| Project/Area Number |
06640603
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Stratigraphy/Paleontology
|
|---|
| Research Institution | Tokyo Gakugei University (1995-1996)
Teikyo University of Science & Technology (1994) |
|---|
Principal Investigator |
MATSUKAWA Masaki Tokyo Gakugei University, Dept.of Science Education, Associate professor, 教育学部, 助教授 (30127914)
|
|---|
| Project Period (FY) |
1994 – 1996
|
| Project Status |
Completed (Fiscal Year 1996)
|
| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1996: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1994: ¥1,200,000 (Direct Cost: ¥1,200,000)
|
|---|
| Keywords | Japan / Dinosaur facies / Geological age / Sedimentary environment / Mollusks / Paleontological approaches / 恐竜足跡 / 前期白亜紀 / 手取層群 / 二枚貝化石 / 運搬集積集団 / 残留集団 / 群棲集団 / 日本産 |
|---|
| Research Abstract |
1. Early Cretaceous slender-toed bipedal dinosaur tracks are reported from the eastern part of the Tetori area, central Japan. They are small, bipedal and tridactyl impressions assigned to Toyamasauripus masuiae ichnogen, and ichnosp.nov.based on biometric analysis. Thirty-three individuals to Toyamasauripus masuiae show the highest density of footprints of any dinosaur track-sites in Japan. This is also the first trackway evidence of gregarious dinosaurs reported from Japan. Toyamasauripus masuiae appears to represent a small bipedal dinosaur track-maker that was relatively abundant. As no bones are known from the track-bearing beds, the footprints add much to our knowledge of dinosaur faunas at this time.
2. Nonmarine mlluscan species are rather abundant in many horizons in the Upper Jurassic to Lower Cretaceous Tetori Group. In its southern distribution (the northern part of the Gife Prefecturecentral Japan), there is the typical section of the Group that have an interfingering relat
… More
ionship between nonmarine and marine strata. I analyzed molluscan assemblages in the middle part of the group to understand the taphonomic and other features in marine to nonmarine transitional environments. Four assemblages of nonmarine molluscs among that of five defined by Matsukawa and Ido (1993) are recognized : [1] Ostreidae gen.et sp.indet.-Myrene (Mesocorbicula) tetoriensis [Phenotype J] assemblage, [2] Myrene (Mesocorbicula) tetoriensis [Phenotype J] assemblage, [3] Sphaerium sp.assemblage and [4] Plicatounio (P.) naktongensis-Trigonioides (WAkinoa) tetoriensis assemblage. These assemblages reflect certain grades of environments from backish- to fresh-water, and the species composition of an assemblage varies with salinity (Matsukawa and Ido, 1993). The section of the middle part of the group shows from backish- to fresh-water environments.
3. Nonmarine molluscan species are common throughout Upper Jurassic to Lower Cretaceous sediments in Japan. Many species reveal ecological indices more strongly than chronological indices during early Cretaceous time. Less
|
