The Cretaceous acorn barnacle <i>Archaeochionelasmus nekvasilovae</i> Kočí, Newman and Buckeridge, 2017 (Cirripedia, Neobalanomorpha) is a fragmentary rudist (Bivalvia, Mollusca)

The unique holotype of Archaeochionelasmus nekvasilovae Kočí, Newman and Buckeridge, 2017, from the upper Cenomanian of the Czech Republic, supposedly an early neobalanomorph belonging to the extant family Chionelasmatidae, is compared in detail with chionelasmatids and rudist bivalves. The morphology and shell structure demonstrate that, rather than being a barnacle, it is a poorly preserved fragment of a rudist, which roughly mimics the form of an incomplete balanomorph wall

Prehistoric anthropogenic introduction of partulid tree snails in Papua New Guinean archipelagos

Aim  Members of the tropical tree snail family Partulidae are endemic to Pacific high oceanic islands and typically have single‐island ranges. Two nominal Papua New Guinean species, Partula carteriensis and Partula similaris , deviate from familial norms by having extensive multi‐island ranges that include low islands. We hypothesized that undocumented anthropogenic introductions may underlie this regional biogeographical anomaly and evaluated this hypothesis with novel field distributional and genotypic data. Location  Papua New Guinean archipelagos between 1.4 and 11.4° S and 146.5 and 154.2° E. Methods  Ethanol‐preserved museum lots of P. carteriensis (from New Britain, Bismarck Archipelago) and P. similaris (from Woodlark, Boiaboiawaga and Goodenough islands) were genotyped for a standard mitochondrial marker, cytochrome c oxidase subunit I (COI), and the resulting haplotypes were subjected to phylogeographical analyses. Results  All four genotyped populations showed very little genetic or conchological differentiation, irrespective of nominal taxonomic status, the archipelago sampled or whether the island was low, high, oceanic or continental. Partula carteriensis and P. similaris exhibit atypical distributions on larger high islands, being restricted to coastal villages and absent from native forest. Main conclusions  Our results strongly indicate that P. carteriensis and P. similaris are conspecific, although a formal taxonomic revision is beyond the scope of this present study. They collectively exhibit the most heterogeneous geographical range known among partulids and their explicitly synanthropic association with high island coastal villages strongly implicates human introduction as the regional dispersal mechanism. We currently lack insights into the timeframe (apart from regional prehistory) and cultural context of these translocations. We also lack a convincing source population, and it may be necessary to survey the partulid fauna of the neighbouring Solomon Islands to identify one. Partulids are critically endangered throughout much of their range and the discovery of populations that apparently thrive in human‐altered landscapes is noteworthy. Their study may provide clues of broad relevance to partulid conservation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86895/1/j.1365-2699.2011.02489.x.pd

Evolution of whole-body enantiomorphy in the tree snail genus Amphidromus

Diverse animals exhibit left–right asymmetry in development. However, no example of dimorphism for the left–right polarity of development (whole-body enantiomorphy) is known to persist within natural populations. In snails, whole-body enantiomorphs have repeatedly evolved as separate species. Within populations, however, snails are not expected to exhibit enantiomorphy, because of selection against the less common morph resulting from mating disadvantage. Here we present a unique example of evolutionarily stable whole-body enantiomorphy in snails. Our molecular phylogeny of South-east Asian tree snails in the genus Amphidromus indicates that enantiomorphy has likely persisted as the ancestral state over a million generations. Enantiomorphs have continuously coexisted in every population surveyed spanning a period of 10 years. Our results indicate that whole-body enantiomorphy is maintained within populations opposing the rule of directional asymmetry in animals. This study implicates the need for explicit approaches to disclosure of a maintenance mechanism and conservation of the genus

Exploring the shell-based taxonomy of the Sri Lankan land snail Corilla H. and A. Adams, 1855 (Pulmonata: Corillidae) using mitochondrial DNA

The land-snail genus Corilla is endemic to Sri Lanka and India’s Western Ghats. The ten extant Sri Lankan species belong to two distinct shell forms that are associated respectively with lowland and montane rainforest. We here present the first molecular phylogenetic analysis for Corilla. Our dataset includes nine nominal Sri Lankan species and is based on three mitochondrial genes (CO1, ND1 and 16S). Although the deeper nodes in the trees are not fully resolved, the results do suggest speciation in Corilla has involved repeated, ecologically-driven convergence in shell form. The mtDNA data agree with the current shell-based taxonomy for C. adamsi, C. beddomeae, C. carabinata, C. humberti and C. colletti, consistently supporting the first four as monophyletic, and supporting the last also as monophyletic in nearly all analyses. Corilla adamsi, C. beddomeae and C. colletti may each contain at least one additional, previously undescribed species. The relationship between northern and eastern C. odontophora couldn’t be reliably resolved, but our results suggest that they are distinct species and that there is further species-level or intraspecific (geographical) differentiation within eastern C. odontophora. The current, morphologically-defined species limits of the three remaining nominal species, C. gudei, C. erronea and C. fryae, are inconsistent with the mtDNA sequence data. Northern and southern C. gudei appear to be distinct species: the sister taxon of southern C. gudei is C. humberti, and most analyses showed that the sister taxon of northern C. gudei is the lowland C. carabinata. Corilla erronea and C. fryae constitute a well supported clade in which both nominal species are paraphyletic. While most intra-clade CO1 p-distances are moderate to relatively large, the phylogenetic structuring within the clade does not seem to correspond to any obvious morphological, elevational or geographical patterns. These results are difficult to interpret, and further detailed study is needed before the taxonomic status of C. erronea and C. fryae can be resolved

