Wood-based functional materials have developed rapidly.But the flammability significantly limits its further application.To improve the flame retardancy,the balsa wood was delignified by NaClO2 solution to create a ce...Wood-based functional materials have developed rapidly.But the flammability significantly limits its further application.To improve the flame retardancy,the balsa wood was delignified by NaClO2 solution to create a cellulose scaffold,and then alternately immersed in CaCl_(2) ethanol solution and NaHCO3 aqueous solution under vacuum.The high porosity and wettability resulting from delignification benefited the following mineralization process,changing the thermal properties of balsa wood significantly.The organic-inorganic wood composite showed abundant CaCO_(3) spherical particles under scanning electron microscopy.The peak of the heat release rate of delignified balsa-CaCO_(3) was reduced by 33%compared to the native balsa,according to the cone calorimetric characterization.The flame test demonstrated that the mineralized wood was flame retardant and selfextinguish.Additionally,the mineralized wood also displayed lower thermal conductivity.This study developed a feasible way to fabricate a lightweight,fire-retardant,self-extinguishing,and heat-insulating wood composite,providing a promising route for the valuable application of cellulosic biomass.展开更多
The newly discovered large(350 m^2) Yantan dinosaur tracksite, in the Lower Jurassic Ziliujing Formation of Guizhou Province, China, reveals at least 250 footprints of which ~97 can be resolved into trackways of sauro...The newly discovered large(350 m^2) Yantan dinosaur tracksite, in the Lower Jurassic Ziliujing Formation of Guizhou Province, China, reveals at least 250 footprints of which ~97 can be resolved into trackways of sauropodomorphs. All the trackways are sub parallel likely indicating gregarious behavior. One theropod track(cf. Grallator) was recorded. The sauropodomorph tracks predominantly represent quadrupedal progression(Morphotype A), and footprint morphology is similar to the ichnospecies Liujianpusshunan, characterized by outward pes rotation. Three trackways indicate bipedal progression, and two of these(Morphotype B) indicate inward pes rotation, accompanied by elongate pes digit scratch marks. For the latter phenomenon three possible scenarios are discussed:(1) significant rotation changes accompanying changes in gait,(2) swimming behavior,(3) formation of undertracks.Sedimentological evidence indicates the tracks were made on a linguloid rippled, muddy, immature sandstone substrate characterized by significant differences in substrate consistency across the trackbearing surface. Microbially induced sedimentary structures(MISS) characterized by distinctive wrinkle marks indicate a stressed, probably semi-arid, paleoenvironment that was not conducive to habitation by invertebrate organisms. This is consistent with other evidence that Lower Jurassic sauropodomorph tracks are often associated with semi-arid paleoenvironments.展开更多
A newly discovered Jiaguan Formation(Lower Cretaceous) tracksite from the Linjiang region of Guizhou Province, China, reveals the first example of a Cretaceous track morphotype attributable to the non-avian theropod i...A newly discovered Jiaguan Formation(Lower Cretaceous) tracksite from the Linjiang region of Guizhou Province, China, reveals the first example of a Cretaceous track morphotype attributable to the non-avian theropod ichnogenus Gigandipus, here named Gigandipus chiappei ichnosp nov. The theropod dominated locality also reveals the second report of the avian theropod ichnogenus Wupus, one of the largest avian traces currently known from the Lower Cretaceous. The Linjiang site provides evidence to support previous interpretations of a distinctive Lower Cretaceous theropod-dominated ichnofauna that was widespread in China and East Asia and highlights the similarity between Lower Cretaceous theropod ichnotaxa in East Asia and those found in the Lower Jurassic both in East Asia and elsewhere. These similarities in turn create various ichnotaxonomic challenges familiar to researchers working on theropod tracks, and we recommend caution in the naming of new theropod ichnotaxa at the ichnogenus level.展开更多
