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Migration of a Late Cretaceous fish
Scott J Carpenter1, J Mark Erickson, F D Holland
1Paul H. Nelson Stable Isotope Laboratory, Department of Geoscience and Center for Global and Regional Environmental Research, University of Iowa, Iowa City, Iowa 52242-1379, USA. scott-j-carpenter@uiowa.edu
Nature
|May 2, 2003
Summary
This study tracked the life history of Vorhisia vulpes, an ancient fish, using otolith isotopes. Vorhisia vulpes lived in brackish and marine waters, migrating seasonally and indicating a stable 18°C temperature.
Area of Science:
- Paleontology
- Paleoclimatology
- Isotope Geochemistry
Background:
- Late Cretaceous sediments offer insights into climate change before the Cretaceous/Tertiary boundary.
- Fossils from the Western Interior of North America provide crucial climate proxies.
Purpose of the Study:
- To reconstruct the ontogenetic history of the Maastrichtian fish Vorhisia vulpes.
- To utilize isotope ratios from otoliths to understand fish life history and paleoenvironment.
Main Methods:
- Analysis of carbon, oxygen, and strontium isotope ratios.
- Examination of four aragonite otoliths from Vorhisia vulpes fossils.
- Dating of fossils from the Fox Hills Formation, South Dakota.
Main Results:
- Vorhisia vulpes individuals hatched in brackish water (70-80% seawater).
- They migrated to the Western Interior Seaway, staying for approximately 3 years.
- Otolith isotopes indicate a mean seawater temperature of 18°C during their marine phase.
Conclusions:
- Vorhisia vulpes exhibited a complex life cycle involving migration between estuarine and marine environments.
- The reconstructed temperature aligns with other paleoclimate indicators for the latest Maastrichtian.
- This study enhances understanding of fish paleoecology and Late Cretaceous climate dynamics.
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