Foliar cuticle of Ruflorinia orlandoi nov. sp. (Pteridospermophyta) from the Lower Cretaceous of Patagonia

Foliar cuticle of a new species of Ruflorinia, R. orlandoi Carrizo et Del Fueyo, from the Lower Cretaceous Springhill Formation in Santa Cruz province, Argentina, is herein described with light and electronic (scanning and transmission) microscopy. The fronds of R. orlandoi nov. sp. are bipinnate and imparipinnate with a conspicuous main rachis bearing alternate to sub-opposite pinnae. Cuticular striations and hairs are present in both epidermises whereas stomata are only on the abaxial cuticle. Stomata have several papillate subsidiary cells and the guard cells are sunken. Ultrastructurally the adaxial and abaxial cuticles are composed of three and two cuticular layers, respectively. The cuticular characters here described are interpreted as a response to a possible adaptation to a wet climate as well as to the fluctuating environment produced by the gradual transition from fluvial to an estuarine and marine setting that characterizes the Springhill Formation. The discovery of this new species allows expanding the previous knowledge of the paleofloristic composition of the Springhill Formation with the addition of the first pteridospermous megafossil described for this formation. Moreover, the record of Ruflorinia orlandoi nov. sp. in the Springhill Formation highlights the importance of the Caytoniales during the Cretaceous in Patagonia.     

Numerical analyses of selected microencrusters from the Cipit boulders of the St Cassian Formation (Dolomites,NE Italy): palaeoecological implications

The ecological relationships among six microencruster species from the Cipit boulders of the St Cassian Formation (Ladinian–Carnian of the Dolomites, NE Italy) were studied in detail. 112 thin sections in postcard format (10 × 15 cm) and in 7.5 × 10 cm from the localities Alpe di Specie and Misurina were taken into account. Initially, twelve microencruster species were found: Koskinobullina socialis, Terebella lapilloides, Tubiphytes obscurus, Baccanella floriformis, Reptonoditrypa cautica, Plexoramea cerebriformis, Ladinella porata, Microtubus communis, Pseudorothpletzella schmidi, Alpinophragmium perforatum, Planiinvoluta sp and Tethysocarnia cautica. A phenetic algorithm combining three cluster analyses in R‐mode (UPGMA, WPGMA and nearest neighbour) as well as two indices (Jaccard and Bray–Curtis) was performed on all samples. Six microencruster species – grouped in three pairs – were found to have high Jaccard and low Bray–Curtis values at all algorithms. These pairs are represented by Koskinobullina socialis – Pseudorothpletzella schmidi, Terebella lapilloides – Tubiphytes obscurus and Reptonoditrypa cautica – Baccanella floriformis, and were clearly recognizable as robust branches in all phenograms. A further index (Simpson's similarity index) was included successfully in the algorithm in order to sustain the robustness of these phena. This method proved to render reliable results and could be successfully applied in all reef and reef‐like fossil ‘communities’, with the aim of establishing the palaeoecological implications and the specific constraints of selected microencrusters.     

Origin of the white shark Carcharodon (Lamniformes: Lamnidae) based on recalibration of the Upper Neogene Pisco Formation of Peru

Abstract: The taxonomic origin of the white shark, Carcharodon, is a highly debated subject. New fossil evidence presented in this study suggests that the genus is derived from the broad‐toothed ‘mako’, Carcharodon (Cosmopolitodus) hastalis, and includes the new species C. hubbelli sp. nov. – a taxon that demonstrates a transition between C. hastalis and Carcharodon carcharias. Specimens from the Pisco Formation clearly demonstrate an evolutionary mosaic of characters of both recent C. carcharias and fossil C. hastalis. Characters diagnostic to C. carcharias include the presence tooth serrations and a symmetrical first upper anterior tooth that is the largest in the tooth row, while those indicative of C. hastalis include a mesially slanted third anterior (intermediate) tooth. We also provide a recalibration of critical fossil horizons within the Pisco Formation, Peru using zircon U‐Pb dating and strontium‐ratio isotopic analysis. The recalibration of the absolute dates suggests that Carcharodon hubbelli sp. nov. is Late Miocene (6–8 Ma) in age. This research revises and elucidates lamnid shark evolution based on the calibration of the Neogene Pisco Formation.     

