Subjects -> PALEONTOLOGY (Total: 46 journals)
Showing 1 - 21 of 21 Journals sorted alphabetically
Acta Palaeontologica Polonica     Open Access   (Followers: 6)
Alcheringa: An Australasian Journal of Palaeontology     Hybrid Journal   (Followers: 7)
Ameghiniana     Open Access   (Followers: 1)
Annales de Paléontologie     Full-text available via subscription   (Followers: 7)
Annals of Carnegie Museum     Full-text available via subscription   (Followers: 1)
Boreas: An International Journal of Quaternary Research     Hybrid Journal   (Followers: 12)
Comptes Rendus Palevol     Full-text available via subscription  
European Journal of Protistology     Hybrid Journal   (Followers: 6)
EvoDevo     Open Access   (Followers: 4)
Facies     Hybrid Journal   (Followers: 10)
Fossil Record     Open Access   (Followers: 5)
Geobios     Full-text available via subscription   (Followers: 6)
Historical Biology: An International Journal of Paleobiology     Hybrid Journal   (Followers: 9)
Ichnos: An International Journal for Plant and Animal Traces     Hybrid Journal  
International Journal of Speleology     Open Access   (Followers: 3)
Journal of Paleolimnology     Hybrid Journal   (Followers: 6)
Journal of Paleontology     Hybrid Journal   (Followers: 11)
Journal of Quaternary Science     Hybrid Journal   (Followers: 32)
Journal of Vertebrate Paleontology     Full-text available via subscription   (Followers: 12)
Marine Micropaleontology     Hybrid Journal   (Followers: 2)
Micropaleontology     Full-text available via subscription  
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen     Full-text available via subscription   (Followers: 4)
Novitates Paleoentomologicae     Open Access   (Followers: 1)
Open Quaternary     Open Access   (Followers: 1)
Palaeogeography, Palaeoclimatology, Palaeoecology     Hybrid Journal   (Followers: 13)
Palaeontology     Hybrid Journal   (Followers: 18)
Palaeoworld     Hybrid Journal   (Followers: 3)
PALAIOS     Hybrid Journal   (Followers: 7)
Paläontologische Zeitschrift     Hybrid Journal   (Followers: 4)
Paleobiology     Full-text available via subscription   (Followers: 6)
PaleoBios     Open Access   (Followers: 1)
Paleoceanography and Paleoclimatology     Full-text available via subscription   (Followers: 4)
Paleontological Journal     Full-text available via subscription   (Followers: 5)
Paleontological Research     Full-text available via subscription   (Followers: 3)
Palynology     Hybrid Journal   (Followers: 2)
Papers in Palaeontology     Hybrid Journal   (Followers: 1)
Quaternaire     Open Access   (Followers: 3)
Quaternary Research     Full-text available via subscription   (Followers: 20)
Quaternary Science Reviews     Hybrid Journal   (Followers: 25)
Review of Palaeobotany and Palynology     Hybrid Journal   (Followers: 2)
Revue de Micropaleontologie     Full-text available via subscription  
Rivista Italiana di Paleontologia e Stratigrafia (Research In Paleontology and Stratigraphy)     Open Access   (Followers: 2)
Spanish Journal of Palaeontology     Open Access  
Swiss Journal of Palaeontology     Hybrid Journal   (Followers: 4)
Vertebrate Anatomy Morphology Palaeontology     Open Access   (Followers: 2)
Zitteliana     Open Access   (Followers: 4)
Similar Journals
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European Journal of Protistology
Journal Prestige (SJR): 0.897
Citation Impact (citeScore): 2
Number of Followers: 6  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0932-4739 - ISSN (Online) 1618-0429
Published by Elsevier Homepage  [3305 journals]
  • The opportunistic pathogen Encephalitozoon cuniculi in wild living Murinae
           and Arvicolinae in Central Europe
    • Abstract: Publication date: June 2019Source: European Journal of Protistology, Volume 69Author(s): Agnieszka Perec-Matysiak, Kinga Leśniańska, Katarzyna Buńkowska-Gawlik, Šárka Čondlová, Bohumil Sak, Martin Kváč, Dušan Rajský, Joanna Hildebrand Encephalitozoon spp. is an obligate intracellular microsporidian parasite that infects a wide range of mammalian hosts, including humans. This study was conducted to determine the prevalence of Encephalitozoon spp. in wild living rodents from Poland, the Czech Republic and Slovakia. Faecal and spleen samples were collected from individuals of Apodemus agrarius, Apodemus flavicollis, Apodemus sylvaticus, and Myodes glareolus (n = 465) and used for DNA extraction. PCR, targeting the ITS region of the rRNA gene was performed. The overall prevalence of microsporidia was 15.1%. The occurrence of Encephalitozoon cuniculi in the abovementioned host species of rodents has been presented for the first time, with the highest infection rate recorded for A. flavicollis. Sequence analysis showed that the most frequent species was E. cuniculi genotype II (92.5%). E. cuniculi genotypes I (1.5%) and III (6.0%) were also identified.
       
