Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

A mammalian dentary discovered in the Coniacian Ashizawa Formation (Fukushima, northeastern Japan) is described. The specimen is a fragment of the horizontal ramus of a left edentulous dentary with five alveoli, the distal four of which are plugged with broken roots. Based on the morphologies of the dentary and the roots, it is considered to be of a therian mammal. This constitutes the first discovery of a Mesozoic mammal in northeastern Japan and highlights the potential for future mammal discoveries in the Cretaceous System in northeastern Japan, which will be significant for disclosure of the mammalian faunal evolution in East Asia during the Late Cretaceous.

DOI： 10.1111/iar.12133

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

Two new gobiconodontid mammals, Gobiconodon tomidaisp. nov. and Gobiconodon haizhouensissp. nov., from the Lower Cretaceous (Aptian to Albian) Shahai and Fuxin Formations, respectively, in Liaoning Province, northeastern China, are described. Gobiconodon tomidaisp. nov. is a small-sized species of the genus characterised by the lower dental formula 2.1.2.5, a double-rooted p2, the molariform crown being mesiodistally longer than tall, and a distinct and almost continuous lingual cingulid on m2-m4. Gobiconodon haizhouensissp. nov. is of similar size to Gobiconodon tomidaisp. nov. and is characterised by the lower dental formula 2.1.3.5, the molariform crown being slightly taller than the mesiodistal length, and a well-developed and almost continuous lingual cingulid on m1-m3. The new materials indicate that the upper molariform count of most species of Gobiconodon is likely to be four, one less than the lower molariform count. Gobiconodon is the second mammalian genus common to the Jehol and Fuxin mammalian faunas.http://www.zoobank.org/urn:lsid:zoobank.org:pub:608F5A43-AE4D-41CF-A2E4-1C9C6CFCA67C

DOI： 10.1080/08912963.2014.977881

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SEPM-SOC SEDIMENTARY GEOLOGY  

Oxygen isotope compositions of tooth enamel increments in theropod dinosaurs are investigated as potential climate seasonality. Six teeth of large carnivorous theropods collected from four Cretaceous formations deposited under contrasted climates have been sampled. These teeth have been analyzed for the oxygen isotope compositions of their apatite phosphate (delta O-18(p)) through incremental sampling performed along the major growth axis. Significant fluctuations in oxygen isotope compositions along the growth axis of each tooth are observed and interpreted as reflecting seasonality in ingested local surface water delta O-18(w) values. Fluctuations in delta O-18(p) values of theropod teeth from the Aptian of Thailand and Cenomanian of Morocco vary similarly to meteoric water d delta O-18(mw) values occurring today in sub-tropical regions subjected to large seasonal amounts of precipitations. A dinosaur tooth recovered from the more inland and mid-latitude Nemegt Formation of Mongolia shows a seasonal pattern similar to present-day cold temperate and continental climate. Finally, the high latitude and coastal Kakanaut Formation (Russia) experienced strongly dampened seasonal variations, most likely due to the influence of warm Pacific oceanic currents. Such conditions occur today in high latitude regions submitted to marine influence. These results further highlight the potential of using the oxygen isotope compositions of large theropod teeth to reconstruct past seasonal variations of terrestrial climates. Increased knowledge of past seasonality may help to better understand the complex interactions between climate and the dynamics of land biodiversity in terms of ecological adaptations, biogeography and the evolutionary history of organisms.

DOI： 10.2110/palo.2015.018

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS INC  

We describe tritylodontid remains from the Lower Cretaceous Kuwajima Formation (Tetori Group) in central Japan as representing a new genus, Montirictus kuwajimaensis, gen. et sp. nov. Montirictus is a medium-sized tritylodontid genus characterized by upper cheek teeth having the cusp formula 2-2-2 with subequal cusps, buccal and lingual cusps retaining a crescentic shape with both buccal and lingual ridges anteriorly, and 'V'-shaped buccolingual cross-sections of two anteroposterior grooves between the three cusp rows. Tentative dating of the Kuwajima Formation to the Barremian-Aptian makes it the stratigraphically youngest representative of a long-lived, globally distributed and abundant mammaliamorph lineage and extends the known geographic range of tritylodontids.

