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Stephanodiscus

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Journal Article
Published: 01 July 2015
Journal of Micropalaeontology (2015) 34 (2): 165-179.
...Megumi Saito-Kato; Yoshihiro Tanimura; Shinobu Mori; Matthew L. Julius Abstract A series of intermittent changes in Stephanodiscus (Bacillariophyta) valve morphology was observed in sediment core materials collected from Lake Biwa, Japan. A constant sedimentation rate reveals a continuous...
FIGURES | View All (10)
Journal Article
Published: 01 January 2001
Micropaleontology (2001) 47 (1): 47-71.
...Galina K. Khursevich; Eugene B. Karabanov; Alexander A. Prokopenko; Douglas F. Williams; Mikhail I. Kuzmin; Svetlana A. Fedenya Abstract Three new extinct taxa of the genus Stephanodiscus Ehrenberg (S. williamsii sp. nov., S. princeps sp. nov., S. yukonensis var. antiquus var. nov.) and four new...
Journal Article
Published: 01 October 1981
Micropaleontology (1981) 27 (4): 379-383.
Series: GSA Special Papers
Published: 01 January 1993
DOI: 10.1130/SPE276-p189
... Abundance maps of diatom percentages from 174 Minnesota lakes sediment surface samples show that many diatom species have centers of abundance in lake types from particular regions of the state. Small Stephanodiscus species characterize lakes in the southwestern prairies and in urbanized...
Journal Article
Journal: AAPG Bulletin
Published: 01 October 1982
AAPG Bulletin (1982) 66 (10): 1693.
... . The upper Miocene (Hemphillian) Chalk Hills Formation is highly diatomaceous and is characterized by the presence of primitive forms of Stephanodiscus at its base and by extinct forms of Cyclotella in its upper part. Ash correlations within the Chalk Hills Formation demonstrate that fossil freshwater...
Journal Article
Journal: Paleobiology
Published: 01 January 2006
Paleobiology (2006) 32 (1): 38-54.
...Edward C. Theriot; Sherilyn C. Fritz; Cathy Whitlock; Daniel J. Conley Abstract The centric diatom Stephanodiscus yellowstonensis Theriot and Stoermer is endemic to Yellowstone Lake, where it can be an important component of the summer phytoplankton assemblage. Its close relative, Stephanodiscus...
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Series: GSA Special Papers
Published: 01 January 1993
DOI: 10.1130/SPE276-p215
... throughout this time is consistent with the continuous presence of varves in the record and the predominantly autochthonous character of sediment in the profundal part of the lake. The planktonic diatom assemblages are dominated by two species, Fragilaria crotonensis and Stephanodiscus minutulus...
Series: GSA Special Papers
Published: 01 January 1988
DOI: 10.1130/SPE214-p97
... are dominated by planktonic genera such as Stephanodiscus , Cyclotella , and Melosira . Shallow-water species of Fragilaria and Amphora are common and sometimes abundant. Several planktonic diatoms from the core are also found in the Kelseyville Formation, which is exposed on the southern margin of Clear...
Image
Stratigraphic changes in valve morphology of  <b>Stephanodiscus</b>  species, whic...
Published: 01 July 2015
Fig. 4. Stratigraphic changes in valve morphology of Stephanodiscus species, which occurred monospecifically. From left to right; valve diameter, open squares (minimum), solid small circles (average) and solid squares (maximum); distribution of initial valve diameter; frequency of vestibule
Image
Tempo and mode of morphological evolution of Lake Biwa  <b>Stephanodiscus</b> , re...
Published: 01 July 2015
Fig. 6. Tempo and mode of morphological evolution of Lake Biwa Stephanodiscus , results of paleoTS statistical test. Estimated best models for each window ( n  = 10, 20 and 30) from five models, stasis, punctuation (Punc-1), random walk (URW), Stasis-directional-Stasis (SGS) and directional
Image
SEM images of  <b>Stephanodiscus</b>  cf.  vestibulis  from Lake Biwa 200 m core. ...