  • Heat shock protein genes in the green alga Tetraselmis suecica and their
           role against redox and non-redox active metals
    • Abstract: Publication date: June 2019Source: European Journal of Protistology, Volume 69Author(s): Ramaraj Sathasivam, Jang-Seu Ki Microalgae are capable of tolerating variations in water temperature and sudden exposures to toxic substances, and cellular heat shock proteins (HSPs) help to protect cells from such stress. Here, we determined the complete open reading frames (ORF) of small TsHSP20 and large TsHSP70 and 100 in the chlorophyte Tetraselmis suecica, and examined the expression levels of these genes after exposure to thermal stressors, redox-active metals, and non-redox-active metals. Putative TsHSP20, TsHSP70, and TsHSP100 proteins had conserved HSP-family motifs with different C-terminus motifs. Phylogenetic analyses of individual HSPs showed that T. suecica clustered well with other chlorophytes. Real-time PCR analysis showed that thermal stress did not significantly change the expression of all the tested TsHSPs. In addition, TsHSP20 showed little gene expression after being exposed to copper, whereas TsHSP70 and 100 genes greatly responded to the redox-active metals in CuSO4 followed by CuCl2, but not to the non-redox active metals. Redox-active metals strongly affected the physiology of the cells, as judged by cell counting, reactive oxygen species imaging and photosynthetic efficiency. These findings suggest that small and large HSPs are differentially involved in the response against environmental stressors. Moreover, metal toxicity may be specifically controlled by the anions in the metal compounds.
       
  • A new oligotrich (Ciliophora, Oligotrichia) from Argentina, with
           redefinition of Novistrombidium Song and Bradbury
    • Abstract: Publication date: June 2019Source: European Journal of Protistology, Volume 69Author(s): Gabriela Cristina Küppers, Thiago da Silva Paiva, Bárbara do Nascimento Borges, Elisa Raquel Alfaro, María Cristina Claps A new oligotrich similar to Novistrombidium was discovered in plankton samples from an artificial tributary of the Salado River, Buenos Aires province, Argentina, in summer 2010. Propecingulum fistoleramalliei sp. n. has an obovate and anteriorly truncated body, with a conspicuous ventral furrow, is flattened ventrally, and has a prominent right apical protrusion. It temporarily attaches to the substratum by a posterior mucous thread. Rod-shaped extrusomes arranged equidistantly and insert directly above the girdle kinety. The macronucleus is globular to ellipsoidal. The contractile vacuole is located in the left, anterior quarter of the cell and the adoral zone is composed of 30–35 collar, 9–14 buccal, and two thigmotactic membranelles. The girdle kinety is dextrally spiraled and ventrally open; the ventral kinety is posterior to anterior end of the girdle kinety. The oral primordium develops posterior to the right thigmotactic membranelle and anterior the stripe of extrusomes above left, lateral portion of the girdle kinety. The SSUrDNA phylogeny confirms one more time that Novistrombidium is not monophyletic; consequently, we elevate the subgenus Propecingulum up to genus rank and redefine the genus Novistrombidium.
       
