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Healing nomenclature: making the names Australoheros mboapari and Australoheros ricani available (Teleostei: Cichlidae)
No full textA close analysis of a publication effort by the authors of the present paper suggests that they need to issue a clarificationto avoid confusion about the nomenclatural status of two species in the genus Australoheros, also known as chanchitos(‘piglets’)
Unique trackway on Permian Karoo shoreline provides evidence of temnospondyl locomotory behaviour
No full textLarge-bodied temnospondyl amphibians were the dominant predators in non-marine aquatic ecosystems from the Carboniferous to the Middle Triassic. In the Permian-aged lower Beaufort Group ofthe main Karoo Basin, South Africa, temnospondyls are represented exclusively by the family Rhinesuchidae and are well represented by body fossils, whereas trace fossils are scarce. Accordingly, most interpretations of the behaviour of this family are based on skeletal morphology and histological data. Here we document the sedimentology and palaeontology of a late Permian palaeosurface situated immediately below the palaeoshoreline ofthe Ecca Sea (transition from the Ecca Group to the Beaufort Group) near the town of Estcourt in KwaZulu-Natal Province. The surface preserves numerous ichnofossils, including tetrapod footprints and fish swim-trails, but most striking are seven body impressions and associated swim trails that we attribute to amedium-sized (~1.9 mlong) rhinesuchid temnospondyl. These provide valuable insight into the behaviour of these animals. The sinuous shape ofsome of the traces suggest that the tracemaker swam with continuous sub-undulatory propulsion of the tail
Morphology of the larvae of Rhantaticus congestus (Klug, 1833) and phylogenetic comparison with other known Aciliini (Coleoptera: Dytiscidae: Dytiscinae)
No full textWe describe the second- and third instar larvae of the diving beetle Rhantaticus congestus (Klug, 1833), including detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, terminal abdominal segment and urogomphi in order to discover useful characters for distinguishing Rhantaticus Sharp, 1882 larvae from those of other known Aciliini (Coleoptera: Dytiscidae: Dytiscinae). A parsimony analysis based on 94 larval characteristics of nine Aciliini species in five genera (Acilius Leach, 1817, Graphoderus Dejean, 1833, Rhantaticus, Sandracottus Sharp, 1882, Thermonectus Dejean, 1833) was conducted using the program TNT. Rhantaticus shares with all these genera several larval character states which support its inclusion in the Aciliini. Whereas Rhantaticus larva stands out from other known genera by several unique character states, our parsimony analysis did not recover any clear phylogenetic position of this genus within the Aciliini
Unusual Miocene hydrocarbon-seep faunas from the Brisighella area in northern Italy: embedded in clastics and first records of the lucinid bivalves Megaxinus and Miltha
No full textAncient hydrocarbon-seep sites known as “Calcari a Lucina” are common in Miocene strata of northern Italy and typically consist of carbonate deposits dominated by large lucinid, bathymodiolin, and vesicomyid bivalves. Here we report two new sites found in Upper Miocene strata at Monte Mauro near Brisighella in the Emilia-Romagna province. One is unusual by being embedded in unconsolidated siltstone without any carbonate, but yet, consisting of the typical, seep-restricted bivalves Bathymodiolus moroniae and Archivesica aharoni vesicomyid clams and bathymodiolin mussels. The second deposit is dominated by the lucinid Megaxinus bellardianus, which has never been reported from a Miocene seep deposit in this region, despite being common in coeval siliciclastic sediments nearby. This species emphasizes biogeographic relationships between Upper Miocene seep faunas in the Mediterranean region and the tropic Indo-West Pacific Ocean.ISMAR-CNR Bologna scientific contribution n. 2070</p
Niche evolution in a northern temperate tree lineage: biogeographical legacies in cork oaks (Quercus section Cerris)
No full textBackground and Aims: Cork oaks (Quercus section Cerris) comprise 15 extant species in Eurasia. Despite being a small clade, they display a range of leaf morphologies comparable to the largest sections (>100 spp.) in Quercus. Their fossil record extends back to the Eocene. Here, we explore how cork oaks achieved their modern ranges and how legacy effects might explain niche evolution in modern species of section Cerris and its sister section Ilex, the holly oaks. Methods: We inferred a dated phylogeny for cork and holly oaks using a reduced-representation next-generation sequencing method, restriction site-associated DNA sequencing (RAD-seq), and used D-statistics to investigate gene flow hypotheses. We estimated divergence times using a fossilized birth–death model calibrated with 47 fossils. We used Köppen profiles, selected bioclimatic parameters and forest biomes occupied by modern species toinfer ancestral climatic and biotic niches. Key Results: East Asian and Western Eurasian cork oaks diverged initially in the Eocene. Subsequently, four Western Eurasian lineages (subsections) differentiated during the Oligocene and Miocene. Evolution of leaf size, form and texture was correlated, in part, with multiple transitions from ancestral humid temperate climates to mediterranean, arid and continental climates. Distantly related but ecologically similar species converged on similar leaf traits in the process. Conclusions: Originating in temperate (frost-free) biomes, Eocene to Oligocene ranges of the primarily deciduous cork oaks were restricted to higher latitudes (Siberia to north of Paratethys). Members of the evergreen holly oaks (section Ilex) also originated in temperate biomes but migrated southwards and south-westwards into then-(sub)tropical southern China and south-eastern Tibet during the Eocene, then westwards along existing pre-Himalayan mountain ranges. Divergent biogeographical histories and deep-time phylogenetic legacies (in cold and drought tolerance, nutrient storage and fire resistance) thus account for the modern species mosaic of Western Eurasian oak communities, which are composed of oaks belonging to four sections
