The cosmopolitan phytoplankter Emiliania huxleyi contrasts with its closest relatives that are restricted to narrower latitudinal bands, making it interesting for exploring how alternative outcomes in phytoplankton range distributions arise. Mitochondrial and chloroplast haplogroups within E. huxleyi are shared with their closest relatives: Some E. huxleyi share organelle haplogroups with Gephyrocapsa parvula and G. ericsonii which inhabit lower latitudes, while other E. huxleyi share organelle haplogroups with G. muellerae, which inhabit high latitudes. We investigated whether the phylogeny of E. huxleyi organelles reflects environmental gradients, focusing on the Southeast Pacific where the different haplogroups and species co-occur. There was a high congruence between mitochondrial and chloroplast haplogroups within E. huxleyi. Haplogroup II of E. huxleyi is negatively associated with cooler less saline waters, compared to haplogroup I, both when analyzed globally and across temporal variability at the small special scale of a center of coastal upwelling at 30° S. A new mitochondrial haplogroup Ib detected in coastal Chile was associated with warmer waters. In an experiment focused on inter-species comparisons, laboratory-determined thermal reaction norms were consistent with latitudinal/thermal distributions of species, with G. oceanica exhibiting warm thermal optima and tolerance and G. muellerae exhibiting cooler thermal optima and tolerances. Emiliania huxleyi haplogroups I and II tended to exhibit a wider thermal niche compared to the other Gephyrocapsa, but no differences among haplogroups within E. huxleyi were found. A second experiment, controlling for local adaptation and time in culture, found a significant difference between E. huxleyi haplogroups. The difference between I and II was of the expected sign, but not the difference between I and Ib. The differences were small (≤1°C) compared to differences reported previously within E. huxleyi by local adaptation and even in-culture evolution. Haplogroup Ib showed a narrower thermal niche. The cosmopolitanism of E. huxleyi might result from both wide-spread generalist phenotypes and specialist phenotypes, as well as a capacity for local adaptation. Thermal reaction norm differences can well explain the species distributions but poorly explain distributions among mitochondrial haplogroups within E. huxleyi. Perhaps organelle haplogroup distributions reflect historical rather than selective processes.

The genus Ectinogonia Spinola, 1837 is a genus mainly found in Chile; it currently contains 17 species. Recent exploration in the Andes Mountain Range of the Bio Bio Region in Chile have resulted in the collection of specimens slightly different morphologically from all previously described species. The aim of this paper is to describe this new species of Ectinogonia using morphological and genetic evidence. To establish differences between species we described the external morphology and compared it to species that are morphologically similar (i.e. E. buqueti Spinola 1837 and E. intermedia Kerremans 1903). We also measured the genetic differences in COI sequences, constructing a distance matrix in which we compared it to species that are morphologically similar (E. buqueti and E. intermedia) and other species found in the same region (E. speciosa oscuripennis Moore 1994). We found that E. cryptica sp. n. differs from E. buqueti (which previously contained E. cryptica sp. n.) in pronotum and elytral patterns. The genetic distance matrix shows that E. cryptica sp. n. differs by 4.6% from all other Ectinogonia species compared, supporting the morphological evidence.

Ectinogonia Spinola 1837 is composed of 22 species to date, but its taxonomic history has been complex and is still unresolved. The species of the Santiagan Province of Central Chile are particularly complex because they show important morphological variability and overlapping traits, making species identification and delimitation difficult. The main goal of the present study is to show the phylogenetic relationships among species of Ectinogonia of the Santiagan province and discuss the taxonomic and systematic implications of our findings. Phylogeny reconstructions as well as a haplotype network disclosed four groups, partially inconsistent with the traditional taxonomy. Actually, the two Ectinogonia speciosa subspecies (E. speciosa speciosa (Germain 1856) and E. speciosa oscuripennis Cobos 1954) belong to two distinct clades, which are not reciprocally monophyletic, meaning that Ectinogonia speciosa is polyphyletic. On the other hand, the two other clades each contain, two nominal species (E. buquetii (Spinola 1837) and E. vidali Moore & Guerrero 2017, and E. isamarae Moore 1994 and E. speciosa oscuripennis Cobos 1954) without reciprocal haplotype sorting. These results suggest that: (1) E. speciosa oscuripennis should be raised to species level and (2) the following new synonymies are proposed: E. isamarae Moore 1994 is synonymised with E. oscuripennis Cobos 1954 and E. vidali Moore & Guerrero 2017 is synonymised with E. buquetii (Spinola 1837).

Ectinogonia is a genus of jewel beetles from the western slope of the Andes Cordillera, inhabiting arid and semiarid ecosystems in different biogeographical provinces. Most of the species in this genus have undergone several rearrangements and misassignments over time, making the taxonomic history of Ectinogonia particularly complex. Recent studies based on molecular phylogenies suggest that the taxonomy of the genus should be revised using genetic tools. Because some species are polymorphic and others cryptic and monomorphic, species diversity may be over- or underestimated. We performed here the first comprehensive molecular phylogeny for Ectinogonia s.s. using nuclear and mitochondrial genes. We also performed species delimitation analyses to estimate diversity within Ectinogonia. Results show that Ectinogonia is divided into two main groups: the artificial ‘southern group’ and the natural ‘northern clade’. The southern group matched with the current morphology-based taxonomy, whereas the northern clade contained the largest number of species, several of which do not fit with the current taxonomy. There was both genetic-morphological uncoupling and crypsis by convergence, suggesting a complex evolutionary history. We also provide a new taxonomic arrangement based on our results.

Gyriosomus crispaticollis Fairmaire, 1886 is revalidated from the synonymy of Gyriosomus luczotii Guérin-Méneville, 1831 based on the study of G. crispaticollis syntypes and comparative morphological and genetic analyses. Our results suggest that G. crispaticollis is morphologically closer to Gyriosomus multigranulosus Pizarro-Araya & Flores, 2004 than G. luczotii, but genetically barely closer to G. luczotii. Also habitat preferences, field observations and lectotype designation are provided for G. crispaticollis.