Decapod Crustacea from the Agrio Formation (Lower Cretaceous) of the Neuquén Basin,Argentina

Abstract: Two species of decapod crustacean are recorded from the Agua de la Mula Member of the Agrio Formation (Upper Hauterivian – Lower Barremian) of the Neuquén Basin of west‐central Argentina, namely Astacodes falcifer Bell and a new species of Palaeohomarus, P. pacificus. The preservation of the specimens is exceptional, some showing delicate compound eyes and a stridulatory apparatus, features rarely found in fossil forms. Many specimens are preserved articulated inside calcareous nodules, within dark‐grey shales. The lobster‐bearing sediments accumulated in a low‐energy marine environment and diagenetic mineralization occurred very rapidly, prior to significant decay, thus allowing exceptional preservation of specimens. Palaeohomarus was a rare genus in the Cretaceous with a palaeogeographic distribution restricted to the Mediterranean Tethys, the eastern USA and Madagascar, while Astacodes falcifer has been recorded only from Speeton (eastern England) and Neuquén.     

Firmground crustacean burrow systems (Glossifungites ichnofacies) in marine shelf deposits,Paleocene Clayton Formation,Alabama, USA

The Paleocene (Danian) Clayton Formation of western Alabama, USA, includes multiple marine shelf parasequences, each comprising a relatively thick marl, capped by a thin limestone, the latter variably reflecting marine flooding episodes. The marls host relatively large firmground burrow systems that penetrate 50–60 cm beneath, and are cast by, superjacent limestones. Excavation of two partially exposed burrow systems – one beneath a highstand parasequence-bounding flooding surface and the other beneath an overlying coplanar sequence boundary/transgressive surface (SB/TS) – reveals complex, primarily horizontal, irregularly branching networks. The former, allied with Thalassinoides paradoxicus, lacks wall bioglyphs, whereas the latter, allied with Spongeliomorpha iberica, is characterized by pervasive, mainly rhombohedral wall bioglyphs that reflect a relatively more firm substrate. Contrasts between these burrow systems are consistent with sequence stratigraphical context and inferred differences in the mechanism and magnitude of depositional hiatuses responsible for firmground development. Both excavated burrow systems likely represent cumulative structures produced by multiple organisms over extended periods of time. The cumulative nature and potential taphonomic biases associated with these and comparable burrow systems in the stratigraphical record preclude confident interpretation of tracemakers and their behaviours. The Clayton burrow systems likely were produced by one or more species of decapod crustacean that engaged in suspension-feeding, surface detritus feeding, gardening or some combination thereof.     

Teisseirei barattinia Roselli : the first sphinx moth trace fossil from palaeosols,and its distinct type of wall

The trace fossil Teisseirei barattinia, found in Cenozoic formations of Uruguay and Argentina, is an elongated chamber recognizable by its depressed cross‐section, antechamber, and its multi‐layered lining with an inner surface texture composed of densely packed sub‐rectangular to sub‐triangular pits. Our recent behavioural observations on larval and pupal stages of Sphingidae (Lepidoptera), particularly on Manduca rustica, suggest that Teisseirei barattinia is the pupation chamber of a sphinx moth. Last instar larvae of Manduca rustica, Eumorpha anchemolus and E. labruscae were placed in terraria to observe their burrowing behaviour and to recover pupation chambers. Chambers show depressed or plane convex cross‐sections as T. barattinia. The internal surface texture of walls is also similar to that of T. barattinia. The same pattern could be obtained experimentally by pressing the true legs of Manduca rustica larva against plasticine. The multi‐layered wall structure, shown by T. barattinia, is a new type of lining for insect trace fossils in palaeosols that result from soil packing combined with discharges of abundant liquid excretion by soft‐bodied larvae, as in the case of Manduca rustica. T. barattinia is the first trace fossil documented in palaeosols attributed to sphinx moths and supported by macro and micromorphological comparisons with extant pupation chambers. The shallow emplacement of moth pupation chambers in soils suggests that T. barattinia would be a good indicator of palaeosol upper horizons.     

