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
A new theropod dinosaur, Shidaisaurusjinae gen. et sp. nov., has been described on the basis of an incomplete skeleton. The specimen was found near the base of the Upper Lufeng Formation （early Middle Jurassic） in Y...A new theropod dinosaur, Shidaisaurusjinae gen. et sp. nov., has been described on the basis of an incomplete skeleton. The specimen was found near the base of the Upper Lufeng Formation （early Middle Jurassic） in Yunnan, China. It is the first theropod dinosaur from the Middle Jurassic of Yunnan. Shidaisaurus jinae is distinguishable from other Jurassic theropods by certain features from the braincase, axis, and pelvic girdle. The absence of any pleurocoels in the axis or in any anterior dorsal vertebrae suggests that the new Lufeng theropod is relatively primitive and more plesiomorphic than most of the Middle to Late Jurassic theropods from China. Most Chinese taxa of Jurassic theropod dinosaurs have not been well described; a further detailed study will be necessary for us to determine their phylogenetic relationships with Shidaisaurusjinae.展开更多
中国西部准噶尔盆地东北缘中侏罗世晚期到晚侏罗世早期沉积的石树沟组(Eberth et al.,2001)产出过巨型的蜥脚类恐龙化石(Russell and Zheng,1993),但产出的兽脚类恐龙个体则相对较小(Currie and Zhao,1993)。我们近年来在石树沟组中采...中国西部准噶尔盆地东北缘中侏罗世晚期到晚侏罗世早期沉积的石树沟组(Eberth et al.,2001)产出过巨型的蜥脚类恐龙化石(Russell and Zheng,1993),但产出的兽脚类恐龙个体则相对较小(Currie and Zhao,1993)。我们近年来在石树沟组中采集到大量脊椎动物化石(Clark et al.,2006),其中包括许多零散的骨骼和牙齿标本。本文报道一个产自石树沟组上部的兽脚类牙齿化石(IVPP V 15310),对于全面了解石树沟脊椎动物群具有一定意义。V 15310保存了一个近乎完整的上颌齿或下颌齿的齿冠。它具有典型兽脚类恐龙牙齿的特征:强烈侧扁,向后弯曲,前后缘有锯齿。齿冠有几种不同的磨蚀面:齿尖磨蚀成近圆形,靠近齿尖的齿冠前缘有一较大的平的磨蚀面,锯齿也受到不同程度的磨蚀。V 15310很大,相关的测量数据和一些白垩纪的巨型兽脚类恐龙牙齿的测量数据相近。依据我们定义的一个定量评估锯齿大小的指标(锯齿大小指数),得出V 15310的锯齿大小指数非常小,与霸王龙相似,这与锯齿和齿冠大小具有反比关系的结论是一致的(Farlow et al,1991)。V 15310的另外一些形态特征对于推断它在兽脚类中的系统位置也提供了帮助。这些特征包括后缘锯齿明显高于前缘锯齿以及齿冠的唇侧和舌侧都有微弱的釉质褶皱。根据牙齿大小、釉质褶皱的发育程度以及锯齿的形态(Sereno et al.,1996;Chure et al.,1999;Holtz,2004),V 15310被归入中国盗龙类。其中,后缘锯齿和前缘锯齿的基部长度近似,但前者明显高于后者这一特征组合可能是中国盗龙类的一个鉴定特征。这一特征组合也见于四川的中国盗龙类。相比而言,V 15310在已报道的侏罗纪兽脚类恐龙牙齿中尺寸最大(Smith,2005;Smith et al.,2005),大小接近白垩纪的一些巨型兽脚类恐龙牙齿。新材料的发现表明兽脚类至少在晚侏罗世早期就已演化出了这种巨型体型。展开更多
The accurate identification of dinosaur egg accumulations as nests or clutches is crucial for understanding the reproductive behaviour of these extinct species.However,existing methods often rely on the presence of co...The accurate identification of dinosaur egg accumulations as nests or clutches is crucial for understanding the reproductive behaviour of these extinct species.However,existing methods often rely on the presence of complete eggs and embryo remains,and sedimentological criteria that are only applicable to well-structured sediments.In this study,we introduce an innovative approach to characterize egg accumulations in structureless sediments,where traditional nest structures may not be preserved.Our methodology employs a unique combination of sedimentological,taphonomic,geochemical,and geophysical proxies for the study of egg accumulations.We applied this approach to the egg accumulation from Paimogo(Jurassic,Portugal),traditionally interpreted as a nest.Our findings reveal that the Paimogo egg assemblage is a secondary deposit,resulting from a flooding event in a fluvial plain that dismantled several allosauroid and crocodylomorph clutches.The eggshell vapor conductance results,coupled with sedimentological evidence,suggest that allosauroid dinosaurs buried their eggs in the dry terrain of overbank areas close to a main channel during the breeding season,likely during the dry season to prevent the embryos from drowning.This research underscores the necessity of multidisciplinary approaches in interpreting egg accumulations and offers a novel methodology for studying these accumulations in structureless sediments.Our findings provide new insights into the breeding behaviour and nesting preferences of these extinct organisms,contributing to our understanding of dinosaur ecology.展开更多
