- Tytuł:
- Aragonitic rostra of the Turonian belemnitid Goniacamax: arguments from diagenesis
- Autorzy:
-
Dauphin, Y
Williams, C.T.
Barskov, I.S. - Powiązania:
- https://bibliotekanauki.pl/articles/20211.pdf
- Data publikacji:
- 2007
- Wydawca:
- Polska Akademia Nauk. Instytut Paleobiologii PAN
- Tematy:
-
Turonian
sea shell
Cephalopoda
belemnite
calcite
Goniocamax
rostrum
skeleton
sea cephalopod
diagenesis
paleoenvironment
freshwater shell
Belemnitida
aragonite
Siberia
belemnitid rostrum
Piasina River
paleontology - Opis:
- The hypothesis that belemnitid rostra are formed by primary biogenic low−Mg calcite is widespread. However, the coexistence in the same rostrum of both aragonitic and calcitic components has been reported in true belemnites (Goniocamax, Turonian). A combined microstructural and chemical composition study of the comparison of shells with undisputed mineralogy from the same site as the Turonian Goniocamax, shows that these aragonitic shells display the effects of diagenetic alteration. These observations favour the hypothesis that belemnite rostra are composed of primary aragonite, rather than low−Mg calcite, and are consistent with all other cephalopod shells. Calcitic and aragonitic rostra are also known in other Dibranchiata such as Triassic Aulacocerida and Eocene Belopterina. Diagenetic changes such as shown here may clearly affect palaeo−environmental interpretations based on carbonate shells.
- Źródło:
-
Acta Palaeontologica Polonica; 2007, 52, 1
0567-7920 - Pojawia się w:
- Acta Palaeontologica Polonica
- Dostawca treści:
- Biblioteka Nauki
Artykuł