Poorly preserved tracks have limited ichnotaxonomic or biotaxon utility,but may reveal useful information about the paleoenvironment,behavior and track taphonomy.Eight mostly parallel to sub parallel trackway segments...Poorly preserved tracks have limited ichnotaxonomic or biotaxon utility,but may reveal useful information about the paleoenvironment,behavior and track taphonomy.Eight mostly parallel to sub parallel trackway segments(T1–T8)were registered on a truncation surface in the Lower Cretaceous Luohe Formation of Shaanxi Province.These attest to the passage of several bipeds,probably all theropods,in a paleo-contour-parallel,south-north direction in an arid setting.Quality of preservation in these trackways is poor,but notably superior in two additional trackways(T9–T10)on a foreset surface.Trackway T9 indicates a didactyl trackmaker,probably a deinonychosaurian,heading north to south.This is the 13th report of deinonychosaurian tracks from the Lower Cretaceous of China.If any or all the eight south-north oriented trackway segments represent continuations of other segments in the same trackways,the total number of individual trackmakers heading in this direction may have been as lowas three.Although the trackway pattern and sedimentological evidence could indicate a physically controlled pathway influencing the direction taken by these trackmakers,the possibility that the trackways also represented small social or gregarious group cannot be ruled out.展开更多
The Zhaojue(ZJ)tracksites represent multiple steeply-inclined,track-bearing exposures in the clastic Feitianshan Formation of Sichuan Province that have been sequentially,excavated,mapped,expanded and destroyed,by qua...The Zhaojue(ZJ)tracksites represent multiple steeply-inclined,track-bearing exposures in the clastic Feitianshan Formation of Sichuan Province that have been sequentially,excavated,mapped,expanded and destroyed,by quarrying,erosion or collapse,for almost three decades.The quarried area extends for more almost 1.0 km from north to south and-0.5 km from east to west.Four important track-bearing surfaces have been identified and identified as ZJ-Ⅰ,ZJ-Ⅱ,ZJ-ⅡN and ZJ-Ⅲ,some of which are newly exposed surfaces or expanded surfaces that were previously partially described.Others represent surfaces lost since they were first reported in papers published in 2014-2016.The ZJ-Ⅱ site represents a hugely expanded continuation of a much smaller track-bearing surface described in 2014.It was mapped using drone technology,and now represents the largest tracksite in China,with a minimum count of 933 recognizable tracks,and the longest recorded sauropod and ornithopod trackways from China(-80 m and-52 m respectively),which also reveal a pronounced change in the direction of trackmaker movement.The ZJ-Ⅱ surface represents the best Zhaojue paleo-census sample giving a count of 68 individuals from 61 trackways(37 ornithopod,10 theropod,14 sauropod)and isolated tracks(representing 7 individuals).Thus,ornithopods(both large and small trackmakers)represent-54%of the total number of trackways.The smaller ZJ-Ⅲ surface was mapped using traditional methods,and reveals at least 6 ornithopod-and 4 theropod trackways.Both the ZJ-Ⅱ and ZJ-Ⅲ surfaces reveal parallel ornithopod trackways suggestive of social or gregarious behavior.The combined data from all four Zhaojue surfaces reveal a total of 1928 tracks,and include a few previously reported pterosaurs and theropod swim tracks.The Zhaojue quarry complex provide a good example of multiple track-bearing sites(surfaces)that require long term study and monitoring to extract as much trackway data as possible before in situ physical evidence is lost.展开更多
A knowledge graph(KG)is a knowledge base that integrates and represents data based on a graph-structured data model or topology.Geoscientists have made efforts to construct geosciencerelated KGs to overcome semantic h...A knowledge graph(KG)is a knowledge base that integrates and represents data based on a graph-structured data model or topology.Geoscientists have made efforts to construct geosciencerelated KGs to overcome semantic heterogeneity and facilitate knowledge representation,data integration,and text analysis.However,there is currently no comprehensive paleontology KG or data-driven discovery based on it.In this study,we constructed a two-layer model to represent the ordinal hierarchical structure of the paleontology KG following a top-down construction process.An ontology containing 19365 concepts has been defined up to 2023.On this basis,we derived the synonymy list based on the paleontology KG and designed corresponding online functions in the OneStratigraphy database to showcase the use of the KG in paleontological research.展开更多
