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Table T5. Age estimates of diatom datum events. (See table notes.)

Species event Age
(Ma)		 Zone base Reference
T Fragilariopsis reinholdii 0.69 Fragilariopsis doliolus Burckle, 1972
T Nitzschia fossilis 0.92   Barron, 1983; Baldauf and Iwai, 1995
T Rhizosolenia matuyamai 1.02   Burckle, 1978
B Rhizosolenia matuyamai 1.20    
T Rhizosolenia praebergonii var. robusta 1.66 A/B boundary  
B Azpeitia barronii 1.72   Barron, 1983
B Fragilariopsis doliolus 1.88 Fragilariopsis reinholdii Burckle, 1978
T Rhizosolenia praebergonii 1.92   Burckle, 1978; Baldauf and Iwai, 1995
T Thalassiosira convexa 2.18 B/C boundary Burckle, 1978
T Nitzschia jouseae 2.71 A/B boundary Burckle, 1978; Baldauf and Iwai, 1995
B Rhizosolenia praebergonii 3.13 Rhizosolenia praebergonii Burckle, 1978; Baldauf and Iwai, 1995
T Actinocyclus ellipticus f. lanceolata 3.35   Barron, 1983
B Thalassiosira convexa var. convexa 3.84   Burckle and Trainer, 1979; Baldauf and Iwai, 1995
B Asteromphalus elegans 4.21   Burckle, 1978
T Fragilariopsis cylindrica 4.69   Burckle, 1978
B Nitzschia jouseae 4.92 Nitzschia jouseae Burckle, 1978
B Thalssiosira oestrupii 5.70   Burckle, 1978
T Thalssiosira miocenica 5.70 B/C boundary Burckle, 1978
T Asterolampra acutiloba 6.03   Burckle, 1978
T Nitzschia miocenica 6.28   Burckle, 1978
T Nitzschia miocenica var. elongata 6.39    
T Thalssiosira praeconvexa 6.56 A/B boundary Burckle, 1978
T Rossiella praepaleacea 6.76    
B Thalassiosira miocenica 6.86    
B Thalassiosira convexa 6.86 Thalassirosira convexa Burckle, 1978
B Thalassiosira praeconvexa 7.07 A/B boundary Burckle, 1978
T Nitzschia porteri 7.53   Burckle, 1978
B Nitzschia miocenica 7.58 Nitzschia miocenica Burckle, 1978
T Rossiella paleacea 7.64   Burckle, 1978
T Thalssiosira burckliana 7.86 A/B boundary Burckle, 1978
B Fragilariopsis reinholdii 8.20   Barron, 1983
T Actinocyclus ellipticus var. javanicus 8.25    
B Nitzschia marina 8.30   Barron, 1983
T Thalssiosira yabei 8.44 Nitzschia porteri Burckle, 1978
B Fragilariopsis cyclindrica 8.44   Burckle, 1978
B Azpeitia nodulifer var. cyclopa 8.58    
T Coscinodiscus loeblichii 8.77    
B Nitzschia fossilis 8.98   Barron, 1983
B Thalassiosira burcklina 9.09 A/B boundary Barron, 1983
B Cosdinodiscus loeblichii 9.30   Barron, 1983
T Azpeitia vetustissimus var. javanica 9.47   Burckle, 1978
B Azpeitia vetustissimus var. javanica 9.68   Burckle, 1978
T Crucidenticula hustedtii 9.71   Burckle, 1978
T Actinocyclus moronensis 9.77 Thalassiosira yabei Burckle, 1978
B Actinocyclus ellipticus f. lanceolata 9.90   Barron, 1983
T Cavitatus jouseanus 9.97   Barron, 1983
T Crucidenticula punctata 10.13    
B Rossiella paleacea var. elongata 10.13   Barron, 1983
B Thalassionema robusta 10.13   Barron, 1983
T Coscinodsicus gigas var. diorama 10.36 Actinocyclus moronensis Barron, 1983
T Crasepedodicus coscinodiscus 10.36   Barron et al., 1985a
T Actinocyclus ellipticus var. spiralis 10.59   Barron, 1983
B Hemidiscus cuneiformis 11.24   Burckle, 1978
B Rossiella praepaleacea 11.84   Barron, 1983