Early evolution of Declinognathodus close to the Mid‐Carboniferous Boundary interval in the Barcaliente type section (Spain)

Upper Serpukhovian to lower Bashkirian conodonts studied from the lower and middle part of the Barcaliente Formation type section (NW Spain) are not abundant, but the sedimentary record seems unusually well represented. The first occurrence of Declinognathodus bernesgae occurs more than 140 m below the first occurrence of D. inaequalis, the taxon of the D. noduliferus species group appearing in the bed of the Global Standard Stratotype‐section and Point (GSSP) for the Mid‐Carboniferous Boundary (Arrow Canyon, Nevada). P1 elements transitional between D. bernesgae and D. inaequalis are described and considered relevant to the global correlation of the Mid‐Carboniferous Boundary. In addition, D. praenoduliferus, D. cf. noduliferus, D. lateralis, Idiognathoides asiaticus, I. corrugatus and Neognathodus sp. are described and illustrated from the Barcaliente Formation. A phylogeny is proposed for the early species of these genera on the basis of the morphological changes of the P1 element, where the rostral parapet and area, the surface roughness and the length and depth of the adcarinal troughs are diagnostic characters at the specific level, while caudal ornamentation is a secondary taxonomic character.     

Bioerosion in the Miocene Reefs of the northwest Red Sea,Egypt

Macroborings provide detailed information on the bioerosion, accretion and palaeoenvironment of both modern and fossil reefs. Dolomitized reefal carbonates in the Um Mahara Formation exhibit an outstanding example of spatially distributed, well‐preserved bioerosion structures in tropical to subtropical syn‐rift Miocene reefs. Ten ichnospecies belonging to five ichnogenera are identified; three belonging to the bivalve‐boring ichnogenus Gastrochaenolites, three attributed to the sponge‐boring ichnogenus Entobia, and four ichnospecies assigned to three worm‐boring ichnogenera Trypanites, Maeandropolydora and Caulostrepsis. The distribution of the reported borings is strongly linked to the palaeo‐reef zones. Two distinctive ichnological boring assemblages are recognized. The Gastrochaenolites‐dominated assemblage reflects shallower‐marine conditions, under water depths of a few metres, mostly in back‐reef to patch‐reef zones of a back‐reef lagoon. The Entobia‐dominated assemblage signifies relatively deeper marine conditions, mostly in reef core of the fringing Miocene reefs. These ichnological assemblages are attributed herein to the Entobia sub‐ichnofacies of the Trypanites ichnofacies. This ichnofacies indicates boring in hard carbonate substrates (such as corals, rhodoliths, carbonate cements and hardgrounds) during periods of non‐sedimentation or reduced sediment input.     

Conodont chronostratigraphical resolution and Declinognathodus evolution close to the Mid‐Carboniferous Boundary in the Barcaliente Formation type section,NW Spain

The Barcaliente Formation in its type section provides significant conodont occurrences in the Mid‐Carboniferous Boundary interval (between the Mississippian and Pennsylvanian sub‐periods). A sequence of Declinognathodus morphotype appearances (considered here as species) is recognized from the uppermost Serpukhovian to the lower Bashkirian. These morphotypes belong to Declinognathodus noduliferus (Ellison & Graves) sensu lato, the primary marker for the worldwide correlation of the Mid‐Carboniferous Boundary. Among them, D. inaequalis (Higgins) appears to have been the first species to occur at the Mid‐Carboniferous Boundary bed in the Arrow Canyon GSSP. A morphocline between D. bernesgae (Sanz‐López et al.) and D. inaequalis is studied here to identify the bed correlated with the GSSP. Other diagnostic first occurrences of conodonts (Rachistognathus minutus (Higgins & Bouckaert), D. noduliferus, D. lateralis (Higgins & Bouckaert), Idiognathoides asiaticus Nigmadganov & Nemirovskaya and I. corrugatus (Harris & Hollingsworth)) are evaluated as chrono‐markers throughout their worldwide distribution, particularly for the Eurasian faunas. The available secondary markers provide a better resolution and support chrono‐correlation in sections other than that at the GSSP. The worldwide first and late occurrences of studied taxa are considered within the background of the Mid‐Carboniferous Extinction Event and the conodont overturn, where crises progenitor Declinognathodus gave rise to members of the Family Idiognathodontidae. Firstly, progenitor taxa are good biostratigraphic tools, whereas local extinction of genera considered Mississippian in age and new taxa arising later in the post‐crises radiation suggest an early Bashkirian palaeogeography and climatic conditions confining temporarily the biogeographic distribution of conodonts.     