In recent years the Lower Cretaceous red beds of southwestern China have yielded more than 20 significant dinosaur-dominated tracksites. More than half occur in the Jiaguan Formation with the remainder in the Feitians...In recent years the Lower Cretaceous red beds of southwestern China have yielded more than 20 significant dinosaur-dominated tracksites. More than half occur in the Jiaguan Formation with the remainder in the Feitianshan and Xiaoba formations. Collectively these sites provide evidence of at least 13 distinct dinosaurian trackmaker morphotypes, in addition to two avian theropod(bird)morphotypes and pterosaur and turtle tracks. Together these total 17 morphotypes provide a data base of 479 potential trackmakers, probably representing the same number of individuals. Such an ichnological database provides a useful proxy paleoecological census of tetrapod communities in the area during the Early Cretaceous, and is especially significant given the complete absence or scarcity of skeletal remains reported from these formations.The composition of ichnofaunas in all three formations is heavily saurischian(theropod and sauropod) dominated with a high diversity of distinctive theropod morphotypes,mostly assignable to known ichnogenera. Moreover, ichnofaunal data from multiple sites are generally consistent between sites and an indication of the reliability and repeatability of track census data. Such regionally-widespread data are rapidly superseding the information available from the skeletal record in the corresponding area, and must therefore be considered of high paleontological value.展开更多
A large number of Upper Cretaceous(Maastrichtian)dinosaur skeletal fossils have been found in the Nanxiong Basin and adjacent Ganzhou area,including those of theropods,sauropods and hadrosaurids.However,known dinosaur...A large number of Upper Cretaceous(Maastrichtian)dinosaur skeletal fossils have been found in the Nanxiong Basin and adjacent Ganzhou area,including those of theropods,sauropods and hadrosaurids.However,known dinosaur ichnoassemblages from the Nanxiong Basin partly indicate a different fauna,with dominating large-and medium-sized ornithopods,theropods,and pterosaurs(1,2)This is one of many known examples where trace and body fossil assemblages from the same formation or geologically discrete region show a different composition.Palecological and paleobiogeographical analyses therefore should consider data from both,before any conclusions can be drawn.Formations can be classified according to the relative degree of similarity or congruity(or difference/incongruity)between trace and body fossils into the 5 categories proposed by Lockley[3].展开更多
Cretaceous amber from Myanmar(~99 Ma Burmese amber) has become a valuable supplement to the traditional skeletal record of small theropod dinosaurs preserved in sedimentary rocks, particularly for coelurosaurs and en...Cretaceous amber from Myanmar(~99 Ma Burmese amber) has become a valuable supplement to the traditional skeletal record of small theropod dinosaurs preserved in sedimentary rocks, particularly for coelurosaurs and enantiornithines. The specimens recovered from this deposit preserve skeletal material and soft tissues in unmatched detail. This provides opportunities to study three-dimensional preservation of soft tissues, microstructure, and pigmentation patterns that are seldom available elsewhere in the fossil record. Ultimately, this line of research provides insights into life stages that are difficult to preserve, the ecology and appearance of the groups involved, and the evolutionarydevelopment of structures such as feathers. Here we describe the most recent discovery from Burmese amber, an articulated skeleton of an enantiornithine bird. This individual has been sectioned along the coronal plane, providing a unique view inside multiple body regions. Osteological observations and plumage patterns support placement within the Enantiornithes, and suggest that the animal may have been a juvenile at the time of death. The specimen has a complex taphonomic history that includes exposure at the surface of a resin flow prior to encapsulation, and may include scavenging by some of the insects trapped within the same amber piece. The chemical composition observed along surface exposures and shallowly buried regions of the body indicate that the specimen has not undergone significant exchange with its surroundings. High iron concentrations are present in regions that preserve soft tissues as carbon films, and calcium distribution corresponds to regions where bones breach the surface of the amber.展开更多