Dinosaurs due to their diverse species and peculiar forms have drawn the interest of both artists and scientists. One way to unlock the unknown life of dinosaurs is to reconstruct dinosaurs through drawings, computer ...Dinosaurs due to their diverse species and peculiar forms have drawn the interest of both artists and scientists. One way to unlock the unknown life of dinosaurs is to reconstruct dinosaurs through drawings, computer animations or sculptures. Following the Introduction on “Dinosaur Reconstruction” by the present authors, where important Paleontological knowledge was presented, the next step is to examine some specific information along with necessary details for dinosaur reconstruction. The first and basic step to be taken for a reconstruction is the posture of the animal;this is the theme of the current paper. Dinosaurs would move either bipedally or quadrupedally depending on their kind and body construction. Based on the available literature, various issues in relation to the posture of an animal at different instances are examined. These are: postures of bipedal dinosaurs during walking, observation of living bipedal animals, postures of quadruped dinosaurs during walking, feeding styles, and dinosaur tails. Theropods had a locomotor behavior like modern birds, with the step width increasing when the animals decreased speed. The general posture and movement of quadrupeds and especially sauropods, remains a subject of great and much controversy. Some scientists believe that sauropod necks were generally held in a neutral or undeflected state during most of the time, while others believe that sauropod necks behaved like all present-day amniote with the mid-cervical region held nearly vertical. Also, there are indications that dinosaurs usually held their tails above ground. For all dinosaurs, the long tail was acting as a counterbalance to the head and body. As a validating example, the case of Amargasaurus is investigated with the help of a model, where the various positions of the animal are examined. A certain posture was chosen for a full-size steel and concrete reconstruction based on the features of the animal.展开更多
A relatively small number of tetrapod tracksites from Zhejiang Province fills out the fossil record from that region,which is also known to have yielded both saurischian（titanosauriform, coelurosaur） and ornithisch...A relatively small number of tetrapod tracksites from Zhejiang Province fills out the fossil record from that region,which is also known to have yielded both saurischian（titanosauriform, coelurosaur） and ornithischian（basal ornithopod, ankylosaurian） body fossils as well as dinosaurian eggs. We use photogrammetry and 3 D imaging to reinterpret the sauropod tracks from Lishui City, which revealed the existence of trackways. The track record from three documented sites in Zhejiang Province includes avian and non-avian theropod, sauropod, ornithopod and pterosaur tracks. Previous work showed that the purported new bird ichnospecies Dongyangornipes sinensis is a synonym of Uhangrichnus chuni, while we here consider Pteraichnus dongyangensis as a nomen dubium. Such ＂provincial ichnotaxonomy＂ may mask similarities in the ichnofauna across large regions. In fact, we show that the ichnofauna is similar to that found in the Early Cretaceous elsewhere in China.展开更多
Vitakrisaurus saraiki abelisauroid theropod dinosaurs reported from Pakistan and extended distribution into India. Vitakrisaurus saraiki is medium to large sized theropod which is represented by associated vertebral a...Vitakrisaurus saraiki abelisauroid theropod dinosaurs reported from Pakistan and extended distribution into India. Vitakrisaurus saraiki is medium to large sized theropod which is represented by associated vertebral and limb elements and especially hand elements. Out of 14 small to large bodied theropods from Indo-Pakistan subcontinent, only less than half of these are restricted to some common elements. Vitakrisaurus saraiki theropod of Pakistan is based on associated vertebral and limb elements especially hand including articulated carpals, metacarpals, phalanges and claws which are significant for Gondwanan paleobiogeographic link, comparisons and systematic.展开更多