DOI： 10.1080/02724634.2016.1112289

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society  

We here describe a new Early Cretaceous (early Albian) eutherian mammal, Sasayamamylos kawaii gen. et sp. nov., from the 'Lower Formation' of the Sasayama Group, Hyogo Prefecture, Japan. Sasayamamylos kawaii is characterized by a robust dentary, a distinct angle on the ventral margin of the dentary at the posterior end of the mandibular symphysis, a lower dental formula of 3-4: 1: 4: 3, a robust lower canine, a non-molariform lower ultimate premolar, and a secondarily reduced entoconid on the molars. To date, S. kawaii is the earliest known eutherian mammal possessing only four premolars, which demonstrates that the reduction in the premolar count in eutherians started in the late Early Cretaceous. The occurrence of S. kawaii implies that the relatively rapid diversification of eutherians in the mid-Cretaceous had already started by the early Albian. © 2013 The Author(s) Published by the Royal Society. All rights reserved.

DOI： 10.1098/rspb.2013.0142

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS INC  

Two eobaatarid multituberculates, Heishanobaatar triangulus gen. et sp. nov. and Eobaataridae gen. et sp. indet., and an ?albionbaatarid multituberculate, Kielanobaatar badaohaoensis gen. et sp. nov., from the Lower Cretaceous (Aptian to Albian) Shahai and Fuxin formations in Liaoning Province, northeastern China, are described. Heishanobaatar triangulus is a moderate-sized multituberculate characterized by lower jaw dental formula 1.0.3.2, slender lower incisor, single-rooted p2, triangular p3 in lateral view, p4 with eight serrations, m1 with cusp formula 2:2, and m2 with cusp formula 1 (coalesced):2. Kielanobaatar badaohaoensis is characterized by upper anterior premolars with relatively flat occlusal surfaces, roughly pentangular P1 in occlusal view, P1 and P2 with three cusp rows (cusp formulae 1:3:2), and P3 with four cusps (cusp formula 2:2). Together with already described three species of eobaatarids from the same localities, they demonstrate that there were quite diverse multituberculates in Asia in the late Early Cretaceous, and suggest that the mammalian fauna known from the Shahai and Fuxin formations probably show a transitional state from the mammalian fauna of the Yixian Formation to Late Cretaceous Asian faunas.

DOI： 10.1080/02724634.2010.501435

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS INC  

Two eobaatarid multituberculate genera including three species front the Lower Cretaceous (Aptian-Albian) Shahai and Fuxin formations in Liaoning Province, northeastern China are described here: Sinobaatar xiei sp. nov., S. fuxinensis sp. nov., and Liaobaatar changi gen. et sp. nov. Sinobaatar xiei is characterized by in I with cusp formula 3:2 (labial:lingual), P4 with cusp formula 2:4. blade-like P5 with three cusps anteroposteriorly arranged, M I with cusp formula 4:4, and M2 with cusp formula 3:4. P1 to P3 of S. xiei lack distinct posterior cingulum. Sinobaatar fuxinensis has a more distinct posterior cingulum on P1 to P3, and its M2 has cusp formula 3:3. Sinobaatar xiei is within the size range of most other eobaatarids, and S. fuxinensis is slightly larger than S. xiei. Liaobaatar changi is clearly larger than other eobaatarids. The ratio of p4 length and height of L. changi and S. xiei (L./S.) are 1.9 and 1.7, respectively. Liaobaatar changi is also characterized by nil with cusp formula 3:3. A specimen of S. fuxinensis indicates that tooth replacement in eobaatarids occurred in the typical backward sequence seen in Late Cretaceous-Tertiary multituberculates.

