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This study reports on the seasonal, sex, and age differences in the diet composition of a population of the lacertid lizard Podarcis milensis inhabiting an arid sand dune on Milos Island (Aegean Archipelago, Greece). Stomach contents of 191 animals were analyzed and compared with prey availability data. The most important prey types were Hemiptera, Coleoptera (other than Tenebrionidae), spiders, and ants. Other prey items included plant material and insect larvae, both constantly consumed throughout the year. Differences in the taxonomic composition of the diet were found between males and females and between juveniles and all other classes. The greatest similarity of diet composition between the sexes and ages examined was during summer. The foraging patterns observed are discussed within the context of the specific study system: an insular, low productivity, sand dune ecosystem.

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The reproductive strategy of Podarcis milensis exhibits some peculiarities when compared with other congeners. Males and females attain sexual maturity at a min- imum body size of 47 and 42 mm SVL, respectively, both at an age of about one year. Podarcis milensis has a ver y small clutch size, with a mean of 1.73 and a range of 1–3 eggs, and produces multiple clutches annually. Both sexes exhibit a pro- longed reproductive period extending from Januar y to August.

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Field body temperatures (Tbs), activity cycles, and preferred body temperatures maintained in a laboratory thermogradient (Tsel) were studied for Podarcis milensis, a small, endemic, lacertid lizard occurring in Milos Archipelago, Greece. P. milensis is active all year round; overall maximum activity level is recorded in spring, and minimum activity in winter. Daily activity patterns range from unimodal (winter) to strongly bimodal (summer). Body temperature of adults of the examined population (n = 188) averages 31.3 °C (range 21.5-38.4 °C, SD 3.27 °C); mean monthly Tbs are grouped together into `seasons`. The species actively thermoregulates, and effectiveness of thermoregulation for the month of August is high, 0.95. The thermoregulatory behavior, microhabitat utilization, and activity cycle of this population are all discussed in the specific context of our study system: the harsh thermal environment of an insular sand dune.

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Die vorliegende Studie behandelt die Nahrungszusammensetzung dreier nichtsympatrischer Eidechsenarten von den Ägäischen Inseln, Griechenland. Der Mageninhalt von 157 Exemplaren von Podarcis milensis (62), Podarcis gaigeae (50) und Podarcis erhardii (45) wurde auf Beuterückstände untersucht. Alle Tiere kamen aus Museumssammlungen und waren im Sommer gefunden worden. In dieser Jahreszeit nehmen Podarcis milensis und Podarcis gaigeae ähnliche Nahrung auf, hauptsächlich Ameisen, Coleoptera und Insektenlarven, während Podarcis erhardii Coleoptera und Orthoptera erbeutet. Die Ergebnisse werden im Zusammenhang mit der verfügbaren Beute diskutiert.

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The spatial organization of a population of the endemic lacertid Podarcis milensis was studied from May to October in a sandy, back-dune ecosystem on Milos island (Aegean Archipelago, Greece). Male/female home range ratio was l.67.Each male overlapped with up to 6 females, while each female with up to 5 female neighbours closely spaced. Female home ranges were overiapped extensively by male home ranges, up to 100% of their range. Both males and females maintained high fidelity to the same home ranges from season to season. Our data indicate male territorial behavior in this population. Behavioural observations in the field support the above. Males defended territories from intruders even during October. Results are discussed within the context of the specific study system

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Algyroides fitzingeri, Algyroides marchi, Algyroides moreoticus, Algyroides nigropunctatus, Lacerta agilis, Lacerta lepida, Lacerta princeps, Lacerta schreiberi, Lacerta strigata, Lacerta trilineata, Lacerta viridis, Lacerta andreanszkyi, Lacerta armeniaca, Lacerta bedriagae, Lacerta brandtii, Lacerta cappadocica, Lacerta caucasica, Lacerta chlorogaster, Lacerta cyanura, Lacerta danfordi, Lacerta derjugini, Lacerta dugesii, Lacerta fraasii, Lacerta graeca, Lacerta horvathi, Lacerta jayakari, Lacerta laevis, Lacerta monticola, Lacerta mosorensis, Lacerta oxycephala, Lacerta parva, Lacerta perspicillata, Lacerta praticola, Lacerta rudis, Lacerta saxicola, Lacerta vivipara, Gallotia atlantica, Gallotia galloti, Gallotia simonyi, Podarcis erhardii, Podarcis filfolensis, Podarcis hispanica, Podarcis lilfordi, Podarcis melisellensis, Podarcis milensis, Podarcis muralis, Podarcis peloponnesiaca, Podarcis pityusensis, Podarcis sicula, Podarcis taurica, Podarcis tiliguerta, Podarcis wagleriana, Psammodromus algirus, Psammodromus blanci, Psammodromus hispanicus, Psammodromus microdactylus.

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Twenty-four species of lacertid lizards were examined at 31 sites in western Yogoslavia, Greece and Iberia. Comparative observations were made on over 4500 individual lizards, noting such features as times of activitiy, hunting methods, diet, micro- and macrohabitat, refuges used and body temperature. These data are used as a basis for assessing resource partition in related sympatric species, for find out whether different systematic groups have characteristic types of niche, and for comparing cumminity structures in the peninsulas of southern Europa. Acanthodactylus erythrurus, Algyroides marchi, Algyroides moreoticus, Algyroides nigropunctatus, Lacerta agilis, Lacerta graeca, Lacerta horvathi, Lacerta lepida, Lacerta monticola, Lacerta oxycephala, Lacerta mosorensis, Lacerta schreiberi, Lacerta trilineata, Lacerta viridis, Lacerta vivipara, Podarcis bocagei, Podarcis erhardii, Podarcis hispanica, Podarcis melisellensis, Podarcis milensis, Podarcis muralis, Podarcis peloponnesiaca, Podarcis sicula, Podarcis taurica, Psammodromus algirus, Psammodromus hispanicus.

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Es gibt sicherlich verschiedene Möglichkeiten, im Terrarium gehaltene Eidechsen zu überwintern. Der eine schwört auf seinen Keller, der andere auf eine laubgefüllte Grube in seinem Garten. Nun, wem beides nicht zur Verfügung steht, dem kann auch ein Kühlschrank ganz ausgezeichnete Dienste leisten. Freilich ist nicht gemeint, die Eidechsen frei zwischen Wurst und Käse zu betten, vielmehr bedarf es einiger Vorbereitungen. Im wesentlichen stellen sich zur Überwinterung von Eidechsen 4 Fragen: 1. wen? 2. wann? 3. wie? Und 4. wie lange? Auf diese 4 Fragen soll im in diesem Bericht eine Antwort gegeben werden.