Fusarium Species Associated with Mango Malformation in Peninsular Malaysia

Mango malformation has become the most important global disease on mango. Fusarium species previously associated with this disease include F. mangiferae, F. mexicanum, F. sterilihyphosum, F. proliferatum, F. subglutinans and F. tupiense. A few strains of F. proliferatum have been reported from Malaysia, but in this study, we report the results of more extensive sampling. The recovered strains were evaluated with morphology, mating tester strain cross‐fertility, amplified fragment length polymorphisms (AFLPs), and partial DNA sequences of the genes encoding translation elongation factor 1‐α (tef‐1α) and β‐tubulin (tub‐2). Amongst the 43 strains evaluated, three species were identified – F. proliferatum, F. mangiferae and F. subglutinans – with F. proliferatum being the most frequent (69%). None of the Fusarium species that appear to originate in the Americas were recovered in Malaysia, which suggests special measures may be warranted to keep these species from entering the country.     

Genetic dissection of pre‐anthesis sub‐phase durations during the reproductive spike development of wheat

Flowering time is an important factor affecting grain yield in wheat. In this study, we divided reproductive spike development into eight sub‐phases. These sub‐phases have the potential to be delicately manipulated to increase grain yield. We measured 36 traits with regard to sub‐phase durations, determined three grain yield‐related traits in eight field environments and mapped 15 696 single nucleotide polymorphism (SNP, based on 90k Infinium chip and 35k Affymetrix chip) markers in 210 wheat genotypes. Phenotypic and genetic associations between grain yield traits and sub‐phase durations showed significant consistency (Mantel test; r = 0.5377, P < 0.001). The shared quantitative trait loci (QTLs) revealed by the genome‐wide association study suggested a close association between grain yield and sub‐phase duration, which may be attributed to effects on spikelet initiation/spikelet number (double ridge to terminal spikelet stage, DR‐TS) and assimilate accumulation (green anther to anthesis stage, GA‐AN). Moreover, we observed that the photoperiod‐sensitivity allele at the Ppd‐D1 locus on chromosome 2D markedly extended all sub‐phase durations, which may contribute to its positive effects on grain yield traits. The dwarfing allele at the Rht‐D1 (chromosome 4D) locus altered the sub‐phase duration and displayed positive effects on grain yield traits. Data for 30 selected genotypes (from among the original 210 genotypes) in the field displayed a close association with that from the greenhouse. Most importantly, this study demonstrated specific connections to grain yield in narrower time windows (i.e. the eight sub‐phases), rather than the entire stem elongation phase as a whole.     

Onshore expansion of benthic communities after the Late Devonian mass extinction

A detailed ichnological analysis of the Upper Devonian–Lower Mississippian Bakken Formation of sub‐surface Saskatchewan and the partially coeval Exshaw Formation of Alberta indicates the presence of an anomalous ichnofacies gradient. The distal Cruziana Ichnofacies, which in rocks of other ages is restricted to lower‐offshore facies, here ranges from this setting to the lower shoreface. No archetypal Cruziana Ichnofacies is present in these deposits. This pattern is interpreted as resulting from the differential effects of the Late Devonian mass extinction in shallow‐water ecosystems. The onshore expansion evidenced by ichnological data is consistent with the pattern displayed by the body‐fossil record, which indicates a re‐invasion of shallow‐water environments by the Palaeozoic evolutionary fauna during the Late Devonian and into the Early Carboniferous. The ichnofauna studied is overwhelmingly dominated by deposit feeders, with suspension feeders being notably absent, further underscoring the importance of trophic type as a selectivity trait during mass extinctions.     