Over the last 20 years, compression fossils of feathers surrounding dinosaurs have greatly expanded our understanding of the origin and evolution of feathers. One of the most peculiar feather morphotypes discovered to...Over the last 20 years, compression fossils of feathers surrounding dinosaurs have greatly expanded our understanding of the origin and evolution of feathers. One of the most peculiar feather morphotypes discovered to date are rachis dominated feathers(RDFs), which have also been referred to as proximally ribbon-like pennaceous feathers(PRPFs). These elongate feathers are only found in the tail plumage, typically occurring in pairs with both streamer(not proximally ribbon-like) and racket-plume morphologies recognized. Here we describe a large sample set of isolated and paired RDFs from Upper Cretaceous Burmese amber(~ 99 Ma). Amber preserves the finest details of these fragile structures in three dimensions, demonstrating that RDFs form a distinct feather morphotype with a ventrally open rachis, and with significant variability in pigmentation, microstructure, and symmetry.展开更多
Burmite(Burmese amber) from the Hukawng Valley in northern Myanmar is a remarkable valuable and obviously the most important amber for studying terrestrial diversity in the mid-Cretaceous. The diversity of Burmite i...Burmite(Burmese amber) from the Hukawng Valley in northern Myanmar is a remarkable valuable and obviously the most important amber for studying terrestrial diversity in the mid-Cretaceous. The diversity of Burmite inclusions is very high and many new taxa were found, including new order, new family/subfamily, and new genus. Till the end of 2016, 14 phyla, 21 classes, 65 orders, 279 families, 515 genera and 643 species of organisms are recorded, which are summized and complied in this catalogue. Among them, 587 species are arthropods. In addtion, the specimens which can not be identified into species are also listed in the paper. The information on type specimens, other materials, host and deposition of types are provided.展开更多
基金the Guangdong Basic and Applied Basic Research Foundation(2023B1515040013)National Natural Science Foundation of China(22108088)State Key Laboratory of Pulp and Paper Engineering(202105)for the financial support of this work.
文摘Wood-based functional materials have developed rapidly.But the flammability significantly limits its further application.To improve the flame retardancy,the balsa wood was delignified by NaClO2 solution to create a cellulose scaffold,and then alternately immersed in CaCl_(2) ethanol solution and NaHCO3 aqueous solution under vacuum.The high porosity and wettability resulting from delignification benefited the following mineralization process,changing the thermal properties of balsa wood significantly.The organic-inorganic wood composite showed abundant CaCO_(3) spherical particles under scanning electron microscopy.The peak of the heat release rate of delignified balsa-CaCO_(3) was reduced by 33%compared to the native balsa,according to the cone calorimetric characterization.The flame test demonstrated that the mineralized wood was flame retardant and selfextinguish.Additionally,the mineralized wood also displayed lower thermal conductivity.This study developed a feasible way to fabricate a lightweight,fire-retardant,self-extinguishing,and heat-insulating wood composite,providing a promising route for the valuable application of cellulosic biomass.
基金funded by the NationalNatural Science Foundation of China (Grant No. 41772008) StateKey Laboratory of Palaeobiology and Stratigraphy+1 种基金Nanjing Instituteof Geology and PalaeontologyChinese Academy of Sciences (GrantNo. 173127)
文摘The newly discovered large(350 m^2) Yantan dinosaur tracksite, in the Lower Jurassic Ziliujing Formation of Guizhou Province, China, reveals at least 250 footprints of which ~97 can be resolved into trackways of sauropodomorphs. All the trackways are sub parallel likely indicating gregarious behavior. One theropod track(cf. Grallator) was recorded. The sauropodomorph tracks predominantly represent quadrupedal progression(Morphotype A), and footprint morphology is similar to the ichnospecies Liujianpusshunan, characterized by outward pes rotation. Three trackways indicate bipedal progression, and two of these(Morphotype B) indicate inward pes rotation, accompanied by elongate pes digit scratch marks. For the latter phenomenon three possible scenarios are discussed:(1) significant rotation changes accompanying changes in gait,(2) swimming behavior,(3) formation of undertracks.Sedimentological evidence indicates the tracks were made on a linguloid rippled, muddy, immature sandstone substrate characterized by significant differences in substrate consistency across the trackbearing surface. Microbially induced sedimentary structures(MISS) characterized by distinctive wrinkle marks indicate a stressed, probably semi-arid, paleoenvironment that was not conducive to habitation by invertebrate organisms. This is consistent with other evidence that Lower Jurassic sauropodomorph tracks are often associated with semi-arid paleoenvironments.
