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Discoaster

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Journal Article
Published: 01 January 1989
Journal of Paleontology (1989) 63 (1): 10–14.
Journal Article
Published: 01 March 1985
Journal of Paleontology (1985) 59 (2): 309.
Journal Article
Published: 07 December 2016
Journal of Micropalaeontology (2017) 36 (2): 137–152.
...Marina Ciummelli; Isabella Raffi; Jan Backman Abstract Assemblages of upper lower through upper Miocene Discoaster spp. have been quantified from Integrated Ocean Drilling Program (IODP) Site U1338 in the eastern equatorial Pacific Ocean. These assemblages can be grouped into five broad...
FIGURES
First thumbnail for: Biostratigraphy and evolution of Miocene <span cla...
Second thumbnail for: Biostratigraphy and evolution of Miocene <span cla...
Third thumbnail for: Biostratigraphy and evolution of Miocene <span cla...
Journal Article
Published: 01 March 1976
Jour. Geol. Soc. India (1976) 17 (1): 37–44.
...Pratap Singh; K. P. Vimal Abstract The Eastern Coast Mudstone, exposed in Neill island, has yielded a rich assemblage of Late Miocene-Early Pliocene nannoplankton represented by the genera: Discoaster Tan Sin Hok, 1927 and Coccolithus Schwarz, 1894. The genus Discoaster constitutes about ninety...
Journal Article
Published: 01 January 1971
Micropaleontology (1971) 17 (1): 43–52.
Journal Article
Journal: AAPG Bulletin
Published: 01 January 1965
AAPG Bulletin (1965) 49 (1): 98–99.
...John L. Wray; C. Howard Ellis The zone of extinction of discoasters in neritic sediments in the northern Gulf of Mexico is marked by two separate discoaster horizons about 150–500 feet apart ( Fig. 1 ). The lower of these two horizons is characterized by the last occurrence of several species...
FIGURES
First thumbnail for: <span class="search-highlight">Discoaster</span> E...
Journal Article
Published: 01 January 1978
Geological Magazine (1978) 115 (1): 1–19.
Journal Article
Published: 01 July 1954
Journal of Paleontology (1954) 28 (4): 385–403.
Image
1, Discoaster deflandrei (sample U1338C-46H-2, 45 – 46 cm). 2, Intergrading form Discoaster deflandrei–Discoaster variabilis (sample U1338C-31H-3, 122 – 123 cm). 3, Discoaster aulakos (sample U1338B-26H-5, 120 – 121 cm). 4, Discoaster divaricatus (sample U1338C-44H-2, 120 – 121 cm). 5, Discoaster woodringi (sample U1338C-46H-5, 45 – 46 cm). 6, Discoaster signus (sample U1338C-39H-2, 122 – 123 cm). 7, Discoaster cf. signus (sample U1338C-41H-6, 44 – 45 cm). 8, Discoaster exilis (sample U1338A-25H-2, 80 – 81 cm). 9, Discoaster cf. exilis (sample U1338B-42H-4, 45 – 46 cm). 10, Discoaster variabilis (sample U1338B-18H-4, 45 – 46 cm). 11, Intergrading form Discoaster variabilis–Discoaster exilis (sample U1338A-25H-3, 80 – 81 cm). 12, Discoaster icarus (sample U1338B-18H-6, 120 – 121 cm). 13, Intergrading form Discoaster variabilis–Discoaster icarus (sample U1338B-16H-3, 120 – 121 cm). 14, Discoaster cf. bollii (sample U13384 – 24H-4, 58 – 59 cm). 15, Discoaster surculus (sample U1338A-24H, CC). 16, Discoaster loeblichii (sample U1338A-18H-6, 45 – 46 cm). 17 – 18, Discoaster kugleri (sample U1338B-28H-6, 45 – 46 cm). 19 – 20, Discoaster musicus (19 – sample U1338A-25H-4, 120 – 121 cm; 20 – sample U1338B-33H-5, 45 – 46 cm). Scale bar 5 μm.
