Form and environment of <em>Gryphaea arcuata</em>
| Titre | Form and environment of <em>Gryphaea arcuata</em> |
|---|---|
| Titre court | Form and environment of <em>Gryphaea arcuata</em> |
| Type de document | article |
| Auteur(s) | Nori, L. Lathuilière, B. |
| Date | 2003 |
| Titre de la publication | Lethaia |
| Volume | vol. 36 |
| N° | 2 |
| N° de page(s) | 83–96 |
| Résumé | <em>Gryphaea arcuata</em> is one of the most studied fossils, but its detailed palaeoecology has been largely neglected. Specimens were collected within a short stratigraphic range (three ammonite zones) in the ‘Calcaire à gryphées’ of Xeuilley (Lorraine, France) dated Hettangian to Lower Sinemurian. As far as possible, they were sampled from each marly bed of the section. A biometric study and an isotopic analysis are compared in regard to organic matter measurements and palynological data, the results demonstrating a clear relationship between the shape of <em>G. arcuata</em> and environmental parameters. Factors responsible for the various shapes are temperature, oxygen levels on the sea floor and nutrient levels. Two main morphotypes can be related to two kinds of environment. In the first, controlled by a relatively hot and humid climate and tending towards eutrophication, the growth rate of Gryphaea was low, and the shells small, wide and thin. In the second environment, cooler than the first one and closer to the optimal living conditions of <em>G. arcuata</em>, the shell was large, thick and narrow, and exhibited a high growth rate. |
| DOI | 10.1080/00241160310003081 |
| Langue | Anglais |
| Collection |
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