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Giant beaver palaeoecology inferred from stable isotopes
Tessa Plint1,2, Fred J Longstaffe3, Grant Zazula4,5
1Department of Earth Sciences, The University of Western Ontario, London, Ontario, Canada. tplint3@uwo.ca.
Scientific Reports
|May 11, 2019
Summary
The extinct giant beaver (Castoroides) primarily ate aquatic plants, unlike modern beavers. Climate change and habitat loss likely caused its extinction.
Area of Science:
- Paleontology
- Isotope Geochemistry
- Paleoecology
Background:
- The giant beaver (Castoroides) was a widespread Pleistocene megafauna in North America.
- Its ecological role and diet remain subjects of scientific inquiry.
Purpose of the Study:
- To investigate the diet and ecological niche of the extinct giant beaver (Castoroides) using stable isotope analysis.
- To understand the factors contributing to the extinction of Castoroides.
- To establish the chronology of Castoroides' dispersal.
Main Methods:
- Stable carbon (δ13Ccol) and nitrogen (δ15Ncol) isotope analysis of bone collagen from 11 giant beaver individuals.
- Radiocarbon dating of fossil remains.
Main Results:
- Isotope data confirm a diet predominantly of submerged aquatic macrophytes.
- The results do not support a diet of trees or woody plants, differentiating Castoroides from modern beavers (Castor).
- New radiocarbon dates correlate giant beaver dispersal in Beringia with ice sheet retreat.
Conclusions:
- Giant beaver's specialized aquatic diet made it vulnerable to wetland habitat changes.
- Warmer, arid conditions likely contributed to the extinction of Castoroides.
- Giant beaver dispersal patterns are linked to glacial retreat.
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