Cryptic variation in the Moroccan high altitude lizardAtlantolacerta andreanskyi(Squamata: Lacertidae)

Mitogenome analyses elucidate the evolutionary relationships of a probable Eocene wet tropics relic in the xerophile lizard genus Acanthodactylus

Climate has a large impact on diversity and evolution of the world's biota. The Eocene-Oligocene transition from tropical climate to cooler, drier environments was accompanied by global species turnover. A large number of Old World lacertid lizard lineages have diversified after the Eocene-Oligocene boundary. One of the most speciose reptile genera in the arid Palearctic, Acanthodactylus, contains two sub-Saharan species with unresolved phylogenetic relationship and unknown climatic preferences. We here aim to understand how and when adaptation to arid conditions occurred in Acanthodactylus and when tropical habitats where entered. Using whole mitogenomes from fresh and archival DNA and published sequences we recovered a well-supported Acanthodactylus phylogeny and underpinned the timing of diversification with environmental niche analyses of the sub-Saharan species A. guineensis and A. boueti in comparison to all arid Acanthodactylus. We found that A. guineensis represents an old lineage that splits from a basal node in the Western clade, and A. boueti is a derived lineage and probably not its sister. Their long branches characterize them-and especially A. guineensis-as lineages that may have persisted for a long time without further diversification or have undergone multiple extinctions. Environmental niche models verified the occurrence of A. guineensis and A. boueti in hot humid environments different from the other 42 arid Acanthodactylus species. While A. guineensis probably remained in tropical habitat from periods prior to the Eocene-Oligocene boundary, A. boueti entered tropical environments independently at a later period. Our results provide an important baseline for studying adaptation and the transition from humid to arid environments in Lacertidae.

Evolution of morphological crypsis in the Tetramorium caespitum ant species complex (Hymenoptera: Formicidae)

Cryptic species are morphologically very similar to each other. To what extent stasis or convergence causes crypsis and whether ecology influences the evolution of crypsis has remained unclear. The Tetramorium caespitum complex is one of the most intricate examples of cryptic species in ants. Here, we test three hypotheses concerning the evolution of its crypsis: H1: The complex is monophyletic. H2: Morphology resulted from evolutionary stasis. H3: Ecology and morphology evolved concertedly. We confirmed (H1) monophyly of the complex; (H2) a positive relation between morphological and phylogenetic distances, which indicates a very slow loss of similarity over time and thus stasis; and (H3) a positive relation between only one morphological character and a proxy of the ecological niche, which indicates concerted evolution of these two characters, as well as a negative relation between p-values of correct species identification and altitude, which suggests that species occurring in higher altitudes are more cryptic. Our data suggest that species-specific morphological adaptations to the ecological niche are exceptions in the complex, and we consider the worker morphology in this complex as an adaptive solution for various environments.

Cryptic diversity in Ptyodactylus (Reptilia: Gekkonidae) from the northern Hajar Mountains of Oman and the United Arab Emirates uncovered by an integrative taxonomic approach

The Hajar Mountains of south-eastern Arabia form an isolated massif surrounded by the sea to the east and by a large desert to the west. As a result of their old geological origin, geographical isolation, complex topography and local climate, these mountains provide an important refuge for endemic and relict species of plants and animals. With 19 species restricted to the Hajar Mountains, reptiles are the vertebrate group with the highest level of endemicity, becoming an excellent model for understanding the patterns and processes that generate and shape diversity in this arid mountain range. The geckos of the Ptyodactylus hasselquistii species complex are the largest geckos in Arabia and are found widely distributed across the Arabian Mountains, constituting a very important component of the reptile mountain fauna. Preliminary analyses suggested that their diversity in the Hajar Mountains may be higher than expected and that their systematics should be revised. In order to tackle these questions, we inferred a nearly complete calibrated phylogeny of the genus Ptyodactylus to identify the origin of the Hajar Mountains lineages using information from two mitochondrial and four nuclear genes. Genetic variability within the Hajar Mountains was further investigated using 68 specimens of Ptyodactylus from 46 localities distributed across the entire mountain range and sequenced for the same genes as above. The molecular phylogenies and morphological analyses as well as niche comparisons indicate the presence of two very old sister cryptic species living in allopatry: one restricted to the extreme northern Hajar Mountains and described as a new species herein; the other distributed across the rest of the Hajar Mountains that can be confidently assigned to the species P. orlovi. Similar to recent findings in the geckos of the genus Asaccus, the results of the present study uncover more hidden diversity in the northern Hajar Mountains and stress once again the importance of this unique mountain range as a hot spot of biodiversity and a priority focal point for reptile conservation in Arabia.