Forty-seven sediment samples were taken from a borehole core at Oppama Park, Yokosuka City, Kanagawa Prefecture, central Japan. Fifty-eight ostracod species, representing 32 genera, were identified in the 32 samples. Three ostracod biofacies (I–III) were identified using Q-mode cluster analysis. On the basis of ostracod biofacies, the following paleoenvironmental changes were recognized in the study area: land mudflat (no ostracods) → muddy bottom environment of inner bay (biofacies III) → sandy bottom environment of bay near rocky shore (biofacies II) → shallow mudflat (biofacies I). Modern analog technique (MAT) showed that the paleoenvironment of the study area was a warm (maximum bottom temperature in summer around 30°C; minimum bottom temperature in winter around 7°C) and shallow bay, similar to that around Honshu Island today.

An ostracod specimen, Parakrithella pseudadonta, with exceptionally well preserved soft parts was discovered in one of the horizons, at a core depth of 20.4–20.5 m. In this horizon, an event deposit, namely, one indicating an increase in paleobathymetery, was identified from ostracod assemblages, which were identified as tsunami deposits on the basis of previous studies of neighboring areas. Similar soft part-preserved arthropod fossils have been discovered from the Upper Cambrian (500 Ma) of Sweden. Many fecal pellets have also been found in the Orsten limestone. Such “cesspools” were exceptionally phosphatized during early diagenesis owing to the high local phosphorus levels produced by the accumulated fecal pellets. The “cesspool preservation hypothesis” provides an explanation for this kind of exceptional fossilization, found in the marine sediment record from the Late Cambrian onward.

A nearly complete mandible of a large ochotonid lagomorph was recently found from upper Lower Miocene deposits in central Japan, and it is described as a new species, Alloptox japonicus. The new species can be distinguished easily from all known species of the genus by size and several distinct characters of the p3 occlusal pattern. Almost all of these features show opposite character states in other species of Alloptox, suggesting distinction at the subgeneric level, and a new subgenus, Mizuhoptox, is created for A. japonicus. All previously known species are included in the subgenus Alloptox. Geologic age of the new species is about 17.6 (between 18 and 17.5) Ma (late Early Miocene), which is almost the same as A. sihongensis, the smallest and probably earliest species in continental Asia, suggesting that the distinction between those two subgenera was present at an early stage of Alloptox evolution.

Extremely well preserved earliest Cretaceous radiolarians were recovered from a tuffaceous claystone sample collected from a seamount flank of the Mariana Trench's ocean-ward slope by the Japanese submersible “Shinkai 6500”. Several species and genera belonging to Entactinaria have been described previously by the present authors. This study is an addition to the continuing investigation of this fauna, and will introduce one new family Paracuboctostylidae belonging to Entactinaria. Two new genera, Paracuboctostylus and Neoshinkaiera, and four new species, P. tetrayurta, N. simplex, Shinkaiera pacifica and S. robusta, are described.

Apsopelix miyazakii sp. nov. is described on the basis of a single specimen from the Upper Cretaceous (Turonian), Nakagawa Town, Hokkaido, Japan. This new species differs from the other species of the genus Apsopelix by the existence of a median frontal convexity near the posterior end of the frontal bones, the articulation of the lower jaw behind the middle of the orbit and the antorbital contacting with the first infraorbital at the ventral half of its posterior margin. This is the first record of the genus Apsopelix and the family Crossognathidae from the eastern part of the Tethys.

This article presents a taxonomic study of the Late Paleocene-Oligocene ostracode faunas of DSDP (Deep Sea Drilling Project) Site 329, Falkland Plateau. Six species were identified at specific level: Actinocythereis orientalis Guernet, Dutoitella mimica Dingle, Legitimocythere presequenta (Benson), Anebocythereis hostizea (Hornibrook), Poseidonamicus pseudorobustus Coles and Whatley, and Abyssocythere diagrenona (Guernet). Nineteen species were left in open nomenclature, one of them as gen. et sp. indet. Krithe, Cytherella, Cytherelloidea and Pennyella (two species each) are the richest genera. Three faunal groups are identified with characteristic associations, as follows: the Paleocene Fauna—PAF (A. hostizea-Abyssocythere diagrenona-Cytheropteron sp.-D. mimica), the Eocene Fauna-EOF (A. orientalis—Cytherelloidea sp. 2—Pennyella spp.) and the Oligocene Fauna—OLF (P. pseudorobustus—Ambocythere sp.—Krithe morkhoveni lamellalata). Preservational aspects linked to carapace dissolution and their relation to the paleoceanographical context are briefly discussed.

The thin, laminar to low domical, encrusting stromatoporoid Pulchrilamina spinosa is reported from the Tremadocian—Floian in Hubei and Guizhou provinces, South China. The Chinese Pulchrilamina appeared earlier (late Tremadocian—early Floian) than North American equivalents (early Floian), which possess large domical forms and are the main framework-builders. Pulchrilamina appeared much earlier than the observed diversification of other stromatoporoids. These skeletal reef-builders thus provide excellent clues for understanding the initial evolution of the stromatoporoids and the subsequent development of the skeletal-dominated (especially stromatoporoid-dominated) reefs that reached their first acme in the late Middle—Late Ordovician.