Yanhong Pan

Nanjing University | NJU · School of Earth Sciences and Engineering

The mid-Holocene climate optimum saw warm temperatures in large parts of China, but its impact on seasonal environmental changes is not fully understood yet. Here, we use high-resolution geochemical analyses of 7000 to 6000 year-old oyster shells from the Yangtze River Delta to reconstruct climatic and oceanographic patterns. The stable isotope (δ¹...

Belemnites are valuable for reconstructing Jurassic and Cretaceous seawater temperatures, but their reliability hinges on the preservational quality of the fossil materials. Methods for assessing the pres- ervational quality of fossils vary among studies. This research examined altered Cretaceous belemnites and seemingly well preserved Upper Jurass...

The impact of sexual selection on the evolution of birds has been widely acknowledged. Although sexual selection has been hypothesized as a driving force in the occurrences of numerous morphological features across theropod evolution, this hypothesis has yet to be comprehensively tested due to challenges in identifying the sex of fossils and by the...

The middle Mesozoic of the southern Junggar Basin is a source of abundant Late Triassic-Jurassic non-marine and Early Jurassic marine–littoral bivalves. The bivalve chronology provides a framework for dating the strata and documents Early Jurassic transgressions and the end-Triassic mass extinction in the Junggar Basin. The first occurrences (FOs)...

Exceptional preservation of fossils has often been attributed to the actions of bacteria that aid in the preservation of soft tissues that normally decay rapidly. However, it is well known that fungi play a major role in organic matter decomposition, biogeochemical cycling of elements, and metal-mineral transformations in modern ecosystems. Althoug...

Most modern birds have scales covering feet, but our knowledge of early avian scales is limited, mainly due to their scarcity in the fossil record. Here we describe the morphological details of scutellate and interstitial scales preserved in IVPP V15077, a specimen of the Early Cretaceous bird Gansus from the Changma Basin in northwestern Gansu Pro...

Hydrofluoric acid (HF) is commonly used in geological and paleontological research to extract organic fossils for morphological and chemical studies. However, during HF treatment, organic matter can also be altered, which raises concerns that HF‐treated organic matter may not be representative of the original organic matter. To provide reference da...

Fossil feathers have greatly improved our understanding of the evolutionary transition from non-avian dinosaurs to birds and the evolution of feathers, and may be the only evidence for their source animals in the fossil record. Hot spring environments have been demonstrated to be conducive to the preservation of fossils, but internal silicification...

A unique form of melanosomes contributing to brilliant iridescent colors in modern bird feathers, previously unknown in fossil birds, is identified in the Early Cretaceous bird Eoconfuciusornis. The discovery highlights the complexity of plumage color nanostructures utilized early in bird evolution as far back as 130 million years ago.

Most modern birds have scales covering the foot, while our knowledge of early avian scales is limited, mainly due to the scarcity of fossil record. Here we characterize the morphological details of two types of scales preserved in IVPP V15077, a referred specimen of the Early Cretaceous bird Gansus . The scutellate and interstitial scales, which, i...

Enantiornithes are the most successful group of Mesozoic birds, arguably representing the first global avian radiation,1, 2, 3, 4 and commonly resolved as the sister to the Ornithuromorpha, the clade within which all living birds are nested.1,3 The wealth of fossils makes it feasible to comparatively test evolutionary hypotheses about the pattern a...

Most modern birds have scales covering the foot and feathers elsewhere. Discoveries of fossil feathers attached to the metatarsus in non-avian dinosaurs and basal birds suggests that the avian scales are secondarily derived from feathers. However, our knowledge of early avian scales and their taphonomy is still limited, due to the scarcity of fossi...

Structural colours, nature's most pure and intense colours, originate when light is scattered via nanoscale modulations of the refractive index. Original colours in fossils illuminate the ecological interactions among extinct organisms and functional evolution of colours. Here, we report multiple examples of vivid metallic colours in diverse insect...

Protopteryx fengningensis is from the 130.7 Ma Huajiying Formation making it one of the oldest known enantiornithines. Contributing to its significance, this taxon is also commonly resolved as the basal-most enantiornithine in phylogenetic analyses. Protopteryx preserves several unusual morphologies that are otherwise absent in the Enantiornithes b...