基金funded by the National Natural Science Foundation of China(Grant Nos.41772008,41790455)the Fundamental Research Funds for the Central Universities(Grant No.2652017215)the State Key Laboratory of Palaeobiology and Stratigraphy(Nanjing Institute of Geology and Palaeontology,CAS)(Grant No.173127)
文摘A newly discovered Jiaguan Formation(Lower Cretaceous) tracksite from the Linjiang region of Guizhou Province, China, reveals the first example of a Cretaceous track morphotype attributable to the non-avian theropod ichnogenus Gigandipus, here named Gigandipus chiappei ichnosp nov. The theropod dominated locality also reveals the second report of the avian theropod ichnogenus Wupus, one of the largest avian traces currently known from the Lower Cretaceous. The Linjiang site provides evidence to support previous interpretations of a distinctive Lower Cretaceous theropod-dominated ichnofauna that was widespread in China and East Asia and highlights the similarity between Lower Cretaceous theropod ichnotaxa in East Asia and those found in the Lower Jurassic both in East Asia and elsewhere. These similarities in turn create various ichnotaxonomic challenges familiar to researchers working on theropod tracks, and we recommend caution in the naming of new theropod ichnotaxa at the ichnogenus level.
基金the National Natural Science Foundation of China(No.41888101,41790455,41772008)the 111 project(B20011)。
文摘Poorly preserved tracks have limited ichnotaxonomic or biotaxon utility,but may reveal useful information about the paleoenvironment,behavior and track taphonomy.Eight mostly parallel to sub parallel trackway segments(T1–T8)were registered on a truncation surface in the Lower Cretaceous Luohe Formation of Shaanxi Province.These attest to the passage of several bipeds,probably all theropods,in a paleo-contour-parallel,south-north direction in an arid setting.Quality of preservation in these trackways is poor,but notably superior in two additional trackways(T9–T10)on a foreset surface.Trackway T9 indicates a didactyl trackmaker,probably a deinonychosaurian,heading north to south.This is the 13th report of deinonychosaurian tracks from the Lower Cretaceous of China.If any or all the eight south-north oriented trackway segments represent continuations of other segments in the same trackways,the total number of individual trackmakers heading in this direction may have been as lowas three.Although the trackway pattern and sedimentological evidence could indicate a physically controlled pathway influencing the direction taken by these trackmakers,the possibility that the trackways also represented small social or gregarious group cannot be ruled out.
基金funded by the National Natural Science Foundation of China(Grant No.41772008,41772023)the 111 project(Grant No.B20011).
文摘The Zhaojue(ZJ)tracksites represent multiple steeply-inclined,track-bearing exposures in the clastic Feitianshan Formation of Sichuan Province that have been sequentially,excavated,mapped,expanded and destroyed,by quarrying,erosion or collapse,for almost three decades.The quarried area extends for more almost 1.0 km from north to south and-0.5 km from east to west.Four important track-bearing surfaces have been identified and identified as ZJ-Ⅰ,ZJ-Ⅱ,ZJ-ⅡN and ZJ-Ⅲ,some of which are newly exposed surfaces or expanded surfaces that were previously partially described.Others represent surfaces lost since they were first reported in papers published in 2014-2016.The ZJ-Ⅱ site represents a hugely expanded continuation of a much smaller track-bearing surface described in 2014.It was mapped using drone technology,and now represents the largest tracksite in China,with a minimum count of 933 recognizable tracks,and the longest recorded sauropod and ornithopod trackways from China(-80 m and-52 m respectively),which also reveal a pronounced change in the direction of trackmaker movement.The ZJ-Ⅱ surface represents the best Zhaojue paleo-census sample giving a count of 68 individuals from 61 trackways(37 ornithopod,10 theropod,14 sauropod)and isolated tracks(representing 7 individuals).Thus,ornithopods(both large and small trackmakers)represent-54%of the total number of trackways.The smaller ZJ-Ⅲ surface was mapped using traditional methods,and reveals at least 6 ornithopod-and 4 theropod trackways.Both the ZJ-Ⅱ and ZJ-Ⅲ surfaces reveal parallel ornithopod trackways suggestive of social or gregarious behavior.The combined data from all four Zhaojue surfaces reveal a total of 1928 tracks,and include a few previously reported pterosaurs and theropod swim tracks.The Zhaojue quarry complex provide a good example of multiple track-bearing sites(surfaces)that require long term study and monitoring to extract as much trackway data as possible before in situ physical evidence is lost.
