Larval shell morphology of four Cretaceous inoceramid species, Inoceramus tenuistriatus, Inoceramus hobetsensis, Inoceramus amakusensis and Sphenoceramus naumanni was examined on the basis of well-preserved specimens from the Yezo Group in the Tappu area, northwestern Hokkaido. SEM observations reveal that all of the four species possess large prodissoconchs with a similar shape. Relatively small prodissoconch I and large prodissoconch II indicate that they all underwent a long planktotrophic larval stage. This result as well as the available biogeographic data in the north Pacific Bioprovince suggest that these four species had a high dispersal capability in the larval stage.

The Kutch basin developed due to the fragmentation of Gondwana during the Middle Jurassic and hosted diverse endemic fauna, of which brachiopods are one of the chief constituents. The dominant brachiopod faunal element is the terebratulid genus Kutchithyris Buckman. The genus is represented throughout the exposed Middle Bathonian to Oxfordian sequence in Kutch and is also reported sporadically from outside Kutch. The systematics of this small but distinct clade is in a state of flux. The present paper focuses on revising the systematics of the genus and its three dominant species, namely, K. acutiplicata, K. propinqua and K. euryptycha, based on numerous specimens collected from the field with precise stratigraphical and sedimentological background and the type materials. They constitute an evolving lineage, and have been known from the Upper Bathonian rocks of the Pamirs, where they are cited as one of the celebrated examples of rapid speciation. A detailed comparison of the specimens from these two areas reveals that the speciation took place in Kutch and involved cladogenesis. Thus, it provides a good example of the punctuational model of evolution.

A phylogenetic analysis of 14 genera of the family Goneplacidae MacLeay (Decapoda: Brachyura: Xanthoidea) is presented based upon 45 adult morphological characters. Two most-parsimonious trees were obtained (length = 87, CI = 0.6667, RI = 0.8242, RC = 0.5495). The present analysis suggests that the Goneplacidae is divided into six subfamilies: Carinocarcinoidinae subfam. nov., Chasmocarcininae Serène, Euryplacinae Stimpson, Goneplacinae MacLeay, Mathildellinae subfam. nov., and Trogloplacinae Guinot. The Carcinoplacinae H. Milne Edwards is synonymised with the Goneplacinae. The family and six subfamilies are defined or redefined based upon the phylogenetic analysis. Within the Goneplacidae, the Trogloplacinae and Chasmocarcininae are sister groups nested as the most derived clade, followed by the Carinocarcinoidinae, Goneplacinae, Euryplacinae, and the most basal Mathildellinae. Our analysis supports recognition of the family Pseudoziidae Alcock by Ng and Liao and suggests that it is the sister to the Eriphiidae MacLeay. A reexamination of fossil records of the Goneplacidae shows that 62 species, 20 genera, and five subfamilies are recognized as fossils. A new monotypic genus Viaplax (Euryplacinae) is erected for Pilumnoplax urpiniana Via. Chlinocephalus Ristori and Gillcarcinus Collins and Morris are moved to the Goneplacidae. Paleopsopheticus Hu and Tao is synonymised with Psopheticus Wood-Mason. Glaessneria Takeda and Miyake is here the junior synonym of Goneplax. Eleven extinct genera previously assigned to the Goneplacidae are not referred to any subfamilies and are transferred out of the Goneplacidae. New combinations include: Carcinoplax proavita (Glaessner), Goneplax arenicola (Glaessner), Euphylax zariquieri (Via) (Portunidae Rafinesque), and Psopheticus shujienae (Hu and Tao).

This paper describes two species of the leptosporangiate fern genus Osmunda Linnaeus (Osmundaceae) based on permineralized rhizomes from late Middle Miocene sediments in the Mosanru Formation, Shimokawa Group, in Shimokawa, north-central Hokkaido, Japan. Osmunda shimokawaensis sp. nov. has an ectophloic dictyoxylic siphonostele radiating numerous leaf traces in spiral order, and stipulate leaf bases characteristic of the Osmundaceae. Mode of leaf-trace departure and sclerenchyma distribution at the leaf base strengthen its affinity with Osmunda (Osmunda). This species is important in being the first record of the subgenus from Asia based on permineralized rhizomes. One rhizome is attributable to the extant species Osmunda cinnamomea L. of subgenus Osmundastrum Presl. Osmunda shimokawaensis and O. cinnamomea provide new evidence for better understanding the evolution and phytogeography of the genus Osmunda.

Yabepecten ogasawarai sp. nov. is proposed from the Hongô Formation in Yamagata Prefecture, northeastern Honshû, Japan. Its occurrence is inferred to be of early late to middle late Miocene age, which makes Y. ogasawarai sp. nov. the oldest Yabepecten in the northwestern Pacific. Yabepecten was derived from Patinopecten in the northeastern Pacific, and migrated into the northwestern Pacific by the early late Miocene. From the early late Miocene onward, Yabepecten followed different evolutionary histories on both sides of the North Pacific. Yabepecten became extinct in the northeastern Pacific by the end of the early late Miocene. However, Yabepecten flourished in the northwestern Pacific from the late Pliocene to early Pleistocene, only becoming extinct at the beginning of the middle Pleistocene, along with many other species of the Omma-Manganji Fauna.