Antiviral Activity of Faramea hyacinthina and Faramea truncata Leaves on Dengue Virus Type‐2 and Their Major Compounds

The defatted fractions of the Faramea hyacinthina and F. truncata (Rubiaceae) leaf MeOH extracts showed in vitro non‐cytotoxic and anti‐dengue virus serotype 2 (DENV2) activity in human hepatocarcinoma cell lineage (HepG2). Submitting these fractions to the developed RP‐SPE method allowed isolating the antiviral flavanone (2S)‐isosakuranetin‐7‐O‐β‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 1 ) from both species and yielded less active sub‐fractions. The new diastereoisomeric epimer pair (2S) + (2R) of 5,3′,5′‐trihydroxyflavanone‐7‐O‐β‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 2a / 2b ) from F. hyacinthina; the known narigenin‐7‐O‐β‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 3 ) from both species; rutin ( 4 ) and quercetin‐4′‐β‐d ‐O‐glucopyranosyl‐3‐O‐rutinoside ( 5 ) from F. hyacinthina, and kaempferol‐3‐O‐rutinoside ( 6 ), erythroxyloside A ( 7 ) and asperuloside ( 8 ) from F. truncata have been isolated from these sub‐fractions. Compounds 4  –  8 are reported for the first time in Faramea spp.     

Evidence of targeted consumption of mosses by birds in sub‐Antarctic South America

Bryophyte consumption is uncommon among bird species globally and is often presumed incidental. We sought to determine whether herbivorous bird species of the high Andes, including the white‐bellied seedsnipe (Attagis malouinus) and Chloephaga geese (C. picta and C. poliocephala), consume bryophytes, and if so, how frequently. We collected 26 seedsnipe and 22 goose droppings from alpine and sub‐alpine habitats of Navarino Island, Chile and examined their contents for bryophyte diaspores. We detected bryophyte fragments in 84.6% and 90.9% of seedsnipe and Chloephaga goose faecal samples, respectively. We also extracted DNA from three bryophyte fragments isolated from goose droppings and sequenced three chloroplast loci for each sample. We inferred through a barcoding analysis that at least one species of Chloephaga goose consumes Polytrichum strictum and Notoligotrichum trichodon. The composition of 11 collected goose droppings was >50% Polytrichaceae bryophyte fragments, suggesting that at least one Chloephaga goose species foraged deliberately on moss species of this family. These new observations suggest that bryophytes are part of the diet of some high Andean birds and that birds might disperse bryophytes internally – via endozoochory – in the sub‐Antarctic.     

Differential Influence of Life Cycle on Growth and Toxin Production of three Pseudo‐nitzschia Species (Bacillariophyceae)

We used a multistrain approach to study the intra‐ and interspecific variability of the growth rates of three Pseudo‐nitzschia species – P. australis, P. fraudulenta, and P. pungens – and of their domoic acid (DA) production. We carried out mating and batch experiments to investigate the respective effects of strain age and cell size, and thus the influence of their life cycle on the physiology of these species. The cell size – life cycle relationship was characteristic of each species. The influence of age and cell size on the intraspecific variability of growth rates suggests that these characteristics should be considered cautiously for the strains used in physiological studies on Pseudo‐nitzschia species. The results from all three species do not support the hypothesis of a decrease in DA production with time since isolation from natural populations. In P. australis, the cellular DA content was rather a function of cell size. More particularly, cells at the gametangia stage of their life cycle contained up to six times more DA than smaller or larger cells incapable of sexual reproduction. These findings reveal a link between P. australis life cycle and cell toxicity. This suggest that life cycle dynamics in Pseudo‐nitzschia natural populations may influence bloom toxicity.     

Impaired sterol ester synthesis alters the response of Arabidopsis thaliana to Phytophthora infestans