Published: 01 July 2015
Fig. C1. SEM images of Stephanodiscus cf. vestibulis from Lake Biwa 200 m core. (a) External view of convex valve showing lifted interfascicles from 393-d (157.5 m depth). (b) Concave resting forms with occluded areolae, well-developed marginal spines and external tube of labiate process
Image
LM and SEM images of  <b>Stephanodiscus</b> umbilicatus  sp. nov. from Lake Biwa 2...
Published: 01 July 2015
Fig. C2. LM and SEM images of Stephanodiscus umbilicatus sp. nov. from Lake Biwa 200 m core. (a , b) Pair valves of holotype from 315-b (127.7 m depth). (c) External view of concave valve with central depression and cast of labiate process tube (arrow) from 315-b (127.7 m depth). ). (d
Image
LM and SEM images of  <b>Stephanodiscus</b> praesuzukii  sp. nov. and  S. suzukii ...
Published: 01 July 2015
Fig. C3. LM and SEM images of Stephanodiscus praesuzukii sp. nov. and S. suzukii from Lake Biwa 200 m core. (a-d, f-g) Stephanodiscus praesuzukii sp. nov. (a) Concave valve of holotype and (b) convex valve from 223-c (93.6 m depth). (c) External view of convex valve with arrow
Image
FIGURE 5 —Frustules of the diatom  <b>Stephanodiscus</b> niagarae  from laminites ...
in > PALAIOS
Published: 01 April 2008
FIGURE 5 —Frustules of the diatom Stephanodiscus niagarae from laminites in the Miyajima Formation. Scale bar is 10 μm
Journal Article
Published: 21 November 1999
Canadian Journal of Earth Sciences (1999) 36 (8): 1299-1314.
... part of the sequence contain AMS dates of 7700-7400 BP and reflect a dramatic change in conditions in the basin. Diatom abundances rise abruptly. Magnetic characteristics change substantially. The presence of freshwater taxa such as Stephanodiscus niagarae , together with brackish water diatoms...
Journal Article
Published: 01 December 1978
Journal of Sedimentary Research (1978) 48 (4): 1331-1340.
...) composed principally of diatomite and an upper zone consisting mainly of fine grained, clastic sediments. The diatoms in the diatomite zone include exclusively centric, planktonic forms, indicating a rather deep, quiet, stratified, slightly alkaline lake, eutrophic ( Stephanodiscus astraea ) for most...
Series: GSA Special Papers
Published: 01 January 1975
DOI: 10.1130/SPE171-p1
... even under the ice. Foremost among these are Stephanodiscus minutus and S. hantzschii , the latter characterizing the most eutrophic lakes studied. Apparently the summer and fall diatom plankton cannot compete with the massive blooms of floating, blue-green algae that occur in the warmer seasons...
Journal Article
Journal: GSA Bulletin
Published: 01 September 1972
GSA Bulletin (1972) 83 (9): 2639-2648.
... of Stephanodiscus minutus, Fragilaria crotonensis, and F. capucina, which are planktonic diatoms living today in the lake and in many highly enriched lakes to the south. This zone coincides with the appearance of hematite and limonite mineral grains that entered the lake when mining began in the area about 1890...
Image
Drill core 2A-10H-2, showing the location of core recovery site 2 in Lake M...
in > Geology
Published: 01 September 2015
Figure 3. Drill core 2A-10H-2, showing the location of core recovery site 2 in Lake Malawi, East Africa. Plotted data are the diatom mixing index (DMI) [( Aulacoseira + Stephanodiscus )/ Cyclotella ], and counts per dry gram of Aulacoseira ( Aul .), Cyclotella , and Stephanodiscus ( Ste
Image
Chronograms inferred with Bayesian relaxed molecular clock methods using fo...
Published: 25 October 2013
circles identify nodes with fossil calibrations, and select other benchmark nodes are shown with open circles. Thickened orange branches identify freshwater taxa, with ancestral ← reconstructions based on Alverson et al. (2007 ). In analysis 3 (left), Cyclostephanos (node 8) and Stephanodiscus (node