A flattened enantiornithine in mid-Cretaceous Burmese amber:morphology and preservation  

作　　者：Lida Xing Jingmai K.O'Connor Ryan C.McKellar Luis M.Chiappe Ming Bai Kuowei Tseng Jie Zhang Haidong Yang Jun Fang Gang Li 

机构地区：[1]State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Beijing 100083,China [2]School of the Earth Sciences and Resources,China University of Gensciences,Beijing 100083,China [3]Key Laboratory of Vertebrate Evolution and Human Origins of the Chinese Academy of Sciences,Institute of Vertebrate Paleontology and Paleoanthropology,Beijing 100044,China [4]Royal Saskatchewan Museum,Regina,Saskatchewan SLIP 4W7,Canada [5]Biology Department,University of Regina,Regina,Saskatchewan S4S OA2,Canada [6]Department of Ecology and Evolutionary Biology,University of Kansas,Lawrence 66045,USA [7]Dinosaur Institute,Natural History Museum of Los Angeles County,Los Angeles 90007,USA [8]Key Laboratory of Zoological Systematics and Evolution,Institute of Zoology,Chinese Academy of Sciences,Beijing 100101,China [9]Department of Exercise and Health Science,University of Taipei,Taipei 11153,China [10]Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Science Bulletin》2018年第4期235-243,共9页科学通报（英文版）

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);Scientific Research Equipment Development Project of Chinese Academy of Sciences(YZ201509);the National Geographic Society,USA(EC0768-15)

摘　　要：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.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 mate- rial 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 else- where in the fossil record. Ultimately, this line of research provides insights into life stages that are dif- ficult to preserve, the ecology and appearance of the groups involved, and the evolutionary- development 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 observa- tions 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 under- gone 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.

关 键 词：EnantiornithesJuvenileOsteologySoft tissue preservation 

分 类 号：Q915[天文地球—古生物学与地层学]