1-20 OF 64 RESULTS FOR

Cyclotella

Results shown limited to content with bounding coordinates.
Follow your search
Access your saved searches in your account

Would you like to receive an alert when new items match your search?
×Close Modal
Sort by
Journal Article
Published: 01 January 2001
Micropaleontology (2001) 47 (1): 47-71.
... extinct species and two new extinct varieties of the genus Cyclotella (Kutzing) Brebisson (C. iris var. insueta var. nov., C. tempereiformica sp. nov., C. distincta sp. nov., C. comtaeformica sp. nov., C. comtaeformica var. spinata var. nov. and C. praeminuta sp. nov.) are described from Upper Cenozoic...
Image
fig. 1.  <b>Cyclotella</b> radiosa  (Grunow) Lemmermann.  figs 2, 3.  <b>Cyclotella</b> r...
Published: 01 November 2003
Explanation of Plate 2. fig. 1. Cyclotella radiosa (Grunow) Lemmermann. figs 2, 3. Cyclotella rossi Håkansson. fig. 4. Cyclostephanus invisitatus (Hohn & Hellerman) Theriot, Stoermer & Håkansson. figs 5, 6. Navicula schmasmannii Hustedt. All SEM micrographs (scale bars: I, 2=5
Image
Plot of DDI vs. DFI indices for  <b>Cyclotella</b> meneghiniana  in contemporary a...
in > PALAIOS
Published: 14 August 2018
Fig. 10.— Plot of DDI vs. DFI indices for Cyclotella meneghiniana in contemporary and fossil samples. Symbols: gray squares = littoral samples; white circles = planktonic samples; white triangles = open waters samples; black circles = fossil samples from Nahuel Rucá core; LP = Puán Lake; LC
Image
figs 1-5.  <b>Cyclotella</b> rossii  Håkansson.  figs 6-11.  Aulacoseira distans  ...
Published: 01 November 2003
Explanation of Plate 1. figs 1-5. Cyclotella rossii Håkansson. figs 6-11. Aulacoseira distans (Ehrenberg) Simonsen. figs 12, 13. Cyclostephanus invisitatus (Hohn & Hellerman) Theriot, Stoermer & Håkansson. figs 14, 15 . Cyclotella antiqua W. Smith. figs 16, 17. Aulacoseira
Journal Article
Journal: Paleobiology
Published: 25 October 2013
Paleobiology (2013) 40 (1): 91-101.
... novel insights into the rates and patterns of species diversification associated with major habitat shifts, as well as provide valuable context for understanding the age and evolutionary history of the model species, Cyclotella nana (= Thalassiosira pseudonana ). The freshwater fossil record...
FIGURES
Journal Article
Journal: PALAIOS
Published: 01 December 2014
PALAIOS (2014) 29 (12): 612-623.
... sedimentary successions from Argentina (Nahuel Rucá and Hinojales–San Leoncio). Fragmentation and fine-scale surface-alteration indices were calculated on two target species: the diatom Cyclotella meneghiniana Kützing and the snail Heleobia parchappii (d'Orbigny, 1835). The taphonomic data were smoothed along...
FIGURES | View All (11)
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...
Journal Article
Published: 01 December 1978
Journal of Sedimentary Research (1978) 48 (4): 1331-1340.
... of the time, with some oligotrophic ( Cyclotella ocellata ) intervals. Most of the diatomite is varved, with couplets of an average thickness of 0.6 mm, consisting of dark diatom laminae alternating with calcite laminae. The major clay mineral in the elastic zone is a nontronitic smectite similar to the clay...
Journal Article
Published: 01 December 1977
Journal of Sedimentary Research (1977) 47 (4): 1623-1629.
... speicmens of the freshwater diatoms Stauroneis anceps , Cyclotella meneghiniana , and Navicula sp. all gave X-ray powder patterns of alpha -quartz, although the lines were broadened and very weak. These diatoms contain about 99% amorphous material and about 0.l to 1% strained alpha -quartz, in comparison...
Journal Article
Journal: GSA Bulletin
Published: 01 September 1972
GSA Bulletin (1972) 83 (9): 2639-2648.
... zone was more extensive or more productive or both than when the upper zones were deposited. The middle zone (75 to 25 cm) contains a planktonic diatom flora characterized by Cyclotella comta, a common form in the unpolluted lakes of this latitude. The upper zone (25 to 0 cm) contains abundant remains...
