Lida Xing

China University of Geosciences (Beijing) · School of Earth Sciences and Resources

The Jurassic period was crucial for continental ecosystems, with dinosaurs rising to dominance and many key vertebrate groups emerging. In the Early Jurassic, theropod tracks were dominant, alongside those of crocodylomorphs, synapsids, ornithischians, and sauropodomorphs. The Middle Jurassic saw a shift to more diverse ichnofaunas, with new tracks...

Despite the utilization of new technologies to objectively record and document dinosaur tracks in the field, the categorization and identification of dinosaur tracks remains a largely subjective process. Track Recognition via Artificial Cognition (TRAC) is a project that seeks to provide an objective method for categorizing and identifying dinosaur...

The Early Cretaceous avian ichnofauna of Laurasia, particularly in East Asia, is remarkably abundant. The northwestern region of China is the most productive area for bird tracks. Recently, four avian-dominatedtrack sites have been discovered in the Cretaceous Lanzhou-Minhe Basin of Gansu, where the shorebirdtrack Koreanaornis, the ankylopollexian...

The Longxiang tracksite (lower Upper Cretaceous, Shanghang Basin) includes twelve didactyl deinonychosaur tracks that fall into two morphologies, differentiated by both size and form. The smaller tracks (∼11 cm long) are referable to the ichnogenus Velociraptorichnus. The larger tracks (∼36 cm long) establish the ichnotaxon Fujianipus yingliangi. B...

Ankylosaurines are the iconic armoured dinosaurs that characterize terrestrial vertebrate faunas in the Late Cretaceous of Asia and Laramidia (western North America). The earliest members of this clade are known from the early Late Cretaceous (Cenomanian–Santonian) times of Asia, but little consensus has emerged as to how they are related to the an...

We report five new dinosaur track sites in Chaya County, about 120 km southeast of Changdu City. The track assemblages are dominated by sauropods (45 tracks), which have been identified tentatively as cf. Brontopodus. Also present are two thyreophoran trackways consisting of 13 tracks that show strong similarities with the ichnogenus Deltapodus, th...

A new Chengyuchelys latimarginalis (Xinjiangchelyidae) specimen is reported based on a well-preserved, nearly complete shell from the upper part of the Upper Jurassic Shangshaximiao Formation of Qijiang District, Chongqing Municipality, China. The Xinjiangchelyidae were widely distributed in Asia during the Jurassic and were the dominant turtle gro...

Recently, dinosaur tracks were discovered in the vicinity of Zhemujiu village in Yimen County, Yunnan Province, representing the first dinosaur footprints found in the purplish-red sandy mudstone of Lower Jurassic Zhanghe Formation. This marks a significant discovery as evidence of dinosaurs from this formation has previously only been reported fro...

A possible turtle swim track from the Third Member of the Late Triassic Xujiahe Formation (Norian-Rhaetian) represents the oldest ichnological evidence of the group from China, supplementing previous reports of more abundant tracks from the Middle Jurassic of the region. The specimen is younger than the known pantestudinate (‘stem-turtle’) body fos...

An ichnoassemblage comprising trackways and trails of horseshoe crabs and fishes has been discovered in the Upper Triassic Wayaobu Formation of the Ordos Basin, Shaanxi Province, northern China. This is a lacustrine coal-bearing succession with sandstones, mudstones and oil shales. Two trace-bearing beds are present, one with fine sandstone, the ot...

A newly discovered dinosaur tracksite in the Middle Jurassic Xietan Formation of the Zigui Basin, is the first reported from Hubei Province, China. Access to the site is difficult due to the steep inclination (~60°) of the track-bearing beds. The tracks are poorly preserved and occur in a fragmented mudstone substrate. However, it is possible to id...

A newly discovered dinosaur tracksite in the Middle Jurassic Xietan Formation of the Zigui Basin, is the first reported from Hubei Province, China. Access to the site is difficult due to the steep inclination (~60°) of the track-bearing beds. The tracks are poorly preserved and occur in a fragmented mudstone substrate. However, it is possible to id...