T Actinocyclus ingens 11.92   Barron, 1983
T Cestodiscus pulchellus 12.05   Barron, 1983
B Nitzschia porteri 12.11   Barron, 1983
B Coscinodiscus temperi var. delicata 12.17 Craspedodiscus coscinodiscus Burckle et al., 1982
T Crucidenticula nicobarica 12.50   Barron, 1983
T2 Annellus californicus 12.68   Barron, 1983
B Coscinodiscus gigas var. diorama 12.84   Barron, 1983
T Coscinodiscus lewisianus 12.99 Coscinodiscus gigas var. diorama Burckle, 1972; Barron et al., 1985b
B Crucidenticula punctata 13.18    
T Thalassiosira tappanae 13.37   Burckle, 1978; Barron, 1983
B Azpeitia nodulifer 13.44   Burckle, 1978
B Triceratium cinnamomeum 13.52    
B Denticulopsis hustedtii 13.70   Burckle, 1978
B Actinocyclus ellipticus var. spiralis 14.19 Coscinodiscus lewisianus Barron, 1983
T Cestodiscus peplum 14.19   Burckle, 1978
B Actinocyclus ellipticus 14.37   Barron, 1983
B Coscinodiscus blysmos 14.55   Barron, 1983
B Thalassirosira tappanae 14.55    
T1 Annellus californicus 14.91 A/B boundary Burckle, 1978
T Azpeitia praenodulifera 15.26   Barron, 1983
B Actinocyclus ingens 15.25   Barron, 1983
T Coscinodiscus lewisianus var. simillis 15.35   Barron, 1983
T Nitzschia maleinterpretaria 15.44   Barron, 1983
T Crucidenticula kanayae 15.78   Barron, 1983
T Thalassirosira fraga 15.96   Barron, 1983
B Cestodiscus pepulum 16.15 Cestodiscus peplum Barron et al., 1985a
T Cavitatus miocenica 16.25    
T Raphidiscus marylandicus 16.49    
B Crucidenticula kanayae 16.63    
T Thalassirosira bukryi 16.72 A/B boundary Barron et al., 1985a
B Coscinodiscus blysmos 16.81    
B Annellus californicus 16.99    
B Craspedodicus coscinodiscus 16.99    
T Coscinodiscus lewisianus var. robusta 17.08    
B Coscinodiscus lewisianus var. similis 17.08    
T Thalassirosira spumellaroides 17.17    
T Triceratium pileus 17.35    
B Crucidenticula nicobarica 17.49 Crucidenticula nicobarica Barron et al., 1985a
T Thalassirosira spinosa 17.64    
T Actinocyclus radionovae 17.64   Barron et al., 1985a
T Craspedodiscus elegans 18.18 Triceratium pileus Barron et al., 1985a
B Nitzschia maleinterpretaria 18.27    
B Triceratium pileus 18.27   Barron, 1983
T Coscinodiscus rhombicus 18.44   Barron, 1983
T Actinocyclus hajosiae 18.96   Barron, 1983
T Bogorovia veniamini 19.21 Craspedodiscus elegans Barron et al., 1985a
B Thalassirosira fraga 19.21   Barron, 1983
B Coscinodiscus lewisianus var. robustus 19.30    
T Azpeitia oligocenica 19.80   Barron et al., 1985b
T Melosira architecuralis 19.89    
B Actinocyclus radionovae 20.61   Barron et al., 2006
T Bogorovia barronii 20.68   Barron et al., 2006
B Azpeitia praenodulifera 20.68   Barron et al., 2006
B Rossiella paleacea 20.96   Barron et al., 2006
T Thalassirosira primalabiata 21.44   Barron et al., 1985b; Burckle, 1972
B Actinocyclus hajosiae 21.44 A/B boundary Barron et al., 2006
B Thalassiosira spumellaroides 21.72   Barron et al., 2006
B Bogorovia barronii 21.72   Barron et al., 2006
B Thalassirosira praefraga 21.99   Barron et al., 2006
B Rossiella fourtanierae 22.74   Barron et al., 2006
T Rocella gelida 23.45 Rossiella fennerae Barron et al., 2006