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Es gibt sicherlich verschiedene Möglichkeiten, im Terrarium gehaltene Eidechsen zu überwintern. Der eine schwört auf seinen Keller, der andere auf eine laubgefüllte Grube in seinem Garten. Nun, wem beides nicht zur Verfügung steht, dem kann auch ein Kühlschrank ganz ausgezeichnete Dienste leisten. Freilich ist nicht gemeint, die Eidechsen frei zwischen Wurst und Käse zu betten, vielmehr bedarf es einiger Vorbereitungen. Im wesentlichen stellen sich zur Überwinterung von Eidechsen 4 Fragen: 1. wen? 2. wann? 3. wie? Und 4. wie lange? Auf diese 4 Fragen soll im in diesem Bericht eine Antwort gegeben werden.

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The longevity of several lacertid lizard species in captivity is reported. The conditions of keeping, which have been successful throughout many years, are briefly presented.

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In the herpetological collection of ZFMK 528 scientific species group names are represented by type materi- al. Of these, 304 names are documented by primary type specimens (onomatophores) while for 224 further names sec- ondary type specimens (typoids) are available, ranging chronologically from 1801 to 2010. The list is a shortened pred- ecessor of a comprehensive type catalogue in progress. It lists name bearing types with their catalogue numbers includ- ing information on further type series members also in other institutions, while secondary types are listed only by pres- ence, both in ZFMK and other collections including holotype repositories. Geographic origin and currently valid names are also provided.

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An as yet undiagnosed illness of lacertid lizards of the genera Algyroides, Gallotia, Lacerta, and Algyroides is described. The main symptoms are runny eyes, apathy, food und water refusal. The illness is almost always fatal. Antibiotics like tetracyclines and sulphathiazole had no effect. It is not known whether the disease is contagious. Some species like green lizards seem to be more susceptible. Stress is thought to possibly play an important role in this disease.

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The interspecific relationships among female size, clutch size, egg size, and hatchling size were examined for 64 European lacertids. The eggs of all species increased linearly in both linear dimensions and mass during incubation. Across species initial egg mass was positively correlated with juvenile mass, with an allometric relationship exponent of 0.87. Initial egg mass across species increased proportionally with female mass to the power of 0.57. Moreover, an increase in maternal mass was also accompanied by an increase in clutch size. The number of eggs per clutch across species scaled with female mass to the power of 0.39. Removing the effect of female mass resulted in a negative correlation between egg mass and clutch size. Species for which the average egg size was lower than expected on the basis of female mass, tended to have larger relative clutch size. The total egg mass per clutch was about one third of female mass (exponent 0.94).

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In der vorliegenden Arbeit werden vor allem die durch menschliche Aktivitäten zunehmend beeinträchtigten Feuchtlebensräume der griechischen Kykladeninseln Milos und Sifiios untersucht. Die Kleinstpopulationen der hygrophilen Amphibien und Reptilien sind stark gefährdet So ist Mauremys rivulata auf Sifiios wahrscheinlich bereits ausgestorben und sind die einzigen zwei auf Milos beobachteten Vorkommen stark gefährdet Auch der Seefrosch (Rana sp.) muß heute auf Sifiios und Milos als stark gefährdet betrachtet werden.

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We discuss three aspects of the thermal biology of lacertid lizards. First, we provide an overview of the available data on field body temperatures (Tb), the thermal sensitivity of various performance functions and selected body temperatures in different species of lacertid lizards. We also briefly summarise information on the mechanisms of thermoregulation. Second, we discuss recent developments to estimate the »precision« of thermoregulation, and the contribution of distinct behavioural mechanisms. Finally, we revise available evidence for the existence of evolutionary adjustments of thermal characteristics in lacertid lizards. Existing studies have mainly dealt with within- and among-species differences in thermoregulatory behaviour (selected temperatures) and thermal physiology of adults (optimal temperatures, heating rates). Available data provide only limited evidence for clear-cut evolutionary shifts in thermal physiology characteristics along climatic gradients.

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The Greek lizard fauna consists of 26 species from which 5 are monotypic and the other ones are represented by a total of 86 subspecies. Five species and 61 subspecies are endemic of Greece. A checklist including the geographical distribution of each taxon in the Greek region is presented.

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The present study examines the genetic variability and the taxonomic relationships among five lacertid species, i.e. Podarcis taurica, P. milensis, P. peloponnesiaca, Lacerta graeca and Algyroides moreoti- cus, representing the three main genera of this family in Europe. The last four of the above species are endemic to Greece and three of them live sympatrically in Peloponnisos. These relationships were studied by allozyme analysis. Of the loci analyzed, the Mpi-1 locus was found to be a convenient molecular marker for discrimi- nation of the genera Podarcis(allele a), Lacerta(allele b) and Algyroides(allele c). The values of Nei’s genetic distances between the examined species ranged from 0.025 to 0.484. According to the UPGMA-dendrogram plotted using the Nei’s genetic distances, two species groups are formed indicating that the genera Lacertaand Algyroidesshow a stronger relationship to one another than either does to Podarcis. These results are in agree- ment with DNAsequence data but are not in accordance with previous electrophoretic and immunological studies, which suggest that Lacertais more closely related to Podarcis than to Algyroides. The studied Podarcistaxa were found to be close relatives (Nei’s distances <0.18), especially P. taurica and P. milensis. These values are lower than those usually given in the literature for the distinction of lacertid species.

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The aim of the present study is to synthesise the available data on the occurrence of lacertid lizards on Mediterranean islands better to understand how far human influence is involved in the present distributional patterns of insular lacertid lizard fauna. At present, the Mediterranean islands are inhabited by several lacertid genera, including endemic species of the genera Algyroides (viz. fitzingeri), Lacerta [Archaeolacerta] (viz. bedriagae) and Podarcis (atratus, filfolensis, gaigae, lilfordi, milensis, pityusensis, raffonei, tiliguerta, waglerianus). Recently reported data shed new light on the relationships between these endemics and some continental species that have recently colonised the islands. The arrival of the latter might be directly related to the progressive human colonisation of these islands. The arising conservation problems are also considered.

