Benthic Foraminifera Across the Cretaceous/Paleogene Boundary in the Eastern Tethys (Northern Alborz, Galanderud Section): Extinction Pattern and Paleoenvironmental Reconstruction

2020 ◽  
Vol 50 (1) ◽  
pp. 25-40 ◽  
Author(s):  
Masoud A. Rostami ◽  
Fabrizio Frontalini ◽  
R. Mark Leckie ◽  
Rodolfo Coccioni ◽  
Eric Font ◽  
...  
Keyword(s):  
Species Richness ◽  
Benthic Foraminifera ◽  
Oxygen Index ◽  
Major Change ◽  
Partial Recovery ◽  
Paleoenvironmental Reconstruction ◽  
The Third ◽  
Paleoenvironmental Changes ◽  
Abundance And Distribution ◽  
Depositional Setting

Abstract Extinction patterns, paleobathymetric inferences, and paleoenvironmental changes based on benthic foraminifera were investigated across the Cretaceous/Paleogene (K/Pg) boundary at the Galanderud section (Northern Alborz, Iran), which contains one of the most continuous and expanded K/Pg transitions in the eastern Tethys. On the basis of benthic foraminiferal taxa abundance and distribution, an outer neritic to uppermost bathyal paleo-depositional setting is inferred. In addition, benthic foraminiferal assemblages and planktic/benthic ratios do not indicate any major change in relative sea level during latest Maastrichtian-early Danian time. Changes in benthic foraminiferal assemblages, morphotypes, diversity, heterogeneity, and benthic foraminiferal oxygen index, coupled with statistical analyses, define three intervals. In the first interval (uppermost Maastrichtian Plummerita hantkeninoides Zone), benthic foraminiferal assemblages are moderately to well preserved and highly diverse, with a combination of epibenthic and endobenthic taxa indicating stable, mesotrophic to weakly eutrophic, normal marine conditions. A major change in benthic foraminiferal assemblages at the K/Pg boundary defines a second interval (basal Danian Guembelitria cretacea and lower part of Parvularugoglobigerina eugubina Zones) that is marked by a decrease in the endobenthic morphogroups as well as a decrease in diversity, heterogeneity, genus and species richness. This second interval denotes highly oligotrophic conditions and a collapse in productivity and food availability due to the extinction of some primary producers, with the exception of the three chalk beds representing short-lived blooms of calcareous dinoflagellates. Benthic foraminifera do not show significant extinction at the end of the Cretaceous at this section with only about an 8% loss of species. Additionally, the abundance of some opportunistic species, including Cibicidoides pseudoacutus and Tappanina selmensis, may reflect instability in the benthic foraminiferal assemblages. The third interval (middle-upper part of the Pv. eugubina Zone) is characterized by the dominance of epibenthic morphogroups (up to 70% of the assemblages) with a partial recovery of endobenthic groups. The characteristics of the benthic foraminiferal assemblages indicate that the flux of food to the benthos had not fully recovered during the early Danian.

THE ABUNDANCE OF RECENT FORAMINIFERA IN SURFACE SEDIMENT OF AMBON BAY

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Suhartati M. Natsir
Keyword(s):  
Surface Sediment ◽  
Benthic Foraminifera ◽  
Sea Water ◽  
Planktonic Foraminifera ◽  
Sediment Characteristic ◽  
Abundance And Distribution

Foraminifera are generally live in sea water with various sizes. These organisms consist of planktonic and benthic foraminifera. Geological activity on plutonic and volcanic with vomiting magma is transpiring on, and then affects sedimentation and foraminiferal abundance of Ambon Bay. The study was determined to study the abundance and distribution of foraminifera based on the sediment characteristic of Ambon Bay. Sample collected in 2007 of Ambon Bay showed that only 29 samples of 50 samples containing foraminifera. The collected sediments have 86 species of foraminifera, consisting 61 species of benthic foraminifera and 25 species of planktonic foraminifera. The dominant benthic foraminifera in the surface sediment of Ambon bay were Amphistegina lessonii, Ammoniabeccarii,Elphidium craticulatum,Operculina ammonoides and Quinqueloculina parkery. The planktonic foraminifera that were frequently collected from the bay were Globorotalia tumida, Globoquadrina pseudofoliata, Globigerinoides pseudofoliata, Globigerinoides cyclostomus dan Pulleniatina finalis. Generally, the species dwelled as abundant on substrate sand, whereas the areas within substrate mud have no foraminifera lie on them. Keywords: Foraminifera, Abundance, Sediment, Ambon Bay