  • Diversity of Cryptosporidium spp. in Apodemus spp. in
           Europe
    • Abstract: Publication date: June 2019Source: European Journal of Protistology, Volume 69Author(s): Šárka Čondlová, Michaela Horčičková, Nikola Havrdová, Bohumil Sak, Lenka Hlásková, Agnieszka Perec-Matysiak, Marta Kicia, John McEvoy, Martin Kváč The genetic diversity of Cryptosporidium spp. in Apodemus spp. (striped field mouse, yellow-necked mouse and wood mouse) from 16 European countries was examined by PCR/sequencing of isolates from 437 animals. Overall, 13.7% (60/437) of animals were positive for Cryptosporidium by PCR. Phylogenetic analysis of small-subunit rRNA, Cryptosporidium oocyst wall protein and actin gene sequences showed the presence of Cryptosporidium ditrichi (22/60), Cryptosporidium apodemi (13/60), Cryptosporidium apodemus genotype I (8/60), Cryptosporidium apodemus genotype II (9/60), Cryptosporidium parvum (2/60), Cryptosporidium microti (2/60), Cryptosporidium muris (2/60) and Cryptosporidium tyzzeri (2/60). At the gp60 locus, novel gp60 families XVIIa and XVIIIa were identified in Cryptosporidium apodemus genotype I and II, respectively, subtype IIaA16G1R1b was identified in C. parvum, and subtypes IXaA8 and IXcA6 in C. tyzzeri. Only animals infected with C. ditrichi, C. apodemi, and Cryptosporidium apodemus genotypes shed oocysts that were detectable by microscopy, with the infection intensity ranging from 2000 to 52,000 oocysts per gram of faeces. None of the faecal samples was diarrheic in the time of the sampling.Graphical abstractGraphical abstract for this article
       
  • Loricate choanoflagellates (Acanthoecida) from warm water seas. III.
           Acanthocorbis Hara and Takahashi and Stephanoeca Ellis
    • Abstract: Publication date: June 2019Source: European Journal of Protistology, Volume 69Author(s): Helge Abildhauge Thomsen, Jette Buch Østergaard A large-scale investigation of warm water loricate choanoflagellate communities has revealed the presence of close to 80 species, which is approximately half of all loricate choanoflagellate taxa described when including also hitherto undescribed forms known to us. We are in the process of stepwise providing a monographic treatment of these communities. The overall aim is to contribute the best possible account of species diversity, based on traditional light and electron microscopical techniques, as a tool for future identification work based on microscopy, and in support of the work in progress with establishing a quality assured molecular tool for future recognition of diversity. In this paper we summarize our findings of species of Acanthocorbis and Stephanoeca, which include the description of several new taxa: A. conicella sp. nov., A. gladiella sp. nov., S. broomia sp. nov., S. naja sp. nov., and S. andemanica sp. nov.
       
  • Towards an ecological understanding of the killer trait – A reproducible
           protocol for testing its impact on freshwater ciliates
    • Abstract: Publication date: April 2019Source: European Journal of Protistology, Volume 68Author(s): Lars Koehler, Felicitas E. Flemming, Martina Schrallhammer Paramecium strains with the ability to kill other paramecia often harbour intracellular bacteria belonging to the genera Caedibacter or Caedimonas. Central structures of this killer trait are refractile bodies (R-bodies) produced by the endosymbionts. Once ingested by a sensitive Paramecium, R-bodies presumably act as delivery system for an unidentified toxin which causes the death of endosymbiont-free paramecia while those infected gain resistance from their symbionts. The killer trait is therefore considered as competitive advantage for the hosts of R-body producers. While its effectiveness against paramecia is well documented, the effects on other aquatic ciliates are much less studied.In order to address the broadness of the killer trait, a reproducible killer test assay considering the effects on predatory ciliates (Climacostomum virens and Dileptus jonesi) as well as potential bacterivorous Paramecium competitors (Dexiostoma campyla, Euplotes aediculatus, Euplotes woodruffi, and Spirostomum teres) as possibly susceptible species was established. All used organisms were molecularly characterized to increase traceability and reproducibility. The absence of any lethal effects in both predators and competitors after exposure to killer paramecia strongly suggests a narrow action range for the killer trait. Thus, R-body producing bacteria provide their host with a complex, costly strategy to outcompete symbiont-free congeners only.
       