Here, we describe a pathological sub-adult theropod dinosaur from the Late Jurassic Morrison Formation in Dana Quarry, Wyoming, U.S.A. It exhibits multiple pathologies, involving three dorsal vertebrae, the right scapula and coracoid, and apparent pathology of the left scapula. The fourth dorsal vertebra has four irregularly shaped growths on the v...

We analysed the stable isotope compositions of dinosaur eggshells and their associated depositional settings of the egg-bearing rocks in the Upper Cretaceous of the Qiyunshan area, Anhui Province, China. Data show that δ¹³C values for Similifaveoloolithus qiyunshanensis and Umbellaoolithus xiuningensis range between −5.94‰ and −3.55‰; this suggests...

Parataxidea is a Late Miocene-Early Pliocene genus of omnivorous mustelids best known from the fossil record of China. Here we report a new skull of Parataxidea sp. from the Liushu Formation, Linxia Basin, which is unusual in having abnormal cellular hyperplasia in the region of P4-M1 on maxillae and a bulbous bone growth on the right side. The hyp...

Background Dinosaur eggs containing embryos are rare, limiting our understanding of dinosaur development. Recently, a clutch of subspherical dinosaur eggs was discovered while blasting for a construction project in the Upper Cretaceous red beds (Hekou Formation) of the Ganzhou Basin, Jiangxi Province, China. At least two of the eggs contain identif...

An increasing number of theropod-dominated tracksites have been reported from the Jurassic and Cretaceous of China. These include a significant number from the Lower Jurassic of the Lufeng Basin, famous for its Lufengosaurus fauna and known for a typical Lower Jurassic globally-distributed tetrapod footprint biochron. Here we report another localiz...

An isolated but moderately well-preserved theropod track from the coal-bearing strata of the Zhangjiakou City region of Hebei Province was reported to have originated from the Xiahuayuan Formation, which is considered Middle Jurassic in age. Although the track has a wide divarication angle and length-width ratio reminiscent of Cretaceous tracks lik...

Dinosaur tracks have been known and reported sporadically from the coal-bearing beds of the Fuxin Formation (upper Aptian–Albian, upper Lower Cretaceous) of Liaoning Province, northeastern China for some time but have not been described in detail. Here available material is illustrated suggesting a diversity of theropod track morphotypes, including...

Background: Dinosaur eggs containing embryos are rare, limiting our understanding of dinosaur development. Recently, a clutch of subspherical dinosaur eggs was discovered while blasting for a construction project in the Upper Cretaceous red beds (Hekou Formation) of the Ganzhou basin, Jiangxi Province, China. At least two of the eggs contain identi...

Monospecific assemblages of non-avian theropod tracks are relatively rare in the Cretaceous of Korea, where assemblages dominated by the tracks of diverse tetrapods (birds, sauropods, ornithopods, and pterosaurs) are well known and widely distributed in the Haman and Jindong formations (Hayang Group). To date, few high-density assemblages of therop...

Two newly discovered dinosaur track locations near the town of Bijie in Guizhou Province, southwestern China are named the Yuanbaoqing and Yejiatian tracksites. They represent the Lower Jurassic Maanshan Member of the Zijiujing Formation and Upper Jurassic Xiashaximiao Formation, respectively. The former Yuanbaoqing tracksite reveals a minimum of t...

The Jurassic and Cretaceous tetrapod track record in China has incrementally expanded due to the discovery of small sites in widely dispersed geographical locations, which often lack body fossils. Many of these are theropod dominated tracksites where, despite morphological variation, identification of ichnotaxa is difficult at low taxonomic levels...

Despite the discovery of many dinosaur eggs and nests over the past 100 years, articulated in-ovo embryos are remarkably rare. Here we report an exceptionally preserved, articulated oviraptorid embryo inside an elongatoolithid egg, from the Late Cretaceous Hekou Formation of southern China. The head lies ventral to the body, with the feet on either...

Amber fossils provide snapshots of the anatomy, biology, and ecology of extinct organisms that are otherwise inaccessible. The best-known fossils in amber are terrestrial arthropods—principally insects—whereas aquatic organisms are rarely represented. Here we present the first record of true crabs (Brachyura) in amber—from the Cretaceous of Myanmar...

