Colombellinidae is an extinct family of marine gastropods occurring in carbonate facies from the Middle Jurassic to the lowermost Upper Cretaceous, primarily in Europe and rarely in Asia. Members of the family are characterized by thick, oval shells with a narrow aperture bearing anterior and posterior canals, a thickened peristome and a denticulate outer lip. Colombellinids share several shell characters with representatives of Cypraeoidea, including a narrow, elongated aperture, but unlike cypraeids, their shells are not convolute. Based on a comprehensive revision of all described species, the taxonomy of Colombellinidae is clarified, and the family is restricted to only two genera: Colombellina d’Orbigny, 1842, and Zittelia Gemmellaro, 1869. One new species, Colombellina crassigranulata sp. nov., from the Upper Jurassic of Bulgaria, and one new genus, Wadeina gen. nov., from the Upper Cretaceous (Campanian) of Tennessee, USA – with a type species previously included in Colombellinidae but here assigned to the family Personidae (Tonnoidea) – are described. The distribution of the family and associated facies indicates a preference for shallow marine carbonate environments, while their low abundance may indicate a carnivorous mode of life. A comparison of Colombellinidae with Tonnoidea, Cypraeoidea and Purpurinidae sheds a new light on the phylogenetic relationships of these groups and supports the interpretation of Colombellinidae as a stem or sister group of Cypraeoidea. This study contributes to a refined systematics of Jurassic–Cretaceous gastropods and provides new evidence for the early diversification of higher caenogastropods.

During a helminthological survey conducted in the southern Peruvian Amazon, nematodes representing an undescribed species of Aplectana Railliet & Henry, 1916 (Cosmocercidae) were recovered from the intestine of Leptodactylus bolivianus Boulenger, 1898 (Anura: Leptodactylidae). The new species, Aplectana peruensis n. sp., is described herein based on an integrative taxonomic approach combining detailed morphological analysis using light and scanning electron microscopy with molecular characterization of the partial 18S rDNA gene. Aplectana peruensis n. sp. is distinguished from its congeners by a unique combination of characters, including 13 pairs of caudal papillae (3 precloacal, 5 adcloacal, and 5 poscloacal papillae) plus a single unpaired papilla, the presence of a gubernaculum, and relatively long spicules (152–194) with a clearly defined distal bifurcation. Phylogenetic analyses based on Bayesian inference methods recovered the new species as a well-supported sister lineage to A. hylambatis (Baylis, 1927) from the Neotropical region. Genetic divergence values further support its specific distinctiveness. This study represents the first description of an Aplectana species from L. bolivianus in the Amazon region of Peru and increases the number of recognized species within the genus.

Species of genus Clavellotis (Castro-Romero & Baeza-Kuroki, 1984) are parasites of marine fishes across the world. During the course of a survey on the metazoan parasites of marine fish across the Yucatán Peninsula, Mexico, specimens of a lerneapodid copepod consistent with the concept of Clavelotis were collected from the gills of three species of sparids, and were described as a new species using morphological and molecular characters. Clavellotis mayae n. sp. represents the second species of the genus reported in Mexican coastal waters. The new species morphologically resembles C. dubius and C. sebastidis in the trunk shape but can be readily distinguished by having a short maxilla which is separated to its distal end, a sub-oval and conspicuously larger aliform process, and a distal margin of the trunk bearing pronounced subcircular flaps covering the attachment sites of the egg sacs. The new species further differs from all other known congeners by having a short genital process and mandibles without secondary dentition. Molecular analyses through 28S rDNA and cox1 sequences further corroborate all these morphological distinctions and support the taxonomic placement of the new species within Clavellotis. The relationships of this species with other congeners are discussed in light of molecular evidence.

Recent studies have highlighted divergent change as a more common outcome of language contact than previously thought. While convergent change is often attributed to bilingual cognitive pressures, divergent change has usually been explained by appealing to sociocultural factors. We argue that the effects of social pressures on linguistic systems must nevertheless be realized in how language is processed in the individual bilingual speaker and, therefore, that divergent change is also ultimately rooted in bilingual cognition. Since lexical forms are most susceptible to contact-induced divergent change we focus on their production. We begin by developing a cognitive model that combines Grosjean's language mode with a later output-monitoring stage. The parameters to the model are then fit to the results of an experiment in which bilinguals are seen to avoid shared lexical items. These best-fit parameters form the basis of a series of multi-agent simulations that show rapid divergence in the lexica of languages with large proportions of bilinguals. We consider the implications of these findings for the psycholinguistic study of bilingual lexical selection, the construction of phylogenies, and the reconstruction of language family histories.

