To resolve mystery of convergent evolution of secondary symmetrical skull in Odontoceti: using structures of the inner ear
| Project/Area Number |
26800268
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Stratigraphy/Paleontology
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| Research Institution | Waseda University |
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Principal Investigator |
Murakami Mizuki 早稲田大学, 教育・総合科学学術院, 助手 (70710614)
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| Project Period (FY) |
2014-04-01 – 2016-03-31
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| Project Status |
Completed (Fiscal Year 2015)
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| Budget Amount *help |
¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
Fiscal Year 2015: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2014: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Keywords | ハクジラ類 / 頭骨の二次的な左右対称性の進化 / 内耳構造 / 頭骨の左右対称性 / アカボウクジラ科 / 頭骨の左右非対称性 / 歯鯨 |
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| Outline of Final Research Achievements |
Micro CT scanning of fossil odontocete periotics and reconstruction of the zone of audibility could not carry out several reasons. However, cranial asymmetry of both extant and extinct odontocetes in many museums are measured quantitatively (16 families, 37 genera, 53 species). As a result, examinations revealed following points: (1) deviation of bones from the sagittal line and size differences between left and right bones do not always show same trend; (2) from deviation of bones from the sagittal line and size differences between left and right bones, secondary cranial symmetry in Phocoenidae evolved; (3) to compare other odontocetes, right nasal of Delphinidae significantly is larger than its left nasal; (4) Ziphius and Mesoplodon carlhubbsi show strong cranial asymmetry in Ziphiidae.
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Report
(3 results)
Research Products
(5 results)