Published: 07 December 2016
Fig. 1. 1 , Discoaster deflandrei (sample U1338C-46H-2, 45 – 46 cm). 2 , Intergrading form Discoaster deflandrei – Discoaster variabilis (sample U1338C-31H-3, 122 – 123 cm). 3 , Discoaster aulakos (sample U1338B-26H-5, 120 – 121 cm). 4 , Discoaster divaricatus (sample U1338C-44H-2
Image
1, Discoaster brouweri (sample U1338A-13H-3, 120 – 121 cm). 2, Discoaster cf. brouweri (sample U1338C-31H-3, 122 – 123 cm). 3, Discoaster intercalaris (sample U1338A-22H-5, 80 – 81 cm). 4, Intergrading form Discoaster variabilis–Discoaster intercalaris (sample U1338A-19H-5, 45 – 46 cm). 5, Discoaster brouweri &gt;20 µm (sample U1338A-13H-3, 120 – 121 cm). 6, Discoaster neorectus (sample U1338A-18H-5, 120 – 121 cm). 7, Discoaster neohamatus (sample U1338B-13H-2, 120 – 121 cm). 8, Discoaster bellus (sample U1338B-18H-5, 120 – 121 cm). 9, Intergrading form Discoaster bellus–Discoaster hamatus (sample U1338B-24H-3, 142 – 143 cm). 10, Discoaster hamatus (sample U188A-24H-2, 68 – 69 cm). 11 – 12, Intergrading form Discoaster bellus–Discoaster berggrenii (11 – sample U1338B-18H-5, 120 – 121 cm; 12 – sample U1338B-18H-4, 45 – 46 cm). 13 – 14, Discoaster berggrenii (13 – sample U133A-18H-6, 45 – 46 cm; 14 – sample U1338B-13H-2, 120 – 121 cm). 15, Discoaster quinqueramus (sample U1338B-13H-2, 120 – 121 cm). 16, Discoaster asymmetricus (sample U1338A-16H-3, 45 – 46 cm). 17, Discoaster moorei (sample U1338A-25H-3, 80 – 81 cm). 18 – 19, Discoaster pentaradiatus (sample U1338A-9H-5, 70 – 71 cm). 20, Discoaster prepentaradiatus (sample U1338A-21H-2, 66 – 67 cm). Scale bar 5 μm.
Published: 07 December 2016
Fig. 5. 1 , Discoaster brouweri (sample U1338A-13H-3, 120 – 121 cm). 2 , Discoaster cf. brouweri (sample U1338C-31H-3, 122 – 123 cm). 3 , Discoaster intercalaris (sample U1338A-22H-5, 80 – 81 cm). 4 , Intergrading form Discoaster variabilis–Discoaster intercalaris (sample U1338A-19H
Journal Article
Published: 01 July 2012
Journal of Micropalaeontology (2012) 31 (2): 169–178.
...Inga Preiss-Daimler; Karl-Heinz Baumann; Rüdiger Henrich Abstract Mass estimates for Late Miocene and Pliocene (8.6–3.25 Ma) Discoaster species and Sphenolithus are determined using samples of the equatorial Atlantic (Ceara Rise: ODP Site 927). Based on morphometric measurements, 3D computer models...
FIGURES
First thumbnail for: Carbonate budget mass estimates for Neogene <span ...
Second thumbnail for: Carbonate budget mass estimates for Neogene <span ...
Third thumbnail for: Carbonate budget mass estimates for Neogene <span ...
Image
Sequence of Discoaster evolutionary events across the early/middle Miocene boundary at Site U1338, together with abundance data of D. deflandrei and D. variabilis. These changes represent the first major evolutionary transition among Miocene discoasters. Biozonations from Okada &amp; Bukry (1980) and Backman et al. (2012). Depth refers to compressed metres composited depth (see ‘Methods’ section). These changes represent the first major evolutionary transition among Miocene discoasters.
Published: 07 December 2016
Fig. 3. Sequence of Discoaster evolutionary events across the early/middle Miocene boundary at Site U1338, together with abundance data of D. deflandrei and D. variabilis . These changes represent the first major evolutionary transition among Miocene discoasters. Biozonations from Okada
Image
Total abundance of Discoaster spp. (n mm−2) plotted v. age. The Mid Miocene Climatic Optimum onset and the East Antarctica Ice Sheet growth are indicated by arrows.
Published: 07 December 2016
Fig. 12. Total abundance of Discoaster spp. ( n  mm −2 ) plotted v. age. The Mid Miocene Climatic Optimum onset and the East Antarctica Ice Sheet growth are indicated by arrows.
Image
Plot revealing the poor correlation between total Discoaster abundance (n mm−2) and carbonate content (wt%) at Site U1338. All points over 440 specimens represent D. bellus.
Published: 07 December 2016
Fig. 13. Plot revealing the poor correlation between total Discoaster abundance ( n  mm −2 ) and carbonate content (wt%) at Site U1338. All points over 440 specimens represent D. bellus .
Image
Plot revealing the poor correlation between total Discoaster abundance (n mm−2) and oxygen isotopes (left panel) and carbon isotopes (right panel). Dotted line represents isotope data (Reghellin et al. 2015).
Published: 07 December 2016
Fig. 14. Plot revealing the poor correlation between total Discoaster abundance ( n  mm −2 ) and oxygen isotopes (left panel) and carbon isotopes (right panel). Dotted line represents isotope data ( Reghellin et al. 2015 ).
