Comparison of mandibular with cemental growth-layer counts for ageing Atlantic walrus ( Odobenus rosmarus rosmarus )
The relationship between the numbers of growth layers counted in the mandible and in the cementum of lower canines from 87 walrus (Odobenus rosmarus rosmarus) was examined. A 1:1 correlation between counts of growth layers in the two tissues was found in males ≤ 19 years old and females ≤ 9 years ol...
| Published in: | Canadian Journal of Zoology |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1993
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/z93-022 http://www.nrcresearchpress.com/doi/pdf/10.1139/z93-022 |
| Summary: | The relationship between the numbers of growth layers counted in the mandible and in the cementum of lower canines from 87 walrus (Odobenus rosmarus rosmarus) was examined. A 1:1 correlation between counts of growth layers in the two tissues was found in males ≤ 19 years old and females ≤ 9 years old. No correlation was found in males with ≥ 21 or in females with ≥ 10 cemental growth layers. In physically mature walrus, mandibular layering was unreliable for age analysis. Resorption and a reduced mandibular growth rate appear to be the main factors limiting mandibular age estimates in mature walrus. |
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