A new species of laqueoid brachiopod from Macclesfield Bank, South China Sea, Shimodaia macclesfieldensis sp. nov., is described and compared with the Japanese type species of the genus Shimodaia, S. pterygiota MacKinnon, Saito, and Endo, 1997. S. macclesfieldensis sp. nov. is also compared with Frenulina sanguinolenta (Gmelin), a similarly coloured but generally larger laqueoid which is widely distributed in the tropical western Pacific. Since the annular adult loop phase of Shimodaia is comparable with the juvenile loop phases of other laqueoids, the possibility of evolutionary convergence of the two geographically disjunct species from independent preexisting laqueoid stocks cannot be ruled out entirely.

A cyrtoconic nautiloid, Arcuatoceras saundersi gen. et sp. nov., from the upper shale member of the Imo Formation (late Chesterian, Early Carboniferous) in north central Arkansas, U.S.A., is described and tentatively assigned to the family Scyphoceratidae. One specimen of the new taxon retains the embryonic conch and the earliest growth stages of the post-hatching shell; this specimen is the first record of the embryonic shell of nautiloid cephalopods having cyrtoconic brevicones in the Carboniferous. The morphology of the shell ornament and the shape of the early shell suggest that the newly hatched animal was an active swimmer after hatching, whereas in later growth stages, the animal probably lived and crawled on the bottom as part of the nektonicbenthonic community. Additionally, some conchs of this new genus show the remains of color patterns preserved as dark gray markings on a lighter gray background. There is considerable variation in the color patterns. One small specimen has conspicuous longitudinal bands and spots on the venter and ventrolateral surface together with a faint chevron on the lateral and dorsolateral parts of the conch. Several larger specimens have only well developed chevrons on the venter, ventrolateral, lateral, and dorsolateral parts of their conchs. This color-pattern variation is interpreted as a change during ontogenetic development rather than as a systematic difference.

Conodont biostratigraphy, paleobiogeography, and depositional environments reveal detailed eustatic changes and paleogeography of the Sibumasu terrane during the Ordovician. Based on lithologic data, the Ordovician sequences on the Sibumasu terrane are classified into two types. One was deposited in the Thong Pha Phum-Li basin, which extends from northern to western Thailand, and the other formed in the Tarutao-Langkawi basin ranging from southern Thailand to northern Malaysia. Five regressive events, RE 1 to 5, and a transgressive event TE 1 are recognized in these basins. On the basis of the conodont biostratigraphy, RE 1, 2, 4, and 5 are correlated with the Peltocare Regressive Event, the Ceratopyge Regressive Event, the Basal Whiterockian Lowstand interval, and the global regression caused by the end-Ordovician glaciation, respectively. TE 1 continued through Darriwilian time. The faunal affinity of Ordovician conodonts makes it clear that the Sibumasu terrane was close to both Australia and North China, which were located in low paleolatitudes. The Darriwilian transgressive event, TE 1, led to a remarkable conodont faunal change from a shallow-water to a deeper, cool-water assemblage.

The concept of the Carboniferous nautiloid Brachycycloceras normale Miller, Dunbar and Condra, 1933, is emended on the basis of new material from the Desmoinesian to Missourian sequences in Oklahoma. Because the species represents the type of Brachycycloceras and the family Brachycycloceratidae is monogeneric, this emendation requires modification of both the generic and familial diagnoses. This cephalopod genus has a longiconic conch with an annulated immature shell with a slight endogastric curvature, a rapidly inflated, straight, mature conch without annulations, and a siphuncle in a supracentral position. Contrary to earlier interpretations, new evidence from yet undescribed specimens shows that the living orientation of the convex side of the conch was dorsal. These discoveries suggest that assignment of the Brachycycloceratidae to the order Orthocerida is questionable.

The Pliocene Epoch represents a significant period in the palaeozoogeography of North Atlantic, Arctic and northern Pacific podocopid ostracods. A climate crash during Marine Isotope Stage (MIS) G6 (c. 2.74 Ma) resulted in the extinction of early-mid Pliocene thermophilic ostracods and the subsequent emergence of oligothermal assemblages during the late Pliocene. During the numerous cold stages of the late Pliocene-early Pleistocene Arctic ostracod species were able to disperse southwards into the mid-latitudes of the North Atlantic. The Pre-Ludhamian Stage of the Red Crag Formation, Suffolk, England spans one such episode (c. 2.7–2.41 Ma) and thus offers new insight into the vagility of shallow marine ostracods as they responded to glacio-eustatic and isostatic changes. Five podocopid ostracods are described from the Sizewell Member (Pre-Ludhamian Stage) of the Red Crag Formation and new information regarding their phylogeny and palaeozoogeography is presented. Four of the species are new to science, Microcytherura gelida sp. nov., Thaerocythere liebaui sp. nov., Thaerocythere russus sp. nov. and Pectocythere hollowayae sp. nov., while the fifth, Neomonoceratina tsurugasakensis (Tabuki), is reexamined and reassigned. The comparative morphology of Pectocythere Hanai and Kotoracythere Ishizaki is reviewed and a morphological continuum recognized between phenotypic end-members. Pectocythere hollowayae sp. nov. forms part of a distinctive morphological group comprising Arctic and northern Pacific species: P. ishizakii Irizuki and Yamada, Pectocythere? sp. cf. P.? dentarticulata (Smith) sensu Swain and Gilby, Kotoracythere sp. Irizuki, P. janae Brouwers and P. parkerae Swain and Gilby. Although lacking a distinctive caudal process, Paijenborchella tsurugasakensis Tabuki is reassigned to Neomonoceratina sensu Zhao and Whatley. Neomonoceratina tsurugasakensis displays some minor polymorphism over an enormous geo-temporal range that extends from the early Miocene of the northwestern Pacific to the late Pliocene-early Pleistocene of the southern North Sea Basin. Despite its lack of pelagic larvae N. tsurugasakensis was capable of transoceanic dispersal, evidenced by its occurrence in the early Pliocene (c. 4.90–4.81 Ma), Oosterhout Formation, Western Netherlands Basin, alongside other pan-Arctic and North Pacific ostracod taxa. Mechanisms of dispersal remain unclear but could involve passive transport on Fucus brown algae, aided by the Transpolar Drift. Further agents of dispersion could include fish and birds. The viability of water birds as vectors of invertebrate dispersal is given further credence by the discovery of Phoebastria anglica (Lydekker), a fossil albatross, in the Pliocene crags of East Anglia.

The middle Pleistocene Matsugae mammalian fauna from the Matsugae limestone cave deposits in northern Kyushu, West Japan is reexamined based on the original fossil specimens and its biostratigraphical age is estimated. The Matsugae fauna includes 13 mammalian species representing 6 orders, 10 families and 12 genera that can be confirmed based on currently available fossil specimens. The taxa of the Matsugae fauna fall into four categories: the first encompasses a mammal that has been in existence since the early middle Pleistocene; the second comprises mammals that existed only during the middle middle Pleistocene; the third includes those that have specific characteristics of this age but may have a phyletic relationship to later Japanese mammals; and the fourth includes the direct ancestors of modern Japanese endemic species. The second and the third categories include several endemic taxa which are only known from this fauna. The mammalian fauna suggests an age referable to the Quaternary Mammal zone 4 (QM4), which is the middle part of the middle Pleistocene.