Third edition of goodman & gilman

1965 ◽  
Vol 3 (26) ◽  
pp. 104-104
Keyword(s):  
United States ◽  
Major Change ◽  
The United States ◽  
The Third ◽  
Pharmacological Basis

We hardly ever review a book, but ‘The Pharmacological Basis of Therapeutics’ by L. S. Goodman and A. Gilman is an exception. It has always been an outstanding book, full of balanced, reliable and detailed facts about all important drugs. This is still true of the third edition (Collier-MacMillan 1965, pp. 1785; 180/-) which marks a major change, for it has been largely written and re-written by 42 experts: Goodman and Gilman have concentrated on rigorous editing. Anyone who wants detailed information will find it here, backed with ample references, and we recommend it to all who have a more than average interest in drugs. It does not aim to help directly with the choice of drugs in practice, and it contains little about general principles. Some drugs marketed only outside the United States are naturally not mentioned.

Benthic Macroinvertebrate Changes in Lakes near Sudbury, Ontario, following a Reduction in Acid Emissions

1992 ◽  
Vol 49 (S1) ◽  
pp. 63-75 ◽  
Author(s):  
Ronald W. Griffiths ◽  
W. Keller
Keyword(s):  
Species Richness ◽  
Benthic Macroinvertebrate ◽  
Lake Basin ◽  
Chemical Toxicity ◽  
The Third ◽  
Refuge Area ◽  
Before And After ◽  
Littoral Habitats ◽  
Macroinvertebrate Density ◽  
Lake Basins

Benthic macroinvertebrates were sampled from three lake basins before and after a reduction in acidity, a result of reduced acid emissions from the smelting industry in Sudbury, Ontario. The number of taxa and macroinvertebrate density were greater in the later surveys of the lakes than expected by chance alone. Species richness and macroinvertebrate density were higher in all littoral habitats and in profundal habitats of two lake basins. Species richness showed little change and macroinvertebrate density was lower in the profundal habitat of the third lake basin. Increased survival, probably as a result of reduced chemical toxicity, best accounted for the higher species richness and benthic density. Trout predation, through a numerical response, probably masked these responses in the profundal habitat of the third lake basin because the refuge area from predation (i.e. region of the hypolimnion low in dissolved oxygen) was small. These data indicate that biological recovery of industrially acidified lakes is possible solely by reducing emissions, provided that recolonizing species are not locally extinct.

EPIPELAGIC EUPHAUSIDS (EUPHAUSIACEA) AND SPRING MESOSCALE FEATURES IN THE GULF OF MEXICO

Crustaceana ◽  
1999 ◽  
Vol 72 (4) ◽  
pp. 391-404 ◽  
Author(s):  
◽  
Keyword(s):  
Gulf Of Mexico ◽  
Surface Waters ◽  
Abundant Species ◽  
Time Of Day ◽  
Migratory Behaviour ◽  
The Third ◽  
Density Values ◽  
Hydrographic Features ◽  
Anticyclonic Eddies ◽  
Abundance And Distribution