Series: AAPG Special Publication
Published: 01 January 1960
DOI: 10.1306/SV21353C5
EISBN: 9781629812403
... be detected. 8. Two hundred species of phytoplankton were identified from the delta, of which 86 per cent were diatoms. Two associations of primary species were recognized. One of these, consisting of species of Cyclotella, Melosira , and Navicula , was found in the river plume, and Blind Bay. The other...
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
Scanning electron micrographs (C, D, G, I) and light micrographs (A, B, E, ...
in > PALAIOS
Published: 01 December 2014
Fig. 2.— Scanning electron micrographs (C, D, G, I) and light micrographs (A, B, E, F, H) of A–D) pristine and E–I) dissolved valves of Cyclotella meneghiniana preserved in Hinojales–San Leoncio and Nahuel Rucá. Scale bars  =  5 µm.
Image
Figure 4. Diatoms, rotifers, and diatom accumulation rates (DARs). A: Plank...
in > Geology
Published: 01 September 2004
Figure 4. Diatoms, rotifers, and diatom accumulation rates (DARs). A: Planktonic diatom species expressed as percentages of total diatom valves (minimum 500 valves counted per sample). Diatom species from left to right are Cyclotella bodanica v. lemanica , Stephanodiscus spp. (sum of at least
Image
Conceptual illustration showing Lake Malawi dynamics under warm and colder ...
in > Geology
Published: 01 September 2015
Figure 2. Conceptual illustration showing Lake Malawi dynamics under warm and colder climatic conditions. A: Under warm conditions, the lake is strongly stratified, Chaoborus finds refuge in anoxic hypolimnion, and the diatom Cyclotella dominates. H—hypolimnion; E—epilimnion. B: Under colder
Image
Diatoms associated with Lake Taupo spring deposits. ( a – c ) and ( e – k )...
Published: 01 January 2007
Fig. 7.  Diatoms associated with Lake Taupo spring deposits. ( a – c ) and ( e – k ) from sample 583d; ( d ) from sample 583g. ( a ) Aulacoseira cf. granulata ; ( b ) Asterionella formosa ; ( c ) Cyclotella stelligera ; ( d ) Synedra ulna ?; ( e ) Epithemia sorex ; ( f ) colony
Image
FIGURE 8 —Examples of near-monospecific sublaminae and blebs from silty dia...
in > PALAIOS
Published: 01 December 2003
FIGURE 8 —Examples of near-monospecific sublaminae and blebs from silty diatomaceous laminae. A and B were taken by BSEM; C and D were taken by LM. (A) Sublamina of Cyclotella sp. within silty diatom hash. (B) Bleb of Operculodinium centrocarpum dinoflagellate cysts (d) within diatom hash. (C
Image
Chronograms inferred with Bayesian relaxed molecular clock methods using fo...
Published: 25 October 2013
and Stephanodiscus were uncalibrated. Genus abbreviations are as follows: Po, Porosira ; R, Roundia ; T, Thalassiosira ; C, Cyclotella ; Sk, Skeletonema ; Sh, Shionodiscus ; B, Bacterosira ; De, Detonula ; M, Minidiscus ; Di, Discostella ; Pu, Puncticulata ; Cs, Cyclostephanos ; St, Stephanodiscus
Image
Relative abundances of the dominant* diatom taxa in samples.  A ) Open wate...
in > PALAIOS
Published: 14 August 2018
. Abbreviations: ACOP = Amphora copulata ; ADAL= Adlafia bryophila ; AGRA = Aulacoseira granulata ; ANGU = A. granulata var. angustissima ; ASPH = Anomoeonoeis sphaeropora ; AVEN = Amphora veneta ; CPLA = Cocconeis placentula ; CYME = Cyclotella meneghiniana ; DPUE = Diploneis puella ; EADN
Journal Article
Published: 01 September 2014
Journal of Micropalaeontology (2014) 33 (2): 111-120.
... on the morphology of a particular taxon. Although valve shape does not change in many radial centric diatoms, there can be changes in the relative proportions of central and peripheral areas. Thus, in some species, the size of marginal alveoli in Cyclotella (Kützing) Brébisson may remain approximately...
FIGURES | View All (5)