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Quantitative studies of some Jurassic belemnite assemblages |
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| Authors: | Roger Alfred Hewitt |
| Abstract: | Belemnite deposits were studied in the Jurassic of Britain and the Bathonian-Callovian of the Aar Massif. Special attention was given to a Middle Callovian Belemnopsis concentration at Brora in Sutherland. Studies of guard size, ontogeny, abundance and orientation suggest that these Belemnopsis had seasonal fluctuations in growth, a low mortality rate compared to living coleoids and were probably deposited in local concentrations, by hybodont sharks. Cylindroteuthis abundance is a better guide to the sedimentation rate, than Belemnopsis. |
| Keywords: | Population Belemnoidea (Belemnopsis) Callovien Bathonien Périodicité Action 081 Climatique (Saison) Structure Directionnelle Thanatocoenose Prédation Chondrichthyes Northern Highlands Scotland (Brora) Alpes Suisses Nord (Stufenstein) Population Belemnoidea (Belemnopsis) Callovian Bathonian Periodicity Climatic Effect (Season) Directional Structure Death Assemblage Predatory Trace Chondrichthyes Northern Highlands Scotland (Brora) Alpes Suisses Nord (Stufenstein) |
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