AbstractThe abundance and distribution of 21 species of euphausids collected in surface waters (0-200 m) at 69 stations of the Gulf of Mexico and the Yucatan Shelf was analyzed. Zooplankton samples were taken during the JS8601 cruise on board the R/V "Justo Sierra" of the UNAM, in April-May, 1986. During this survey mesoscale hydrographic features such as anticyclonic and cyclonic gyres, and upwelling, were detected in the area. The most abundant species was Stylocheiron carinatum (29.86%), followed by Euphausia tenera (19.97%) and S. suhmi (15.18%). Species richness increased at night: densities were 3.07 times higher then. Apparently, the migratory behaviour, of euphausids buffered the expected effect of the mesoscale features in the local euphausid community. The Bray-Curtis Index revealed three clusters of stations. The first one represented the influence of coastal and shelf waters on the euphausid community. The second group is a mixed oceanic-shelf community, and the third one was related to the Gulf oligotrophic oceanic waters. A fourth group included shallow areas in which no euphausids occurred. The relatively poor anticyclonic eddies did not influence the local euphausid community although low euphausid densities were expected. The relatively richer features, the cyclones, showed higher average densities. Euphausid densities related to the influence of upwelling areas showed density values similar to those recorded in the anticyclones. Two species (S. suhmi and S. carinatum) occurred in all the Gulf of Mexico regardless of the mesoscale environments or the time of day. L'abondance et la repartition de 21 especes d'Euphausiaces recoltes dans les eaux de surface (0-200 m) sur 69 stations du Golfe du Mexique et du plateau du Yucatan ont ete analysees. Les echantillons de zooplancton ont ete preleves au cours de la campagne JS8601 a bord du R/V "Justo Sierra" de l'UNAM, en avril-mai 1986. Au cours de cette mission, de variations hydrographiques d'amplitude moyenne comme les phenomenes cycloniques et anticycloniques, ainsi que l'upwelling, ont ete detectees dans la region. Les especes les plus abondantes etaient Stylocheiron carinatum (29,86%) suivie de Euphausia tenera (19,97%) et S. suhmi (15,18%). La richesse specifique augmentait dans les echantillons nocturnes; les densites etaient 3,07 fois plus elevees la nuit. Apparemment le comportement migratoire des Euphausiaces compensait l'effet attendu des particularites hydrographiques dans la communaute locale d'Euphausiaces. L'indice de Bray-Curtis a revele trois groupes de stations. Le premier representait l'influence des eaux cotieres et de la plate-forme continentale sur la communaute des Euphausiaces. Le second groupe etait une communaute mixte oceanique-plate-forme et le troisieme se rapportait aux eaux oceaniques oligotrophes du Golfe. Un quatrieme groupe incluait les zones peu profondes sans Euphausiaces. Les phenomenes anticycloniques relativement faibles n'avaient pas d'influence sur la communaute locale des Euphausiaces, bien que l'on se soit attendu a des densites d'Euphausiaces basses. Les phenomenes relativement plus marques, les cyclones, ont montre des densites moyennes plus elevees. Les densites d'Euphausiaces liees a l'influence des zones d'upwelling ont indique des valeurs similaires a celles relevees pour les anticyclones. Deux especes (S. suhmi and S. carinatum) sont presentes dans tout le Golfe du Mexique independamment des environnements consideres et du moment de la journee.

scholarly journals Hydrozoan diversity on hard bottom in Kongsfjorden, Svalbard

2010 ◽  
Vol 90 (7) ◽  
pp. 1337-1352 ◽  
Author(s):  
Andrey Voronkov ◽  
Sofia D. Stepanjants ◽  
Haakon Hop
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Environmental Conditions ◽  
Depth Range ◽  
Factors Influencing ◽  
Main Factors ◽  
Abundance And Distribution ◽  
First Time

Hydroids in Kongsfjorden, Svalbard, were studied on five hard-bottom transects along gradients of environmental conditions from the glacier at the fjord's head to the fjord's mouth at depth-range 0–30 m. Hydrozoa colonies are widely distributed on rock and gravel substrata in Kongsfjorden. In general, however, hydroids are not dominant or subdominant in zoobenthic communities. The exception isSymplectoscyphus tricuspidatusvar.acuminatus, colonies of which were sometimes abundant enough to determine the community structure and characteristics of benthic diversity. Of the 23 species recorded in this study,Laomedea flexuosa,Phialella quadrataandHalecium tenellumas well as representatives of family Stylasteridae were recorded from Svalbard waters for the first time. Hydroid diversity was highest in the zoobenthic community structured by branched bryozoans. The abundance and distribution of hydroids were reduced, to some extent, in the inner part of the fjord compared to the outer fjord. Species richness of hydroids was high at shallow depths, decreased at around 15 m and then increased again to 30 m depth. Species with Low-boreal–Arctic and Panoceanic distributional ranges were the most frequently occurring species. Depth, type of background substratum and amount of silt on its surface were the main factors influencing hydroid distribution. Description of all recorded taxa distributions together with data on their habitat and associations in zoobenthic communities are presented in an Appendix.

