Saurischian track assemblages from the Lower Cretaceous Shenhuangshan Formation in the Yuanma Basin,Southern China

Cretaceous dinosaur tracks from Hunan Province are historically significant as the basis for three ichnotaxa: Xiangxipus chenxiensis, Xiangxipus youngi, and Hunanpus jiuquwanensis all representing theropodan tracks, described from a single site in 1982. Although the type locality has since been destroyed, the type specimen and replicas remained available for restudy in 2006, when paratype Hunanpus tracks and sauropod footprints were described from a second, nearby locality. Material from both localities is here re-described in detail. It is proposed that while Xiangxipus chenxiensis can be regarded as a distinct ichnospecies, probably representing an ornithomimid trackmaker, Xiangxipus youngi cannot be accommodated in the same ichnogenus. We consider it similar to the ichnogenus Wupus from the Lower Cretaceous of Sichuan Province, and therefore of possible avian affinity. We also find no justification for regarding Hunanpus jiuquwanensis as generically distinct from the widespread ichnogenus Grallator, and therefore rename it Grallator jiuquwanensis comb. nov. The Hunan track record is generally consistent with the sparse record of theropod skeletal remains in the province, but adds evidence of sauropods that was previously lacking.     

Small scale scrapes suggest avian display behavior by diminutive Cretaceous theropods

A set of about 25 diminutive sub-parallel scrapes in the Cretaceous Haman Formation of South Korea fit the morphology of the small theropod track Minisauripus which is also known from this formation. The scrapes are interpreted as evidence of display behavior, and suggest that the trace maker was an adult engaged in avian-like courtship behavior. Although avian theropods are also known from this formation, the scrapes are inconsistent with their foot morphology. Although large theropod scrapes have been interpreted as evidence of display behavior they are only known from North America. Thus, the scrapes described here are the first reported from Asia, and the first interpreted as evidence of display behavior in such a diminutive species.     

The first fossil Perilestidae (Odonata: Zygoptera) from mid-Cretaceous Burmese amber

Palaeoperilestes electronicus gen. et sp. nov. is the first perilestid damselfly described from mid-Cretaceous Burmese amber. This new damselfly can be attributed to the family Perilestidae by the midfork being distal of the subnodus and the base of IR2 quite near to the base of RP2, both features found in the extant genera Perilestes and Perissolestes. Palaeoperilestes electronicus gen. et sp. nov. has a strongly zigzagged IR1, however, differing from Perilestes and Perissolestes which have a straight IR1. The discovery not only adds to the diversity of damselflies in Burmese amber, but also puts the origin of Perilestidae back to at least the mid-Cretaceous.     

Cranial anatomy of Pholidosaurus purbeckensis from the Lower Cretaceous of France and its bearing on pholidosaurid affinities

New and nearly complete cranial remains of Pholidosaurus purbeckensis are described on the basis of specimens recovered from the Berriasian locality of Cherves-de-Cognac, France. Two skulls, associated mandibles and a set of dorsal osteoderms are available and allow a refinement of the anatomy of the genus, known otherwise from coeval deposits in Germany and England. Because of its longirostrine morphology, convergent with other crocodylomorph lineages, the phylogenetic relationships of Pholidosaurus are likely to be affected by Long Branch Attraction problems. Various tests of removing/excluding longirostrine lineages confirm that Dyrosauridae have a labile position and that their affinities with Pholidosauridae are weakly supported. Results from comparative anatomy and phylogenetic analyses recover Pholidosaurus as the basalmost member of Pholidosauridae, a group closely related to Goniopholididae. Pholidosaurus is recovered together with abundant remains of Goniopholis and with more limited remains of Theriosuchus. The paleoecology of Pholidosaurus and more generally, of Pholidosauridae, is discussed.     

Carbon-isotope records of the Early Jurassic (Toarcian) oceanic anoxic event from the Valdorbia (Umbria–Marche Apennines) and Monte Mangart (Julian Alps) sections: palaeoceanographic and stratigraphic implications

The Toarcian oceanic anoxic event ( ca 183 Ma) coincides with a global perturbation marked by enhanced organic carbon burial and a general decrease in calcium carbonate production, probably triggered by changes in the composition of marine plankton and elevated carbon dioxide levels in the atmosphere. This study is based on high-resolution sampling of two stratigraphic successions, located in Valdorbia (Umbria–Marche Apennines) and Monte Mangart (Julian Alps), Italy, which represent expressions of the Toarcian oceanic anoxic event in deep-water pelagic sediments. These successions are characterized by the occurrence of black shales showing relatively low total organic carbon concentrations (compared with coeval strata in Northern Europe), generally < 2%, and low hydrogen indices. On this basis, they are similar to other Toarcian black shales described from the Tethyan region. The positive and negative carbon-isotope records from the two localities permit a high-resolution correlation such that ammonite biostratigraphy information from Valdorbia can be transferred to those parts of the Monte Mangart section that lack these fossils. Spectral analyses of δ¹³C_org values and of CaCO₃ percentages from the sedimentary records of both the Valdorbia and Monte Mangart sections reveal a strong cyclic pattern, best interpreted as an eccentricity signal which hence implies a duration of ca 500 kyr for the negative carbon-isotope excursion. Based on the carbon-isotope curves obtained, the high-resolution correlation between the Italian successions and a section in Yorkshire (Northern Europe) confirms the supposition that the apparent mismatch between the dating of the Toarcian oceanic anoxic event in the Boreal and Tethyan realms is an artefact of biostratigraphy.     