Exceptionally preserved fossil feathers and feather-like integumentary structures provide valuable insights into the early evolution of feathers and flight, but taphonomic biases often make interpretations at the microstructural and ultrastructural levels ambiguous. Maturation experiments have been demonstrated to be useful for investigating the ta...

A new polyconitid rudist Shajia tibetica gen. et sp. nov., of late Aptian to Albian age, is described from the Langshan Formation of Nyima County, northern Lhasa Block, Tibet. Though comparable in size and external morphology with Horiopleura haydeni Douvill�e, which is a common endemic species in southwestern Asia, Shajia differs from the latter s...

Chemical imaging techniques, based on a combination of microscopy and spectroscopy, are designed to analyse the composition and spatial distribution of heterogeneous chemical complexes within a sample. Over the last few decades, it has become an increasingly popular tool for characterizing trace elements, isotopic information and organic biomarkers...

The density of vertebrate fossils on bedding planes is generally very low in the Upper Jurassic plattenkalks forming the Solnhofen fossil Lagerstätte. There are, however, a few bedding planes where large concentrations of the small fish Leptolepides sprattiformis (Blainville, 1818) occur. The aim of this paper is to analyse and interpret these fish...

The Jehol and Yanliao Biota constitute two world-famous Mesozoic lacustrine Konservat Lagerstätten. In contrast to numerous comparative studies on their different fossil assemblages, their taphonomic features have rarely been compared. Here we investigate the diagenetic pathways of spinicaudatans from the Lower Cretaceous Yixian Formation and the J...

The Shanwang Fauna has been one of the well-known Miocene Konservat-Lagerstätten for a long time, but the high-fidelity preservation of the fossils has been often ignored. This paper illustrates the exceptional preservation displayed by some fossil insects from the Shanwang Formation. The microstructures of the preserved exoskeletons were analyzed...

During the dinosaur–bird transition, feathers of bird ancestors must have been molecularly modified to become biomechanically suitable for flight. We report molecular moieties in fossil feathers that shed light on that transition. Pennaceous feathers attached to the right forelimb of the Jurassic dinosaur Anchiornis were composed of both feather β-...

Significance Archaeorhynchus spathula is a basal member of the Ornithuromorpha, the lineage that includes neornithines. Although this is the fifth reported specimen, unlike the others it preserves significant soft tissue, revealing a tail morphology previously unknown in Mesozoic birds and an exceptional occurrence of fossilized lung tissue. This i...

This work provides the first detailed taxonomic study of ostracod species from the Shenjiatun section (Nenjiang Formation, Songliao Basin, northeast China). Ten species belonging to seven genera are recognized. At the species level, this ostracod fauna shows a high degree of endemicity. The ontogeny of two species is recognized in this study, and s...

Diagnostic characters of the recently established new genus of radiolitid rudist Auroradiolites include an entirely compact outer shell layer, a distinctly convex upper (left) valve and a robust myocardinal apparatus surrounding a strongly internally projected ligamentary infolding. Until now, A. biconvexus (previously considered to be exclusively...

We report on an exceptional specimen of Eoconfuciusornis preserving rare soft-tissue traces of the ovary and wing. Ovarian follicles preserve a greater hierarchy than observed in Jeholornis and enantiornithines, suggesting confuciusornithiforms evolved higher rates of yolk deposition in parallel with the neornithine lineage. The preserved soft tiss...

Enantiornithes are the most successful clade of Mesozoic birds. Here, we describe a new enantiornithine bird, Cruralispennia multidonta gen. et sp. nov., from the Protopteryx-horizon of the Early Cretaceous Huajiying Formation of China. Despite being among the oldest known enantiornithines, Cruralispennia displays derived morphologies that are unex...

Description of morphological character used in the phylogenetic analysis (from Wang et al. 2015)

The six most parsimonious trees resultant from the phylogenetic analysis.

Dataset of 262 morphological characters for the 59 taxa included in the phylogenetic analysis.

Supplementary Figures, Supplementary Tables, Supplementary Notes and Supplementary References

Significance We report fossil evidence of feather structural protein (beta-keratin) from a 130-My-old basal bird ( Eoconfuciusornis ) from the famous Early Cretaceous Jehol Biota, which has produced many feathered dinosaurs, early birds, and mammals. Multiple independent molecular analyses of both microbodies and associated matrix recovered from th...