Upper Triassic and Middle Jurassic strata of the Xichang Basin in Sichuan Province, southwestern China, yielded important dinosaur ichnofossils. From the Xujiahe Formation of the Yiguojiao tracksite, we report a Late ...Upper Triassic and Middle Jurassic strata of the Xichang Basin in Sichuan Province, southwestern China, yielded important dinosaur ichnofossils. From the Xujiahe Formation of the Yiguojiao tracksite, we report a Late Triassic footprint assemblage in China and the first discovery of diagnostic Triassic sauropodomorph tracks in this region. The tracks share a number of features in common with the ichnogenera Eosauropus(Late Triassic) and Liujianpus(Early Jurassic). The neighboring Bingtu tracksite is stratigraphically younger(Shaximiao Formation, Middle Jurassic) and preserves small tridactyl theropod tracks that represent the first occurrence of the ichnotaxon Carmelopodus in China and Asia. While these tracks are morphologically comparable to those from the Middle Jurassic type locality in North America, the specimens from China show the proximal margin of the digit IV impression in a more cranial position, which may indicate a trackmaker with a relatively short metatarsal IV. In addition to the skeletal record, the Carmelopodus footprints document the presence of small theropods in the dinosaur fauna of the Middle Jurassic Shaximiao Formation.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 sauropodomorph Thecodontosaurus caducus and theropod Coelophysis bauri are the earliest known dinosaurs with postcranial skeletal pneumaticity.In both taxa,postcranial pneumatic features are confined to the cervic...The sauropodomorph Thecodontosaurus caducus and theropod Coelophysis bauri are the earliest known dinosaurs with postcranial skeletal pneumaticity.In both taxa,postcranial pneumatic features are confined to the cervical vertebrae.This distribution of pneumaticity in the skeleton is most consistent with pneumatization by diverticula of cervical air sacs similar to those of birds.Other hypotheses,including pneumatization by diverticula of the lungs,larynx and trachea,or cranial air spaces,are less well-supported.展开更多
Tracks previously examined between 2002 and 2015 from an incompletely-studied,and now partially lost tracksite site in the Santai Formation of Shandong Province were restudied based on new ex-cavations of additional s...Tracks previously examined between 2002 and 2015 from an incompletely-studied,and now partially lost tracksite site in the Santai Formation of Shandong Province were restudied based on new ex-cavations of additional surfaces.In contrast to the previous reports of tridactyl tracks,including Grallator,the present study discovered an additional assemblage of unequivocal pterosaur tracks(Pteraichnus)and a possible didactyl deinonychosaurian track.The age of the Santai Formation is controversial but it is probably Late Jurassic,which corresponds to the epoch when pterosaur tracks appear worldwide.Age interpretations,based on palynology and isotopic data,tentatively suggests an earlier Middle-Late Jurassic age and might suggest that the pterosaurian tracks are as old or somewhat older than any previously reported.展开更多
The Jiaguan Formation and the underlying Feitianshan Formation(Lower Cretaceous) in Sichuan Province yield multiple saurischian(theropod–sauropod) dominated ichnofaunas. To date, a moderate diversity of six theropod ...The Jiaguan Formation and the underlying Feitianshan Formation(Lower Cretaceous) in Sichuan Province yield multiple saurischian(theropod–sauropod) dominated ichnofaunas. To date, a moderate diversity of six theropod ichnogenera has been reported, but none of these have been identified at the ichnospecies level. Thus, many morphotypes have common "generic" labels such as Grallator, Eubrontes, cf. Eubrontes or even "EubrontesMegalosauripus" morphotype. These morphotypes are generally more typical of the Jurassic, whereas other more distinctive theropod tracks(Minisauripus and Velociraptorichnus) are restricted to the Cretaceous. The new ichnospecies Eubrontes nobitai ichnosp nov. is distinguished from Jurassic morphotypes based on a very wellpreserved trackway and represents the first-named Eubrontes ichnospecies from the Cretaceous of Asia.展开更多
A fossil theropod dinosaur discovered in China is thought to be vegetarian, in sharp contrast with its meat-eating cousins, according to research published in Nature on September 19,2002.……
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supported by grants from the Canadian Museum of Nature and the National Science and Engineering Research Counsel of Canada (Grant No:203091-98).
