The fossilized limuloid tracks, Kouphichnium isp., are reported from a Lower Cretaceous bed of Tetori Group distributed along the Tedori River in Setono, Hakusan City, Ishikawa Prefecture, central Japan. Many well preserved tracks are found on the top surface of the single black siltstone bed. There are no “under tracks” at this locality. Instead, the tracks reflect various ethological reactions of individuals, as the bedding surface treaded by crabs is covered by a 30 cm thick fine tuff layer. One morphological classification of the limuloid tracks of this locality is based on the existence of telson drag marks. The tracks with telson drag marks are usually rather indistinct, while the ones with no telson drag marks have clear footprints of the 1st to 4th walking legs and the 5th pusher. It is supposed here that the former type of tracks were left when they kept pace with the dragging telson, while the latter type is a reflection of when they were hopping. A curious track in this locality has the complete set of prints of the five appendages from the animal’s right side. The left side, however, has no pusher marks, but rather many sets of scratches left by the walking legs. These sets of scratches are the same length as the complete sets of prints from the animal’s right side. The track curves to the right, indicating the crab’s direction of travel. Combined flow ripple marks around this track indicate that the paleocurrent forced the crab from left to right as the animal moved. This curious track shows the behavior of a horseshoe crab being affected by a lateral current, trying to catch the seafloor and not be swept away. The authors propose to use “a Pompeii-style event” to describe this locality, because of the sedimentological characteristics that preserved the crabs’ “lifestyle marches” instantaneously.

抄録全体を表示

 A large number of ichnofossils have been found in the geological section, corresponding to the Nojima Group of the Lower Miocene, in Hizen-cho, Karatsu city, northern Kyushu, Japan. These footprints seem to be of a large tetradactyl mammal not previously reported in Japan. Fossil footprints of elephants, rhinoceroses, crocodiles, birds, and artiodactyls such as deer are also present on the bedding plane of the same horizon. The footprints reported herein are wider than long, with four toes that are nearly symmetrical, while the track is characterized by an extremely short stride and wide tread. Judging from the size and shape of the footprints and tracks, the trackmaker would probably be a desmostylian or a tetradactyl nonruminant artiodactyl.

抄録全体を表示

 Eighty years have passed since the beginning of fossil footprint research in Japan, and currently 56 sites have been discovered. The majority of these sites, 43 in total, are from Plio-Pleistocene sediments.
 Frequent observations of Plio-Pleistocene fossil sites and some experiments of tracking have shown the importance of 1) a survey as soon as possible after discovery for morphology analysis; 2) carrying out an investigation in a unified way; 3) utilizing samples in diverse ways, including cutting out of the original fossil footprints without removing the infilling sediment in a fossil footprint examination.
 Furthermore identification of animal tracking has to be carried out carefully. In this research program, field observations of footprints of living wild animals were conducted mainly in Japan and Southeast Asia, and 800 casts of footprints from 80 species were collected.
 It is difficult to preserve unconsolidated fossil footprints from Plio-Pleistocene sediments in situ. We therefore have to organize a survey of the footprints with the local residents during the excavation process. We think it is important to inspire people to be aware of the natural history of their native land, check up on things by themselves, and foster a nature-conscious future for the local people.

抄録全体を表示

 Mammalian and other animals fossil footprints had been found from the Early Miocene beds in Fukui and Hyogo Prefectures since the first discovery from Fukui in 1996. Fossils were found from the Ito-o Formation and the lower part of the Kunimi Formation in Fukui and the Yoka Formation in Hyogo.
 Mammalian footprints are identified to that of the three orders (Proboscidea, Pressodactyla, Artiodactyla). From the Yoka Formation a few other animals (Crocodila, Aradeiidae, Gruidae or Ciconida) and a Proboscidan morlar of Stegolophodon sp. were collected.

抄録全体を表示

 The fossil footprints were found from the three sites along the middle stream of Tama River, in the western part of Kanto Plain, central Japan. The authors have investigated on these sites and recognized so many fossil footprints of Proboscidea and Artiodactyla.
 By the precise observation, morphological analysis of the footprints and geological correlation of fossil yielding beds, the footprints are assumed as Stegodon aurorae and Cervus sp. It is difficult to identify the animals which left the fossil footprints with just overhead observation, and more detailed studies and the development of the analytical method will be required after this.

抄録全体を表示