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Mediterranean islands have complex reptile assemblages, but little is known about the factors that determine their organization. In this study, the structure of as-semblages of Squamata was evaluated based on their species richness and two measures of phylogenetic diversity (variability and clustering). I evaluated the com-position of the assemblages comparing distinct biogeographic subregions within the Mediterranean: Adriatic, Aegean, Balearic, Corsica–Sardinia, Crete, Gulf of Gabés, Ionian Sea, Ligurian Sea, Malta, Sicily, and Tyrrhenian Sea. The effect of island en-vironments and geographical isolation on the diversity metrics was assessed using generalized linear models. The analyses indicated that species richness was mostly influenced by island area and geographical isolation. Assemblages on smaller islands were poorer in species and phylogenetically dispersed, possibly as an effect of inter-specific competition. The species composition of the assemblages was determined by similar environmental drivers within the biogeographic subregions, including is-land area, island elevation, geographical isolation, and aridity. In several subregions, significant patterns of phylogenetic attraction were found in species co-occurrences, caused by the limits imposed by the island size on large predatory species

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Background Lizards of the genus Podarcis are widespread in the Mediterranean region, including islands and island archipelagos. These small-bodied lizards have a predominantly protective green-brown colouration. However, some populations display unusual patterns, in which the colouration is predominantly blue or uniformly black. This study explores the factors that influence this chromatic variation, whether environmental (climate and island conditions) or evolutionary (phylogenetic trait conservatism). The colouration of 1400 individuals (27 species) was analysed in the CIELAB colour space. Results Pagel’s λ indicated that colouration is weakly conserved within phylogenetic lineages. Although the island surface plays a key role in the chromatic variability of these lacertids, geographic isolation and climate hold less influence. The colouration of some small island populations tends to be uniform and dark, possibly due to intense intraspecific competition and lower predatory pressure. Conclusions This study highlights the importance of island populations in understanding the processes that favour the emergence of extreme phenotypes in small ectothermic vertebrates.

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Climatic conditions changing over time and space shape the evolution of organisms at multiple levels, including temperate lizards in the family Lacertidae. Here we reconstruct a dated phylogenetic tree of 262 lacertid species based on a supermatrix relying on novel phylogenomic datasets and fossil calibrations. Diversification of lacertids was accompanied by an increasing disparity among occupied bioclimatic niches, especially in the last 10 Ma, during a period of progressive global cooling. Temperate species also underwent a genome- wide slowdown in molecular substitution rates compared to tropical and desert-adapted lacertids. Evaporative water loss and preferred temperature are correlated with bioclimatic parameters, indicating physiological adaptations to climate. Tropical, but also some popu- lations of cool-adapted species experience maximum temperatures close to their preferred temperatures. We hypothesize these species-specific physiological preferences may con- stitute a handicap to prevail under rapid global warming, and contribute to explaining local lizard extinctions in cool and humid climates.

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In recent years there has been an exponential increase in the amount of published DNA sequences, as it has become one of the most popular sources of data for reconstructing phylogenies. A number of studies have attempted to resolve the relationships of groups of lacertids using mitochondrial DNA sequence data, in particular Podarcis and Gallotia (e.g. THORPE et al., 1994; 1996; GONZALEZ et al., 1996; FU et al., 1997; HARRIS, 1997; HARRIS et al., 1998a; 1999; CASTILLA et al., 1999a,b). Reassessment of these data suggest some alternative phylogenies to those previously published, and also highlight possible problems. Two studies have attempted to unravel the phylogeny of the whole family using mitochondrial DNA sequences (FU, 1998; HARRIS et al., 1998b). By combining these essentially congruent data sets, and reanalysing levels of support for the phylogenies produced, a more complete estimate of relationships across the family is produced. This is then compared to alternative sources of evidence, primarily morphological (ARNOLD, 1989), biochemical (MAYER & BENYR, 1994) and karyological (OLMO et al., 1993). Reasons for discrepencies are discussed, as are the relative advantages and disadvantages of the different sources of phylogenetic inference.

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Aim: Animal body sizes are often remarkably variable across islands, but despite much research we still have a poor understanding of both the patterns and the drivers of body size evolution. Theory predicts that interspecific competition and predation pressures are relaxed on small, remote islands, and that these conditions promote body size evolution. We studied body size variation across multiple insular populations of 16 reptile species co-occurring in the same archipelago and tested which island characteristics primarily drive body size evolution, the nature of the common patterns, and whether co-occurring species respond in a similar manner to insular conditions. Location: Aegean Sea islands. Time period: 1984–2016. Major taxa studied: Reptiles. Methods: We combined fieldwork, museum measurements and a comprehensive literature survey to collect data on nearly 10,000 individuals, representing eight lizard and eight snake species across 273 islands. We also quantified a large array of predictors to assess directly the effects of island area, isolation (both spatial and temporal), predation and interspecific competition on body size evolution. We used linear models and meta-analyses to determine which predictors are informative for all reptiles, for lizards and snakes separately, and for each species. Results: Body size varies with different predictors across the species we studied, and patterns differ within families and between lizards and snakes. Each predictor influenced body size in at least one species, but no general trend was recovered. As a group, lizards are hardly affected by any of the predictors we tested, whereas snake size generally increases with area and with competitor and predator richness, and decreases with isolation. Main conclusions: No factor emerges as a predominant driver of Aegean reptile sizes. This contradicts theories of general body size evolutionary trajectories on islands. We conclude that overarching generalizations oversimplify patterns and processes of reptile body size evolution on islands. Instead, species’ autecology and island particularities interact to drive the course of size evolution.

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The assessment of biodiversity by means that ignore the evolutionary relationships of the living forms can be quite misleading, resulting in the over-evaluation of some morphs and the ignorance of other evolutionary significant units. Molecular phylogeny, which is a potentially powerful tool for the conservation of biodiversity, provides essential evidence for setting conservation priorities on several taxa. Phylogenetic analyses can identify cryptic, genetically distinct lineages as well as non-distinctive lineages earlier perceived as separate taxa. The herpetofauna of the east Mediterranean region, which could be considered as one of nature’s most intensively active evolutionary laboratories, serves as an excellent example. Phylogenetic analyses on several lacertid taxa of this area have revealed cases of hidden diversity, paraphyly, new species and new endemics. In several cases the presence of cryptic species (Podarcis levendis, P. cretensis), species with very restricted distributions (P. gaigeae, P. milensis), paraphyletic (M. guttulta) or even polyphyletic species (O. elegans) were revealed. Such cases impose a considerable revision of the taxonomic views and conservation priorities. Based on these findings, many questions have been answered and certainly new ones have emerged, contributing not only to our knowledge on the east Mediterranean herpetofauna, but to broader issues of conservation biology, prioritizing conservation efforts and enhancing the need for a new multidisciplinary and innovative tool for screening and re-evaluating biodiversity.