The Callovian–Lower Kimmeridgian Kamar-e-Mehdi Formation of the western Tabas Block, part of the Central-East Iranian Microcontinent, represents the fill of an extensive carbonate shelf lagoon situated between a barrier carbonate platform in the east and the uplifted Yazd Block in the west. In the course of its development, the shelf lagoon experie...

Three continuous cores acquired in the Sihetun area of Liaoning Province, famous for feathered non-avian dinosaurs of the Jehol Biota, reveal the stratigraphic and facies relationships of the divisions of the Early Cretaceous Yixian and underlying ?Jurassic-Early Cretaceous Tuchengzi formations. Based on these cores, we propose a modified lithostra...

In this study, we describe a new occurrence of the well preserved freshwater bivalve Trigonioides (Trigonioides) quadratus from Lazha, Baingoin County, Tibet. It suggests an Early Cretaceous (Aptian—Albian, most likely Aptian) age for the fossil-yielding sediments, which can now be correlated to the Duoba Formation (equal to the lower part of the L...

Bivalves are comparatively rare elements of the benthic faunas of Jurassic and Early Cretaceous lakes of northeastern China. In the past, Arguniella and Sphaerium have been regarded as belonging to the communities that populated the offshore areas of lake Sihetun, represented by the Lower Cretaceous Yixian Formation of western Liaoning. A detailed...

Based on newly collected material from the Lower Cretaceous Yixian and Jiufotang formations, twenty-one ostracod species belonging to 12 genera are described, including: Yumenia? acutiuscula, Yumenia? sp., Scabriculocypris pingquanensis, Limnocypridea grammi, Candona praevara, Candona sp., Cheilocypridea trapezoidea, Rhinocypris jurassica, Rhinocyp...

Fossil eggs of clam shrimps (Spinicaudata) are rare and little attention has been paid to the study of their shape and microstructures. Here, we report the discovery of exceptionally preserved three-dimensional eggs from numerous specimens of Eosestheria elliptica Chen, 1976 from the lacustrine Early Cretaceous Yixian Formation in western Liaoning,...

In contrast to the numerous excellently preserved arthropods, vertebrates and plants from the Mesozoic lacustrine fossil lagerstätten of northeastern China, which have calcium phosphate or organic skeletons, the preservation of taxa with a calcareous skeleton is fairly poor. Here we investigate, using a scanning electron microscope and energy dispe...

The wings of birds and their closest theropod relatives share a uniform fundamental architecture, with pinnate flight feathers as the key component. Here we report a new scansoriopterygid theropod, Yi qi gen. et sp. nov., based on a new specimen from the Middle-Upper Jurassic period Tiaojishan Formation of Hebei Province, China. Yi is nested phylog...

Significance Geological records of paleoclimate provide the only constraints on Solar System orbital solutions extending beyond the ∼50-Ma limit imposed by chaotic diffusion. Examples of such constraints are coupled high and low latitude, Triassic–Jurassic (∼198–202 Ma) sedimentary cyclicity in coal-bearing outcrops from the ∼60° N-paleolatitude Ju...

Little is known about the palaeoenvironments of the Early Cretaceous lakes of western Liaoning. Uncertainties exist especially about the water depth, water temperatures and annual temperature fluctuations. Here, we analyse the preservation of the most abundant fish of the lakes, the teleost Lycoptera, articulated skeletons of which occur in large c...

The Early Cretaceous ostracod fauna in western Liaoning is divided into eight successive ostracod assemblages. These assemblages have provided information about age constraint of relevant nonmarine Early Cretaceous strata: Yixian Formation-Hauterivian to Barremian, probably up to Aptian; Jiufotang Formation-Barremian to Aptian; Fuxin Formation-Apti...

The taphonomic pathways of "Ephemeropsis trisetalis'' nymphs (mayfly larvae) were systematically investigated based on fossils of different preservational types, collected during three high-stratigraphic-resolution (mm to cm) excavations in the Lower Cretaceous Yixian Formation in the Sihetun area of western Liaoning, China. All fossils studied are...