基金supported by the National Natural Science Foundation of China(Nos.41725007,42250104,41830323,42002015,and 42302001)the Fundamental Research Funds for the Central Universities(Nos.020614380168,JZ2023HGQA0144 and JZ2023HGTA0175)。
文摘A knowledge graph(KG)is a knowledge base that integrates and represents data based on a graph-structured data model or topology.Geoscientists have made efforts to construct geosciencerelated KGs to overcome semantic heterogeneity and facilitate knowledge representation,data integration,and text analysis.However,there is currently no comprehensive paleontology KG or data-driven discovery based on it.In this study,we constructed a two-layer model to represent the ordinal hierarchical structure of the paleontology KG following a top-down construction process.An ontology containing 19365 concepts has been defined up to 2023.On this basis,we derived the synonymy list based on the paleontology KG and designed corresponding online functions in the OneStratigraphy database to showcase the use of the KG in paleontological research.
基金supported by the National Basic Research Program of China (2012CB822000)a Special Project Grant of Chongqing People’s Government (QDBLR-2007-2015)the 2013 and 2015 Support Fund for Graduate Students’ Science and Technology Innovation from China University of Geosciences (Beijing), China (51223229)
文摘In recent years the Lower Cretaceous red beds of southwestern China have yielded more than 20 significant dinosaur-dominated tracksites. More than half occur in the Jiaguan Formation with the remainder in the Feitianshan and Xiaoba formations. Collectively these sites provide evidence of at least 13 distinct dinosaurian trackmaker morphotypes, in addition to two avian theropod(bird)morphotypes and pterosaur and turtle tracks. Together these total 17 morphotypes provide a data base of 479 potential trackmakers, probably representing the same number of individuals. Such an ichnological database provides a useful proxy paleoecological census of tetrapod communities in the area during the Early Cretaceous, and is especially significant given the complete absence or scarcity of skeletal remains reported from these formations.The composition of ichnofaunas in all three formations is heavily saurischian(theropod and sauropod) dominated with a high diversity of distinctive theropod morphotypes,mostly assignable to known ichnogenera. Moreover, ichnofaunal data from multiple sites are generally consistent between sites and an indication of the reliability and repeatability of track census data. Such regionally-widespread data are rapidly superseding the information available from the skeletal record in the corresponding area, and must therefore be considered of high paleontological value.
基金supported by the National Natural Science Foundation of China(41888101,41790455,41772008)the Fundamental Research Funds for the Central Universities(2652017215)+2 种基金the Funds of State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences(173127)SLB’s work on Qianzhousaurus was funded by National Science Foundation(NSF)Doctoral Dissertation Improvement Grants(DEB 1110357)the American Museum of Natural History Division of Paleontology,and Columbia University
文摘A large number of Upper Cretaceous(Maastrichtian)dinosaur skeletal fossils have been found in the Nanxiong Basin and adjacent Ganzhou area,including those of theropods,sauropods and hadrosaurids.However,known dinosaur ichnoassemblages from the Nanxiong Basin partly indicate a different fauna,with dominating large-and medium-sized ornithopods,theropods,and pterosaurs(1,2)This is one of many known examples where trace and body fossil assemblages from the same formation or geologically discrete region show a different composition.Palecological and paleobiogeographical analyses therefore should consider data from both,before any conclusions can be drawn.Formations can be classified according to the relative degree of similarity or congruity(or difference/incongruity)between trace and body fossils into the 5 categories proposed by Lockley[3].
