Modern human teeth unearthed from below the ∼128,000-year-old level at Punung, Java: A case highlighting the problem of recent intrusion in cave sediments.

The emergence of modern humans in the eastern edge of the Eurasian Continent is debated between two major models: early (∼130-70 ka) and late (∼50 ka) dispersal models. The former view is grounded mainly on the claims that several cave sites in Southeast Asia and southern China yielded modern human fossils of those early ages, but such reports have been disputed for the lack of direct dating of the human remains and insufficient documentation of stratigraphy and taphonomy. By tracing possible burial process and conducting direct dating for an early Late Pleistocene paleontological site of Punung III, East Java, we here report a case that demonstrates how unexpected intrusion of recent human remains into older stratigraphic levels could occur in cave sediments. This further highlights the need of direct dating and taphonomic assessment before accepting either model. We also emphasize that the state of fossilization of bones and teeth is a useful guide for initial screening of recent intrusion and should be reported particularly when direct dating is unavailable. Additionally, we provide a revised stratigraphy and faunal list of Punung III, a key site that defines the tropical rainforest Punung Fauna during the early Late Pleistocene of the region.

Geographic Variation of Absolute and Relative Lower Molar Sizes in the Japanese Macaque (Macaca fuscata: Primates, Mammalia).

We examined geographic variations of absolute and relative lower molar sizes (size proportions among M1, M2, and M3) in the Japanese macaque (Macaca fuscata) using skull specimens obtained from 13 locations. We compared the geographic patterns and climatic factors. The size of M1 significantly and negatively correlated to the annual and coldest month mean temperatures and precipitation for both males and females. The M2/M1 and M3/M1 scores significantly and positively correlated to the annual and coldest month mean temperatures. The geographic pattern in the size of M1 was consistent with Bergmann's rule; however, the sizes of M2 and M3 did not correlate with temperature, and were not consistent with the rule. The geographic pattern in relative molar sizes (M2/M1 and M3/M1 scores) indicated that populations living in colder climates possess a larger M1 in relation to M2 and M3. Therefore, the correlations of M1, M2/M1, and M3/M1 scores to temperature involve an increase in the size of M1 in a colder climate. In macaques, the functions of the different molars (M1, M2, and M3) do not differ (they all exhibit grinding function, unlike differentiation between carnassial and other molars in Carnivora), whereas the timing of molar eruption does. In other words, at young ages (1.5-3.5 years), M1 erupts and is in occlusion, whereas M2 and M3 do not erupt and are not used for mastication. Therefore, the geographic pattern in the relative molar sizes may be attributed to increasing survivability in harsh winter climates by increasing occlusal surface in younger animals.

First discovery of colobine fossils from the Late Miocene/Early Pliocene in central Myanmar.

Here we report two kinds of colobine fossils discovered from the latest Miocene/Early Pliocene Irrawaddy sediments of the Chaingzauk area, central Myanmar. A left mandibular corpus fragment preserving M1-3 is named as a new genus and species, Myanmarcolobus yawensis. Isolated upper (M(1)?) and lower (M2) molars are tentatively identified as Colobinae gen. et sp. indet. Although both forms are medium-sized colobines, they are quite different from each other in M2 morphology. The isolated teeth of the latter show typical colobine-type features, so it is difficult to identify their taxonomic position, whereas lower molars of Myanmarcolobus have unique features, such as a trapezoid-shaped long median lingual notch, a deeply concave median buccal cleft, a strongly developed mesiobuccal notch, and rather obliquely running transverse lophids. Compared with fossil and living Eurasian colobine genera, Myanmarcolobus is most similar in lower molar morphology to the Pliocene Dolichopithecus of Europe rather than to any Asian forms. In Dolichopithecus, however, the tooth size is much larger and the median lingual notch is mesiodistally much shorter than that of Myanmarcolobus. The discovery of Myanmarcolobus in central Myanmar is the oldest fossil record in Southeast Asia not only of colobine but also of cercopithecid monkeys and raises many questions regarding the evolutionary history of Asian colobine monkeys.

Taxonomic examination of longgu (Fossilia Ossis Mastodi, "dragon bone") and a related crude drug, longchi (Dens Draconis, "dragon tooth"), from Japanese and Chinese crude drug markets.

