Ellobium mizutanii sp. nov. is described from the lower Miocene Yamanouchi Member of the Akeyo Formation (Mizunami Group) in Shitaoki-cho, Mizunami City, Gifu Prefecture. This is the third fossil species of the genus Ellobium from the Cenozoic of Japan. The present species closely resembles Ellobium chinense (Pfeiffer), a living species that can be found in regions including Mikawa Bay (Aichi Prefecture, central Japan), northern Kyushu, and southern China, but differs in having an inflated body whorl and rather broadly expanded callus on the parietal area of the aperture.
Petrographic examination of tuffs in the Miocene Mizunami and Iwamura Groups has been carried out to provide basic data for characterization of each tuff beds. This paper presents the descriptions of 16 and 4 tuff samples from the Mizunami and Iwamura Groups, respectively. Specifically, the following properties have been analyzed; mineral and heavy mineral compositions, shape of volcanic glass, and refractive indices of volcanic glass and plagioclase.
Although T-type shards of volcanic glass were dominated in most of the tuffs studied, the study shows that it is possible to characterize each tuff based on these petrographic properties. This means that petrographical properties of tuff in the Miocene series can be utilized as the fundamental data for stratigraphic correlation in this region.
Heavy mineral and plagioclase compositions of tuffs studied have a close similarity to those of host tuffaceous sedimentary rocks in the Mizunami Group. Tuffaceous material in the sedimentary rock has been derived from volcanic ash generated from unrecognized volcanic activity occurred around the Mizunami sedimentary basin. Thus, it is considered that tuffs in the Mizunami and Iwamura Groups have been formed by a volcanic activity around the Mizunami sedimentary basin.
Thelecarcinus Böhm is removed from Xanthoidea sensu lato and placed within the raninoidan family Paranecrocarcinidae Förster. Placement of the genus within the family confirms the North Atlantic and Tethyan range of the family in the Late Cretaceous and its occurrence in predominantly marl and carbonate environments.
The study of the Aktuo-Paläontologie of modern shell accumulations may provide important insights
of relevance to, particularly, palaeoecology, taphonomy and ichnology. The broad, flat beach at Southport, north-west England, UK, where the sea retreats over 2 km at low tide, is a notable collecting site for shells of allochthonous benthic molluscs. Selected for discussion here is a specimen of the mussel, Mytilus edulis (Linnaeus), which is densely encrusted in two layers on its well-preserved left valve by the barnacle Balanus crenatus Bruguière; the broken right valve has a sparse infestation of this balanid. The valves remain conjoined because the ligament was overgrown by balanids from the left valve, an unusual preservation. The shell was presumably buried, smothering the initial balanid infestation of the left valve; on reexposure, the surface of dead balanids was covered by a new, conspecific layer. For much of its pre- and post-mortem existence, the right valve was probably buried. The superior preservation of the left valve was favoured by the thick, balanulith-like coating of cemented barnacles. The inner surfaces of both valves remained clean and lack any encrustation.
Strontium isotope (87Sr/86Sr) ratios for molluscan fossil fragments from the Tokorozawa observation well by Saitama Prefecture, two water wells and three surface samples were measured. Although most samples were altered due to surface water circulation and diagenesis, the highest 87Sr/86Sr ratio among samples shall be nearly equal to the original 87Sr/86Sr ratio.
Sr isotope ages for less altered samples are estimated using Look-Up Table by McArthur and Howarth (2004). It was found that there was no inconsistency in vertical relationship among the obtained Sr ages of the wells. However, it is not possible to evaluate the Sr ages due to lack of reliable age data. Sr isotope age of 10.5 Ma for the Tsuchishio Formation is slightly older than its geological age by diatom fossils due to alteration.
For Sr isotope ages using molluscan fossil fragments, it is necessary to analyze multiple samples in
the same stratum as much as possible.
The palaeontological collections of the Museo di Storia Naturale of the University of Pavia, Italy, house marine arthropods from the Solnhofen Lithographic Limestones (Late Jurassic, Germany). These arthropods include decapod crustaceans and limulids. A commented systematic list is proposed in order to give to the specialists an instrument of comparison and reference.
The multi-component skeletons of many groups of organisms, such as plants, arthropods, echinoderms and vertebrates, are commonly found disintegrated into separate elements in the fossil record. A new Early to Late Devonian crinoid morphospecies, Pseudobystrowicrinus (col.) fionae gen. et sp. nov., based on disarticulated columnals, is known from in-situ occurrences in south-west England and as float (erratics) of Pleistocene forerunners of the present-day River Maas (Meuse) in the province of Limburg, the Netherlands. Specimens are commonly preserved in sandstones. Columnals are probably derived from the mesistele; they are large nodals with rounded epifacets and also a small, central, pentagonal, lumen with a symplectial perilumen. The most distinctive feature is a broad, deep, pentastellate areola, appearing like a wide, Bystrowicrinus-like lumen in natural moulds. The column is heteromorphic; nodals are robust. This particular crinoid was likely a cladid or camerate adapted to high-energy environments.
Molluscan fossils were collected from the lower Miocene Akeyo Formation (18 Ma) of the Mizunami Group at the outcrop exposed during the construction of Togari-Tsukiyoshi City Road in Akeyo-cho, Mizunami City. Minor Minolia tukiyosiensis (Oyama and Saka), “Pseudomurex?”
tukiyosiensis Oyama and Saka, and Hiatula minoensis (Yokoyama) occur in a lenticular shell bed
dominated by Crassostera sp. in the middle part of the Togari Member, Akeyo Formation. The oyster
shells seem to have been transported and accumulated into the final depositional site from a small
oyster reef within estuary environment by tidal or storm currents.
A large gastropod shell, Hemifusus crassicauda (Philippi) (Caenogastropoda, Melongenidae), has
been collected from the middle Pleistocene Ogushi Formation (marine oxygen isotope stage 7: 250 to
230 ka) in Itsuwa-machi, Amakusa City, Kumamoto Prefecture, southwest Japan. Crassostrea gigas
attached to be inner aperture of the present specimen and Spirorbidae gen. et sp. indet. also attached
its shell surface of apertural side.
A new reef-associated decapod assemblage from one locality of the Messinian (late Miocene) of the Alicante province (Spain) is described herein. This assemblage is similar to other Messinian reef-associated fauna from different localities of the circum-Mediterranean area. Surprisingly, Aethra stalennyii, an aethrid crab is reported from the same outcrop, being the second fossil record for the genus and the westernmost occurrence. This discovery sheds light and provides clues on the migration pattern of the Paratethyan decapods in the middle and late Miocene.
Epistrenoceras sp. was newly found from the Lower Formation of the Kuzuryu Group, Fukui Prefecture in Central Japan. This genus occurs from the early Late Bathonian age in the Tethys Province and the southeastern Panthalassa. This is the first record of this genus in Japan. It indicates that the age of the Lower Formation of the Kuzuryu Group can be determined for the first time following the late Late Bathonian in age represented by Pseudoneuqueniceras yokoyamai from the Middle Formation of the Kuzuryu Group. The first occurrence in East Asia indicates that the habitat of this genus extended to western Panthalassa Ocean.
There was an error in the type designation of the genus Ellobium [Röding], 1798 (page 3, left 3–5th lines). We thank Dr. T. Matsubara (Hokkaido University of Education) for his pointing out.
Genus Ellobium Röding, 1798
Type species: Ellobium midae Röding, 1798, by original designation.
Genus Ellobium [Röding], 1798
Type species: Ellobium midae [Röding], 1798, [= Bulla aurismidae Linnaeus, 1758], by subse-quent designation.