Enantionithine birds are the most blooming branch of early birds and have distinct diversities. A large number of enantionithine birds have been reported from the Early Cretaceous Jiufotang Formation in western Liaoni...Enantionithine birds are the most blooming branch of early birds and have distinct diversities. A large number of enantionithine birds have been reported from the Early Cretaceous Jiufotang Formation in western Liaoning, China. Recently, we discovered a new eoenantiornithid bird from the Jiufotang Formation in Dapingfang Town, western Liaoning. A new eoenantiornithid bird, Dapingfangornis sentisorhinus gen. et sp. nov., is erected based on this complete skeleton with a skull. The new bird is distinguished from other known Mesozoic birds in a medium to small size, a distinct thorn-like process on the nasals, a sternum with a long and a short lateral processes. The thorn-like process on the nasal has not been discovered among known fossil birds, thus the discovery also provides new materials on the diversities of early birds.展开更多
Recent discoveries of basal birds have greatly improved our understanding of early bird evolution, yet the evolution of several important features such as cranial kinesis and arboreality remain debated. A new sapeorni...Recent discoveries of basal birds have greatly improved our understanding of early bird evolution, yet the evolution of several important features such as cranial kinesis and arboreality remain debated. A new sapeornithid bird, Shenshiornis primita gen. et sp. nov., based on an articulated skeleton from the Early Cretaceous Jehol Group of western Liaoning, China, sheds new light on these issues. Shenshiornis possesses a skull as primitive as or even more primitive than that of Archaeopteryx and hind limbs modified for an improved arboreal capability. A cladistic analysis shows that： 1） presence of a diapsid skull is a plesiomorphy of the Aves and a kinetic skull evolved incrementally later in avian evolution; and 2） cursorial capability significantly weakens at the base of the Pygostylia due to a change in locomotor system.展开更多
In recent years,many fossil vertebrates,including feathered dinosaurs,have been discovered at Nanshimenzi village,Gangou Town,Qinglong County,Hebei Province,China.A geological section including the fossil-bearing stra...In recent years,many fossil vertebrates,including feathered dinosaurs,have been discovered at Nanshimenzi village,Gangou Town,Qinglong County,Hebei Province,China.A geological section including the fossil-bearing strata was measured at Nanshimenzi,to determine the exact geological age and sedimentary characteristics of the section,and a new lithostratigraphic unit was named as the Nanshimenzi Bed.The Nanshimenzi Bed is about 56.6 m in thickness,mainly consisting of gray sandstones and siltstones and containing fossil vertebrates and several coal streaks.On the basis of survey and comparison,the Nanshimenzi Bed should be assigned to Tiaojishan Formation and probably to the upper part of the formation.展开更多
The last two decades have witnessed great advances in reconstructing the transition from non-avian theropods to avians,but views in opposition to the theropod hypothesis still exist.Here we highlight one issue that is...The last two decades have witnessed great advances in reconstructing the transition from non-avian theropods to avians,but views in opposition to the theropod hypothesis still exist.Here we highlight one issue that is often considered to raise problems for the theropod hypothesis of avian origins,i.e.the "temporal paradox" in the stratigraphic distribution of theropod fossils - the idea that the earliest known avian is from the Late Jurassic but most other coelurosaurian groups are poorly known in the Jurassic,implying that avians arose before their supposed ancestors.However,a number of Jurassic nonavian coelurosaurian theropods have recently been discovered,thus documenting the presence of most of the major coelurosaurian groups in the Jurassic alongside,or prior to,avians.These discoveries have greatly improved the congruence between stratigraphy and phylogeny for derived theropods and,effectively,they reject the "temporal paradox" concept.Most importantly,these discoveries provide significant new information that supports the relatively basal positions of the Tyrannosauroidea and Alvarezsauroidea among the Coeluro-sauria.Indeed,they imply a new phylogenetic hypothesis for the interrelationships of Paraves,in which Archaeopteryx,the Dromaeosauridae,and the Troodontidae form a monophyletic group while the Scansoriopterygidae,other basal birds,and probably also the Oviraptorosauria,form another clade.Mapping some of the salient features onto a temporally-calibrated theropod phy-logeny indicates that characteristics related to flight and arboreality evolved at the base of the Paraves,earlier than the Late Jurassic.展开更多
文摘Enantionithine birds are the most blooming branch of early birds and have distinct diversities. A large number of enantionithine birds have been reported from the Early Cretaceous Jiufotang Formation in western Liaoning, China. Recently, we discovered a new eoenantiornithid bird from the Jiufotang Formation in Dapingfang Town, western Liaoning. A new eoenantiornithid bird, Dapingfangornis sentisorhinus gen. et sp. nov., is erected based on this complete skeleton with a skull. The new bird is distinguished from other known Mesozoic birds in a medium to small size, a distinct thorn-like process on the nasals, a sternum with a long and a short lateral processes. The thorn-like process on the nasal has not been discovered among known fossil birds, thus the discovery also provides new materials on the diversities of early birds.