Image
Light microphotographies of the selected calcareous nannofossils reported in fig. 3 (scale bar is 10 micron): 1) Discoaster tamalis from sample SQ24; 2) Discoaster brouweri from sample SQ15; 3) Discoaster surculus from sample SQ15; 4) Discoaster pentaradiatus from sample SQ23; 5, 8) Discoaster intercalaris from samples SQ15 and SQ24, respectively; 6) Discoaster asymmetricus from sample SQ18; 7) Discoaster triradiatus from sample SQ18.
Published: 01 October 2016
Pl. 2 Light microphotographies of the selected calcareous nannofossils reported in fig. 3 (scale bar is 10 micron): 1) Discoaster tamalis from sample SQ24; 2) Discoaster brouweri from sample SQ15; 3) Discoaster surculus from sample SQ15; 4) Discoaster pentaradiatus from sample SQ23; 5
Image
Abundance of Catinaster mexicanus and Discoaster berggrenii in the Upper Miocene at IODP Site U1338. 1, 2. Catinaster mexicanus: 1, sample U1338B-18H-4, 50–51 cm; 2, sample U1338B-18H-4, 60–61 cm. 3, 4. Discoaster berggrenii: 3, sample U1338B-13H-2, 120-121 cm; 4, sample U1338B-13H-3, 45-46 cm. Magnification 1250×. Scale bars 5 µm.
Published: 01 July 2013
Fig. 3. Abundance of Catinaster mexicanus and Discoaster berggrenii in the Upper Miocene at IODP Site U1338. 1, 2. Catinaster mexicanus : 1, sample U1338B-18H-4, 50–51 cm; 2, sample U1338B-18H-4, 60–61 cm. 3, 4. Discoaster berggrenii : 3, sample U1338B-13H-2, 120-121 cm; 4, sample U1338B
Image
Abundance of Catinaster mexicanus and Discoaster berggrenii in the Upper Miocene at ODP Site 845. 1–6. Catinaster mexicanus: 1, 2, same specimen at different focus (sample 845A-12H-2, 141–142 cm); 3, 4, sample 845A-12H-3, 42–43 cm; 5, 6, same specimen at different focus (sample 845A-12H-3, 42–43 cm). 7, 8. Discoaster berggrenii (sample 845A-12H-3, 42–43 cm). Magnification 1250×. Scale bars 5 µm.
Published: 01 July 2013
Fig. 4. Abundance of Catinaster mexicanus and Discoaster berggrenii in the Upper Miocene at ODP Site 845. 1–6. Catinaster mexicanus : 1, 2, same specimen at different focus (sample 845A-12H-2, 141–142 cm); 3, 4, sample 845A-12H-3, 42–43 cm; 5, 6, same specimen at different focus (sample 845A
Image
Abundance of Catinaster mexicanus and Discoaster altus in the Lower Pliocene at IODP Site U1338. 1, 2. Catinaster mexicanus: 1, sample U1338B-6H-4, 120–121 cm; 2, sample U1338B-6H-5, 5–6 cm. 3–5. Discoaster altus with short rays: 3, sample U1338B-6H-5, 110–111 cm; 4, sample U1338B-6H-5, 90–91 cm; 5, sample U1338A-7H-6, 120–121 cm. 6-8. Discoaster altus with long rays: 6, sample U1338B-7H-5, 45–46 cm; 7, 8, same specimen at different focal levels (sample U1338B-7H-6, 70–71 cm). Magnification x1250. Scale bar 5 µm.
Published: 01 July 2013
Fig. 6. Abundance of Catinaster mexicanus and Discoaster altus in the Lower Pliocene at IODP Site U1338. 1, 2. Catinaster mexicanus : 1, sample U1338B-6H-4, 120–121 cm; 2, sample U1338B-6H-5, 5–6 cm. 3–5. Discoaster altus with short rays: 3, sample U1338B-6H-5, 110–111 cm; 4, sample U1338B
Image
Models (left) and SEM pictures of Discoaster groups (right) with increasing ks: 1.D. pentaradiatus;2.D. exilis;3.D. calcaris;4.D. quinqueramus;5.D. hamatus;6.D. brouweri;7.D. surculus;8.D. bellus;9.D. variabilis;10.D. berggrenii, Sphenolithus abies, Discoaster bergenii.
Published: 01 July 2012
Explanation of Plate 1. Models (left) and SEM pictures of Discoaster groups (right) with increasing k s : 1. D. pentaradiatus; 2. D. exilis; 3. D. calcaris; 4. D. quinqueramus; 5. D. hamatus; 6. D. brouweri; 7. D. surculus; 8. D. bellus; 9. D. variabilis; 10. D. berggrenii