  • Developmental features and associated symbiont bacterial diversity in
           essential life cycle stages of Heterostelium colligatum
    • Abstract: Publication date: April 2019Source: European Journal of Protistology, Volume 68Author(s): Pu Liu, Jiangan Hou, Yue Zou, Steven L. Stephenson, Xingze Huo, Xuping Hu, Yu Li Dictyostelium discoideum is a specialized amoebozoan protist that can feed on, carry and disperse bacteria. However, the symbiont bacterial diversity in other species of dictyostelids and the diversity associated with essential life cycle stages are still unknown until now. Here, another species of dictyostelids, Heterostelium colligatum, a new record for tropical China, was isolated from the soil collected in Xishuangbanna Tropical Botanical Garden, Yunnan Province, China. We describe the complete life cycle of this species and illustrate details of spore-to-spore development. The symbiont bacterial diversity and relative abundance associated with life cycle stages of H. colligatum, including the aggregation, pseudoplasmodium, and sorocarp stages, were investigated by high throughput metagenomic techniques. H. colligatum appears to be capable of carrying different types of bacteria during its life history in addition to those used as a food resource. The dominant groups of those three stages in its life cycle were the Proteobacteria, Actinobacteria and Firmicutes. The relative abundance of the dominant phyla and shared OTUs were different for the aggregation, pseudoplasmodium, and sorocarp stages. A comparison of the symbiont bacterial assemblages associated with D. discoideum and H. colligatum indicated that different dictyostelid species carried different species of symbiont associated bacteria.
       
  • Recovery of an Acanthamoeba strain with two group I introns in
           the nuclear 18S rRNA gene
    • Abstract: Publication date: April 2019Source: European Journal of Protistology, Volume 68Author(s): Daniele Corsaro, Martina Köhsler, Danielle Venditti, Marilise B. Rott, Julia Walochnik Nuclear group I introns are parasitic mobile genetic elements occurring in the ribosomal RNA genes of a large variety of microbial eukaryotes. In Acanthamoeba, group I introns were found occurring in the 18S rDNA at four distinct insertion sites. Introns are present as single elements in various strains belonging to four genotypes, T3 (A. griffini), T4 (A. castellanii complex), T5 (A. lenticulata) and T15 (A. jacobsi). While multiple introns can frequently be found in the rDNA of several algae, fungi and slime moulds, they are usually rare and present as single elements in amoebae. We reported herein the characterization of an A. lenticulata strain containing two introns in its 18S rDNA. They are located to already known sites and show basal relationships with respective homologous introns present in the other T5 strains. This is the first and unique reported case of multiple nuclear introns in Acanthamoeba.
       
  • The complete mitochondrial genome of Paravannella minima
           (Amoebozoa, Discosea, Vannellida)
    • Abstract: Publication date: April 2019Source: European Journal of Protistology, Volume 68Author(s): Natalya Bondarenko, Anna Glotova, Elena Nassonova, Alexey Masharsky, Dmitry Polev, Alexey Smirnov We present a complete sequence and describe the organization of the mitochondrial genome of the amoeba Paravannella minima (Amoebooza, Discosea, Vannellida). This tiny species represents a branch at the base of Vannellida tree, to the moment being its earliest-branching lineage. The circular mitochondrial DNA of this species has 53,464 bp in length and contains 30 protein-coding genes, 2 ribosomal RNAs, 23 transfer RNAs, and 15 open reading frames. This genome is significantly longer and contains more protein-coding genes than any yet sequenced mitochondrial genome of vannellid amoebae. Unlike the previously sequenced mitochondrial genomes of Vannellida, which should be translated using the “Table 4” (the mold, protozoan, and coelenterate mitochondrial code), that of P. minima can be properly translated using the universal genetic code.
       