Spatial patterns in species richness and priority areas for conservation of anurans in the Cerrado region, Central Brazil

2004 ◽  
Vol 25 (1) ◽  
pp. 63-75 ◽  
Author(s):  
Divino Brandão ◽  
Rogério Bastos ◽  
Márcia De Souza ◽  
Cleiber Vieira ◽  
Luis Bini ◽  
...  
Keyword(s):  
Species Richness ◽  
Detailed Data ◽  
Population Declines ◽  
Conservation Units ◽  
Central Brazil ◽  
Alternative Systems ◽  
Macro Scale ◽  
Regional System ◽  
Abundance And Distribution ◽  
Effective Conservation

AbstractDeclines in anuran populations worldwide are increasingly creating demands for quick and urgent strategies to maximize efforts to conserve amphibian populations, especially in areas in which few detailed data on diversity, abundance and distribution are available, such as the Cerrado of Central Brazil. We used extent of occurrence of 105 species of Anura (Amphibia) in the Cerrado region to establish a regional system of potential areas that preserves all anuran species in the region, at a macroecological scale. The final network, obtained using a simple "greedy" algorithm based on complementarity, has a total of 10 regions, widely distributed in the biome. These areas were also evaluated in terms of their human demographic parameters (human population size and growth rate). Strong spatial autocorrelation in species richness indicates that alternative systems based on pre-existing conservation units will also be efficient in terms of biodiversity conservation. Although macro-scale approaches are usually coarse, they can provide overall guidelines for conservation and define the focus for more local and effective conservation efforts, which is particularly important when dealing with a taxonomic group such as anurans for which quick and drastic population declines have been reported in many regions of the world.

scholarly journals Drosophilidae (Insecta, Diptera) in the state of Pará (Brazil)

2017 ◽  
Vol 17 (1) ◽  
Author(s):  
Rosângela Santa-Brígida ◽  
Hermes José Schmitz ◽  
Marlúcia Bonifácio Martins
Keyword(s):  
Species Richness ◽  
Native Species ◽  
New Records ◽  
Current Knowledge ◽  
The State ◽  
Detailed Account ◽  
The Third ◽  
Brazilian State ◽  
High Species Richness ◽  
Scientific Collections

Abstract This list contains information on the Drosophilidae that occur in the Brazilian state of Pará, Amazon biome, and an analysis of the current knowledge of Drosophilidae based on museum material and literature records. This list includes a detailed account of the material deposited in the entomological collections of the Museu Paraense Emílio Goeldi and Museu de Zoologia da Universidade de São Paulo, up to 2015. In total, 122 species of Drosophilidae were registered, including 27 new records for the state of Pará and 22 are new records for the Amazon; for instance, the genera Diathoneura and Rhinoleucophenga, and three new records for Brazil, (Drosophila fasciola, Diathoneura flavolineata and Drosophila neochracea). The state of Pará is the third state in Brazil in terms of numbers of species of Drosophilidae, with 17% locally native species. Despite the high species richness, there is still a lot to be known about the states's Drosophilidae fauna. This study highlights the importance of scientific collections, particularly as an aid to study regional biodiversity.

Use of null models to explain crustacean zooplankton assemblages in North Patagonian lakes with presence or absence of mixotrophic ciliates (38°S, Chile)

Crustaceana ◽  
2017 ◽  
Vol 90 (3) ◽  
pp. 311-319 ◽  
Author(s):  
Patricio De los Ríos-Escalante ◽  
Stefan Woelfl
Keyword(s):  
Species Richness ◽  
Random Effect ◽  
Null Model ◽  
Model Analysis ◽  
Null Models ◽  
Crustacean Zooplankton ◽  
Calanoid Copepods ◽  
The Third ◽  
Patagonian Lakes ◽  
Mixotrophic Ciliates

Zooplankton assemblages in Northern Patagonian lakes are characterized by a low species richness and a marked dominance of calanoid copepods. The aim of the present study was to do a null model analysis to explain the composition of the zooplankton assemblages in two North Patagonian lakes. The first aspect to which null model analysis was applied was species co-occurrence, and there the model indicates that the species associations found are not random. The second aspect was niche sharing, and that analysis denotes that the species do not share niches. The third aspect tested was size overlap, and the model there denotes that the species have no size overlap. The results obtained indicate that the sites are relatively homogeneous, which would explain the random effect in species co-ocurrence, whereas the absence of niche sharing is due to the presence of different energetic resources at both sites investigated, which would separate the niche of each species from those of other faunistic elements. Finally, the third application of the null model analysis demonstrates that there is no competition among the species reported upon herein.

Sign in / Sign up

Export Citation Format

Share Document