DOI： 10.1671/039.029.0433

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER  

The first triconodontids from Asia have been discovered from the Lower Cretaceous (Aptian to Albian) Shahai and Fuxin formations in Liaoning Province, northeastern China: Meiconodon lii gen. and sp. nov. and M. setoguchii gen. and sp. nov. M. lii is characterized by molariform teeth with a developed cusp d, an m3 with taller cusp a, an m4 with three primary cusps of subequal height, the posteriorly decreasing transverse width of the m4, and a considerably reduced m5. M. seloguchii is slightly larger than M. lii, and characterized by a sharp labial cingulum on the m4, and a less developed cusp d on the molariform teeth than M. lii. The extensive interlocking system between molariforms, posteriorly recumbent primary molariform cusps, and their great degree of asymmetry in occlusal view with rounded labial faces and more angulate lingual faces in lateral view, indicate that Meiconodon belongs to the triconodontid subfamily Alticonodontinae. These new taxa are the first record of Triconodontidae from Asia, and of Alticonodontinae outside North America, suggesting the occurrence of mammalian faunal exchange between North America and Asia during or before the Aptian-Albian. (C) 2009 Elsevier Masson SAS. All fights reserved.

DOI： 10.1016/j.geobios.2009.06.003

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：INST PALEOBIOLOGII PAN  

Hakusanobaatar matsuoi gen. et sp. nov. and Tedoribaatar reini gen. et sp. nov. are multituberculate mammals recovered from the Lower Cretaceous (Barremian to lower Aptian) Kuwajima Formation of the Tetori Group in the Shiramine district, Hakusan City, Ishikawa Prefecture, central Japan. Hakusanobaatar matsuoi is an eobaatarid multituberculate characterized by a P4 with cusp formula 3:5, and a P5 with cusp formula 2:6:?2. One of the specimens of H. matsuoi has the best preserved upper premolar series among known eobaatarid specimens. Based on the dentition of H. matsuoi, it is highly probable that the cimolodontan P4 is homologous with the "plagiaulacidan" P5. Tedoribaatar reini is also tentatively attributed to Eobaataridae, and shows a single-rooted p3 and loss of at least the permanent p2. On the basis of these apomorphic features, T reini is considered to be the "plagiaulacidan" multituberculate that is most closely related to cimolodontans.

DOI： 10.4202/app.2008.0302

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：PALAEONTOLOGICAL SOC JAPAN  

DOI： 10.2517/1342-8144(2008)12[199:AMFFTU]2.0.CO;2

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：BLACKWELL PUBLISHING  

The upper Mesozoic Tetori Group contains numerous fossils of plants and marine and non-marine animals. The group has the potential to provide key information to improve our understanding of the Middle Jurassic to Early Cretaceous biota of East Asia. However, the depositional age of the Tetori Group remains uncertain, and without good age constraints, accurate correlation with other areas is very difficult. As a first step in obtaining reliable ages for the formations within the Tetori Group, we used laser ablation-inductively coupled plasma-mass spectrometry to measure the U-Pb ages of zircons collected from tuff beds in the Shokawa district, Takayama City, Gifu Prefecture, central Japan. The youngest reliable U-Pb ages from the tuff beds of the Ushimaru, Mitarai and Okurodani Formations are 130.2 +/- 1.7, 129.8 +/- 1.0 and 117.5 +/- 0.7 Ma, respectively (errors represent 2 SE). These results indicate that the entire Tetori Group in the Shokawa district, which was previously believed to be correlated to the Upper Jurassic to Lower Cretaceous, is in fact correlated to the Lower Cretaceous. The maximum ages of the Ushimaru, Mitarai and Okurodani Formations are late Hauterivian to Barremian, late Hauterivian to Barremian and Barremian to Aptian, respectively.

DOI： 10.1111/j.1440-1738.2006.00544.x

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publisher：日本地質学会  

Did intra-arc deformations in SW Japan occur associated with the opening of the Japan Sea back-arc basin? To answer this question, we studied the Lower Miocene Kuma Group, central SW Japan. The Group is shown to be alluvial fan deposits. The sedimentary basin of the Kuma Group may have been formed as half grabens. The multiple inverse method was applied to mesoscale faults of the Kuma Group and detected six stresses from in situ and from tilt corrected fault-slip data. One stress state determined from the tilt corrected data is consistent with the paleostress that formed the E-W trending half grabens in the Kuma Group. One other stress is consistent with that inferred from 15 m.y. old dike swarm in this area. Accordingly, this area was subject to extensional tectonics in the Early to early Middle Miocene.