  • Morphological and molecular characterization of Neogastrostyla aqua nov.
           gen., nov. spec. (Ciliophora, Hypotrichia) from River Yamuna, Delhi;
           comparison with Gastrostyla-like genera
    • Abstract: Publication date: April 2019Source: European Journal of Protistology, Volume 68Author(s): Harpreet Kaur, Shashi, R.K. Negi, Komal Kamra A novel hypotrichous ciliate, Neogastrostyla aqua nov. gen., nov. spec. isolated from River Yamuna, Delhi, India, is described using morphological, morphometric and morphogenetic characters from live and stained cells supplemented with derivation of phylogenetic relationships using SSU rRNA gene. Neogastrostyla aqua nov. gen., nov. spec., is characterized by light yellow cortical granules present singly or in clusters of two to five, distributed randomly; parental adoral zone of membranelles retained unchanged for proter; Oxytricha-pattern of paroral and endoral; 25–27 frontal-ventral-transverse cirri including a distinct bipartite frontoventral row of composite origin; three dorsal kineties with no fragmentation of the third kinety, two dorsomarginal kineties, three caudal cirri, two macronuclear nodules and two or three micronuclei. Though Neogastrostyla aqua nov. gen., nov. spec. has a frontoventral row like Gastrostyla species, it differs distinctly in the combination of characters from Gastrostyla and other genera with Gastrostyla-like ventral ciliature (Protogastrostyla, Hemigastrostyla, Apogastrostyla and Pseudogastrostyla) particularly in the colour and distribution of cortical granules as well as arrangement and formation of ciliature. According to the phylogenetic analyses, Neogastrostyla aqua nov. gen., nov. spec. clustered consistently with Gastrostyla sp. Y2 (no description available), Oxytricha granulifera and Architricha indica as close neighbours.
       
  • Monographic treatment of Paraholosticha muscicola (Ciliophora,
           Keronopsidae), including morphological and molecular biological
           characterization of a brackish water population from Korea
    • Abstract: Publication date: April 2019Source: European Journal of Protistology, Volume 68Author(s): Jae-Ho Jung, Helmut Berger Paraholosticha muscicola, type species of Paraholosticha Wenzel, inhabits mainly terrestrial habitats, but also freshwater. A brackish water population from Korea is described, the first record from such a habitat. Principal component analysis shows that this population is more similar to a terrestrial population from Denmark than to a population from Antarctic soil. Keronopsids have two strong morphological/ontogenetic apomorphies (frontal corona formed from anlagen I–III; division in cysts). However, the SSU rRNA sequence of the Korean population does not cluster with that of the Antarctic population in the phylogenetic tree, but both branch off consecutively and immediately before a mixture of other non-dorsomarginalian hypotrichs, including two further keronopsids. Furthermore, the keronopsids cluster in the phylogenetic network, providing phylogenetic conflicts, which cannot be exemplified in the conventional gene tree. To complete the picture of P. muscicola, we provide a detailed overview about nomenclature, history, taxonomy, and its geographic distribution. From the four synonyms proposed so far, we tentatively accept only P. lichenicola and P. ovata. Paraholosticha algivora is likewise very similar. Thus we propose to include these three taxa as members of the P. muscicola complex. Stylonethes sterkii and P. algivora are transferred to Paraholosticha Wenzel. A key to the Paraholosticha species is provided.
       
  • On the morphology and predatory behavior of the dinoflagellate Oxyrrhis
           marina exposed to reduced salinity
    • Abstract: Publication date: April 2019Source: European Journal of Protistology, Volume 68Author(s): Benedikt Heyerhoff, Tien Nguyen, Helmut Hillebrand, Erhard Rhiel Changes in salinity are known to alter the morphology of protists, and we hypothesized that these changes subsequently alter also the predatory behavior of the dinoflagellate Oxyrrhis marina. Oxyrrhis was grown in media of 33, 25, 20, and 10% of the regular salinity of f/2 medium (31–32‰). In all cases, the cells discharged trichocysts and swelled. Cell surfaces and volumes increased with decreasing salinity, such that cell surface area at least doubled at 10% and the cell volume increased approximately fourfold. After 1 h, the cells started to regain their regular shape, which was almost completed after 24 h. Oxyrrhis immediately regained its regular shape when culture medium was added 5–10 min after the osmotic stress. When incubated with Pyramimonas grossii as prey, those short-term stressed cells showed no significant different prey uptake in comparison to non-stressed cells. In contrast, 24 h after the addition of prey, short-term stressed Oxyrrhis cells had, with weak statistical significance, more Pyramimonas cells engulfed than non-stressed cells. These results indicated that (1) trichocysts were most likely not involved in prey capture and (2) salinity-stressed Oxyrrhis either enhanced its capability to capture more prey, or its digestion apparatus was hampered.
       