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Species–area relationships and nestedness patterns were studied in three groups of small terrestrial vertebrates (mammals, reptiles, amphibians) on 14 landbridge islands of the eastern Adriatic. islands ranged in surface area between 15 and 410 km2 and contained from eight to 36 species from a total species pool of 48. reptiles were the most species rich group (S = 28), and had more species than mammals (S = 13) and amphibians (S = 7) combined. island surface area predicted species richness best in reptiles (r2 = 0.79) and most poorly in amphibians (r2 = 0.52). Mammals showed a significantly lower slope of the species–area curve than amphibians and reptiles, and thus accumulated species counts with increase in area at the lowest rate. Nestedness patterns in all groups were significantly more organised than expected by chance. Amphibian nested structure points to extinction dominated and well insularised populations with no subsequent recolonisations. frequent unexpected presences and absences in the nestedness patterns of mammals and reptiles suggest complex biogeographic histories for these two groups, with several factors putatively in operation: heterogeneity in habitats and the original source fauna, post- isolation immigrations and differential extinction rate due to human-caused habitat degradation.

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The energy metabolism of three lizard species (Podarcis milensis, Podarcis muralis and Lacerta agilis) was investigated by means of microcalorimetry and polarography over the range of environmental temperatures between 17 and 35 °C encountered by active lizards during summer in Europe. In non-stimulated animals, the maximum and mean heat production rates were highest around 30°C for all species and amounted to 3.9±1.1 mWg-1 and 2.1±0.5 mWg-1, respectively. Resting metabolism contributed approximately 60% to the mean routine heat dissipation; the remainder originated from locomotory activity, 43% of which was based on anaerobic energy metabolism. From simultaneous determinations of heat dissipation and oxygen consumption, an average oxycaloric equivalent of 18.6±3.2 J ml-1 O2 was calculated, which rose to 26.6±7.1 J ml-1 O2 during short bursts of locomotion.

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Though biological invasions constitute one of the biggest threats for global biodiversity, our understanding of the mechanisms that enable invasive species to outperform native species is still limited, especially, in terms of behavior. Most available studies have examined behavioral traits which favor invasive species on the later stages of invasion, however, our knowledge on earlier stages, namely, when alien species face novel environments and must exploit new resources, remains obscure. Here, we focus on one crucial behavioral trait, finding food. The Italian wall lizard (Podarcis siculus) has been widely introduced and established viable populations in S. Europe and N. America. We examined whether P. siculus has enhanced exploratory behavior and abilities to find food compared to two native congeneric species with which it may come in contact in the near future, an insular endemic (P. milensis) and a widely distributed lizard (P. erhardii). We performed a Y-maze experiment, in which we varied arm markings in a standard way to prevent learning. Podarcis siculus was more efficient than its congenerics in finding and consuming food. This exploitative superiority was persistent, more frequent and repetitive. Interesting behavioral differences were also detected within the native species. Some P. milensis individuals showed no interest in exploring the maze, while few P. erhardii individuals remained rather indifferent to food even after detecting it. Our results suggest that the invasive P. siculus displays behavioral traits that could provide better opportunities for survival in the new environment and thus facilitate establishment even in the presence of congenerics. This provides further support to the idea that behavior plays a crucial role in animal invasions.

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Small-lizards from the Greek islands Milos and Skiros are compared with populations from the continent of Podarcis taurica ionica, Podarcis muralis albanica and Podarcis erhardii by employing protein-electrophoretic data for 18 genloci. The gen frequencies of the polymorph loci are given and the genetic distances are calulated according to Nei. Extension of genetic distances is discussed. Podarcis milensis can be confirmed as a species. Populations of Milos and Skiros have shown to be closest related, both have to be considered as closely related to Podarcis taurica and not to Podarcis muralis.

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The collection of Amphibians and Reptiles of the Museum of Natural History of Ferrara has characteristics of historical representation, taxonomic and zoogeography that may be considered as examples of medium-sized types of collections more preva- lent in Italian museums. It consists of a historic part of the study and a donation from Guido Campadelli. The collection consists of 1739 specimens of amphibians (1734 of which held in 437 containers with ethanol and 5 taxidermized specimens) for a total of 78 amphibian species. There are 811 specimens of Reptiles (769 of which are stored in 526 containers with ethanol and 42 taxidermized specimens) representing a total of 108 species. The findings that form the collection of Amphibians come from 153 loca- lities of 15 states and 12 regions and 29 provinces of Italy. In the batrachological col- lection 62.1% of the total European species, and 94.3% of the total species in Italy, are represented. Zoogeographic regions most represented are the Palaearctic with 67% of the species of Amphibians in the collection and the Neotropical with 29%, fol- lowed by the Ethiopian (6%) and Nearctic (5%). Reptiles specimens come from 247 lo- calities of 15 states and 15 regions and 36 provinces of Italy. In the collection 46,2% of European species and 91,5% of the Italian ones are represented. The most represen- ted zoogeographic region are the Palaearctic with 89% of species in the collection, followed by the Ethiopian (14%), the Eastern (13%), Neotropical (11%) and the Nearctic (7%); australian and malagasy species do not exceed 3%. The herpetology collection was the subject of taxonomic and biogeographic analysis.

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Aim Body size is instrumental in influencing animal physiology, morphology, ecology and evolution, as well as extinction risk. I examine several hypotheses regarding the influence of body size on lizard evolution and extinction risk, assessing whether body size influences, or is influenced by, species richness, herbivory, island dwelling and extinction risk. Location World-wide. Methods I used literature data and measurements of museum and live specimens to estimate lizard body size distributions. Results I obtained body size data for 99% of the world`s lizard species. The body size–frequency distribution is highly modal and right skewed and similar distributions characterize most lizard families and lizard assemblages across biogeographical realms. There is a strong negative correlation between mean body size within families and species richness. Herbivorous lizards are larger than omnivorous and carnivorous ones, and aquatic lizards are larger than non-aquatic species. Diurnal activity is associated with small body size. Insular lizards tend towards both extremes of the size spectrum. Extinction risk increases with body size of species for which risk has been assessed. Main conclusions Small size seems to promote fast diversification of disparate body plans. The absence of mammalian predators allows insular lizards to attain larger body sizes by means of release from predation and allows them to evolve into the top predator niche. Island living also promotes a high frequency of herbivory, which is also associated with large size. Aquatic and nocturnal lizards probably evolve large size because of thermal constraints. The association between large size and high extinction risk, however, probably reflects a bias in the species in which risk has been studied.