DOI： 10.5575/geosoc.107.26

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Abstract

We present a model for the petrogenesis of magma with adakitic affinity in an old subduction zone, which does not involve slab melting and is constrained by new geochronological and geochemical data for Mt. Popa, the largest of three Quaternary volcanoes in central Myanmar (Popa, Monywa and Singu). The edifice is composed of Popa Plateau (0.8–0.6 Ma) with high-K rocks and a stratovolcano (< 0.33 Ma) predominantly composed of medium-K rocks with adakitic affinity (Mg# 45–63, Sr/Y > 40). The distinct K contents indicate that the adakitic magmas cannot be derived from Popa high-K rocks, but they share trace-element signatures and Sr–Nd isotope ratios with medium-K basalts from Monywa volcano. Our estimation of water contents in Popa magma reveals that primary magma for medium-K basalts was generated by partial melting of wedge mantle with normal potential temperature (T_P 1330–1340 °C) under wet conditions (H₂O 0.25–0.54 wt%). Its melting was probably induced by asthenospheric upwelling that is recognized by tomographic images. Mafic adakitic magma (Mg# ~ 63, Sr/Y ~ 64) was derived from the medium-K basaltic magma in fractional crystallization of a garnet-bearing assemblage at high pressure, and felsic adakitic rocks (Mg# ~ 45, Sr/Y ~ 50) were produced by assimilation-fractional crystallization processes at mid-crustal depths.

DOI： 10.1038/s41598-022-07097-4

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Other Link： https://www.nature.com/articles/s41598-022-07097-4

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Geological Society of Japan  

DOI： 10.5575/geosoc.2021.0007

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Anthropological Society of Nippon  

DOI： 10.1537/ase.2012131

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Informa UK Limited  

DOI： 10.1080/02724634.2021.1879100

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

We investigated the environmental conditions that prevailed in continental ecosystems recorded in sedimentary deposits of Japan during the Cretaceous through the analysis of oxygen and carbon isotope compositions phosphate (delta O-18(p)) and apatite-bound carbonate (delta O-18(c) and delta C-13(c)) of vertebrate teeth and bones. Local surface water delta O-18(w) values were calculated using known phosphate-water isotope fractionation equations. Anomalously low delta O-18(w) values of local waters strongly suggest a significant contribution of high-altitude precipitation from nearby mountains to local surface waters. Mean air temperatures were estimated using a global meteoric water delta O-18(mw) value - Mean Annual Air Temperature relationship, and compared to surface water temperatures estimated from fish apatite delta O-18(p) values. Local mean annual precipitations (MAP) were estimated using the known relationship existing between MAP and C3 plant delta C-13(p) value, the latter being calculated using apatite-diet C-13 enrichment applied to plant-eating sauropod and ornithopod dinosaur delta C-13(c) values. Reconstructed environmental conditions suggest that climate changed from cool temperate to warm temperate, being relatively cold and dry during the Late Hauterivian and Barremian to warmer and seasonally more humid during the Aptian and Albian, and even warmer during the Cenomanian-Coniacian. Proposed thermal evolution during the Early Cretaceous is compatible with the absence of thermophilic taxa such as crocodylomorphs before the Aptian in the fossil record of Japan.

DOI： 10.1016/j.jseaes.2020.104602

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Table 2 of this paper has an unnecessary value of 1.88 in the row of PIN 3101/63 (Eobaatar magnus), which is not related with this table. This is just an authors’ mistake, and please ignore this value. Please see below correct table: (Table presented.).

DOI： 10.1007/s10914-019-09486-5

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Informa UK Limited  

DOI： 10.1080/14772019.2020.1749147

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Mammal Society of Japan  

DOI： 10.11238/mammalianscience.60.251

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DOI： 10.5575/geosoc.2019.0010

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Geological Society of Japan  

<p>The Tetori Group in the Shiramine area (Ishikawa Prefecture, central Japan) is subdivided into the Gomijima, Kuwajima, Akaiwa, and Kitadani formations (from bottom to top). A variety of animal and plant fossils have been reported from the Kuwajima, Akaiwa, and Kitadani formations, but the depositional ages are still poorly constrained. We obtained the first reliable zircon U-Pb age from the Akaiwa Formation of the Tetori Group in the Shiramine area using laser ablation inductively coupled plasma mass spectrometry. The dated sample was taken from the lower part of the Akaiwa Formation along the Osugidani River (Shiramine area), and its U-Pb age is 121.2±1.1 Ma (95% confidence interval).</p>