Non‐host resistance of Arabidopsis thaliana against Phytophthora infestans, the causal agent of late blight disease of potato, depends on efficient extracellular pre‐ and post‐invasive resistance responses. Pre‐invasive resistance against P. infestans requires the myrosinase PEN2. To identify additional genes involved in non‐host resistance to P. infestans, a genetic screen was performed by re‐mutagenesis of pen2 plants. Fourteen independent mutants were isolated that displayed an enhanced response to Phytophthora (erp) phenotype. Upon inoculation with P. infestans, two mutants, pen2‐1 erp1‐3 and pen2‐1 erp1‐4, showed an enhanced rate of mesophyll cell death and produced excessive callose deposits in the mesophyll cell layer. ERP1 encodes a phospholipid:sterol acyltransferase (PSAT1) that catalyzes the formation of sterol esters. Consistent with this, the tested T‐DNA insertion lines of PSAT1 are phenocopies of erp1 plants. Sterol ester levels are highly reduced in all erp1/psat1 mutants, whereas sterol glycoside levels are increased twofold. Excessive callose deposition occurred independently of PMR4/GSL5 activity, a known pathogen‐inducible callose synthase. A similar formation of aberrant callose deposits was triggered by the inoculation of erp1 psat1 plants with powdery mildew. These results suggest a role for sterol conjugates in cell non‐autonomous defense responses against invasive filamentous pathogens.     

Endo‐ and epilithic faunal succession in a Pliocene–Pleistocene cave on Rhodes,Greece: record of a transgression

A fossil cave and associated sediments and fossil fauna located on the Greek island of Rhodes in the eastern Aegean Sea is reported here, and the depositional history discussed. The sediments were deposited during the late Pliocene, in the interstitial space between basement boulders of up to 1500 tons. The depositional history of the cave comprises eight stages. From initial flooding, the basin experienced a continuous transgression with sea‐level rise in excess of 500 m, followed by a rapid, forced regression of similar magnitude. The recognition of a succession of fossil communities illustrates this transgression, with a seemingly abrupt shift from endolithic to epilithic biota dominance late in the transgressive cycle. The communities recording the increasing water depth from 0 to >150 m are: The Gatrochaenolithes torpedo (bivalve boring) and Entobia gonioides (sponge boring) ichnocoenosis, with peak distribution between 0 and 1 m water depth; the E. gonioides – E. magna ichnocoenosis, with 1–5 m depth peak distribution; the exclusive E. magna ichnocoenosis, with 5–40 m depth peak distribution; and the E. gigantea ichnocoenosis, with a peak distribution approaching 150–200 m. Below this depth, an epilithic community without boring organisms takes over, characterized by the calcareous sponge Merlia cf. normani, and the inarticulate brachiopod Novocrania turbinata. Simultaneously with the succession of the endo‐ and epilithic cave wall fossil communities, skeletal calcarenite accumulated on the cave floor; the erosional remnants of this sediment are insufficient to further expand the overall transgression–regression model.     

Regional mapping of myocardial hibernation phenotype in idiopathic end‐stage dilated cardiomyopathy

Myocardial hibernation (MH) is a well‐known feature of human ischaemic cardiomyopathy (ICM), whereas its presence in human idiopathic dilated cardiomyopathy (DCM) is still controversial. We investigated the histological and molecular features of MH in left ventricle (LV) regions of failing DCM or ICM hearts. We examined failing hearts from DCM (n = 11; 41.9 ± 5.45 years; left ventricle‐ejection fraction (LV‐EF), 18 ± 3.16%) and ICM patients (n = 12; 58.08 ± 1.7 years; LVEF, 21.5 ± 6.08%) undergoing cardiac transplantation, and normal donor hearts (N, n = 8). LV inter‐ventricular septum (IVS) and antero‐lateral free wall (FW) were transmurally (i.e. sub‐epicardial, mesocardial and sub‐endocardial layers) analysed. LV glycogen content was shown to be increased in both DCM and ICM as compared with N hearts (P < 0.001), with a U‐shaped transmural distribution (lower values in mesocardium). Capillary density was homogenously reduced in both DCM and ICM as compared with N (P < 0.05 versus N), with a lower decrease independent of the extent of fibrosis in sub‐endocardial and sub‐epicardial layers of DCM as compared with ICM. HIF1‐α and nestin, recognized ischaemic molecular hallmarks, were similarly expressed in DCM‐LV and ICM‐LV myocardium. The proteomic profile was overlapping by ~50% in DCM and ICM groups. Morphological and molecular features of MH were detected in end‐stage ICM as well as in end‐stage DCM LV, despite epicardial coronary artery patency and lower fibrosis in DCM hearts. Unravelling the presence of MH in the absence of coronary stenosis may be helpful to design a novel approach in the clinical management of DCM.