An assemblage of small, Middle Jurassic tracks from the Xishanyao Formation, located about 100 km west of Urumqi in the Junggar Basin, Xinjiang Province, is here designated the Nanshan site. The site reveals three ornithischian trackways identified as Anomoepus. These represent the eleventh report of the ichnogenus from the Jurassic of China. Two o...

The Jurassic-Cretaceous Tuchengzi Formation has yielded at least 16 known theropod-dominated tracksites from northeast China, and in this paper, a new locality, the Lishi site in Hebei Province, is documented. A tuff layer positioned stratigraphically 90 m below the trackway layer yielded a UPb date of 142.2 ± 0.9 Ma, placing the site in the Berria...

New umbellaoolithid and faveoloolithid eggs were discovered from the early Late Cretaceous deposit in the Xiuning Basin, Anhui Province, China, and the samples were examined for elemental and isotopic compositions to reconstruct the geochemical environment. The results show that the trace elements consist of Sr, Mn, Ti, Ba, As, La, Cr, Ni, Pb, Cu,...

In recent years the number of track sites discovered and reported from the Lower Cretaceous Jiaguan Formation, Sichuan Basin has increased steadily. Here we report on the 20th and 21st sites which are situated in unusual locations in a cave and on a steep bedding plane surface in association with Tang Dynasty grottoes. The ichnofauna is represented...

Previously known theropod dinosaur footprints preserved as natural casts in the Tuchengzi Formation, on a rock wall beside the railway in Nanshuangmiao Village, Shangbancheng Town, Chengde City, were originally assigned to ichnogenus Anchisauripus and tentatively attributed to oviraptosaurs. The assemblage was restudied in more detail by examining...

The smallest non-avian theropods have often attracted attention of palaeobiological and ichnological research. Here, we describe a diminutive tridactyl track (10.2 mm in length) from the Lower Jurassic Ma’anshan Member of the Ziliujing Formation, Wuli site, Sichuan Province, China. The Wuli specimen may be the smallest theropod track in the world....

An assemblage of eubrontid-type theropod tracks, representing terrestrial progression and turtle track swim tracks representing subaqueous progression characterises a newly reported site in the Middle Jurassic Zhiluo Formation in Shaanxi Province China. While eubrontid tracks are common in the Jurassic of China, turtle swim tracks have only compara...

Many Mesozoic formations have yielded substantial dinosaur dominated ichnofaunas, which help characterize coeval communities. When compared with dinosaurian skeletal data (faunal lists) from the same and/or coeval deposits, the completeness and diversity of trace and body fossil records may be shown to be of equal or quite different value for paleo...

Rich tetrapod ichnofaunas, known for more than a decade, from the Huangyangquan Reservoir (Wuerhe District, Karamay City, Xinjiang) have been an abundant source of some of the largest Lower Cretaceous track collections from China. They originate from inland lacustrine clastic exposures of the 581–877 m thick Tugulu Group, variously divided into fou...

A single well-preserved theropod trackway identified as Eubrontes was discovered in the Lower Cretaceous (Berriasian-Valanginian) Cangxi Formation on the northern margin of the Sichuan Basin This is the first report of tracks from this formation. The occurrence is consistent with reports of theropod dominated ichnofaunas from broadly coeval deposit...

A newly discovered saurischian dominated tracksite in the Lower Cretaceous Jiaguan Formation in southeastern Sichuan province reveals 13 sauropod trackway segments representing ichnogenus Brontopodus and three theropod trackways. This is a typical Type 1 Jiaguan Formation deposit dominated by tetrapod tracks with no significant tetrapod body fossil...

Tracks from two sites in the Middle Jurassic Xintiangou Formation in the Wuma Village area, Wuhuang Township, Zizhong have been known and intermittently studied and excavated since the 1980s. The track-bearing surfaces were exposed by a combination of natural weathering and deliberate excavation by residents in a rural agricultural area. The surfac...

