We describe two new species of Tetraconodon, T. irramagnus sp. nov. and T. irramedius sp. nov., from the late Miocene of Myanmar recognized when reevaluating large Tetraconodon specimens. Tetraconodon had also been recovered from the late Miocene Siwalik sediments of India/Pakistan. However, in the Siwalik specimens, the dimensions of the last two premolars and the third molar with respect to those of the first molar are distinctly greater than those of the Myanmar specimens. In Myanmar species, the relative dental sizes are similar, and the most obvious interspecies distinctions are their dental size differences. Considering the variation in the relative sizes of the last two premolars and third molar with respect to the first molar among the Siwalik and Myanmar Tetraconodon, the enlargement of the last two premolars and the third molar could be regarded as a characteristic of the interspecies distinction.

The taxonomy of extant animal species is often based on biological information that is not normally preserved in fossils. Reducing discrepancies between taxonomy based only on hard tissues and that based on other biological information to a minimal level is crucial in studies focusing on species diversity that integrate extant and fossil material. In the present study, I address this issue using morphological analysis of the endemic Ogasawara Island land snails in the genus Mandarina. I first examine pairwise differences in shell morphology among 39 populations of 15 extant species that were discriminated by differences in their reproductive organs and their phylogenetic relationships. A classification model to assess whether the observed differences in fossil shell characters were inter- or intra-specific was developed by training an artificial neural network (ANN) with the patterns of differences in shell characters among the extant species. The average probability that the trained ANN misclassifies extant forms was 1.4%. The trained ANN was applied to discriminate morphological differences among the Pleistocene-Holocene fossil samples of Mandarina luhuana that occurred in Chichijima and Minamijima. As a result, three species were identified in the samples previously referred to M. luhuana. Mandarina pallasiana, previously treated as a synonym of M. luhuana, is separated, and one new species and one new subspecies are described.

Two new species of orthocerid cephalopods from the Bashkirian (Late Carboniferous) Panching Limestone in Pahang, West Malaysia are described. They are an orthoceratid Kionoceras panchingense and a pseudorthoceratid Dolorthoceras malaysiense. The detailed internal structure of K. panchingense is documented, this being the first time that the internal structure of a Carboniferous species of Kionoceras is revealed. A species which was previously reported as Hesperoceras cf. laudoni is reexamined, and is revised as D. malaysiense sp. nov. It shows the closest affinity with D. circulare Miller, 1931 of northern Kashmir. Species of Kionoceras and Dolorthoceras are recorded in the Carboniferous of Southeast Asia for the first time.

Middle Permian (Midian in the Tethyan standard scale) foraminifers of 34 species assignable to 27 genera were identified in erratic limestone blocks collected on the left bank of the middle course of the Kuma River (Osakama), west Kyushu, Japan, where four species of fusulinoideans have been reported. These blocks are thought to have been derived from a small limestone contained in basaltic rocks embedded within uppermost Jurassic mudstone along the southern margin of the Chichibu Terrane (Sambosan Terrane). An Osakama foraminiferal fauna in comparison with contemporaneous faunas known from the Jurassic to Early Cretaceous terranes of Japan and in relation to the limestone lithology are described and discussed in this paper. The Osakama fauna is characterized by dominant occurrence of a newly proposed species Yabeina osakamensis contained in weakly dolomitized gray limestone consisting of fusulinoidean crinoidal bioclastic packstone/grainstone with lithic clasts of limestone. The limestone lithology and bioclasts of a primitive species of Pseudodoliolina suggest that limestone deposition initiated on the Sambosan Seamount in equatorial Panthalassa as early as early Middle Permian (early Murgabian in the Tethyan scale). The Osakama fauna is more closely related to the Kaize fauna than the Gozenyama, both of which are known from the Southern Chichibu Terrane of the Kanto Mountains. Yabeina globosa, a diagnostic species in the fusulinoidean faunas of the Chichibu and Tamba-Mino-Ashio terranes and common in black to dark gray micritic limestone, is completely absent in the present Osakama and Kaize faunas.

The Northern Caucasus is a large region of southwestern Russia that was located on the northern periphery of the Neotethys Ocean during the Triassic-Jurassic interval. Several crises impacted the evolution of the local fauna of brachiopods during this time as evidenced by changes in the taxonomic diversity of brachiopod associations in the region. The taxonomic diversity structure determines the relative importance of superfamilies to govern the species diversity, and the changes in it are measured with coefficient of rank correlation calculated for any two associations. The available stratigraphic ranges of species, which belong to 113 genera and 22 superfamilies, indicate that a recovery after the Permian/Triassic mass extinction is expressed by a rapid change in the taxonomic diversity structure in the Early Triassic-Anisian. The regional Ladinian crisis, which occurred after an abrupt deepening of the marine basin, did not result in major changes in the structure. The Triassic/Jurassic and Pliensbachian/Toarcian mass extinctions did not produce remarkable turnovers among brachiopods, but those superfamilies which dominated the Early Triassic species diversity of brachiopods rose again after these extinctions. The Pliensbachian/Toarcian event diminished significantly the importance of the Late Triassic superfamilies. The potential Aalenian mass extinction did not affect the taxonomic diversity structure. The changes in this structure recorded in the Northern Caucasus did not correspond to those seen in the Alpine Region.