T Coscinodiscus lewisianus var. rhomboides 23.45   Barron et al., 2006
T Rocella schraderi 23.73   Barron et al., 2006
Bc Rossiella fennerae 23.97   Barron et al., 2006
T Rocella vigilans 24.05   Barron et al., 2006
T Rocella princeps 24.12   Barron et al., 2006
B Rocella schraderi 24.30   Barron et al., 2006
B Craspedodiscus barronii 24.95   Barron et al., 2006
B Rocella gelida 25.14 Rocella gelida Barron et al., 2006
B Coscinodiscus lewisianus var. rhomboides 25.14   Barron et al., 2006
B Rocella princeps 25.38   Barron et al., 2006
T Cestodiscus kugleri 25.38   Barron et al., 2006
T Rossiella symmetrica 25.77   Barron et al., 2006
T Kozloviella minor 27.23   Barron et al., 2006
B Cestodiscus kugleri 27.23   Barron et al., 2006
B Coscinodiscus lewisianus var. levis 27.81   Barron et al., 2006
B Bogorovia veniamini 27.81 Bogorovia veniamini Barron et al., 2006
T Baxteriopsis brunii 27.81   Barron et al., 2006
Tc Cestodiscus trochus 28.07   Barron et al., 2006
B Coscinodiscus rhombicus 28.17   Barron et al., 2006
B Cavitatus rectus 28.17   Barron et al., 2006
B Kozloviella minor 28.31   Barron et al., 2006
B Cavitatus jouseanus 28.31 B/C boundary Barron et al., 2006
B Rossiella symmetrica 28.75 A/B boundary Barron et al., 2006
B Rocella vigilans 29.66 Rocella vigilins Barron et al., 2006
Tc Cestodiscus robustus 30.78   Barron et al., 2006
T Skeletonemopsis barbadiensis 30.95   Barron et al., 2006
T Cestodiscus trochus, marginal labiate processes 30.95   Barron et al., 2006
T Cestodiscus convexus 30.95   Barron et al., 2006
T Coscinodiscus excavatus 31.12 Cestodiscus trochus Barron et al., 2006
B Cavitatus miocenicus 21.12   Barron et al., 2006
B Thalassionema cf. nitzschioides 31.48   Barron et al., 2006
T Coscinodiscus excavatus var. semilunaris 31.72   Barron et al., 2006
B Coscinodiscus excavatus var. semilunaris 32.48   Barron et al., 2006
T Cestodiscus reticulatus 32.48   Barron et al., 2006
B Thalassiothrix cf. primitiva 33.18   Barron et al., 2006
B Cestodiscus reticulatus 33.18   Barron et al., 2006
T Cestodiscus sp. 2 of Fenner 1981 33.27   Barron et al., 2006
B Cestodiscus convexus 33.50   Barron et al., 2006
B Coscinodiscus excavatus 33.71 Coscinodiscus excavatus Barron et al., 2006
B Cestodiscus robustus 33.71   Barron et al., 2006
B Baxteriopsis brunii — Baxteriopsis brunii Fenner, 1985
B Asterolampra marylandica — Asterolampra marylandica Fenner, 1985
B Brightwellia imperfecta — Brightwellia imperfecta Fenner, 1985
T Pyxilla caput-avis —   Fenner, 1985
B Hemiaulus gondolaformis — Hemiaulus gondolaformis Fenner, 1985
B Hemiaulus lyriformis —   Fenner, 1985
B Hemiaulus exiguus —   Fenner, 1985
B Hemiaulus alatus — Hemiaulus alatus Fenner, 1985
B Pyxilla caput-avis — Pyxilla caput-avis Fenner, 1985
B Triceratium inconspicum var. trilobata —   Fenner, 1985
B Triceratium kanayae — Triceratium kanayae Fenner, 1985

Notes: T = top, B = bottom, T1 = lowermost top, T2 = uppermost top, Bc = bottom common occurrence, Tc = top common occurrence. A/B and B/C in Zone column = subzonal boundary.

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