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The genetic structure and heterogeneity of Podarcis sicula (Reptilia, Lacertidae) was studied in insular (Pontine Archipelago) and mainland (central and southern Italy) populations by means of allozyme electrophoresis at 20 presumptive gene loci. Genetic variability in the species is low and genetic subdivision is high. The highest values of percent polymorphism and heterozygosity were found in the samples from the southernmost part of Italy (Calabria). The insular samples from the Pontine Archipelago were characterized by loss of alleles and erosion of genetic variability. Population heterogeneity analysis carried out by the estimation of Wright`s F-statistics demonstrated substantial genetic differentiation among populations. F-statistics and genetic distance data show that genetic variation is distributed into three population groups. The first group includes the genetically very similar populations from central Italy and the Pontine Archipelago, the second includes the populations from Campania (southern Italy), the third comprises the populations from the southernmost part of the Italian Peninsula (Calabria). Based on the results of the allozyme data, the systematic status of the subspecies of P. sicula occurring in the studied areas is discussed.

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Based on genetic and morphological evidence, Senczuk et al. (2019) formally raised the Podarcis populations from the Western Pontine Islands, previously classified as several subspecies of P. siculus, to species rank, i.e. Podarcis latastei (Bedriaga, 1879). This taxonomic change was not accepted in the checklist of the European herpetofauna by Speybroeck et al. (2020), recently published on Amphibia-Reptilia. In this note we respond to the reasons given by Speybroeck and colleagues and support the validity of Podarcis latastei as an endemic Italian species.

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Although it was obvious to us that it would be useful to include a list of the herpetofauna found on the Italian islands, it immediately became clear that this would be no easy task: the information in the literature is often incomplete, inaccurate and difficult to check, and precise data are available only for the circum-Sardinian islands (POGGESI et al., 1996), the circum-Sicilian islands (L ANZA, 1973; CORTI et al., 1998) and the Tuscan Archipelago (HOTZ, 1973; COR- TI et al., 1991; VANNI & NISTRI, 1999, 2000). In order to form as complete a picture as possible, we also consulted numerous works on single islands or groups of islands, e.g. the Handbuch der Rep- tilien und Amphibien Europas. Finally, we had access to a large vol- ume of as yet unpublished data from the Progetto Atlante, including reports for the Ligurian and Apulian islands, gathered by the region- al chapters of the Societas Herpetologica Italica. For the sake of brevity, lacustrian and riverine populations and those of delta bars, beaches and island lakes have been omitted. Apart from the fact that few data are available, these populations are not actually separate from those of adjoining coasts. We do make an important exception to this rule in mentioning the taxon Lacerta muralis borromeica Mertens, 1932, described for the Isola Madre on Lago Maggiore and later declared invalid by the author. The subspecies status of many island populations of lacertids of the Podarcis genus remains open to debate, and is discussed in more detail in the chapter “Checklist of the Italian herpetofauna with tax- onomic remarks”. These populations can present far greater variabil- ity in patterning than continental populations [e.g. Podarcis sicula caporiaccoi (Taddei, 1949) see HOTZ (1973)] or unusual colouring (e.g. melanotic) which, although they make island and archipelago populations easier to identify, are considered by modern taxono- mists to be of doubtful systematic validity. It was decided to include the description of a species or sub- species for an island as a note, with the type locality in square brack- ets, and with the name supplied by the author without commenting on its validity.

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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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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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During the first decades of the last century, an enigmatic extinction was documented to have occurred on the small Mediterranean island of Santo Stefano in the Pontine Archipelago. Although islands are fascinating systems for studying microevolutionary processes, they may nevertheless host unstable communities that make their populations particularly vulnerable to anthropogenic effects and, ultimately, extinction. Here, we investigated the variation of head morphology of 374 individuals of Podarcis siculus from mainland Italy, Sicily and the Pontine Archipelago, using geometric morphometrics. We also included in the analysis samples of the extinct population of Santo Stefano Island, aiming to shed light on the extinction and provide additional information on the historical biogeography of the Archipelago. We found a strong relationship between morphological differences and phylogeographical structure based on previously published genetic data, indicating that the western Pontine populations seem to be a case of incipient speciation. In addition, the extinct population of Santo Stefano Island clustered in all analyses with the western Pontine populations. The results not only provide information on the evolutionary history of P. siculus, but also lead to broader considerations of taxonomy and conservation.

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Groups of proximate continental islands may conceal more tangled phylogeographic patterns than oceanic archipelagos as a consequence of repeated sea level changes, which allow populations to experience gene flow during periods of low sea level stands and isolation by vicariant mechanisms during periods of high sea level stands. Here, we describe for the first time an ancient and diverging lineage of the Italian wall lizard Podarcis siculus from the western Pontine Islands. We used nuclear and mitochondrial DNA sequences of 156 individuals with the aim of unraveling their phylogenetic position, while microsatellite loci were used to compare several a priori insular biogeographic models of migration with empirical data. Our results suggest that the western Pontine populations colonized the islands early during their Pliocene volcanic formation, while populations from the eastern Pontine Islands seem to have been introduced recently. The inter-island genetic makeup suggests an important role of historical migration, probably due to glacial land bridges connecting islands followed by a recent vicariant mechanism of isolation. Moreover, the most supported migration model predicted higher gene flow among islands sharing a longitudinal arrangement. Considering the threatened status of small insular endemic populations, we suggest this new evolutionarily independent unit be given priority in conservation efforts.

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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).