Speculations on the ethology of some heteromorph ammonites
Autor: | Mikheil V. Kakabadze |
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Rok vydání: | 2015 |
Předmět: | |
Zdroj: | Swiss Journal of Palaeontology. 135:63-68 |
ISSN: | 1664-2384 1664-2376 |
Popis: | The mode of life of the turricones and colchicones are considered against the background of functional–morphological analyses of their shell modifications during ontogeny. Among turricones, there were more or less differently adapted (nektobenthos, planktobenthos, demersal) habitants. In colchicones transformation from helical to planispiral coiling indicates a transition to a more active, free-swimming mode of life. At the adult stage, with U-shaped shaft–hook morphology, colchicones could passively float or migrate up and down, not in far distance from the seafloor in a near-vertical position of the shaft, with the aperture facing upward. Though, they were able to maneuver and change the orientation of the shell to establish contact with the substrate. |
Databáze: | OpenAIRE |
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