A Late Devonian to Early Carboniferous radiolarian fauna is present in chert and siliceous shale of a chert-clastic section along the Khong River, Pak Chom area, at the Thai-Lao border of northeastern Thailand. The radiolarian fauna is composed of Stigmosphaerostylus variospina, Astroentactinia stellata, Astroentactinia multispinosus, Archocyrtium wonae, Archocyrtium riedeli, and other species and corresponds to the Famennian (Late Devonian) to Tournaisian (Early Carboniferous) radiolarian fauna reported from northwestern Europe, Australia, northern and southern Thailand, and southern China. Ten radiolarian species belonging to four genera including one unidentified genus are investigated. The radiolarian-bearing sequence was probably deposited in a pelagic or hemipelagic environment within the Paleotethys Ocean during Late Devonian to Early Carboniferous time. Furthermore, this chert-clastic section of Pak Chom area is thought to be deposited on the Nakhon Thai Block and subducted beneath the Indochina Block. This suggests that the age of subduction and accretion of the Naknon Thai Block is thought to have occurred at least after Early Carboniferous indicated by the occurrence of Late Devonian to Early Carboniferous radiolarians.

A new theoretical morphological model is introduced to describe various shell ornament patterns of cytheroidean ostracods. A wave-source model proposed here was designed with reference to the kinematics of adductor muscles. This model depicts the ornament patterns as composite waves that are defined in terms of amplitude and frequency of wave elements. Computer models successfully mimicked most of the ornament patterns seen in the Cytheroidea. The theoretical morphospace places the multiple-bracket ornamentation as an intermediate pattern among concentric, radial, and smooth patterns. The result suggests that any observed pattern can be readily derived from a multiple-bracket one by a slight change of developmental parameters.

In North Vietnam, the Hua Tat, Pa Khom and Lang Son Formations yield abundant Lower Triassic bivalves. The occurrence of Eumorphotis sp. cf. E. multiformis, represents the first fossil reported from the Hua Tat Formation, while Claraia aurita, C. concentrica, and C. intermedia multistriata are found in the upper Lang Son Formation. The Pa Khom Formation contains C. intermedia multistriata, Claraia sp., and Lopha sp. The occurrence of C. intermedia multistriata indicates that the Pa Khom Formation and the upper Lang Son Formation are Olenekian in age. These Claraia spp. are found in wave-dominated nearshore deposits characterized by hummocky cross stratification and wave-ripple laminations, although Claraia in other areas is generally found in deep-sea mudstone.

Erraticodon hexianensis, a conodont with an octomembrate species apparatus, is described and illustrated from the upper part of the Meitan Formation in Guizhou, South China. Cooccurrence of Erraticodon hexianensis and Lenodus variabilis at the top of the Meitan Formation in the Honghuayuan Section of Tongzi suggests an early Darriwilian age for this level. Recovery of Oepikodus communis from the base of the Meitan Formation in the Ganxi Section of Yanhe indicates a correlation with the communis Zone of the Early Ordovician.

Although many workers have investigated the ecological and evolutionary significance of cryptic organisms and short-term (seasonal to annuals) fluctuations in environments and fauna within submarine caves, no studies have examined millennia-scale variations in the organisms and environments. In this study, we analyzed the sedimentary characters and species composition of bivalves from surface and cored sediments within the Daidokutsu submarine limestone cave on the fore-reef slope of Ie Island, off the island of Okinawa, Japan. The sediments in the central and innermost area of the cave consist of carbonate mud. Their deposition indicates that a still-water environment prevailed over the past 5,000 years. Analysis of the spatial and temporal distribution of the bivalves shows that species living in the innermost area of the cave became dominant over at least the past 5,000 yrs, while species living near the entrance of the cave declined in abundance. This indicates that the environmental conditions of the innermost cave area gradually spread to the entrance of the cave. We believe that this phenomenon is explained by spreading nutritional deficiency within Daidokutsu cave.

Thirteen living species of the genus Xestoleberis were found from 122 samples collected from the coast of Japan. Samples were mainly collected from algae, Corallina pilulifera and Sargassum thunbergii, in the intertidal zone and the uppermost infralittoral zone. Seven species are new and are described herein; Xestoleberis ikeyai sp. nov., Xestoleberis kuroshio sp. nov., Xestoleberis magnoculus sp. nov., Xestoleberis notoensis sp. nov., Xestoleberis planuventer sp. nov., Xestoleberis ryukyuensis sp. nov. and Xestoleberis sesokoensis sp. nov. Xestoleberis sagamiensis Kajiyama, 1913 is redescribed. The thirteen Xestoleberis species studied in this paper are subdivided into three groups based on the morphology of their carapace pore-systems. This grouping is consistent with their estimated phylogeny. The grouping is supported by general carapace shape, morphology of muscle scars, male copulatory organ and “Differentiation of Distributional pattern of Pore-systems (DDP)” analysis, and is considered to reflect phylogeny. The geographical distribution of Xestoleberis around Japan is shown for the first time, and the distinctive distribution of species and groups, which correspond to marine climates, is clearly recognized.