The lichen genus Lecanora is one of the largest genera of lichenized fungi. The core part of the genus is the L. subfusca group and within this group, Lecanora hybocarpa (Tuck.) Brodo, initially described from North America and thought to be endemic, has been reported from several European countries. However, the identity of these European specimens has been increasingly questioned. This study aimed to clarify the relationship between North American L. hybocarpa and European collections, including the morphologically similar L. sinuosa Herk & Aptroot. We performed morphological, chemical (TLC) and molecular analyses (nrITS and mtSSU) on a broad collection of specimens from Europe, Macaronesia and North America. Our phylogenetic analyses revealed that true L. hybocarpa has not yet been confirmed in Europe. Instead, several genetically distinct European taxa share the L. hybocarpa morphotype. Our findings resulted in the description of three new species: Lecanora cryptosinuosa (differing only genetically from L. sinuosa), L. macaronesica (characterized by quite large apothecia with constricted bases and a finely crenulate margin, and the presence of gangaleoidin) and L. subsinuosa (difficult to separate from L. sinuosa, but may sometimes be recognized by darker apothecial discs with inconsistent pigmentation, the occasional presence of a tiny pruina on young discs, and the usually thicker apothecial margin, dentate in the inner edge). Furthermore, we report L. pseudargentata as a new species for Europe. Due to the high morphological variability and cryptic speciation within this group, reliable identification often requires DNA analysis. Therefore, we propose using the name Lecanora hybocarpa agg. for all species sharing this particular morphotype. A key to the epiphytic esorediate species of the L. subfusca group in Europe and northern Africa is provided.

An extensive survey of North American catostomid fishes yielded insights into the diversity, host specificity and phylogenetic relationships of monopisthocotylans belonging to Pseudomurraytrematidae. Parasites were recorded from 14 of 16 host species surveyed. In total, 22 species of Anonchohaptor, Icelanonchohaptor and Pseudomurraytrema were collected, including 7 new species. Most species were recovered from gills, whereas two Icelanonchohaptor species were found on fins. Phylogenetic analyses based on 28S rDNA support the monophyly of Pseudomurraytrematidae and its sister relationship to Diplectanidae. Within the family, Pseudomurraytrema asiaticum – a parasite of the East Asian fish Myxocyprinus asiaticus – was recovered as sister to the clade of Nearctic pseudomurraytrematids, a placement that may reflect geographic and host-associated separation. The remaining Pseudomurraytrema species parasitize North American Catostominae and form a well-supported clade sister to the clade comprising species of Anonchohaptor and Icelanonchohaptor, primarily associated with Ictiobinae. Under this topology, Pseudomurraytrema, as currently circumscribed, may be paraphyletic. Relationships between morphologically similar species of Anonchohaptor and Icelanonchohaptor remain unresolved: in the 28S tree, Anonchohaptor is paraphyletic (with Icelanonchohaptor nested within it), whereas the concatenated 18S–ITS1–28S analyses recover a single clade with Icelanonchohaptor (2 spp.) sister to the remaining species of Anonchohaptor. The parasite phylogeny broadly reflects host relationships, though several incongruences point to historical host switching. Morphological data also support the monophyly of Pseudomurraytrematidae via a synapomorphic male copulatory organ (U-shaped copulatory tube with a submedial spine, 3-ramus accessory piece), indicating structural conservatism within this family.

Clestobothrium Lühe, 1899 is a genus of cestodes belonging to the order Bothriocephalidea, which infects marine fish from the Gadiformes order. Herein, a novel species of Clestobothrium is described from the intestine of the European hake Merluccius merluccius (Linnaeus, 1758) in the Ionian Sea (Eastern Mediterranean Sea), through an integrative taxonomic approach that combines morphological and molecular data. The new species, named Clestobothrium brettiae n. sp., can be distinguished from all congeners by its unique ovary shape, and a combination of characters including the arrangement and number of testes. It shares similar morphological characters, with Clestobothrium crassiceps (Rudolphi, 1819) Lühe, 1899, which overlaps in host and geographic distribution. However, morphological differences between Clestobothrium brettiae n. sp. and C. crassiceps also include the arrangement of gladiate spinitriches, as well as a larger scolex, proglottids, testes and cirrus sac, and different ovary morphology. The establishment of Clestobothrium brettiae n. sp. as a novel taxon is supported by detailed morphological description and biometric statistics, in addition to molecular characterisation (based on partial small subunit ribosomal ribonucleic acid [rRNA], partial large subunit rRNA, and internal transcribed spacer region 2), genetic distance, and phylogenetic analyses.