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Aim Temperature influences most components of animal ecology and life history – but what kind of temperature? Physiologists usually examine the influence of body temperatures, while biogeographers and macroecologists tend to focus on environmental temperatures. We aim to examine the relationship between these two measures, to determine the factors that affect lizard body temperatures and to test the effect of both temperature measures on lizard life history. Location World-wide. Methods We used a large (861 species) global dataset of lizard body temperatures, and the mean annual temperatures across their geographic ranges to examine the relationships between body and mean annual temperatures.We then examined factors influencing body temperatures, and tested for the influence of both on ecological and life-history traits while accounting for the influence of shared ancestry. Results Body temperatures and mean annual temperatures are uncorrelated. However, accounting for activity time (nocturnal species have low body temperatures), use of space (fossorial and semi-aquatic species are ‘colder’), insularity (mainland species are ‘hotter’) and phylogeny, the two temperatures are positively correlated. High body temperatures are only associated with larger hatchlings and increased rates of biomass production. Annual temperatures are positively correlated with clutch frequency and annual longevity, and negatively correlated with clutch size, age at first reproduction and longevity. Main conclusions Lizards with low body temperatures do not seem to have ‘slower’ life-history attributes than species with high body temperatures. The longer seasons prevalent in warm regions, and physiological processes that operate while lizards are inactive (but warm enough), make environmental temperatures better predictors of lizard life-history variation than body temperatures. This surprisingly greater effect of environmental temperatures on lizard life histories hints that global warming may have a profound influence on lizard ecology and evolution.

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Aim We discuss biogeographical hypotheses for the Mediterranean lizard species Podarcis and Teira within a phylogenetic framework based on partial mitochondrial DNA sequences. Methods We derived the most likely phylogenetic hypothesis from our data set (597 aligned positions from the 12S rDNA and phenyl tRNA) under parsimony, distance and maximum likelihood assumptions. Results The species usually included in Teira do not form a strongly monophyletic clade. In contrast, the monophyly of the genus Podarcis is rather well supported. Seven lineages are identified in the genus; in order of appearance within the tree, these are: the Balearic pityusensis and lilfordi pair, the sicula complex, a Tyrrhenian tiliguerta and raffonei pair, muralis, the Siculo-Maltese filfolensis and wagleriana pair, the Balkan group (erhardi, peloponnesiaca, milensis, melisellensis and taurica), and the Ibero-Maghrebian group (bocagei, atrata, hispanica and vaucheri). Conclusions The origin of the three European genera of lacertid assayed (Lacerta, Teira and Podarcis) is hypothesized to have occurred in the Oligocene. For Podarcis, a possible scenario of a Miocene diversification is derived from the sequence data, and the zoogeography of the lineages are discussed in relation to the palaeogeography of the Mediterranean. It is hypothesized that in the early history of the genus the main lineages separated by rapid, numerous and close events that produced a starting point very similar to a polytomy, hard to resolve by parsimony analysis of the data set.

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The ability of an animal to shed its tail is a widespread antipredator strategy among lizards. The degree of expression of this defense is expected to be shaped by prevailing environmental conditions including local predation pressure. We test these hypotheses by comparing several aspects of caudal autotomy in 15 Mediterranean lizard taxa existing across a swath of mainland and island localities that differ in the number and identity of predator species present. Autotomic ease varied substantially among the study populations, in a pattern that is best explained by the presence of vipers. Neither insularity nor the presence of other types of predators explain the observed autotomy rates. Final concentration of accumulated tail muscle lactate and duration of movement of a shed tail, two traits that were previously thought to relate to predation pressure, are in general not shaped by either predator diversity or insularity. Under conditions of relaxed predation selection, an uncoupling of different aspects of caudal autotomy exists, with some elements (ease of autotomy) declining faster than others (duration of movement, lactate concentration). We compared rates of shed tails in the field against rates of laboratory autotomies conducted under standardized conditions and found very high correlation values (r > 0.96). This suggests that field autotomy rates, rather than being a metric of predatory attacks, merely reflect the innate predisposition of a taxon to shed its tail.

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Caudal autotomy is one of the most effective and widespread defensive mechanisms among lizards. When predators grasp the tail, lizards are able to shed it from the point of the attack and further. Numerous factors have been reported to affect tail-shedding performance such as temperature, age, predation pressure, intraspecific competition etc. Interestingly, the impact of sex on tail loss remains greatly understudied. Here, we analyzed tail autotomy performance, simulated in the lab, in 12 species of lacertid lizards belonging to five genera (Algyroides, Anatololacerta, Hellenolacerta, Ophisops, Podarcis). Our aim was to investigate whether sex affects caudal autotomy and/or the duration of post-autotomic tail movement. We failed to detect any effect of sex on tail loss in the species examined. Also, we did not find any sexual impact on the duration of tail movement after autotomy, with a single exception. Our findings suggest that autotomy serves as a defensive tactic equally in both sexes and is used in the same extent.

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Tail autotomy, the self‐induced tail separation from the body, is a common and effective antipredator mechanism in lizards. In this study, we examine the muscle energetics of tail shedding in six lacertid lizard species (Podarcis erhardii, Podarcis peloponnesiaca, Podarcis muralis, Podarcis gaigeae, Podarcis milensis, and Lacerta graeca) from the northeast Mediterranean region. Very long periods of postautotomy tail movement were demonstrated for all species ( min), and differences among species were not statistically significant. Postautotomy tail movement, powered by anaerobic muscle activity, resulted in a strong increase in lactate concentrations and a concomitant depletion of muscle glycogen of exhausted tails relative to resting tails. No significant differences were found in either lactate or glycogen concentrations among the species examined. Duration of movement was negatively correlated with final lactate concentrations. The lack of differentiation in postautotomy energetic physiology in this group of species that have evolved under very different predation environments indicates that postautotomy muscle metabolism involves an overall conservative suite of characters.