Longgu ("dragon bone," Ryu-kotsu, Fossilia Ossis Mastodi, or Os Draconis) is the only fossil crude drug listed in the Japanese Pharmacopoeia. All longgu in the current Japanese market is imported from China, where its resources are being depleted. Therefore, effective countermeasures are urgently needed to prevent resource depletion. One possible solution is the development of a substitute made from bones of contemporary animals that are closely related to the original animal source of the current longgu. However, no research has been conducted on the original animal source of longgu, except for a report on the longgu specimens present in the Shosoin Repository. Taxonomic examination was performed on the fossil specimens related to longgu which are owned by the Museum of Osaka University, Japan. In total, 20,939 fossil fragments were examined, of which 20,886 were mammalian fossils, and 246 of these fossils were classified into nine families. The longgu specimens from the Japanese market belonged to a relatively smaller variety of taxa than those from the Chinese market. Despite the variety of taxa in longgu, medical doctors using Kampo preparations with longgu have not reported any problems due to the presence of impurities in the original animal source. These results suggest that the effect of longgu is independent of its origin as long as it is closely related to the origin of the current longgu. Thus, despite the considerable effects of fossilization, our results could help in developing an optimal substitute for longgu.

Small Mammalian Remains from the Late Holocene Deposits on Ishigaki and Yonaguni Islands, Southwestern Japan.

Yuichiro Nishioka, Ryohei Nakagawa, Shin Nunami, and Satoshi Hirasawa (2016) Small mammalian remains were newly discovered from the Late Quaternary sediments of the Yaeyama region (Ishigaki and Yonaguni Islands) in the southwestern-most part of Japan. We examined these materials based on taxonomical and chronological approaches, in order to reconstruct the past fauna in this region. Accelerator Mass Spectrometry radiocarbon dating indicates that the mammalian assemblages from Ishigaki and Yonaguni Islands are composed mainly of late Holocene fossils. The fossil assemblage from Ishigaki Island comprises five species of small mammals belonging to Soricomorpha (Suncus murinus), Chiroptera (Pteropus sp., Hipposideros turpis, and Rhinolophus perditus), and Rodentia (Niviventer sp.). One rodent bone, collected from the fissure sediments near Sabichi-do Cave, Ishigaki Island, is dated at 230 ± 20 yBP (ca. AD 1,700), and is considered part of the recent remain. Furthermore, the fossil assemblage from Umabana-zaki Fissure, on Yonaguni Island, is dated at 1,760 ± 20 yBP (ca. AD 300) and comprises three species of small mammals belonging to Chiroptera (Pipistrellus cf. abramus) and Rodentia (Niviventer sp. and Mus musculus). Niviventer is not currently distributed in Japan. Only domestic rats (Rattus rattus and R. norvegicus) live on Ishigaki and Yonaguni Islands at the present time. However, the fossil assemblage from Umabana-zaki Fissure is dominated completely by Niviventer sp. Most fossils of small mammals found from the late Holocene Ishigaki and Yonaguni Islands represented species that are currently endemic to the Yaeyama region. Niviventer sp. from these islands is unique because this form has never been found from neighboring regions, such as Taiwan and Miyako Islands, and because it likely existed in the late Holocene. These discoveries support the hypothesis that the Yaeyama region had been isolated zoogeographically from the continent even during the Last Glacial Maximum, when the sea level had drastically fallen.

The extinct river shark Glyphis pagoda from the Miocene of Myanmar and a review of the fossil record of the genus Glyphis (Carcharhiniformes: Carcharhinidae).

We redescribe an extinct river shark, Glyphis pagoda (Noetling), on the basis of 20 teeth newly collected from three different Miocene localities in Myanmar. One locality is a nearshore marine deposit (Obogon Formation) whereas the other two localities represent terrestrial freshwater deposits (Irrawaddy sediments), suggesting that G. pagoda from the Irrawaddy sediments was capable of tolerating low salinity like the extant Glyphis. Glyphis pagoda likely reached up to at least 185 cm in total body length and was probably piscivorous. The fossil species occurs in rocks of Myanmar and eastern and western India and stratigraphically ranges at least from the Lower Miocene (Aquitanian) to the lower Upper Miocene (mid-Tortonian). It has been classified under at least eight other genera to date, along with numerous taxonomic synonyms largely stemming from the lack of understanding of the heterodonty in extant Glyphis in the original description. Our literature review suggests that known Miocene shark faunas, particularly those in India, are manifested with unreliable taxonomic identifications and outdated classifications that warrant the need for a comprehensive taxonomic review in order to evaluate the evolutionary history and diversity pattern of Miocene shark faunas. The genus Glyphis has a roughly 23-million-year-long history, and its success may be related to the evolution of its low salinity tolerance. While extant Glyphis spp. are considered to be particularly vulnerable to habitat degradation and overfishing, the fossil record of G. pagoda provides renewed perspective on the natural history of the genus that can be taken into further consideration for conservation biology of the extant forms.