Globally, the Jurassic cemented ostreid bivalves from northern Tibet, SW China, have a pan-tropical distribution pattern between palaeolatitudes of 60° South and North. Ostreid bivalves have tiny to large larvae, and nearly all of them have a cemented mode of life during their adult stage. The distribution pattern and the habits of the Jurassic ost...

There are abundant nonmarine Cretaceous deposits around the globe, but it is difficult to correlate the nonmarine strata within the international chronostratigraphic framework chart, which was established based on marine rocks and fossils. Fortunately, in the Lower Cretaceous of eastern Asia, there are both alternating nonmarine–marine sections and...

The Kamar-e-Mehdi Formation (Callovian – Oxfordian) is the fill of a shelf lagoon situated in the western and central parts of the so-called Tabas Block for a N-S distance of 200-300 km. From the predominantly fine-grained carbonates, which in the depocenter reach more than 1000 m in thickness, 69 taxa of bivalves are described, which differ greatl...

Sedimentary properties of the fossil-bearing deposits of Lake Sihetun (Yixian Formation, Lower Cretaceous) were investigated on a high-resolution, sub-millimetric scale. Data were obtained from three excavations and 50 thin-sections. Lake evolution is subdivided into four phases, of which Phases 2 and 3 provided suitable conditions for excellent fo...

The brackish-water bivalve WaagenopernaTokuyama, 1959 is reported from the Lower Jurassic Badaowan Formation at four localities, along the southern margin and western margin of the Junggar Basin. Taphonomic features recorded in the field indicate that it occurs in autochthonous or parautochthonous assemblages. The autecology of Waagenoperna therefo...

Based on newly collected materials from the Lower Triassic Feixianguan Formation of Xiongwu section in Xingyi, Guizhou and the Ximatang Formation of Ximatang section in Qiubei, Yunnan, southern China, nine species belonging to seven genera are described. Two bivalve assemblages are recognized and regionally correlated in South China. The bivalve as...

The Early Cretaceous Yixian Formation at Sihetun, Beipiao, western Liaoning, northeastern China, is well-known for yielding diverse and excellently preserved fossils of the Jehol Biota. The lower unit of Yixian Formation, dominated by lacustrine deposits, is rich in concentrations of two freshwater bivalves: Sphaerium anderssoni and Arguniella vent...

Pan, Y., Sha, J., Fürsich, F.T., Wang, Y., Zhang, X. & Yao, X. 2011: Dynamics of the lacustrine fauna from the Early Cretaceous Yixian Formation, China: implications of volcanic and climatic factors. Lethaia, Vol. 45, pp. 299–314. The taphonomy and palaeoecology of the famous Lower Cretaceous Jehol biota of northeastern China are two of its least r...

: The Triassic–Jurassic (Tr–J) boundary marks a major extinction event, which (∼200 Ma) resulted in global extinctions of fauna and flora both in the marine and terrestrial realms. There prevail great challenges in determining the exact location of the terrestrial Tr–J boundary, because of endemism of taxa and the scarcity of fossils in terrestrial...

The Sichuan Basin is geographically located in southwestern China, and is one of the famous large inland basins of China, showing great significance on the geoscience studies in China. The Mesozoic strata are well developed and continuously cropped out in the Sichuan Basin, including marine and non-marine Triassic to Cretaceous sequences. It is a v...

The Sichuan Basin is geographically located in southwestern China, and is one of the famous large inland basins of China, showing great significance on the geoscience studies in China. The Mesozoic strata are well developed and continuously cropped out in the Sichuan Basin, including marine and non-marine Triassic to Cretaceous sequences. It is a v...

The diagnosis of the Middle Jurassic spinicaudatan genus Shizhuestheria is revised following the re-examination under a scanning electron microscope of a type specimen from Yanxi of Shizhu, and the newly collected specimens from Xintiangou of Chengjiang Town, Beibei, Chongqing. Small-sized reticulations occur not only in the middle-sized reticulati...

A comparative analysis of Late Jurassic-Early Cretaceous strata have been done for the Sanjiang-Middle Amur basin, a coal- and oil-bearing area spanning the eastern Heilongjiang of northeastern China and southeastern Far East of Russia. On the basis of various fossils occurring in the formations, particularly by means of the Tithonian-Valanginian i...