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Many animals display complex colour patterns that comprise several adjacent, often contrasting colour patches. Combining patches of complementary colours increases the overall conspicuousness of the complex pattern, enhancing signal detection. Therefore, selection for conspicuousness may act not only on the design of single colour patches, but also on their combination. Contrasting long- and short-wavelength colour patches are located on the ventral and lateral surfaces of many lacertid lizards. As the combination of long- and short-wavelength-based colours generates local chromatic contrast, we hypothesized that selection may favour the co-occurrence of lateral and ventral contrasting patches, resulting in complex colour patterns that maximize the overall conspicuousness of the signal. To test this hypothesis we performed a comparative phylogenetic study using a categorical colour classification based on spectral data and descriptive information on lacertid coloration collected from the literature. Our results demonstrate that conspicuous ventral (long wavelength-based) and lateral (short wavelength-based) colour patches co-occur throughout the lacertid phylogeny more often than expected by chance, especially in the subfamily Lacertini. These results suggest that selection promotes the evolution of the complex pattern rather than the acquisition of a single conspicuous colour patch, possibly due to the increased conspicuousness caused by the combination of colours with contrasting spectral properties.

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Tail autotomy is one of the main anti-predator mechanisms of lacertid lizards, but it has been predicted that it is only retained in its full capacity when its benefits exceed its costs (Arnold, 1988). To test this hypothesis, ease of tail shedding was examined in a number of continental and insular lacertid lizard populations, each of which showed a different shedding capacity. Tails are shed more easily in those continental and insular populations where there is a greater probability of predation. In insular populations not subjected to strong predation, the tail tends to be retained. The relationship of these findings to insular Mediterranean lizard populations and to the extinction of the Balearic lizard, Podarcis lilfordi are discussed.

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Different kinds of interactions between lizards and plants in the Mediterranean basin have been described. Lizards have shown to `use` plants as a refuge against predators, as a foraging site, as a thermal microhabitat or as a food resource. In the last case, they can either act as herbivores (+/- interaction, consuming vegetative and/or reproductive parts, and damaging the plant to a higher or lower degree) or as mutualists (+/+ interaction, by behaving as legitimate pollinators and/or seed dispersers). The importance of plants as a food resource for Mediterranean lizards has been found to be high in insular habitats, espescially in small islands, where the paucity of arthropod prey availability redirects the foraging activity of lizards towards other nutrient resources. In such small islands, plants may play a major role in the trophic ecology of lacertid lizards, as suggested by recent studies. Likewise, lizards may be important both as efficient pollen transporters and seed dispersersfor a variety of plants. Some of these lizard-plant interactions are unique. The effect lizards have on the reproductive and dispersal succes of some species may be very relevant for plant preserveation, and in turn, the preserveation of prticular behavioral and ecological traits of the particular lizard populations depends, at least partly, on the plants they interact with.

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The complex geological history of the Balkan Peninsula and especially of the Hellenic area (multiple geological events of land connections) during the late Tertiary have likely contributed to the diversification and distribution of many terrestrial animals. Located at the margin of the Eurasian and African plates, this area has experienced tremendous geological alterations since the late Tertiary. Connections offered the opportunities for biological dispersal, while submergence of land bridges brought about distributive isolation among related taxa. If this was a major element influencing the formation of the rich fauna of the Hellenic area, then the phylogenetic relationships of terrestrial taxa should reflect these paleogeographic events. Compared with what is known for the geological history of this region, the impact of those geological events on the historical biogeography of terrestrial animals is less well understood. The reconstruction of phylogenies is of primary importance in the understating of the dynamic patterns of evolution, i.e. the biogeography of a group and the bases of its biological diversity at any level. Although the phylogeny of the genus Podarcis has been the subject of much discussion the relationships among the species are still unclear. Because morphology is so uniform, it provides few characters for phylogenetic analysis, and these tend to be conflicting. Various karyological, immunological and protein electrophoretic studies have been made, but these usually involve only a minority of species, and results from different species combinations are equivocal. Wall lizards of the genus Podarcis (Sauria, Lacertidae) comprises 17-18 currently recognized species in southern Europe, where they are the predominant reptile group. The taxonomy of Podarcis is complex and unstable. Based on DNA sequence data the species of Podarcis falls into four main groups that have substantial geographic coherence (Western Island group, South western group, Italian group and Balkan group). The Balkan species are divided in two subgroups: the subgroup of P. taurica (P. taurica, P. milensis, P. gaigeae and perhaps P. melisellensis), and the subgroup of P. erhardii (P. erhardii and P. peloponnesiaca). We addressed the question of phylogenetic relations among the species of Podarcis encountered in Balkan Peninsula, as they can be inferred from partial mtDNA (cyt b and 16S) and nuclear (c-mos) sequences. Our data support the monophyly of Podarcis and suggest that there are three phylogenetic clades: the clade of P. taurica (P. taurica, P. gaigeae, P. milensis, and P. melisellensis); the clade of P. erhardii (P. erhardii and P. peloponnesiaca) and the clade of P. muralis (P. muralis and P. sicula). The phylogenetic affiliations produced from the molecular data do not agree with the species and especially subspecies groupings predicted from the morphological classification of the populations sampled. By examining intraspecific variability we have found that extant populations of P. erhardii are paraphyletic. The high level of genetic differentiation observed in the mtDNA data between the P. erhardii populations from the Crete and Pori islands and the rest of P. erhardii samples from Cyclades and continental Greece and its phylogenetic position raises questions regarding the inclusion of those populations (Crete and Pori) within P. erhardii. Since, based on morphology, P. peloponnesiaca is a well defined species found in sympatry with P. e. livadhiaca and accepted today as such, then Podarcis from Crete and Pori would also need to be raised to specific rank to avoid the paraphyly of P. erhardii. However, although the differentiation of populations from Crete and Pori islands is clear, we suggest the use of PhyloCode in order to avoid taxonomic confusion at least until further research mainly on morphology becomes available. Thus, for the time being, we refer to wall lizards of Crete and Pori P. erhardii*. With regard to morphological subspecies of P. taurica, P. gaigeae and P. erhardii, it is clear that they do not represent monophyletic units and should be re-evaluated in the light of new evidence. The topology of the phylogenetic trees produced and the genetic distances among the clades of the Podarcis may describe a biogeographic hypothesis for these species in the Balkan area. The pattern of the distribution of the proposed taxa is congruent with existing paleogeographic evidence, as inferred by the application of a molecular clock, which supports the view that DNA sequences may be a useful tool for the study of paleogeography. The data analyzed, stress the need for a reconsideration of the evolutionary history of Balkan Podarcis species and help overcome difficulties that classical taxonomy has encountered at both the species and subspecies level. As a whole, the examination of mtDNA lineages in the lizards of genus Podarcis may contribute substantially to the refining of its taxonomic status. Phylogenetic information can now be added to the knowledge of their morphology and distribution, producing a more accurate taxonomy for this group. Our results also confirm that the molecular information in conjunction with geological data can be used to resolve questions about the paleogeography of a region or on the phylogeography of a species.

