著者

ANN FORSTEN

出版者

PALAEONTOLOGICAL SOCIETY OF JAPAN

雑誌

Paleontological Research (ISSN:13428144)

巻号頁・発行日

vol.1, no.4, pp.316-317, 1997-12-30 (Released:2008-02-01)

参考文献数

9

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The species Equus nipponicus Shikama and Onuki is a true horse, possibly even a domestic animal, not an Asiatic wild ass. It has been dated to 1, 530±60 years B. P.

著者

TATSUO OJI SHONAN AMEMIYA

出版者

PALAEONTOLOGICAL SOCIETY OF JAPAN

雑誌

Paleontological Research (ISSN:13428144)

巻号頁・発行日

vol.2, no.1, pp.67-70, 1998-04-30 (Released:2008-02-01)

参考文献数

13

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Paleontological evidence indicates that crinoids (sea lilies : Echinodermata) were a major constituent of Paleozoic and Mesozoic shallow-marine communities (Meyer and Macurda, 1977; Cain, 1968). In the fossil record crinoid stalks usually occur in much greater abundance than other body parts such as arms and calyces. This difference has been attributed to selective preservation, the result of post-mortem process of fossilization or taphonomy (Baumiller and Ausich, 1992; Moore and Jeffords, 1968). Our observation of living crinoids in aquaria demonstrates that stalk fragments detached and isolated from a living crinoid survive more than one year, whereas other body parts tend to disarticulate rapidly. Such long survival of stalk fragments of crinoids firstly explains the dominance of crinoid stalks over other body parts in the fossil record, and secondly, and more importantly, it strongly suggests that such detached fossil stalks, as well as stalk pieces observed on today's sea floor, continued living for a long time, and were not dead body parts as previously considered.

著者

HIROAKI KARASAWA

出版者

PALAEONTOLOGICAL SOCIETY OF JAPAN

雑誌

Paleontological Research (ISSN:13428144)

巻号頁・発行日

vol.2, no.4, pp.217-223, 1998-12-30 (Released:2008-02-01)

参考文献数

42

被引用文献数

1

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Two new species of decapod crustacean, Hoploparia miyamotoi (Astacidea : Nephropidae) and Callianassa masanorii (Thalassinidea : Callianassidae), are described from the Upper Cretaceous lzumi Group of Osaka and Hyogo Prefectures, Japan. H. miyamotoi represents the first record for the genus from Cretaceous deposits of Japan and C. masanorii is the second of a callianassid known from the Japanese Cretaceous. The occurrence of H. miyamotoi extends the known geographic range of Hoploparia to the west side of the North Pacific.

著者

Umeda Masaki

出版者

日本古生物学会

雑誌

Paleontological research (ISSN:13428144)

巻号頁・発行日

vol.2, no.2, pp.96-107, 1998-06-30

参考文献数

20

被引用文献数

3

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This paper focuses on ceratoikiscid radiolarians from the Devonian Nakahata Formation of the Yokokurayama Group in the Kurosegawa Terrane. The fauna is assigned to the Emsian to Eifelian (late Early to early Middle Devonian). There are 13 species of radiolarians, including 4 new species, which belong to the genera Ceratoikiscum, Glanta, Protoholoeciscus, Circulaforma and Helenifore. The morphology and stratigraphic distribution of the genera suggest that Protoholoeciscus evolved from Ceratoikiscum via Glanta with the process of acquisition of shell.

著者

SUSAN E. EVANS MAKOTO MANABE

出版者

PALAEONTOLOGICAL SOCIETY OF JAPAN

雑誌

Paleontological Research (ISSN:13428144)

巻号頁・発行日

vol.2, no.4, pp.275-278, 1998-12-30 (Released:2008-02-01)

参考文献数

23

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The Early Cretaceous Okurodani Formation, Tetori Group, near Shokawa village, Gifu Prefecture, Japan, has yielded a mixed assemblage of terrestrial and aquatic small vertebrates, including the fragmentary remains of a frog (ilium, vertebra) and a salamander (vertebra). These are the first Mesozoic lissamphibians recorded from Japan, and some of the oldest from Asia. The ilium is of rather primitive form and suggests a frog of basal grade, that is outside the Discoglossanura.

著者

Tomohiro NISHIMURA Haruyoshi MAEDA Yasunari SHIGETA

出版者

PALAEONTOLOGICAL SOCIETY OF JAPAN

雑誌

Paleontological Research (ISSN:13428144)

巻号頁・発行日

vol.10, no.1, pp.11-28, 2006 (Released:2007-01-12)

参考文献数

47

被引用文献数

6

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Ontogenetic shell development of the Turonian desmoceratine ammonoid Tragodesmoceroides subcostatus is examined based on more than 200 specimens collected by detailed biostratigraphic survey in the Tappu and Saku areas, Hokkaido, Japan. After the ammonitella stage, the mode of ribbing on the shell surface becomes coarser with growth. The shell surface ornament changes from stage 1 (almost smooth) to stage 3 (coarse ribbing) via stage 2 (weak ribbing). Stage 1 is subdivided into an earlier substage 1a with desmoceratid-type constrictions and a subsequent substage 1b without constrictions. Appearance order of these four ornament stages and substages seems to be ontogenetically fixed in the present species. Other characters, such as ammonitella and early shell shape and whorl geometry are also stable.On the other hand, the shifting-timing from stages 1 to 2 and from stages 2 to 3 changes chronologically, i.e., it becomes ontogenetically earlier in upward sequence. In the Lower and Middle Turonian, the adult or subadult shells still remain stage 1 or 2. In contrast the strongly ribbed holotype and paratypes showing stage 3 are regarded as the Upper Turonian peramorphic endmembers of the single biospecies T. subcostatus. Taking these features into consideration, T. subcostatus should be taxonomically revised.

著者

TANOUE KYO OKAZAKI YOSHIHIKO

出版者

Palaeontological Society of Japan

雑誌

Paleontological Research (ISSN:13428144)

巻号頁・発行日

vol.18, no.2, pp.77-81, 2014-04

著者

BUNJI TOJO FUJIO MASUDA

出版者

日本古生物学会

雑誌

Paleontological Research (ISSN:13428144)

巻号頁・発行日

vol.3, no.3, pp.193-201, 1999-09-30 (Released:2008-02-01)

参考文献数

38

被引用文献数

1

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Continuous growth sequences are recorded in vertical (=median longitudinal) sections of the columella of the fossil potamidid gastropod Vicarya yokoyamai Takeyama, from subtropical Miocene faunas of Japan. Shells from the Mizunami, Uchiura, Bihoku, and Masuda groups show semidiurnal tidal growth patterns. This suggests that V. yokoyamai lived in the intertidal zone. Growth curves were reconstructed on the basis of numbers of tidal growth lines. These growth curves were found to be very similar with one another, and indicated that shell-height increased from 1.5cm to 8cm in two years.

著者

Nishioka Yuichiro Hirayama Ren Kawano Shigenori TOMIDA YUKIMITSU TAKAI MASANARU

出版者

Palaeontological Society of Japan

雑誌

Paleontological research (ISSN:13428144)

巻号頁・発行日

vol.15, no.1, pp.43-50, 2011-04-30