Tracks attributable to small ornithischian dinosaurs (thyreophorans and cerapodans) are generally rare in comparison with those representing large individuals. Here we report a presumed stegosaur track (ichnogenus Deltapodus) only 5.7 cm long originating from the Lower Cretaceous Tugulu Group of Xinjiang Province, China, co-occurring with the track...

A total of 31 Lower Cretaceous tetrapod tracksites have been reported from four areas in Gansu Province, China: Yanguoshia, Guanshan, Zhongpu and Honggu. Here we report on the previously undescribed track types found at seven of these sites, five of which are sauropod dominated, with one site yielding ornithopod tracks and another one yielding ther...

Sauropod tracks, particularly those attributable to the ichnogenus Brontopodus are becoming increasingly well known in the Jurassic and Cretaceous of China. Globally there are indications that wide gauge forms, attributable to titanosauriform sauropods increase in the Cretaceous. However, differentiating wide and narrow gauge, broadly categorized a...

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 an...

Dinosaur trackways that show changes in direction are reported from Jurassic and Cretaceous sites in North and South America, Europe and Asia. Such changes in direction can be defined as tortuosity, and categorised in 45° quadrants. To date only six tortuous theropod trackways have been reported with changes in direction exceeding ¼-¾ turns (~ 45°-...

Multiple sauropod-track-bearing horizons occur in the Middle Jurassic Shaqiaomu Formation, in the Chaya Group of Eastern Tibet. These add to the report of a previously described sauropod trackway, which is a famous tourist attraction and became part of a folkloric legend. From an ichnological point of view, multiple track-bearing levels are consist...

Here we report the discovery of a non-avian theropod manus claw and various closely associated caudal vertebrae from a Lower Cretaceous exposure of the Tugulu Group, in the Junggar Basin. The gross anatomy of the vertebrae indicate an ornithomimosaur affinity, and a morphometric analysis of the claw supports this diagnosis. As is consistent with th...

Dinosaur and other tetrapod tracks are already known from multiple (~25) sites in the Early Cretaceous Hekou Group of Gansu Province. In addition to large sites (e.g. Yanguoxia) which have yielded more than 1500 tracks, small sites are important for verifying the distribution of morphotypes (ichnotaxa) over a wider region. Documentation of five new...

A Late Jurassic ichnofauna from the Suining Formation at the Yejipo site, Huangba Village, Sichuan Province has been locally known for its fossil footprints since the 1980s as the name ‘Yejipo’, meaning feral chicken/pheasant indicates. The best-preserved trackway represents a large theropod (mean footprint length 55.0 cm) assigned to Megalosauripu...

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...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The Society of Vertebrate Paleontology (SVP) has recently circulated a letter, dated 21st April, 2020, to more than 300 palaeontological journals, signed by the President, Vice President and a former President of the society (Rayfield et al. 2020). In this letter, significant changes to the common practices in palaeontology are requested. In our pr...

The Society of Vertebrate Paleontology (SVP) has recently circulated a letter, dated 21st April, 2020, to more than 300 palaeontological journals, signed by the President, Vice President and a former President of the society (Rayfield et al. 2020). In this letter, significant changes to the common practices in palaeontology are requested. In our pr...

Subaqueously-registered trackways of marine tetrapods are only rarely preserved; some of the best examples so far come from the Shizishan Member (Member II) of the Guanling Formation (Middle Triassic, Anisian-Ladinian) of Yunnan Province in southwestern China. The unit is well-known for the Luoping Biota including abundant skeletons of marine repti...

Recently, the Society of Vertebrate Paleontology (SVP) has sent around a letter, dated 21st April, 2020 to more than 300 palaeontological journals, signed by the President, Vice President and a former President of the society (Rayfield et al. 2020). The signatories of this letter request significant changes to the common practices in palaeontology....

Subaqueously-registered trackways of marine tetrapods are only rarely preserved; some of the best examples so far come from the Shizishan Member (Member II) of the Guanling Formation (Middle Triassic, Anisian-Ladinian) of Yunnan Province in southwestern China. The unit is well-known for the Luoping Biota including abundant skeletons of marine repti...