Evidence for early Pliocene and late Miocene transgressions in southern Patagonia (Argentina): 87Sr/86Sr ages of the pectinid “Chlamys” actinodes (Sowerby)

AbstractNumerical ages based on 87Sr/86Sr dating of calcitic shells belonging to the pectinid “Chlamys” actinodes (Sowerby) document the only late Miocene (Tortonian) sea flooding event in the Austral Basin at Cabo Buentiempo (8.95 ± 0.82 Ma, 2 s.e.), and provide evidence of the first documented early Pliocene (Zanclean) transgression in Argentina recorded at Cañadón Darwin (5.15 ± 0.18 Ma, 2 s.e., Austral Basin) and at Terraces of Cerro Laciar (5.10 ± 0.21 Ma, 2 s.e.), southern San Jorge Basin). The sedimentary rocks deposited during the Tortonian are correlated with the youngest beds deposited by the “Entrerriense Sea” that covered northern Patagonia. The Zanclean marine episode is correlated with the long-term cycle represented in the Southern Hemisphere by the flooding events recorded in Cockburn and James Ross Islands (Antarctica) and in North-Central Chile

Cirripedia of Madeira

We give a list of Cirripedia from Madeira Island and nearby deep water, based on specimens in the collection of the Museu Municipal do Funchal (Historia Natural) (MMF), records mentioned in the literature, and recent collections. Tesseropora atlantica Newman and Ross, 1976 is recorded from Madeira for the first time. The Megabalanus of Madeira is M. azoricus. There are 20 genera containing 27 species, of which 22 occur in depths less than 200 m. Of these shallow water species, eight are wide-ranging oceanic forms that attach to other organisms or to floating objects, leaving just 13 truly benthic shallow water barnacles. This low diversity is probably a consequence of the distance from the continental coasts and the small area of the available habitat. No endemic species have been found

The bubble snails (Gastropoda, Heterobranchia) of Mozambique: an overlooked biodiversity hotspot

This first account, dedicated to the shallow water marine heterobranch gastropods of Mozambique is presented with a focus on the clades Acteonoidea and Cephalaspidea. Specimens were obtained as a result of sporadic sampling and two dedicated field campaigns between the years of 2012 and 2015, conducted along the northern and southern coasts of Mozambique. Specimens were collected by hand in the intertidal and subtidal reefs by snorkelling or SCUBA diving down to a depth of 33 m. Thirty-two species were found, of which 22 are new records to Mozambique and five are new for the Western Indian Ocean. This account raises the total number of shallow water Acteonoidea and Cephalaspidea known in Mozambique to 39 species, which represents approximately 50 % of the Indian Ocean diversity and 83 % of the diversity of these molluscs found in the Red Sea. A gap in sampling was identified in the central swamp/mangrove bio-region of Mozambique, and therefore, we suggest that future research efforts concentrate on or at least consider this region.publishedVersio

DNA multigene characterization of Fasciola hepatica and Lymnaea neotropica and its fascioliasis transmission capacity in Uruguay, with historical correlation, human report review and infection risk analysis

Fascioliasis is a highly pathogenic zoonotic disease emerging in recent decades, in part due to the effects of climate and global changes. South America is the continent presenting more numerous human fascioliasis endemic areas and the highest Fasciola hepatica infection prevalences and intensities known in humans. These serious public health scenarios appear mainly linked to altitude areas in Andean countries, whereas lowland areas of non-Andean countries, such as Uruguay, only show sporadic human cases or outbreaks. To understand this difference, we characterized F. hepatica from cattle and horses and lymnaeids of Uruguay by sequencing of ribosomal DNA ITS-2 and ITS-1 spacers and mitochondrial DNA cox1, nad1 and 16S genes. Results indicate that vectors belong to Lymnaea neotropica instead of to Lymnaea viator, as always reported from Uruguay. Our correlation of fasciolid and lymnaeid haplotypes with historical data on the introduction and spread of livestock species into Uruguay allow to understand the molecular diversity detected. We study the life cycle and transmission features of F. hepatica by L. neotropica of Uruguay under standardized experimental conditions to enable a comparison with the transmission capacity of F. hepatica by Galba truncatula at very high altitude in Bolivia. Results demonstrate that although L. neotropica is a highly efficient vector in the lowlands, its transmission capacity is markedly lower than that of G. truncatula in the highlands. On this baseline, we review the human fascioliasis cases reported in Uruguay and analyze the present and future risk of human infection in front of future climate change estimations