文摘A new theropod dinosaur, Shidaisaurusjinae gen. et sp. nov., has been described on the basis of an incomplete skeleton. The specimen was found near the base of the Upper Lufeng Formation （early Middle Jurassic） in Yunnan, China. It is the first theropod dinosaur from the Middle Jurassic of Yunnan. Shidaisaurus jinae is distinguishable from other Jurassic theropods by certain features from the braincase, axis, and pelvic girdle. The absence of any pleurocoels in the axis or in any anterior dorsal vertebrae suggests that the new Lufeng theropod is relatively primitive and more plesiomorphic than most of the Middle to Late Jurassic theropods from China. Most Chinese taxa of Jurassic theropod dinosaurs have not been well described; a further detailed study will be necessary for us to determine their phylogenetic relationships with Shidaisaurusjinae.
文摘中国西部准噶尔盆地东北缘中侏罗世晚期到晚侏罗世早期沉积的石树沟组(Eberth et al.,2001)产出过巨型的蜥脚类恐龙化石(Russell and Zheng,1993),但产出的兽脚类恐龙个体则相对较小(Currie and Zhao,1993)。我们近年来在石树沟组中采集到大量脊椎动物化石(Clark et al.,2006),其中包括许多零散的骨骼和牙齿标本。本文报道一个产自石树沟组上部的兽脚类牙齿化石(IVPP V 15310),对于全面了解石树沟脊椎动物群具有一定意义。V 15310保存了一个近乎完整的上颌齿或下颌齿的齿冠。它具有典型兽脚类恐龙牙齿的特征:强烈侧扁,向后弯曲,前后缘有锯齿。齿冠有几种不同的磨蚀面:齿尖磨蚀成近圆形,靠近齿尖的齿冠前缘有一较大的平的磨蚀面,锯齿也受到不同程度的磨蚀。V 15310很大,相关的测量数据和一些白垩纪的巨型兽脚类恐龙牙齿的测量数据相近。依据我们定义的一个定量评估锯齿大小的指标(锯齿大小指数),得出V 15310的锯齿大小指数非常小,与霸王龙相似,这与锯齿和齿冠大小具有反比关系的结论是一致的(Farlow et al,1991)。V 15310的另外一些形态特征对于推断它在兽脚类中的系统位置也提供了帮助。这些特征包括后缘锯齿明显高于前缘锯齿以及齿冠的唇侧和舌侧都有微弱的釉质褶皱。根据牙齿大小、釉质褶皱的发育程度以及锯齿的形态(Sereno et al.,1996;Chure et al.,1999;Holtz,2004),V 15310被归入中国盗龙类。其中,后缘锯齿和前缘锯齿的基部长度近似,但前者明显高于后者这一特征组合可能是中国盗龙类的一个鉴定特征。这一特征组合也见于四川的中国盗龙类。相比而言,V 15310在已报道的侏罗纪兽脚类恐龙牙齿中尺寸最大(Smith,2005;Smith et al.,2005),大小接近白垩纪的一些巨型兽脚类恐龙牙齿。新材料的发现表明兽脚类至少在晚侏罗世早期就已演化出了这种巨型体型。
基金supported the PLEC2021-008203 project and RYC2021-034473-Ifunded by MCIN/AEI/10.13039/501100011033+4 种基金by the European Union"NextGenerationEU"/PRTRFundação para a Ciência e Tecnologia(FCT-MCTES)of Portugal(projects PTDC/CTA-PAL/31656/2017 and PTDC/CTA-PAL/2217/2021)Research Unit GeoBioTec UIDB/04035/2020Also,the work is part of the Carmen Nunez-Lahuerta is supported by FJC2020-044561-I-MCIN,co-financed by the NextGeneration EU/PRTR.