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Wall lizards of the genus Podarcis (Sauria, Lacertidae) comprises 17 currently recognized species in southern Europe, where they are the predominant reptile group. The taxonomy of Podarcis is complex and unstable. Based on DNA sequence data the species of Podarcis fall into four main groups that they have substantial geographic conherence (Western Island group, Southwestern group, Italian group and Balkan group). The Balkan species, is divided in two subgroups, the subgroup of P. taurica, P. milensis, P. gaigeae, P. melisellensis and the subgroup of P. erhardi and P. peloponnesiaca, which are highly diversified and present great morphological and ecological plasticity, inhabiting many different ecotypes. We address the question of phylogenetic relations among the species of the Podarcis taurica subgroup encountered in Greece, as they can be inferred from partial mtDNA (cyt b and 16S) and nuclear (c-mos) sequences. Our data suggest that P. gaigeae is closely related to P. milensis and both P. gaigae and P. milensis to P. taurica. However the specimens of P. taurica are subdivided in two different groups. The first includes the specimens from Russia and Northeastern Greece and the other the specimens from the rest of continental Greece and Ionian Islands. This result suggests that the evolutionary history of P. taurica in Greece is more complex than a single evolutionary invasion. The data analyzed stress the need for a reconsideration of the evolutionary history of Greek Podarcis species and help overcome difficulties that classical taxonomy has encountered at both the specific but mostly the sub- specific level of this genus.

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Wall lizards of the genus Podarcis (Sauria, Lacertidae) comprise 17 currently recognized species in southern Europe, where they are the predominant reptile group. The taxonomy of Podarcis is complex and unstable. Based on DNA sequence data the species of Podarcis falls into four main groups that have substantial geographical conherence (western island group, southwestern group, Italian group and Balkan group). The Balkan species are divided in two subgroups: the subgroup of Podarcis taurica ( P. taurica, P. milensis, P. gaigeae and perhaps P. melisellensis ), and the subgroup of Podarcis erhardii ( P. erhardii and P. pelopon- nesiaca ). We addressed the question of phylogenetic relations among the species of the P. taurica subgroup encountered in Greece, as they can be inferred from partial mtDNA (cyt b and 16S) sequences. Our data support the monophyly of P. taurica subgroup and suggest that P. gaigeae, P. milensis and P. melisellensis form a clade, which thereinafter connects to P. taurica . Within the previous clade, P. gaigeae is more closely related to P. milensis than to P. melisellensis . However, the specimens of P. taurica were subdivided in two different groups. The first one includes the specimens from northeastern Greece, and the other group includes the specimens from the rest of continental Greece and Ionian islands. Because the molecular clock of the cyt b and 16 rRNA genes was not rejected in our model test, it is possible to estimate times of speciation events. Based on the splitting of the island of Crete from Peloponnisos [ c. 5 million years ago (Ma)], the evolutionary rate for the cyt b is 1.55% per million years (Myr) and for the 16S rRNA is 0.46% per Myr. These results suggest that the evolutionary history of P. taurica in Greece is more complex than a single evolutionary invasion. The data analysed, stress the need for a reconsideration of the evolutionary his- tory of Greek Podarcis species and help overcome difficulties that classical taxonomy has encountered at both the species level.

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Wall lizards of the genus Podarcis (Sauria, Lacertidae) are the predominant reptile group in southern Europe, including 24 recognized species. Mitochondrial DNA data have shown that, with the exception of P. muralis, the Podarcis species distributed in the Balkan peninsula form a species group that is further sub-divided into two subgroups: the one of “P. tauricus” consisting of P. tauricus, P. milensis, P. gaigeae, and P. melisellensis, and the other of “P. erhardii” comprising P. erhardii, P. levendis, P. cretensis, and P. peloponnesiacus. In an attempt to explore the Balkan Podarcis phylogenomic relationships, assess the levels of genetic structure and to re-evaluate the number of extant species, we employed phylogenomic and admixture approaches on ddRADseq (double digested Restriction site Associated DNA sequencing) genomic data. With this efficient Next Generation Sequencing approach, we were able to obtain a large number of genomic loci randomly distributed throughout the genome and use them to resolve the previously obscure phylogenetic relationships among the different Podarcis species distributed in the Balkans. The obtained phylogenomic relationships support the monophyly of both aforementioned subgroups and revealed several divergent lineages within each subgroup, stressing the need for taxonomic re-evaluation of Podarcis’ species in Balkans. The phylogenomic trees and the species delimitation analyses confirmed all recently recognized species (P. levendis, P. cretensis, and P. ionicus) and showed the presence of at least two more species, one in P. erhardii and the other in P. peloponnesiacus.

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The Balkan Peninsula constitutes a biodiversity hotspot with high levels of species richness and endemism. The complex geological history of the Balkans in conjunction with the climate evolution are hypothesized as the main drivers generating this biodiversity. We investigated the phylogeography, historical demography, and popula- tion structure of closely related wall-lizard species from the Balkan Peninsula and southeastern Europe to better understand diversification processes of species with limited dispersal ability, from Late Miocene to the Holocene. We used several analytical methods integrating genome-wide SNPs (ddRADseq), microsatellites, mitochondrial and nuclear DNA data, as well as species distribution modelling. Phylogenomic analysis resulted in a completely resolved species level phylogeny, population level analyses confirmed the existence of at least two cryptic evolutionary lineages and extensive within species genetic structuring. Divergence time estimations indicated that the Messinian Salinity Crisis played a key role in shaping patterns of species divergence, whereas in- traspecific genetic structuring was mainly driven by Pliocene tectonic events and Quaternary climatic oscillations. The present work highlights the effectiveness of utilizing multiple methods and data types coupled with extensive geographic sampling to uncover the evolutionary processes that shaped the species over space and time.

