A comparison of the Neogene lymnocardiine Budmania with Neogene to Recent Cardiinae, and especially Cardium costatum Linnaeus, shows homoplasy in the relatively low shell thickness, presence of conspicuous, internally hollow keels and overall shell geometry. However, Budmania lacks the secondary shell resorption and associated features found in Cardiinae, and an inferential analysis of the adaptive significance of shell morphology reveals further differences between the two taxa. In particular, the keels in C. costatum are optimised for a dual function as mechanical strengthening and as anchors within the sediment, but only for the latter function in Budmania.

A natural assemblage of Ellisonia sp. cf. E. triassica Müller was recovered from the uppermost Permian close to the Permian-Triassic boundary in the Nabejiriyama section in the Mt. Ryozen area, Suzuka Mountains, central Japan. This natural assemblage and collections of similar ellisonids from the Taho Formation of Ehime Prefecture, southwestern Japan, demonstrate that the Ellisonia apparatus is composed of eight kinds of elements: breviform digyrate M, symmetrical S0, extensiform digyrate S1 and S2, bipennate S3 and S4, and angulate P1 and P2 elements. The apparatus structure of Ellisonia is comparable to the standard 15-element plan of Carboniferous ozarkodinids and prioniodinids. The apparatus structure of the present natural assemblage is important in discussing the phylogenetic affinity of the genus Ellisonia.

A new fossil marine diatom resting spore morpho-genus Gemellodiscus Suto gen. nov. is described using samples from DSDP Site 338 in the Norwegian Sea, Sites 436 and 438 in the northwest Pacific and the onland Newport Beach Section, California. Gemellodiscus is characterized by possessing a valve with setae of several types: bifurcated seta, fused seta and crossed seta. Eleven taxa are described and their stratigraphic ranges are presented: G. incurvus (Bailey) Suto comb. nov., G. pliocenus (Brun) Suto comb. nov., G. cingulus Suto var. cingulus sp. nov., G. cingulus var. longus Suto var. nov., G. bifurcus Suto sp. nov., G. hirtus Suto sp. nov., G. caveatus Suto sp. nov., G. micronodosus Suto sp. nov., G. dicollinus Suto sp. nov., G. geminus Suto sp. nov. and G. dimontanus Suto sp. nov.

Fossil marine diatom resting spore species in the morpho-genus Xanthiopyxis Ehrenberg are described using samples from DSDP Site 338 in the Norwegian Sea, Sites 436 and 438 in the northwest Pacific and from the onland section at Newport Beach, California. Xanthiopyxis is characterized by numerous knobs, spines and bristles covering the entire valve face. In this paper eleven species, of which seven are new species, are described and their stratigraphic ranges are presented: X. polaris Gran, X. norwegica Suto, sp. nov., X. brevispinosa Suto, sp. nov., X. teneropunctata Suto, sp. nov., X. lanceolatus Suto, sp. nov., X. circulatus Suto, sp. nov., X. reticulata Suto, sp. nov., X. obesa Suto, sp. nov., X. hirsuta Hanna and Grant, X. oblonga Ehrenberg and X. globosa Ehrenberg. In addition, resting spores which lack sufficient characteristics to identify easily are assigned to three informal species: Xanthiopyxis type A (knobbly type), X. type B (short spiny type) and X. type C (long spiny type).

The pattern of shell breakage in the Recent trochid gastropods Umbonium (Suchium) moniliferum (Lamarck) and U. (S.) giganteum (Lesson) was observed under durophagous predation by crabs and in tumbling experiments, and the results of these experiments were applied to recent population samples from the natural environment. The experiments were carried out in order to learn if the pattern of shell breakage by durophagy (shell crushing) is different from that induced by water currents and waves. After predation by the predatory crabs Calappa lophos (Herbst) and Portunus trituberculatus (Miers), shell apertures of U. (S.) moniliferum and U. (S.) giganteum were broken in a characteristic fashion. In contrast, shells tumbled with sand and artificial seawater rarely lost the apertural margins, although other parts of the shells were relatively severely abraded. These results suggest that a shell from the natural environment with a similarly broken apertural margin was probably attacked by a durophagous crab, and that water currents and waves are not agents that cause breakage of shell apertures. The results were then applied to samples of Recent U. (S.) moniliferum from Lake Hamana-ko and fossil U. (S.) costatum (Kiener) from the Pleistocene Jizodo Formation in Japan. Shells with broken apertural margins amounted to 60% of all dead empty shells in the sample of Recent U. (S.) moniliferum, and over 90% in the sample of Pleistocene U. (S.) costatum, suggesting that these shells were extensively preyed upon by durophagous crabs. Shell repair frequencies of Recent U. (S.) moniliferum, calculated as a percentage of individuals with one or more repair scars, were 24–55%. The high repair frequencies indicate that considerable numbers of U. (S.) moniliferum can escape from attacks by crabs. All the results suggest that shell breakage along the apertural margins of gastropods is a good indicator of durophagy and that broken apertures, as well as shell repairs, are a useful tool for the investigation of predatory-prey interaction.

Late Jurassic and Early Cretaceous well preserved radiolarians are obtained from the Taukha Terrane in the southern Sikhote-Alin, Russia. The Taukha Terrane consists of three tectono-stratigraphic units, the Erdagou, Gorbousha and Skalistorechenka units. Three new species (Stichocapsa (?) pseudoconvexa, Sethocapsa taukhaensis and Cinguloturris primorika) are described from Late Jurassic chertterrigenous sequences of the Gorbousha Unit cropping out in the Roudnaya River and Koreyskaya River areas, and their stratigraphic ranges are made precise.