文摘The accurate identification of dinosaur egg accumulations as nests or clutches is crucial for understanding the reproductive behaviour of these extinct species.However,existing methods often rely on the presence of complete eggs and embryo remains,and sedimentological criteria that are only applicable to well-structured sediments.In this study,we introduce an innovative approach to characterize egg accumulations in structureless sediments,where traditional nest structures may not be preserved.Our methodology employs a unique combination of sedimentological,taphonomic,geochemical,and geophysical proxies for the study of egg accumulations.We applied this approach to the egg accumulation from Paimogo(Jurassic,Portugal),traditionally interpreted as a nest.Our findings reveal that the Paimogo egg assemblage is a secondary deposit,resulting from a flooding event in a fluvial plain that dismantled several allosauroid and crocodylomorph clutches.The eggshell vapor conductance results,coupled with sedimentological evidence,suggest that allosauroid dinosaurs buried their eggs in the dry terrain of overbank areas close to a main channel during the breeding season,likely during the dry season to prevent the embryos from drowning.This research underscores the necessity of multidisciplinary approaches in interpreting egg accumulations and offers a novel methodology for studying these accumulations in structureless sediments.Our findings provide new insights into the breeding behaviour and nesting preferences of these extinct organisms,contributing to our understanding of dinosaur ecology.
文摘Dinosaurs due to their diverse species and peculiar forms have drawn the interest of both artists and scientists. One way to unlock the unknown life of dinosaurs is to reconstruct dinosaurs through drawings, computer animations or sculptures. Following the Introduction on “Dinosaur Reconstruction” by the present authors, where important Paleontological knowledge was presented, the next step is to examine some specific information along with necessary details for dinosaur reconstruction. The first and basic step to be taken for a reconstruction is the posture of the animal;this is the theme of the current paper. Dinosaurs would move either bipedally or quadrupedally depending on their kind and body construction. Based on the available literature, various issues in relation to the posture of an animal at different instances are examined. These are: postures of bipedal dinosaurs during walking, observation of living bipedal animals, postures of quadruped dinosaurs during walking, feeding styles, and dinosaur tails. Theropods had a locomotor behavior like modern birds, with the step width increasing when the animals decreased speed. The general posture and movement of quadrupeds and especially sauropods, remains a subject of great and much controversy. Some scientists believe that sauropod necks were generally held in a neutral or undeflected state during most of the time, while others believe that sauropod necks behaved like all present-day amniote with the mid-cervical region held nearly vertical. Also, there are indications that dinosaurs usually held their tails above ground. For all dinosaurs, the long tail was acting as a counterbalance to the head and body. As a validating example, the case of Amargasaurus is investigated with the help of a model, where the various positions of the animal are examined. A certain posture was chosen for a full-size steel and concrete reconstruction based on the features of the animal.
基金funded by the National Natural Science Foundation of China (Grant Nos. 41790455, 41772008)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, Chinese Academy of Sciences) (Grant No. 173127)
文摘A relatively small number of tetrapod tracksites from Zhejiang Province fills out the fossil record from that region,which is also known to have yielded both saurischian（titanosauriform, coelurosaur） and ornithischian（basal ornithopod, ankylosaurian） body fossils as well as dinosaurian eggs. We use photogrammetry and 3 D imaging to reinterpret the sauropod tracks from Lishui City, which revealed the existence of trackways. The track record from three documented sites in Zhejiang Province includes avian and non-avian theropod, sauropod, ornithopod and pterosaur tracks. Previous work showed that the purported new bird ichnospecies Dongyangornipes sinensis is a synonym of Uhangrichnus chuni, while we here consider Pteraichnus dongyangensis as a nomen dubium. Such ＂provincial ichnotaxonomy＂ may mask similarities in the ichnofauna across large regions. In fact, we show that the ichnofauna is similar to that found in the Early Cretaceous elsewhere in China.
文摘Vitakrisaurus saraiki abelisauroid theropod dinosaurs reported from Pakistan and extended distribution into India. Vitakrisaurus saraiki is medium to large sized theropod which is represented by associated vertebral and limb elements and especially hand elements. Out of 14 small to large bodied theropods from Indo-Pakistan subcontinent, only less than half of these are restricted to some common elements. Vitakrisaurus saraiki theropod of Pakistan is based on associated vertebral and limb elements especially hand including articulated carpals, metacarpals, phalanges and claws which are significant for Gondwanan paleobiogeographic link, comparisons and systematic.