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The monophyletic species subgroup of Podarcis tauricus is distributed in the western and southern parts of the Balkans, and includes four species with unresolved and unstudied inter- and intra-specific phylogenetic relationships. Using sequence data from two mitochondrial and three nuclear genes and applying several phylogenetic methods and species delimitation approaches to an extensive dataset, we have reconstructed the phylogeny of the Podarcis wall lizards in the Balkans, and re-investigated the taxonomic status of the P. tauricus species subgroup. Multilocus analyses revealed that the aforementioned subgroup consists of five major clades, with P. melisellensis as its most basal taxon. Monophyly of P. tauricus sensu stricto is not supported, with one of the subspecies (P. t. ionicus) displaying great genetic diversity (hidden diversity or cryptic species). It comprises five, geographically distinct, subclades with genetic distances on the species level. Species delimitation approaches revealed nine species within the P. tauricus species subgroup (P. melisellensis, P. gaigeae, P. milensis, and six in the P. tauricus complex), underlining the necessity of taxonomic re-evaluation. We thus synonymize some previously recognized subspecies in this subgroup, elevate P. t. tauricus and P. g. gaigeae to the species level and suggest a distinct Albanian-Greek clade, provisionally named as the P. ionicus species complex. The latter clade comprises five unconfirmed candidate species that call for comprehensive studies in the future.

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Colour polymorphism in reptiles is generally associated with the coexistence of alternative reproductive strategies that involve specific trade-offs among different life history traits. Notably, body temperature trades off with immunocompetence: temperature has relevant effects on immune-response, but maintaining the optimal temperature increases both energetic costs and predatory risk. This trade-off gains complexity by sex, since males and females could optimize fitness by different strategies. Given that there is no single solution for trade-offs, different links among alternative evolutionary stable solutions and morphs might evolve independently in each sex. We tested this hypothesis in the common wall lizard (Podarcis muralis) by means of in vitro cultures of blood cells in order to examine the response of the immune-system to phytohemoagglutinin stimulation in male and female morphs at two different temperatures (i.e. 22 and 32 °C), corresponding to the thermal optima of the two sexes. We found (i) morphspecific immunity in both sexes, i.e. yellow lizards suffer immunosuppression with respect to the other morphs, and (ii) sex-specific immunity under hot conditions, i.e. females of all morphs were immunosuppressed with respect to males. Results support the hypothesis that morphs might differently invest in immunocompetence, according to different set-up for the trade-offs between immunity and other life-history traits, resulting in alternative strategies with different fitness optima.

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Tissue regeneration is a fundamental evolutionary adaptation, which is well known in lizards that can regenerate their entire tail. However, numerous parameters of this process remain poorly understood. Lizard tail serves many functions. Thus, tail autotomy comes with many disadvantages and the need for quick regeneration is imperative. To provide the required energy and materials for caudal tissue building, lizards are expected to undergo a number of physiological and biochemical adjustments. Previous research showed that tail regeneration induces changes in the digestive process. Here, we investigated if and how tail regeneration affects the digestive performance in five wall lizard species deriving from mainland and island sites and questioned whether the association of tail regeneration and digestion is affected by species relationships or environmental features, including predation pressure. We expected that lizards from high predation environments would regenerate their tail faster and modify accordingly their digestive efficiency, prioritizing the digestion of proteins; the main building blocks for tissue repair. Second, we anticipated that the general food shortage on islands would inhibit the process. Our findings showed that all species shifted their digestive efficiency, as predicted. Elongation rate was higher in sites with stronger predation regime and this was also applied to the rate with which protein digestion raised. Gut passage time increases during regeneration so as to improve the nutrient absorbance, but among the islanders, the pace was more intense. The deviations between species should be attributed to the different ecological conditions prevailing on islands rather than to their phylogenetic relationships.

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In recent years, great attention has been paid to many Podarcis species for which the observed intra-specific variability often revealed species complexes still characterized by an unresolved relationship. When compared to other species, P. siculus underwent fewer revisions and the number of species hidden within this taxon may have been, therefore, underestimated. However, recent studies based on genetic and morphological data highlighted a marked differentiation of the populations inhabiting the western Pontine Archipelago. In the present work we used published genetic data (three mitochondrial and three nuclear gene fragments) from 25 Podarcis species to provide a multilocus phylogeny of the genus in order to understand the degree of differentiation of the western Pontine populations. In addition, we analyzed new morphometric traits (scale counts) of 151 specimens from the main islands of the Pontine Archipelago. The phylogenetic analysis revealed five principal Podarcis groups with biogeographic consistency. The genetic distinctiveness of the Podarcis populations of the western Pontine Islands is similar or even more ancient than those observed in numerous other pairs of Podarcis sister species. In the light of these evidences we raise the western Pontine lizards to specific rank; thus they should be referred to as Podarcis latastei.

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Research on the taxonomy of European amphibians and reptiles has increased noticeably over the last few decades, indicating the need for recognition of new species and the cancellation of others. This paper provides a critical review of recent changes and draws up a tentative species list.

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The last species list of the European herpetofauna was published by Speybroeck, Beukema and Crochet (2010). In the meantime, ongoing research led to numerous taxonomic changes, including the discovery of new species-level lineages as well as reclassifications at genus level, requiring significant changes to this list. As of 2019, a new Taxonomic Committee was established as an official entity within the European Herpetological Society, Societas Europaea Herpetologica (SEH). Twelve members from nine European countries reviewed, discussed and voted on recent taxonomic research on a case-by-case basis. Accepted changes led to critical compilation of a new species list, which is hereby presented and discussed. According to our list, 301 species (95 amphibians, 15 chelonians, including six species of sea turtles, and 191 squamates) occur within our expanded geographical definition of Europe. The list includes 14 non-native species (three amphibians, one chelonian, and ten squamates).

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Elements of the herpetofauna are in the author`s opinion of great importance for the zoogeographical division of the Palaearctic region. It is suggested that this region be divided into the following four subregions: 1/ arctic, 2/ boreal Euro-Siberian, 3/ bo- real Himalayan-Manchurian and 4/ Mediterranean-Central-Asiatic.

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Most recent molecular studies revealed the phylogeny of Greek Podarcis species, which for years remained elusive, due to discordant data produced from various chromosomal, complement fixation and protein studies. In this report, we analyzed cellular immune responses of spleen- derived lymphocytes from six allopatric Podarcis species encountered in Greece, by assessing two-way mixed lymphocyte reaction (MLR)- induced proliferation. On the basis of stimulation indices (S.I.) as determined from cultures set up from xenogeneic splenocytes coincubated in pairs, we generated a phylogenetic tree, fully consistent with the phylogenetic relationships of Podarcis as determined by parallel analyses based on partial mitochondrial (mt) DNA sequences. Although the exact mechanisms triggering lymphocyte responses in lizard two-way xenogeneic MLR are not fully understood, our results show the potential use of cell-mediated immune responses as an additional approach to mtDNA analysis, for species delimitation within specific lizard taxa.