| Project/Area Number |
11640467
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Stratigraphy/Paleontology
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| Research Institution | Himeji Insititute of Technology |
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Principal Investigator |
SAEGUSA Haruo DEPARTMENT Insititute of Nature and Environmental Sciences, Institute of Technology, Researcher, 自然環境科学研究所, 助手 (70254456)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2001: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 2000: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1999: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Vertebrate Paleontology / Proboscidea / mastication / molar / DMA / Elephantoidea / Phiomia / gomphotheres / 古脊椎動物学 / 咀嚼 / 古第三紀 / 咬合面 / 機能形態 / 咬耗面 / 写真計測 / 頭蓋 / 古生物 |
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| Research Abstract |
Cheek teeth of Phiomia were examined qualitatively under SEM in an attempt to recognize basic wear pattern of cheek teeth in Elephantoidea. In Phiomia, wear facets of molars can be classified into three categories; facet with distinct margin formed by tooth to tooth contact, and inner and outer abrasion facets with vague margin formed by tooth to food contact. Parallel striae with ligualobuccal orientation are developed on valley slopes and the outer abrasion facet, while pits dominate on inner abrasion facet, central conule and apex of posttrite cones. Wear pattern seen in Phiomia must have been formed by deep interlocking between valley and ridges of molars during trituration of food.
Some of non-tetralophodont gomphotheres, such as Sinomastodon and the mammutid Zygolophodon, retain wear pattern seen in Phiomia. However, wear feature in Gomphotherium, Cuvieronius, Anancus, Stegodontidae and Elephantidea differs from that of Phiomia in that striae are found also on inner abrasion surface. The latter wear pattern must be formed by shallow or no interlocking between valley and ridges of molars during mastication.
A deformed skull of stegolophodon from Japanese Miocene was reconstructed. The reconstruction suggested that some Japanese stegolophodons could be dwarf form, which is the oldest example proboscidean dwaft.
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