  • The utilization and digestion of cellulose by the rumen ciliate
           Diploplastron affine
    • Abstract: Publication date: April 2019Source: European Journal of Protistology, Volume 68Author(s): Marian Czauderna, Krzysztof Wereszka, Tadeusz Michałowski Rumen protozoa are known to contribute to fibre digestion, but the fibrolytic enzymes of the majority of ciliate species have been poorly recognised to date. The aims of the study were, first, to determine the influence of crystalline cellulose on the survival and population density of the ciliate Diploplastron affine when cultured in vitro, and second to identify and characterise the protozoal enzymes catalysing the hydrolysis of cellulose. It was found that crystalline cellulose, when added to a culture medium, increased the number of protozoa maintained in vitro. We observed that the bacteria-free ciliates fermented microcrystalline cellulose and produced 43.3 nmol volatile fatty acids/protozoon/h. A cell extract prepared from the bacteria-free ciliates degraded crystalline cellulose in the rate of 11.5 nmol released glucose/mg protein/min, whereas the degradation rates of carboxymethyl-cellulose (CMC), avicel and cellobiose were 343, 6.8 and 145 nmol released glucose/mg protein/min respectively. Two distinct peaks in the activity of relevant enzymes were identified following ion exchange chromatography of the protozoal cell extract and the presence of two different CMC-ases were confirmed by zymographic studies. CMC was mainly degraded to mono- and disaccharides but that some other oligosaccharides were also present. Cellobiose was the only product of avicel digestion.
       
  • Assessing the ecological value of small testate amoebae (
    • Abstract: Publication date: April 2019Source: European Journal of Protistology, Volume 68Author(s): Michelle M. McKeown, Janet M. Wilmshurst, Clément Duckert, Jamie R. Wood, Edward A.D. Mitchell Methodological advances are essential for robust ecological research. Quantitative reconstructions of environmental conditions using testate amoebae rely on sound taxonomy. While the taxonomy of large species is relatively well resolved, this is not the case for most small taxa (typically
       
  • New phagotrophic euglenids from deep sea and surface waters of the
           Atlantic Ocean (Keelungia nitschei, Petalomonas acorensis, Ploeotia
           costaversata)
    • Abstract: Publication date: Available online 6 March 2019Source: European Journal of ProtistologyAuthor(s): Alexandra Schoenle, Suzana Živaljić, Dennis Praussea, Janine Voß, Kirsten Jakobsen, Hartmut Arndt New phagotrophic euglenoid species from marine surface waters and the deep sea were isolated and described by light and scanning electron microscopy and 18S rDNA sequencing: Keelungia nitschei, Petalomonas acorensis and Ploeotia costaversata. The morphological characteristics of Keelungia nitschei agree with Keelungia pulex besides the slightly truncated anterior front of the cell of our strain. Phylogenetic analysis indicated low sequence similarity between K. nitschei and K. pulex (87.3%). Ploeotia costaversata clustered within the Ploeotia costata clade with a sequence similarity of 96.1% to P. costata strain Tam. Ultrastructural characteristics of our strain revealed helically twisted strips towards both poles of the protoplast. 18S rDNA phylogenies showed that Petalomonas acorensis is related to the clade of Petalomonas cantuscygni/Scytomonas saepesedens with the highest sequence similarity of 81.2% to P. cantuscygni. Six pellicle strips are visible, while two of them reach only the middle of the cell and four (two longitudinal, two helically twisted) join at the posterior front of the cell. Pressure experiments showed that the deep-sea strain K. nitschei was better adapted to high hydrostatic pressures (up to 500 bar) at 4 °C than the two surface water strains. All three strains increased the database (18S rDNA) of the underrepresented group of phagotrophic euglenids.
       
 
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