogeography comparing original cladograms of taxa with general area cladograms is a way to asses how our historical hypothesis are congruent with that history of the geography they occupies as it was recovered from the phylogenies of other taxa (plants or animals). Our four hypothesis for Phymaturus are incongreunt among them in many nodes of the tree, but some part of the relationships recovered are congruent to the general area cladogram published by Flores & Roig-Juñent (2001), Roig-Juñent & Flores (2001) and Roig-Juñent et al., (2002), the relationship between Monte Austral and Patagonia Central is suggested in three of the four trees: (( somuncurensis ( spectabilis spurcus )) in two runs, the any instance and missing analysis, and the relationship between patagonicus and indistinctus in the scaled analysis. The relationship between Payunia and Patagonia Occidental is suggested here by tenebrosus and zapalensis in three runs, any instance, scaled and missing analysis. The relationship between Cordillera Andina Valle Central as basal of these two pairs of areas is not seen here in Phymaturus cladograms, in the four analysis species distributed in that area are close related to the norther subclade (Transitional Puna). Area relationships suggested by the frequency bins analysis is not congruent with the other three analysis of Phymaturus and with general area cladograms known. In this hypothesis ( Figure 6 ) a repeated vicariant hypothesis is suggested within both groups of species: there exist a pair of sister taxa linking the Payunia plateau (Mendoza) with Laguna Blanca (Neuquén), cf. palluma (PA) with cf. palluma (LB) in the palluma group and other couple of species in the patagonicus group, payunae and zapalensis .

In Figure 8 a majority rule consensus tree of the four original analysis show species of Prepuna and Puna areas of the palluma group forming a monophyletic group with cf. palluma (EP) inhabiting Valle Central and Cordillera Andina as the sister taxon. Phymaturus dorsimaculatus found in Patagonia Occidental is sister taxon of cf. palluma (CH) a Chilean species distributed not far from this locality. Phymaturus cf. palluma (LB) distributed at southern latitude as dorsimaculatus and cf. palluma (CH) is the subsequent basal species. Western central Argentina species as cf. palluma (ME) and cf. palluma (PA) are more related to the cf. palluma (EP) and the northern clade than any other. In the patagonicus group there exist a repeated pattern where Monte Austral was related to the patagonian areas, at Node 5 somuncurensis basal species of this clade, and cf. patagonicus (EC) basal to the other clade.

Figures

FIGURE 2. (A) Dorsal view of the holotype of Phymaturus spectabilis sp. nov. (B) Ventral view of the same specimen. Snout-vent length = 95.8 mm. (C) Dorsal view of the holotype of Phymaturus tenebrosus sp. nov. (D) Ventral view of the same specimen. Snout-vent length = 87.2 mm.

FIGURE 4. Live specimens of Phymaturus from western Rio Negro province. Phymaturus spectabilis sp. nov. (MCN 1203 female holotype, SVL = 95.8 mm); Phymaturus tenebrosus sp. nov. (MCN 1271 male holotype, SVL = 87.2).

FIGURE 5. Map of the western region of Rio Negro province of Argentina showing known localities for the new species belonging to the patagonicus group described here plus Phymaturus spurcus. 1 Phymaturus tenebrosus sp. nov. (between Bariloche and Pilcaniyeu, 20 km south of Cerro Alto); 2 Phymaturus spurcus (Estancia Huanuluan, Alto El Escorial south of Las Bayas and Ojo de Agua); 3 Phymaturus spectabilis sp. nov. (28 km south of Ing. Jacobacci on Provincial Road 6); 4 Phymaturus excelsus sp. nov. (Ojo de Agua, in syntopy with Phymaturus spurcus).

FIGURE 6. Two hypotheses of phylogenetic relationships among species of Phymaturus using two different methods for coding binary polymorphisms (any-instance and frequency-bins analysis). Values at some nodes refer to Jacknife support>50% from 1000 replications.

FIGURE 7. Two additional methods for coding binary polymorphic characters (scaled and missing analyses). An additional topology was recovered differing only in the relationships within the patagonicus group (see text for details).Values at some nodes refer to Jacknife support>50% from 1000 replications.

FIGURE 8. Majority-rule consensus tree of the four original runs. Numbered nodes are common to all topologies and their corresponding apomorphies are indicated in the text.

FIGURE 9. Character 60: (A) Subocular complete, not divided (Phymaturus zapalensis, MCN 1600); (B) Subocular fragmented, in this case into four scales (Phymaturus spurcus, MCN 1241); Character 62: (C) Mental in contact with four scales (Phymaturus tenebrosus, MCN 1271); (D) Mental in contact with six scales (Phymaturus cf. palluma ME, IBA 760-3). Images are at different scales.

FIGURE 10. Characters 84 and 85: (A) Unique row of precloacal pores, supernumerary precloacal pores absent (Phymaturus cf. palluma ME, IBA 760-1), the arrow indicates enlarged scales in tail base typically present in males; (B) Divided row of precloacal pores, supernumerary pores present (one supernumerary indicated by an arrow) (Phymaturus cf. palluma EP, MNHN 2461); Character 90: dorsal tail patterns: (C) ringed (Phymaturus dorsimaculatus, MCN 1568); (D) variegated (Phymaturus excelsus, MCN 1582) and (E) absence of tail pattern (Phymaturus cf. palluma ME, IBA 760-1). Images are at different scales.

FIGURE 12. Character 91: (A) Lateral black band on the sides of trunk (Phymaturus zapalensis, MCN 1600). Character 132: (B) Transverse fine stripes on the back (Phymaturus indistinctus,MCN 1274). Character 128: (C) Dense homogeneous “spray” pattern (Phymaturus antofagastensis SC, MCN 313); (D) Aggregate pattern (Phymaturus antofagastensis, MCN 1432). Images are at different scales.