Penguins are the only extant family of flightless diving birds. They currently comprise at least 18 species, distributed from polar to tropical environments in the Southern Hemisphere. The history of their diversification and adaptation to these diverse environments remains controversial. We used 22 new genomes from 18 penguin species to reconstruct the order, timing, and location of their diversification, to track changes in their thermal niches through time, and to test for associated adaptation across the genome. Our results indicate that the penguin crown-group originated during the Miocene in New Zealand and Australia, not in Antarctica as previously thought, and that Aptenodytes is the sister group to all other extant penguin species. We show that lineage diversification in penguins was largely driven by changing climatic conditions and by the opening of the Drake Passage and associated intensification of the Antarctic Circumpolar Current (ACC). Penguin species have introgressed throughout much of their evolutionary history, following the direction of the ACC, which might have promoted dispersal and admixture. Changes in thermal niches were accompanied by adaptations in genes that govern thermoregulation and oxygen metabolism. Estimates of ancestral effective population sizes (Ne) confirm that penguins are sensitive to climate shifts, as represented by three different demographic trajectories in deeper time, the most common (in 11 of 18 penguin species) being an increased Ne between 40 and 70 kya, followed by a precipitous decline during the Last Glacial Maximum. The latter effect is most likely a consequence of the overall decline in marine productivity following the last glaciation.

The emerging picture of non-monophyly of scolecophidian snakes is increasingly indicative that fossorial lifestyle, myrmecophagous diet, and miniaturisation are powerful drivers of morphological evolution in squamate skulls. We provide a detailed description of the skull of Xenotyphlops grandidieri, with reference to the skulls of other scolecophidian snakes. The skull, which shows dramatic ventral inflection of the snout complex, is remarkably bizarre, and the mouth opening is more ventrally oriented than in other typhlopoids. The eyes are strongly reduced, and the enlarged and rather flat anterior head shield is covered in numerous sensillae. We put forward several potential explanations for the evolution of these unusual modifications. On the other hand, Xenotyphlops shares numerous synapomorphies with other typhlopoid snakes, including the highly specialized jaw mechanism. We argue that the key differences between the jaw mechanisms of Leptotyphlopidae, Anomalepididae, and Typhlopoidea provide compelling evidence for a strong role of convergence in the evolution of the scolecophidian bauplan, and these clades therefore cannot be interpreted as representative of ancestral anatomy or ecology among snakes. HighlightThe skull of the typhlopoid snake Xenotyphlops grandidieri is ventrally inflected, resulting in positional rearrangement of its snout bones and the formation of a robust anterior plate to the skull. It shares the unique rotational jaw mechanism seen in Gerrhopilidae and Typhlopidae, making this mechanism a synapomorphy of the superfamily Typhlopoidea. Differences in jaw morphology among major scolecophidian sensu lato lineages implicates convergent evolution in generating the blindsnake bauplan.Correspondence Mark D. Scherz, Zoologische Staatssammlung M€ unchen (ZSM-SNSB), M€ unchhausenstr. 21,

Aim:The conservation of biodiversity is hampered by data deficiencies, with many new species and subspecies awaiting description or reclassification. Population genomics and ecological niche modelling offer complementary new tools for uncovering functional units of phylogenetic diversity. We hypothesize that phylogenetically delineated lineages of gentoo penguins (Pygoscelis papua) distributed across Antarctica and sub-Antarctic Islands are subject to spatially explicit ecological conditions that have limited gene flow, facilitating genetic differentiation, and thereby speciation processes.Location: Antarctica and sub-Antarctic area. Methods:We identify divergent lineages for gentoo penguins using ddRAD-seq and mtDNA, and generated species distribution models (SDMs) based on terrestrial and marine parameters.Results: Analyses of our genomic data supports the existence of four major lineages of gentoo penguin: (i) spanning the sub-Antarctic archipelagos north of the Antarctic Polar Front (APF); (ii) Kerguelen Island; (iii) South America; and (iv) across maritime Antarctic and the Scotia Arc archipelagos. The APF, a major current system around Antarctica, acts as the most important barrier separating regional sister lineages. Our ecological analyses spanning both the terrestrial (breeding sites) and marine (feeding sites) realms recover limited niche overlap among the major lineages of gentoo penguin. We observe this pattern to correspond more closely with regional differentiation of marine conditions than to terrestrial macroenvironmental features.Main conclusions: Recognition of regional genetic lineages as discrete evolutionary entities that occupy distinct ecological niches and also differ morphologically should be considered a priority for conservation. Gentoo penguins provide a good example of