DOI： 10.5575/geosoc.2018.0062

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J-GLOBAL

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Other Link： http://www.palaeo-soc-japan.jp/publications/103_Takai_etal.pdf

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Palaeontological Society of Japan  

DOI： 10.14825/kaseki.104.0_51

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DOI： 10.5575/geosoc.2017.0035

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER HEIDELBERG  

Oxygen isotope compositions of bone phosphate (delta O-18(p)) were measured in broiler chickens reared in 21 farms worldwide characterized by contrasted latitudes and local climates. These sedentary birds were raised during an approximately 3 to 4-month period, and local precipitation was the ultimate source of their drinking water. This sampling strategy allowed the relationship to be determined between the bone phosphate delta O-18(p) values (from 9.8 to 22.5% V-SMOW) and the local rainfall delta O-18(w) values estimated from nearby IAEA/WMO stations (from -16.0 to -1.0% V-SMOW). Linear least square fitting of data provided the following isotopic fractionation equation: delta O-18(w) = 1.119 (+/- 0.040) delta O-18(p) - 24.222 (+/- 0.644); R-2 = 0.98. The delta O-18(p)-delta O-18(w) couples of five extant mallard ducks, a common buzzard, a European herring gull, a common ostrich, and a greater rhea fall within the predicted range of the equation, indicating that the relationship established for extant chickens can also be applied to birds of various ecologies and body masses. Applied to published oxygen isotope compositions of Miocene and Pliocene penguins from Peru, this new equation computes estimates of local seawater similar to those previously calculated. Applied to the basal bird Confuciusornis from the Early Cretaceous of Northeastern China, our equation gives a slightly higher delta O-18(w) value compared to the previously estimated one, possibly as a result of lower body temperature. These data indicate that caution should be exercised when the relationship estimated for modern birds is applied to their basal counterparts that likely had a metabolism intermediate between that of their theropod dinosaur ancestors and that of advanced ornithurines.

DOI： 10.1007/s00114-017-1468-2

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DOI： 10.14825/kaseki.97.0_23

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

During the cold Late Barremian-Early Albian interval, terrestrial environments in East Asia were populated by rich and diverse vertebrate faunas characterized by a strong provincialism. The latitudinal gradient of temperature and the existence of geographic barriers likely accounted for some aspects of this heterogeneous distribution of faunas. Other factors, however, such as local environmental conditions and interactions within vertebrate communities, which could have influenced their distribution, have not yet been fully identified and understood. Therefore, new and published oxygen and carbon isotope compositions of apatite from Chinese and Thai reptiles (dinosaurs, crocodilians and turtles) have been analyzed and interpreted in terms of ecology, local air temperature and precipitation amounts. Differences in carbon and oxygen isotope compositions between various groups of sympatric plant-eating dinosaurs (sauropods, ornithopods and ceratopsians) indicate food resources partitioning among them most likely to avoid competition. Mid-latitude environments, where the Jehol Biota flourished, were submitted to cool temperate climatic conditions with Mean Air Temperature (MAT) of 10 +/- 4 degrees C and Mean Annual Precipitations (MAP) of about 600 mm/yr compatible with the existence of forest environments. By contrast, sub-tropical regions, characterized by MAT of about 20-25 degrees C were either submitted to high amounts of seasonal precipitations (of about 1200 mm/yr in Thailand) or to significant aridity (MAP of about 400 mm/yr in South China). This difference in precipitation regime between Thailand and South China may be attributed to the occurrence of the Coastal Cordillera extending along the East margin of the South China block. These mountain ranges likely prevented humid air masses from the Pacific to penetrate some parts of South China, thus generating a "rain shadow effect". Mosaic environments characterizing East Asia during the Late Early Cretaceous may have acted as a cradle for the origination of advanced dinosaur taxa that subsequently radiated over Eurasia and North America during the Late Cretaceous. (C) 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jseaes.2014,11.032

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DOI： 10.5575/geosoc.2014.0015

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Discovery of Sirenites senticosus (Dittmar) in the upper part of the Sabudani Formation of the Kurosegawa Belt, Kito area, Tokushima Prefecture, Japan, establishes a late Early Carnian age for this part of the stratigraphic unit. Because S.senticosus was mainly distributed in the Tethyan region, its occurrence provides evidence that Late Triassic ammonoids of Japan had strong affinities with those of the Tethyan faunas. This finding clearly differs from the biogeographic distribution of contemporary bivalves in the region, which are referred to as the Kochigatani bivalve faunas, and show strong affinities to faunas of the Boreal region.

