Study on Triassic Smaller Foraminifers

在我们目前的研究之前，日本尚未研究过三叠纪有孔虫。我们试图从日本不同地区暴露的碳酸盐岩中收集许多三叠纪较小的有孔虫。结果，我们在北海道的门士多里、飞高山、神井山等地的碳酸盐岩中发现了许多三叠纪有孔虫标本；在日本关东山的志尾山、奥玉地区和其他地区发现了许多三叠纪有孔虫标本；在米诺飞驒山发现了赤坂石灰岩和其他石灰岩；在四国和九州发现了塔霍和卡村石灰岩；在日本外带其他地方发现了一些未命名的小型碳酸盐岩块。我们的藏品还包括泰国南部和马来西亚西北部的许多三叠纪碳酸盐岩。有些材料是从北美太平洋一侧收集的。这些标本在首选方向上被薄切片和/或通过乙酸和氢氟酸处理和古生物学研究作为分离标本回收。这些室内工程尚未完工，但进展迅速。我们检查了大部分以前描述的三叠纪有孔虫，这些有孔虫主要是在欧洲国家引进的，包括瑞士、奥地利、意大利和保加利亚。经检验的标本达486种，为我们今后的古生物学研究作了概要性的列出。迄今为止，我们已经区分出了从斯基梯到雷蒂梯的三叠纪有孔虫50种。甚至在下三叠统的白云岩灰岩中也发现了一些原始类型的菊石种类。在中上三叠统，渐开线蝇科和眼蝇科的种类和属丰富多样。三叠纪有孔虫的演化趋势与硬核期的珊瑚和海绵相似。

Previous to our present research, Triassic foraminifers have not yet been studied in Japan. We tried to collect many Triassic smaller foraminifers from carbonate rocks exposed in various areas in Japan. As the result, we discovered many specimens of Triassic foraminifers from carbonate rocks exposed in Menashidomari, Hidaka mountains, and Kamiiso (Hokkaido), Ashio Mountains, Okutama area and other areas of the Kanto Mountains, Akasaka Limestone and other limestones in the Mino-Hida Mountains, the Taho and Kamura Limestones of Shikoku and Kyushu, and other small unnamed carbonate rock blocks elsewhere in Outer Zone of Japan. Our collections also contain many Triassic carbonate rocks of southern Thailand and northwestern Malaysia. Some materials were collected from the Pacific Side of North America.These specimens are thin-sectioned in preferred orientation and/or recovered as isolated specimens by acetic acid and hydrofluoric acid treatment and paleontologically studied. These indoor works are not completed but rapidly progressing. We checked most of the previously described Triassic foraminifers which were introduced mainly in European countries including Switzerland, Austria, Italy, and Burgaria. The examined specimens attain 486 species and synoptically listed for our future paleontological investigation.Up to date, we already discriminated about 50 species of Triassic foraminifersfrom the Schytian to Rhaetian. Some primitive type of ammodiscusid species are found even in dolomitic limestone of the Lower Triassic. The species and genera of Involutinidae and Ophthalminiinae are abundant and diversified in the Middle to Upper Triassic. Evolutional tendency of Triassic foraminifers show similar pattern with that of scleractinian corals and sponges.