Hkamti amber contains exquisite fossils, but the age of the amber biota is unclear. In this study, we documented the characteristics of fossils hosted in the amber, and we present zircon UPb ages of tuff layers from the Kachin and Hkamti sites (i.e., the “new mine”). We also present a compilation of arthropod and echinoderm syn-inclusions from the...

Recent discoveries of enantiornithine birds trapped in amber have decreased the lower size limit of members of this clade, increased their morphological diversity, and provided significant new data regarding their plumage. Here, we describe a new specimen that consists of the distal extremities of both forelimbs and hindlimbs. Size and morphology s...

We describe the first partial articulated skeleton from the Ganzhou area, Jianxi Province, China. This basin has not been forthcoming in yielding hadrosaurid remains. The new specimen consists of an articulated rib cage belonging to a relatively large (no less than 9 m in length) hadrosaurid. It was collected from Maastrichtian strata of the Hekou...

We welcome any new interpretation or alternative hypothesis regarding the taxonomic affinity of the enigmatic Oculudentavis khaungraae. However, here we demonstrate that Li et al. have failed to provide conclusive evidence for the reidentification of HPG-15-3 as a squamate. We analyse this specimen in a matrix that includes a broad sample of diapsi...

Large dinosaur tracks were recently reported from locations in the Pterosaur-Yadan National Geological Park situated about 100 km south of Hami in Xinjiang Province, China. The park comprises a substantial area in a much larger arid region comprising and extensive spectrum of Cretaceous, siliciclastic, Tugulu Group, lithofacies representing proxima...

We report the discovery of concentrated invertebrate inchnofossils in close association with a dinosaur nest from the Hekou Formation in Jiangxi Province, China. The seven dinosaurian eggs reported clearly belong to the Elongatoolithidae and burrow traces were most likely made by small crustaceans. This association prompts the question as to whethe...

A dinosaur track assemblage from a remote, high altitude (∼4,500–5,000 m) site on the is the first to be reported from this area. The location, here named the Yangguang tracksite, represents the Lower Cretaceous part of the Kezilesu Group consisting of feldspathic sandstones and dated as Hauterivian–Barremian on the basis of the palynoflora. As the...

It has long been known that Lower Jurassic theropod track assemblages are dominated by theropod tracks including Eubrontes and Grallator, known from North America since the mid 19th century. It was only comparatively recently that it was recognised that these ichnogenera where also abundant in other regions including China, making them important co...

The trace elements and isotopic compositions of macroelongatoolithid eggshells provide insights into the palaeoenvironment of these huge eggs preservation. We analysed the geochemical characteristics of newly discovered macroelongatoolithid eggs from the early Cretaceous Zhaoying Formation in the Xixia Basin, Henan Province, China. X-ray diffractio...

Including zoochory, mechanisms of seed dispersal varied along with the adaptive radiation of angiosperms, but few early fossil records had been reported with specialized pericarp structure. The present study describes a new specimen from Myanmar amber, denominated Rasenganus auricularus gen. et sp. nov. In this specimen, the spirally coiled structu...

Recent discoveries of enantiornithine remains in Burmese amber have provided a wealth of paleobiological data on this extinct clade of Mesozoic birds. Amber, as a unique medium of fossilization, preserves in three dimensions structures with details unmatched elsewhere in the fossil record. This provides the opportunity to combine osteological infor...

Skeletal inclusions in approximately 99-million-year-old amber from northern Myanmar provide unprecedented insights into the soft tissue and skeletal anatomy of minute fauna, which are not typically preserved in other depositional environments1–3. Among a diversity of vertebrates, seven specimens that preserve the skeletal remains of enantiornithin...

A total of 82 lizard specimens in amber have been reported around the world to date. Records of lizard inclusions extend from the Cretaceous to the Neogene: (1) Cretaceous lizard inclusions are dominated by Autarchoglossans from Lebanon and a diverse lizard fauna from Myanmar (Burma); (2) Paleogene lizard inclusions are relatively poorly preserved...