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A nostoceratid ammonoid Yezoceras elegans sp. nov. is newly described from the Coniacian of the Haboro area in Hokkaido, northern Japan. Yezoceras elegans sp. nov. having loosely coiled whorls, a wide umbilicus, and two prominent tubercle rows concentrated in the lower part of the whorls, is distinguished from the other species by these characteristics. Yezoceras elegans sp. nov. might have originated from Y. nodosum, judging from the stratigraphic correlation. The restricted occurrences of three Yezoceras species (Y. elegans sp. nov., Y. nodosum and Y. miotuberculatum) in Hokkaido, northern Japan suggest that the speciation of Yezoceras occurred in the northwestern Pacific realm during the Coniacian age.
A new heteromorph ammonoid Sormaites teshioensis gen. et sp. nov. (Diplomoceratidae) is described from the upper Turonian (Upper Cretaceous) in the Nakagawa area, Hokkaido, northern Japan. Its near planispiral whorls consist of crioceratoid early whorls followed by straight shafts with U-shaped whorls connecting the successive shafts. The shell surface is ornamented with simple, straight, sharp tipped ribs throughout ontogeny, but infrequent flared ribs and constrictions occur on later whorls. Excluding its earliest whorls, its coiling and ornamentation are very similar to Scalarites mihoensis and Sc. densicostatus from the Turonian to Coniacian in Hokkaido and Sakhalin, suggesting that So. teshioensis was probably derived from one of these taxa in the Northwest Pacific during middle to late Turonian time.
Narrow dolphin mandibles with an elongate mandibular symphysis from the Oi Formation, Ichishi Group (late early Miocene) of Tsu City, Mie Prefecture, Japan is reported. The specimen shows different morphologies from “Eurhinodelphis” minoensis and Ninjadelphis ujiharai, which were reported from late early Miocene sediments of the same region. This new record expands our knowledge of lower Miocene odontocetes from Japan and indicates that at least three odontocetes are represented in the Mizunami and Ichishi Groups.
A Late Pleistocene fossil represented by an incomplete right hypoplastron of Cuora amboinensis was recovered from the Wajak site (ca. 37 ka–29 ka: Late Pleistocene) in East Java, Indonesia. The fossil constitutes the first certain prehistoric record of this species from Java, which implies that the current conspecific population in this island is indigenous to the region rather than artificially introduced from the Southeast Asian continent in historic times. The specimen has four small distinct impact pits on the hypoplastron in dorsal view, which were possibly caused by a pointed stone artifact or a bone tool. The presence of such percussion marks suggests that this turtle was consumed by the Wajak people.
Two early Permian radiolarians, Pseudoalbaillella postscalprataIshiga, 1983 and Pseudoalbaillella sakmarensis (Kozur, 1981), are described from a calcareous nodule of the Permian siliciclastic succession distributed in north-central East Timor. The association probably indicates a Sakmarian (early Cisuralian) age. This is the first report of age-diagnostic Permian radiolarians from East Timor and demonstrates a potential source of well-preserved radiolarians of the Permian siliciclastic succession.
Thomas W. Wong Hearing, Mark Williams, Adrian Rushton, Jan Zalasiewicz, Toshifumi Komatsu, Christopher Stocker, Thomas H. P. Harvey, Shuji Niko, Hung Dinh Doan, Ha Thai Trinh, Hung Ba Nguyen, Minh Trung Nguyen
Two new graptolite assemblages are identified from discrete intervals within the Phu Ngu Formation, Na Ri District, Bac Kan Province, north-east Vietnam. The graptolites occur in laminated mud/siltstones thought to be distal turbidite deposits. A low-diversity diplograptid sensu lato assemblage occurs in mud-rich layers that are interlaminated with silty and sandy horizons containing the dendroid graptolite Dictyonema sp. This level also contains orthoconic nautiloids and conulariids. A few metres stratigraphically above, a second more diverse graptolite assemblage comprises a single Dicellograptus, tentatively identified as D. flexuosus, together with Climacograptus dorotheus and Orthograptus truncatus pauperatus in mud and silt laminae that also yield brachiopods, orthoconic nautiloids, conulariids, fragmentary trilobites, and ostracods. The ostracods include the first East Asian occurrence of the typically Baltic genus Kinnekullea, and we describe the new species Kinnekullea gaia. The graptolites suggest a Late Ordovician Katian age, most probably in the Dicranograptus clingani Biozone, this being older than previous biostratigraphical constraints on the Phu Ngu Formation.
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