An arrangement of 15 forms from Dosados Canyon, California, USA. Fossil marine. Mounted in Darax and dated 19/5/2025. Prepared by Michel Haak. Olympus BHB microscope using 450nm LED light. I selected 9 for higher resolution imaging. 63x Leitz Pl Apo 1.4 objective, oil immersion (40x Leitz Pl Apo NA 1.00 objective, oil immersion for A. morenoensis due to its size). Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. Image stacks prepared in Zerene (Pmax).
I have made an attempt at naming some of these.
Top row
1. Rattrayella churchii. Rattrayella churchii Hanna 1934. Published in: Hanna, G.D. (1934). Additional notes on diatoms from the Cretaceous of California. Journal of Paleontology 8: 352-355. Page 355, Plate 48, Figures 3-5. 27 images stacked.
2. Centroporus californicus. Centroporus californicus J.A.Long, Fuge & Js.Smith bis 1946. Published in: Long, J.A., Fuge, D.P. & Smith, J. (1946). Diatoms of the Moreno Shale. Journal of Paleontology 20(2): 89-118, 2 figures, plates 13-19. Page 102, Plate 16, Figure 8. 13 images stacked.
3. Glorioptychus callidus. Glorioptychus callidus Hanna 1927: 20, pl. 2. Published in: Hanna, G.D. (1927). Cretaceous diatoms from California. Occasional Papers of the California Academy of Sciences 13: 5-[49]. Page 20, Plate 2, Figures 7,8.
4. Azpeitiopsis morenoensis. 40x Leitz objective. Azpeitiopsis morenoensis (G.D.Hanna) P.A.Sims 1994. Published in: Sims, P.A. (1994). Benetorus, Gladiopsis and related genera from the Cretaceous. Diatom Research 9(1): 165-187. Page 171, Figures 21-28, 53. Some stacking artifacts (as is often the case with these strongly polygonal structures). 40 images stacked.
Middle row
5. Not sure. Acanthodiscus sp.?? Looks a bit like A. schmidtii (but that is not reported for Dosados. Acanthodiscus schmidtii Jousé 1951. Published in: Jousé, A.P. (1951). Diatomeae Aetatis Palaeocaeni Uralh Septentrionalis. Bot. Mat., Spor. Rast. Bot. Inst. V.L. Komarova, Akad. Nauk. SSSR 7(1-6): 24-42, 4 pl. Page 28, Plate I, Figure 8.).
6. Haynaldia strigillata. Haynaldia strigillata (O.N.Witt) Hanna, nom. illeg. 1934. Published in: Hanna, G.D. (1934). Additional notes on diatoms from the Cretaceous of California. Journal of Paleontology 8: 352-355. Page 353. This name is currently regarded as a synonym of Haynaldella strigillata (O.N.Witt) M.A.Harper. 28 images stacked.
7. Aulacodiscus sp. (A. alternans??) (A. hispidus??).
Bottom row
8. Benetorus sp. I initially thought Pomphodiscus morenoensis (J.A.Long, D.P.Fuge, & J.Smith) J.W.Barker & S.H.Meakin 1947. Published in: Barker, J.W. & Meakin, S.H. (1947). New diatoms from the Moreno shale. J. Quekett Micr. Club, ser. 4 2(3): 143-144. Page 124, Plate 22, Figures 5.6. This name is currently regarded as a synonym of Benetorus morenoensis (J.A.Long, Fuge, & Js.Smith bis) P.A.Sims. Published in: Sims, P.A. (1994). Benetorus, Gladiopsis and related genera from the Cretaceous. Diatom Research 9(1): 165-187. Basionym: Craspedodiscus morenoensis J.A.Long, Fuge & Js.Smith bis. However based on Sims paper, I cannot rule out Benetorus fantasmus. This one would be quite small for both of these. 23 images stacked.
9. Triceratium dignum. Underside view. Triceratium dignum J.A.Long, Fuge & Js.Smith bis 1946. Published in: Long, J.A., Fuge, D.P. & Smith, J. (1946). Diatoms of the Moreno Shale. Journal of Paleontology 20(2): 89-118, 2 figures, plates 13-19. Page 113, Plate 17 Figure 15, Plate 18 Figure 10. 43 images stacked.
10. Trigonium/Trinacria sp.?
11. Triceratium dignum?
12. Trigonium/Triceratium sp.?
13. Trinacria coronata. Underside view. Trinacria coronata O.Witt 1886 ‘1885’. Published in: Witt, O.N. (1886 ‘1885’). Ueber den Polierschiefer von Archangelsk-Kurojedowo im Gouv. Simbirsk. Verhandlungen der Russisch-kaiserlichen Mineralogischen Gesellschaft zu St. Petersburg, Series II 22: 137-177, pls. VI-XII. Page 171, Plate X, Figures 5,8. 43 images stacked.
14. Trinacria interlineata. Top side facing upwards. Trinacria interlineata J.A.Long, Fuge & Js.Smith bis. Published in: Long, J.A., Fuge, D.P. & Smith, J. (1946). Diatoms of the Moreno Shale. Journal of Paleontology 20(2): 89-118, 2 figures, plates 13-19. Page 116, Plate 18, Figure 11. 59 images stacked.
15. Euodiella bicornigera. Underside view. Euodiella bicornigera (Hanna) P.A.Sims 2000. Published in: Sims, P.A. (2000). The early history of the Biddulphiales. II. The genus Euodiella P.A. Sims gen. nov. Diatom Research 15(2): 383-407, 66 figs. Page 385. This name is currently regarded as a synonym of Flexibiddulphia bicornigera (Hanna) P.A.Sims. 59 images stacked.
A beautifully made slide with very clear mountant.