| Creator |
|
| Language |
|
| Publisher |
|
|
|
| Date |
|
| Source Title |
|
| Vol |
|
| Issue |
|
| First Page |
|
| Last Page |
|
| Publication Type |
|
| Access Rights |
|
| Crossref DOI |
|
| Abstract |
To make clear the chronological change of Inoceramus species in the Upper Cretaceous sequences, I have examined numerous specimens which were successively collected from the Onogawa and the Uwajima Gr...oup in Southwest Japan. Another sample from the Futaba Group, Northeast Japan, is added as supplementary material. Selected characters are quantitatively and statistically examined on these samples. As a result I attempt to know the morphological relation of the successive samples and consider the infraspecific subdivision. Inoceramus hobetsensis seems to show chronoclines in the Middle Turonian sequence. In the Upper Turonian it is replaced by Inoceramus teshioensis which is not directly related to it. Inoceramus teraokai of probably labiatus stock occurs together with I. hobetsensis in the lower part of Middle Turonian but has no representatives of its descendants in the higher sequences of the examined areas. In the Coniacian Inoceramus uwajimensis occurs characteristically, showing an enlarging extent of variation as the sequence goes upward. There is probably no relation between I. teshioensis and I. uwajimensis. The relation of I. uwajimensis with Inoceramus mihoensis of the next higher substage is open to question.show more
|
Export Mendeley
23_02_p211