Intraspecific, interpopulation variability of a tardigrade Milnesium tardigradum was investigated by means of integrative taxonomy, including morphology (light and scanning electron microscopy), morphometry, and barcoding of a nuclear (ITS-2) and a mitochondrial marker (COI). The nine analysed European populations revealed low to moderate variability in morphology and in ITS-2 (≤4.0%). In contrast, COI exhibited low to surprisingly high divergence (≤11.4%), questioning the possibility of setting a universal barcoding threshold for tardigrade species delineation. Additionally, novel, taxonomically important traits for M. tardigradum are described.

A new species, Metorchis ussuriensis sp. nov., was described in Russia. The first and second intermediate hosts, as well as the definitive host, were determined in the experiment. Morphometric parameters of M. ussuriensis sp. nov. demonstrate similarities with M. taiwanensis, but the two species differ in some characters. Three molecular markers (ITS2 region, 28S rRNA gene, and cox1 gene) were used for phylogenetic reconstructions. Comparison to other trematodes suggests that the 28S rRNA gene could proof suitable for the differentiation of trematode species.

Six species of neodalyellid rhabdocoel flatworm were discovered and characterized with morphological and DNA sequence data. Three species, Baicalellia solaris, B. daftpunka and Tamanawas kalipis, are new to science. A phylogenetic analysis of neodalyellid rhabdocoels, inferred from 18S and 28S ribosomal RNA gene sequences of 39 taxa, provided further insight into systematics and trait evolution in this understudied group, including the recognition of a new genus, Tamanawas, and the suppression of Canetellia and Coronopharynx.

The Fray Jorge (FJ) forest relict is a wet temperate forest inserted in a xerophile matrix (the Atacama desert, the driest desert in the world) and separated from other similar temperate forests by thousands of km. We performed a phylogeographic analyses of the snail genus Plectostyus to disentangle the origin and timing of the FJ relict. Our tree shows that FJ is sister to all other forest clades. Our molecular clock analysis shows that FJ became isolated in the Paeogene/Neogene.

Using mitochondrial COI sequencing, we revealed strong population structuring in the common cockle Cerastoderma edule (Linnaeus, 1758) populations from the Norwegian and Barents Seas. Low genetic diversity of the subarctic cockle populations predominantly consists of a distinct clade of haplotypes, which is much less common in populations located south of the Arctic Circle and completely lacking in the North Sea. The Barents Sea C. edule seems to be the first conclusive example of true metapopulation revealed in marine broadcast spawners.

Postcopulatory isolating barriers are evident in hybrids of the widespread, occasionally sympatric dung fly sister-species Sepsis cynipsea and Sepsis neocynipsea: Egg-to-adult viability was strongly but not totally suppressed, offspring production approached nil in the F₂ generation. Viable F₁ hybrid males were sterile while females remained largely fertile (Haldane's rule). Crossing geographically isolated European and North American S. neocynipsea showed similar but weaker barriers that can be explained by random genetic drift. S(ubs)pecies status of continental S. neocynipsea appears warranted.

Climatic differences between Global Circulation Models result in differences in the factors that limit and drive the potential distribution of the species during the Last Glacial Maximum, leading to alternative biogeographical hypotheses based on ENM.

Here, we analyze patterns of morphological and molecular variation aimed to assess the taxonomic status of the long-tailed mouse Oligoryzomys destructor and its associated nominal forms. As part of the study, we selected neotypes for Hesperomys destructor and H. melanostoma. We concluded that O. destructor is a species formed by two subspecies, O. d. destructor and O. d. spodiurus.

We used cranium shape data of 14 lacertid lizard speciesto test patterns of modularity using five alternative hypotheses at three levels – static, ontogenetic, and evolutionary. We found somewhat different pattern of covariation at the static compared to the ontogenetic and evolutionary levels. Our results indicate that in lacertid lizards, developmental integration is evolutionarily conservative and ontogenetically constrained. Functional covariation patterns observed at the static but not at the evolutionary level could have been adaptive and arisen through selection.

In this study, we use a comprehensive dataset of Gekkota to test the effect of gene and taxon sampling in recovering the monophyly of Tropiocolotes and the phylogenetic relationships between the four main groups of Palearctic naked-toed geckos. The results show that Tropiocolotes is monophyletic and highlights the importance of including more taxa and more data to resolve contradictory evolutionary relationships. Moreover, an integrative analysis of Tropiocolotes scorteccii uncovered a new species endemic to southern Oman that is described herein.

In this study, we propose a new methodology based on the detailed 3D morphology of the pharyngeal teeth. The results show that the detailed 3D morphology of the pharyngeal teeth is a useful tool for the identification of isolated teeth at the generic and/or specific level. Additionally, the preliminary analysis shows that the morphology of the pharyngeal teeth provides a potential phylogenetic signal. Both these patterns are very important for the taxonomy of cyprinid fishes and especially can be applied to fossil records.

A geometric morphometric analysis of 473 specimens from throughout the broad distribution of the dwarf gerbil (Gerbillus nanus) detected no biologically meaningful variation in cranial shape. Cranial size did show geographic variation—however, this variation does not seem to show strong patterns consistent with isolation by distance, nor with adaptation to local environments, which could indicate that the geographic variation in the cranial size of G. nanus populations may be accounted for by factors unexamined in this study.