重庆合川自流井组植物化石的发现

描述了发现于合川自流井组东岳庙段的三种似木贼植物化石,即Equisetites flus Harris,E．1ateralis(Phillips)和E．columnaris(Brongn．)Phillips。标本保存良好,依据植物和双壳类化石的分布关系,提出自流井组东岳庙段的时代为早侏罗世晚期至中侏罗世早期。同时,分析了东岳庙段的岩相特征和沉积环境。     

The palaeoenvironment associated with a partial Iguanodon skeleton from the Upper Weald Clay (Barremian, Early Cretaceous) at Smokejacks Brickworks (Ockley, Surrey, UK), based on palynomorphs and ostracods

In 2001 a partial skeleton of an Iguanodon was discovered in the Upper Weald Clay (Barremian, Early Cretaceous) at Smokejacks Brickworks near Ockley, Surrey, UK. When the dinosaur was excavated, a detailed stratigraphic section was logged and 25 samples taken for palynological and micropalaeontological (ostracod and megaspore) analysis, including a detailed sample set of the dinosaur bed itself. Qualitative and quantitative analysis of the palynoflora revealed rich and well-preserved non-marine assemblages of pollen and spores, including early angiosperms, and freshwater green algae. Four types of angiosperm pollen are described and assigned to the genus Retimonocolpites Pierce, 1961, but left in open nomenclature. Some marine elements such as dinoflagellate cysts are identified as the result of reworking of Middle and Upper Jurassic sediments. The pollen/spore assemblages depict a vegetational change from principally gymnosperm-dominated assemblages at the base to principally pteridophyte-dominated assemblages at the top of the section. The dinosaur bed shows a pteridophyte-dominated assemblage, with a significantly high amount of the freshwater green alga Scenedesmus novilunaris He Cheng-quan et al., 1992. Samples close to the dinosaur bed yielded the first useful ostracod finds from Smokejacks Brickworks: well-preserved assemblages containing Cypridea clavata (Anderson, 1939), Damonella cf. pygmaea (Anderson, 1941), Stenestroemia cf. cressida Anderson, 1971 and Stenestroemia sp. A, and fragments and damaged valves of a thin-shelled ostracod, possibly belonging to Mantelliana Anderson, 1966. Those identified as Cypridea clavata show a wide range of morphological variety and in opposition to Anderson's (1967, 1985) taxonomic scheme, which would assign them to up to five different taxa, they are considered to be intraspecific variants of a single species. The possibilities and limitations of age determination of the Wealden sediments using palynomorphs and ostracods are discussed; distinct forms of early angiosperm pollen, together with the ostracod fauna, are consistent with an early Barremian age. Pollen and spores are discussed in terms of their parent plants and the reconstruction of vegetation and palaeoclimate. Palynology and ostracods give evidence for temporary freshwater conditions at the time when the Iguanodon died and the carcase was buried.     

塔里木盆地白垩系巴什基奇克组陆相砂岩中碳酸盐岩碎屑特征及其地质意义

从储层的微观特征入手,通过各种实验分析认为:塔里木盆地库车坳陷—塔北隆起白垩系巴什基奇克组砂岩中的碳酸盐岩碎屑有五大特征,明显区别于胶结物:粒度粗,一般比其周围的原生孔隙大,磨圆好（个别有晚期压溶现象）,轮廓清晰;在砂岩中分布相对均匀,非斑块状;碎屑中存在古生物的化石且多为粉细晶;胶结物（铁方解石、铁白云石）多附着在碎屑边缘呈加大边出现,染色有明显变化;灰岩、云岩碎屑在阴极射线下发桔黄色光。碳酸盐岩碎屑的分布具有近源粒度粗、含量低、分选差、磨圆差、均质差;远源粒度细、含量高、分选好、磨圆好、均质好;浅埋粒形好、深埋压溶强的特征。物源区发育的古老碳酸盐岩地层,干旱、炎热、近咸化的古气候、古水体环境,近源快速堆积的古地理环境是碳酸盐岩碎屑的主要成因。碳酸盐岩碎屑的识别和量化具有重要的地质意义:其减孔效应明显低于胶结物,可有效解释高含量碳酸盐高物性砂岩成因,其分布是界定沉积物源区的有效证据。     

长江三峡地区的夷平面在宜昌地区白垩纪—第四纪沉积物中的反映

通过对湖北宜昌地区白垩纪-第四纪沉积演化的研究,发现存在3个明显的沉积旋回,每个旋回由下部颗粒粗大的砾石层和上部颗粒较细小的粉砂-泥质层组成。3个沉积旋回对应了宜昌以西三峡地区3期构造演化旋回,同时反映了三峡地区3期夷平面的存在。结合前人研究结果、古生物化石和对第四系善溪窑组的测年数据,认为3期夷平面形成时代分别为:鄂西期夷平面形成于白垩纪晚期-古近纪的始新世,山原期夷平面形成于上新世-早更新世初,云梦期夷平面形成于早更新世末-中更新世早期。     

Evolution of species diversity of Cretaceous radiolarians from high-latitude paleobiochores

Cretaceous radiolarians of the Boreal regions are considered. Their minimal diversity and low abundance are recorded in stratigraphic intervals corresponding to anoxic events. Paleogeographic and ecostratigraphic distribution trends of Cretaceous radiolarians are established for families Heliodiscidae, Prunobrachidae, Pseudoaulophacidae and some others. The most significant turnovers in evolution of radiolarians are confined to the latest Jurassic-earliest Cretaceous, Albian-Cenomanian, Cenomanian-Turonian, terminal Santonian-earliest Campanian transitions and to the terminal Late Cretaceous.