DOI： 10.1111/iar.12050

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATL ACAD SCIENCES  

Early Cretaceous vertebrate assemblages from East Asia and particularly the Jehol Biota of northeastern China flourished during a period of highly debated climatic history. While the unique characters of these continental faunas have been the subject of various speculations about their biogeographic history, little attention has been paid to their possible climatic causes. Here we address this question using the oxygen isotope composition of apatite phosphate (delta(18)O(p)) from various reptile remains recovered from China, Thailand, and Japan. delta(18)O(p) values indicate that cold terrestrial climates prevailed at least in this part of Asia during the Barremian-early Albian interval. Estimated mean air temperatures of about 10 +/- 4 degrees C at midlatitudes (similar to 42 degrees N) correspond to present day cool temperate climatic conditions. Such low temperatures are in agreement with previous reports of cold marine temperatures during this part of the Early Cretaceous, as well as with the widespread occurrence of the temperate fossil wood genus Xenoxylon and the absence of thermophilic reptiles such as crocodilians in northeastern China. The unique character of the Jehol Biota is thus not only the result of its evolutionary and biogeographical history but is also due to rather cold local climatic conditions linked to the paleolatitudinal position of northeastern China and global icehouse climates that prevailed during this part of the Early Cretaceous.

DOI： 10.1073/pnas.1011369108

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Isolated dinosaur teeth recovered from seven localities near Fuxin (western Liaoning Province, northeastern China) are described. They come from sediments belonging to the Shahai and Fuxin formations, considered to be Aptian to Albian in age. Seven taxa have been recognized. They include the oviraptorosaur Incisivosaurus, dromaeosaurid theropods, Euhelopus-like sauropods, as well as indeterminate nodosaurid, ankylosaurid, iguanodontoid and basal neoceratopsian ornithischians. The Shahai and Fuxin dinosaur faunas show the persistence of some Jehol biota taxa such as the highly specialised Incisivosaurus, basal titanosauriform sauropods, basal neoceratopsians and some dromaeosaurids, and the addition of more derived iguanodontoids and ankylosaurians. The persistence of some dinosaurs of the Jehol Biota into the Shahai and Fuxin formations suggests a long term stability of Liaoning terrestrial environments during the Early Cretaceous. Despite sampling bias and the rather small sample that must be taken into account, teeth abundances show a significant compositional difference between the localities of the Shahai and Fuxin formations, neoceratopsian teeth representing one third of dinosaur tooth remains in the Shahai Formation whereas they are totally absent in the Fuxin Formation. Ankylosaur teeth, in contrast, represent 3% of total remains in the Shahai Formation, whereas they seem to be the only herbivorous dinosaurs in the Fuxin Formation with 40% of the total number of teeth (the rest being theropod dinosaur teeth). Although a difference in micro-environmental conditions between Shahai and Fuxin localities may at least partly explain such pattern, the unusual and unbalanced faunal composition of Fuxin localities remains enigmatic and will need further field collecting in order to be clarified. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jseaes.2010.04.017

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Fossil teeth of the early Cretaceous mammal-like reptile (Tritylodontidae) were observed in the internal texture in relation to tooth development and evolution. The materials were discovered from the Tetori Group which is distributed in the western area of the central mountains of Japan, and these materials are the first mammal-like reptile discovered from the Cretaceous strata in the world. The authors investigated these fossil teeth of Tritylodontidae which is considered as most evolved mammal-like reptile in their microstructure, and found the characteristic texture of the enamel which is similar to the enamel prism which is common in the enamel of the modern mammals. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.msec.2005.08.041

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：SOC VERTEBRATE PALEONTOLOGY  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：English   Presentation type：Oral presentation (general)  

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