基金supported by the Projects of the Education Department of Liaoning Province(Nos.2008S214, 20060805)supported by the Chinese Academy of Sciences.
文摘Recent discoveries of basal birds have greatly improved our understanding of early bird evolution, yet the evolution of several important features such as cranial kinesis and arboreality remain debated. A new sapeornithid bird, Shenshiornis primita gen. et sp. nov., based on an articulated skeleton from the Early Cretaceous Jehol Group of western Liaoning, China, sheds new light on these issues. Shenshiornis possesses a skull as primitive as or even more primitive than that of Archaeopteryx and hind limbs modified for an improved arboreal capability. A cladistic analysis shows that： 1） presence of a diapsid skull is a plesiomorphy of the Aves and a kinetic skull evolved incrementally later in avian evolution; and 2） cursorial capability significantly weakens at the base of the Pygostylia due to a change in locomotor system.
基金Supported by projects of the National Natural Science Foundation of China(41172026,41688103)Education Bureau Foundation(LR2012038)of Liaoning Province
文摘In recent years,many fossil vertebrates,including feathered dinosaurs,have been discovered at Nanshimenzi village,Gangou Town,Qinglong County,Hebei Province,China.A geological section including the fossil-bearing strata was measured at Nanshimenzi,to determine the exact geological age and sedimentary characteristics of the section,and a new lithostratigraphic unit was named as the Nanshimenzi Bed.The Nanshimenzi Bed is about 56.6 m in thickness,mainly consisting of gray sandstones and siltstones and containing fossil vertebrates and several coal streaks.On the basis of survey and comparison,the Nanshimenzi Bed should be assigned to Tiaojishan Formation and probably to the upper part of the formation.
基金supported by the Hundred Talents Program of the Chinese Academy of Sciences (KZCX2-YW-T02)the National Natural Science Foundation of China (40830210)the National Basic Research Program of China (2006CB806400)
文摘The last two decades have witnessed great advances in reconstructing the transition from non-avian theropods to avians,but views in opposition to the theropod hypothesis still exist.Here we highlight one issue that is often considered to raise problems for the theropod hypothesis of avian origins,i.e.the "temporal paradox" in the stratigraphic distribution of theropod fossils - the idea that the earliest known avian is from the Late Jurassic but most other coelurosaurian groups are poorly known in the Jurassic,implying that avians arose before their supposed ancestors.However,a number of Jurassic nonavian coelurosaurian theropods have recently been discovered,thus documenting the presence of most of the major coelurosaurian groups in the Jurassic alongside,or prior to,avians.These discoveries have greatly improved the congruence between stratigraphy and phylogeny for derived theropods and,effectively,they reject the "temporal paradox" concept.Most importantly,these discoveries provide significant new information that supports the relatively basal positions of the Tyrannosauroidea and Alvarezsauroidea among the Coeluro-sauria.Indeed,they imply a new phylogenetic hypothesis for the interrelationships of Paraves,in which Archaeopteryx,the Dromaeosauridae,and the Troodontidae form a monophyletic group while the Scansoriopterygidae,other basal birds,and probably also the Oviraptorosauria,form another clade.Mapping some of the salient features onto a temporally-calibrated theropod phy-logeny indicates that characteristics related to flight and arboreality evolved at the base of the Paraves,earlier than the Late Jurassic.
