Studies on diversity of Cretaceous vascular plants and their symbiotic organisms

在2002财政年度，1对北海道进行了实地收集，在那里收集了大量含有植物碎片的结核。由于几乎没有符合这项研究目的的材料，我继续对之前收集的可能裸子植物的果实进行分类鉴定，并在植物化石组织中进一步寻找真菌和节肢动物化石。虽然我找不到任何真菌和节肢动物，但果实本身被鉴定为裸子植物的一个新物种，可以归入一个新目。一位业余收藏家捐赠的树木蕨类根茎化石被指定为蓝藻科的一个新种，可归因于Dicksonia属。这两个新分类群都将在其他地方描述。我继续在过矿化化石中进行真菌化石的显微搜索，主要是木材，采集自白垩纪，熊本县，Sebayashi，群马县，Kuji和Taneichi系列，岩手县，一个…更多来自北海道的野藏集团。木材腐烂真菌常见于松散组织中。这表明白垩纪陆地生态系统中木质腐烂真菌的广泛活动。在白垩纪乔木-蕨类植物Tempskya的根皮质层中，VA(泡状-丛枝)菌根的优势也被发现。在任何一种苏铁科蕨类植物的根系中都没有VA菌根，这也表现出一种乔木习性。这可能是互惠的VA菌根使Tempskya能够有效地吸收无机物。这种互惠关系的破裂可能导致了坦普斯卡在白垩纪末期灭绝。在北海道过矿化化石中对节肢动物的研究发现，在两个不同的器官中发现了三种不同的昆虫。在裸子植物的果实中发现了一种昆虫，并将其归因于后翅目昆虫。另外两种存在于裸子植物树枝的变形组织中，这可能是昆虫的虫胆。一种是保存不佳的幼虫，很难分类识别，另一种是一只小成虫，筑巢在一个圆形的结构中，可能是它自己做的。成虫的形态与多食目的金龟子总科相似。这些发现为白垩纪生态系统中昆虫利用植物组织的不同方式提供了证据。较少

In the fiscal year of 2002, 1 carried out a field collection trip to Hokkaido, where a large number of nodules containing plant fragments were collected. Since there were few material that can fit the purpose of this study, I continued taxonomic identification of a previously collected fructification of possible gymnosperm, and further search of fossil fungi and arthropods in the fossil plant tissue. Although I could not find any fungi nor arthropods, the fructification itself was identified as a new species of gymnosperm that can be assigned to a new order. A fossil tree fern rhizome donated from an amateur collector was designated as a new species of the Cyatheaceae, which is attributable to the genus Dicksonia. Both new taxa will be described elsewhere.I have continued microscopical search of fossil fungi in permineralized fossils, mainly woods, collected from the Cretaceous of Goshonoura Series, Kumamoto Pref., Sebayashi Series, Gunma Pref., Kuji and Taneichi Series, Iwate Pref., a … More nd Yezo Group, Hokkaido. Wood decaying fungi were commonly found in disorganizing tissues. This shows wide activity of wood decaying fungi in the Cretaceous terrestrial ecosystem. Also found important was the predominant occurrence of VA (vesicular-arbuscular) mycorrhizae in the root cortical layer of a Cretaceous tree-fern Tempskya. The VA mycorrhizae were absent in the root system of any Cyatheaceous ferns, which also exhibit a tree habit. It is likely that mutualistic VA mycorrhizae made Tempskya possible to effectively absorb inorganic materials. Collapse of this mutualistic relationship might have causec extinction of Tempskya by the end of the Cretaceous.Search of arthropods in permineralized fossils from Hokkaido resulted in findings of 3 different insects in two different organs. One insect was found in a gymnosperm fructification, and was attributed to the Psocoptera. Other two existed in a deformed tissue of a gymnospermn twig, which is a possible insect gall. One is a poorly preserved larva hard to taxonomically identify, and the other is a small adult that nested in a round sturucture probably made by itself. The adult form was comparable to the Staphilinoidea of Polyphaga. The findings provided evidence of varying ways of use of plant tissues by insects in the Cretaceous ecosystem. Less