Introgression Underlies Phylogenetic Uncertainty But Not Parallel Plumage Evolution in a Recent Songbird Radiation
No full textFirst report of Sphenothallus Hall, 1847 from the lower Cambrian of North China
No full textSphenothallus is a tubular organism that is one of the most widely distributed and longest-ranging genera through the Palaeozoic. Despite its apparent cosmopolitan distribution, the genus has never been reported from North China. New specimens of Sphenothallus sp. have been discovered in the upper part of the Houjiashan and base of the Mantou formations (early to middle Age 4, Epoch 2, Cambrian) in Jiangsu Province, North China. The specimens are small tubes (up to 5 mm long) and have typical Sphenothallus characteristics, such as a multilayered lamellar structure, and subcircular to elliptical transverse cross-section with a pair of longitudinal thickenings situated at the widest diameter. Our material shows that both the rate of apertural expansion and the curvature of the tubes are significantly larger in early growth stages than in the later growth stages. As the diameter of the aperture increases, the transverse cross-section of the Sphenothallus sp. tube changes from subcircular at the proximal end to elliptical or lenticular at the distal end, and its wall thickness changes from uniform to thickening longitudinally. The discovery of Sphenothallus sp. from the North China Platform represents an extension of its palaeogeographic range during the Cambrian
Evolution and diversity of biomineralized columnar architecture in early Cambrian phosphatic-shelled brachiopods
No full textBiologically-controlled mineralization producing organic-inorganic composites (hard skeletons) by metazoan biomineralizers has been an evolutionary innovation since the earliest Cambrian. Among them, linguliform brachiopods are one of the key invertebrates that secrete calcium phosphate minerals to build their skeletons. One of the most distinct shell structures is the organo-phosphatic cylindrical column exclusive to phosphatic-shelled brachiopods, including both crown and stem groups. However, the complexity, diversity and biomineralization processes of these microscopic columns are far from clear in brachiopod ancestors. Here, exquisitely well-preserved columnar shell ultrastructures are reported for the first time in the earliest eoobolids. The hierarchical shell architectures, epithelial cell moulds, and the shape and size of cylindrical columns are scrutinised in Latusobolus xiaoyangbaensis gen. et sp. nov. and Eoobolus acutulus sp. nov from the Cambrian Series 2 Shuijingtuo Formation of South China. The secretion and construction of the stacked sandwich model of columnar architecture, which played a significant role in the evolution of linguliforms, is highly biologically controlled and organic-matrix mediated. Furthermore, a continuous transformation of anatomic features resulting from the growth of columnar shells is revealed between Eoobolidae, Lingulellotretidae and Acrotretida, shedding new light on the evolutionary growth and adaptive innovation of biomineralized columnar architecture among early phosphatic-shelled brachiopods during the Cambrian explosion
Evolutionary history and seascape genomics of Harbour porpoises (Phocoena phocoena) across environmental gradients in the North Atlantic and adjacent waters
No full textThe Harbour porpoise (Phocoena phocoena) is a highly mobile cetacean species primarily occurring in coastal and shelf waters across the Northern hemisphere. It inhabits heterogeneous seascapes broadly varying in salinity and temperature. Here, we produced 74 whole genomes at intermediate coverage to study Harbour porpoise's evolutionary history and investigate the role of local adaptation in the diversification into subspecies and populations. We identified ~6 million high quality SNPs sampled at eight localities across the North Atlantic and adjacent waters, which we used for population structure, demographic and genotype–environment association analyses. Our results suggest a genetic differentiation between three subspecies (P.p. relicta, P.p. phocoena and P.p. meridionalis), and three distinct populations within P.p. phocoena: Atlantic, Belt Sea and Proper Baltic Sea. Effective population size and Tajima's D suggest population contraction in Black Sea and Iberian porpoises, but expansion in the P.p. phocoena populations. Phylogenetic trees indicate post-glacial colonization from a southern refugium. Genotype–environment association analysis identified salinity as major driver in genomic variation and we identified candidate genes putatively underlying adaptation to different salinity. Our study highlights the value of whole genome resequencing to unravel subtle population structure in highly mobile species, shows how strong environmental gradients and local adaptation may lead to population differentiation, and how neutral and adaptive markers can give different perspectives on population subdivision. The results have great conservation implications as we found inbreeding and low genetic diversity in the endangered Black Sea subspecies and identified the critically endangered Proper Baltic Sea porpoises as a separate population.Hälsoövervakning av marina däggdju