基金supported by the National Natural Science Foundation of China (Grant No.41772008)the State Key Laboratory of Palaeobiology and Stratigraphy(Nanjing Institute of Geology and Palaeontology, CAS)(Grant No.173127)and the comprehensive geological and mineral survey in Wumeng mountainous area conducted by China Geological Survey (Grant No.121201010000150002)
文摘Upper Triassic and Middle Jurassic strata of the Xichang Basin in Sichuan Province, southwestern China, yielded important dinosaur ichnofossils. From the Xujiahe Formation of the Yiguojiao tracksite, we report a Late Triassic footprint assemblage in China and the first discovery of diagnostic Triassic sauropodomorph tracks in this region. The tracks share a number of features in common with the ichnogenera Eosauropus(Late Triassic) and Liujianpus(Early Jurassic). The neighboring Bingtu tracksite is stratigraphically younger(Shaximiao Formation, Middle Jurassic) and preserves small tridactyl theropod tracks that represent the first occurrence of the ichnotaxon Carmelopodus in China and Asia. While these tracks are morphologically comparable to those from the Middle Jurassic type locality in North America, the specimens from China show the proximal margin of the digit IV impression in a more cranial position, which may indicate a trackmaker with a relatively short metatarsal IV. In addition to the skeletal record, the Carmelopodus footprints document the presence of small theropods in the dinosaur fauna of the Middle Jurassic Shaximiao Formation.
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supported by the National Natural Science Foundation of China(No.41790455,41772008)the National Geographic Society,USA(No.EC0768-15)+1 种基金the Fundamental Research Funds for the Central Universities(No.2652017215)the State Key Laboratory of Palaeobiology and Stratigraphy(Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences)(No.173127)
文摘The sauropodomorph Thecodontosaurus caducus and theropod Coelophysis bauri are the earliest known dinosaurs with postcranial skeletal pneumaticity.In both taxa,postcranial pneumatic features are confined to the cervical vertebrae.This distribution of pneumaticity in the skeleton is most consistent with pneumatization by diverticula of cervical air sacs similar to those of birds.Other hypotheses,including pneumatization by diverticula of the lungs,larynx and trachea,or cranial air spaces,are less well-supported.
基金the National Natural Science Foundation of China(No.41888101)the 111 project(B20011)the Fundamental Research Funds for Central Universities(265QZ201903).
文摘Tracks previously examined between 2002 and 2015 from an incompletely-studied,and now partially lost tracksite site in the Santai Formation of Shandong Province were restudied based on new ex-cavations of additional surfaces.In contrast to the previous reports of tridactyl tracks,including Grallator,the present study discovered an additional assemblage of unequivocal pterosaur tracks(Pteraichnus)and a possible didactyl deinonychosaurian track.The age of the Santai Formation is controversial but it is probably Late Jurassic,which corresponds to the epoch when pterosaur tracks appear worldwide.Age interpretations,based on palynology and isotopic data,tentatively suggests an earlier Middle-Late Jurassic age and might suggest that the pterosaurian tracks are as old or somewhat older than any previously reported.
基金supported by the National Natural Science Foundation of China(Grant No. 41772008)the 111 project,China (Grant No. B20011)the Fundamental Research Funds for Central Universities (Grant No.265QZ201903)。
文摘The Jiaguan Formation and the underlying Feitianshan Formation(Lower Cretaceous) in Sichuan Province yield multiple saurischian(theropod–sauropod) dominated ichnofaunas. To date, a moderate diversity of six theropod ichnogenera has been reported, but none of these have been identified at the ichnospecies level. Thus, many morphotypes have common "generic" labels such as Grallator, Eubrontes, cf. Eubrontes or even "EubrontesMegalosauripus" morphotype. These morphotypes are generally more typical of the Jurassic, whereas other more distinctive theropod tracks(Minisauripus and Velociraptorichnus) are restricted to the Cretaceous. The new ichnospecies Eubrontes nobitai ichnosp nov. is distinguished from Jurassic morphotypes based on a very wellpreserved trackway and represents the first-named Eubrontes ichnospecies from the Cretaceous of Asia.
文摘 A fossil theropod dinosaur discovered in China is thought to be vegetarian, in sharp contrast with its meat-eating cousins, according to research published in Nature on September 19,2002.……