基金funded by the National Natural Science Foundation of China(41790455,41772008,31672345,Special Subjects in Animal Taxonomy,NSFC-J1210002)Natural Sciences and Engineering Research Council of Canada(201500681)+1 种基金Scientific Research Equipment Development Project of Chinese Academy of Sciences(YZ201509)the National Geographic Society,USA(EC0768-15)
文摘Cretaceous amber from Myanmar(~99 Ma Burmese amber) has become a valuable supplement to the traditional skeletal record of small theropod dinosaurs preserved in sedimentary rocks, particularly for coelurosaurs and enantiornithines. The specimens recovered from this deposit preserve skeletal material and soft tissues in unmatched detail. This provides opportunities to study three-dimensional preservation of soft tissues, microstructure, and pigmentation patterns that are seldom available elsewhere in the fossil record. Ultimately, this line of research provides insights into life stages that are difficult to preserve, the ecology and appearance of the groups involved, and the evolutionarydevelopment of structures such as feathers. Here we describe the most recent discovery from Burmese amber, an articulated skeleton of an enantiornithine bird. This individual has been sectioned along the coronal plane, providing a unique view inside multiple body regions. Osteological observations and plumage patterns support placement within the Enantiornithes, and suggest that the animal may have been a juvenile at the time of death. The specimen has a complex taphonomic history that includes exposure at the surface of a resin flow prior to encapsulation, and may include scavenging by some of the insects trapped within the same amber piece. The chemical composition observed along surface exposures and shallowly buried regions of the body indicate that the specimen has not undergone significant exchange with its surroundings. High iron concentrations are present in regions that preserve soft tissues as carbon films, and calcium distribution corresponds to regions where bones breach the surface of the amber.
基金This work was supported by the National Natural Science Foundation of China(31672345,41790455,41772008,and 41861134032)the Scientific Research Equipment Development Project of Chinese Academy of Sciences(YZ201509)+2 种基金the Natural Science Foundation of Yunnan,China(2015HA021,2018FA025,2018IA073,and 2019DG050)the Natural Sciences and Engineering Research Council of Canada(2015-00681)the National Geographic Society,USA(EC0768-15).
基金National Natural Science Foundation of China(41772008)Fundamental Research Funds for the Central Universities(2652017215)+2 种基金National Geographic Society,U.S.A.(EC0768-15)Natural Sciences and Engineering Research Council,Canada(2015-00681)RSM and Paul Riegert scholarships(to P.C.)for support
文摘Over the last 20 years, compression fossils of feathers surrounding dinosaurs have greatly expanded our understanding of the origin and evolution of feathers. One of the most peculiar feather morphotypes discovered to date are rachis dominated feathers(RDFs), which have also been referred to as proximally ribbon-like pennaceous feathers(PRPFs). These elongate feathers are only found in the tail plumage, typically occurring in pairs with both streamer(not proximally ribbon-like) and racket-plume morphologies recognized. Here we describe a large sample set of isolated and paired RDFs from Upper Cretaceous Burmese amber(~ 99 Ma). Amber preserves the finest details of these fragile structures in three dimensions, demonstrating that RDFs form a distinct feather morphotype with a ventrally open rachis, and with significant variability in pigmentation, microstructure, and symmetry.
基金supported by the National Natural Science Foundation of China(31301900,31672345)Research Equipment Development Project of Chinese Academy of Sciences(YZ201509)
文摘Burmite(Burmese amber) from the Hukawng Valley in northern Myanmar is a remarkable valuable and obviously the most important amber for studying terrestrial diversity in the mid-Cretaceous. The diversity of Burmite inclusions is very high and many new taxa were found, including new order, new family/subfamily, and new genus. Till the end of 2016, 14 phyla, 21 classes, 65 orders, 279 families, 515 genera and 643 species of organisms are recorded, which are summized and complied in this catalogue. Among them, 587 species are arthropods. In addtion, the specimens which can not be identified into species are also listed in the paper. The information on type specimens, other materials, host and deposition of types are provided.