Decouverte de Septorella brachycera grambast et de Septorella ultima Grambast (Charophytes,Clavatoracees) dans le Maestrichtien superieur des Petites Pyrenees. Consequences stratigraphiques

The discovery of an assemblage of Clavatoraceae including Septorella brachycera and S. ultima in the “Marnes d'Auzas” (upper Maestrichtian) of the Petites Pyrénées constitutes the first element of comparison between the upper Cretaceous of the Petites Pyrénées and Provence, but creates a problem with regard to the subdivision of the provencial Rognacian, based, in part, on the superposition of these two species.     

Parataxonomy and palaeobiogeographic significance of dinosaur eggshell fragments from the Upper Cretaceous strata of the Cauvery Basin,South India

Abstract

In the past, fossilised dinosaur eggshells have been extensively documented from the Upper Cretaceous Lameta Formation of Central India and as many as nine oospecies are known at present from this formation. Compared to this, only one dinosaur oospecies has been described from the Cretaceous succession of the Cauvery Basin. However, the first fossil egg from India, identified as a chelonian egg, was documented from the Aptian – Albian Karai Formation of the Cauvery Basin in 1957. Following this, a solitary titanosaurid dinosaur egg was described from the Upper Cretaceous (Lower Maastrichtian) Kallankuruchhi Formation, Cauvery Basin in 1996. More recently, we have recovered isolated eggshell fragments from the marine part of the Upper Cretaceous (Late Maastrichtian) Kallamedu Formation. Based on eggshell morphology, microstructure and ultrastructure, these eggshell fragments are assigned to the oospecies Fusioolithus baghensis. The new find from the Cauvery Basin is important from palaeobiogeographic point of view as the oofamily Fusioolithidae is found in the Upper Cretaceous strata of India, France, Argentina and Morocco. Based on the common occurrence of similar oospecies in South America, Africa, Europe and India, a Late Cretaceous palaeobiogeographic connection between India and South America as well as Europe via Africa is suggested.     

Titanosaur eggshells from the Tremp Formation (Upper Cretaceous,Southern Pyrenees,Spain)

Hundreds of megaloolithid eggshells have been found at the Costa de la Coma site (Tremp Fm, South-Central Pyrenees, Spain), the microstructural features (spherulitic eggshell units, thickness, ornamentation and pore system) of which agree with the Megaloolithus oogenus diagnosis. Comparisons with other megaloolithids from the Tremp Basin, southern France and South America, however, showed that these eggshells share many features with the South American oospecies Megaloolithus patagonicus. A cladistic analysis of the qualitative eggshell features of the main dinosaur taxa was performed. The results grouped the Costa de la Coma eggshells with Megaloolithus patagonicus, forming a clade separated from other megaloolithids, and revealed a polytomy of megaloolithids (associated with sauropods) and spheroolithids (associated with hadrosaurs). The finding of Megaloolithus cf. patagonicus in the Tremp Fm agrees with skeletal evidence provided by four indeterminate titanosaur forms from the Formation's late Cretaceous deposits. Other Megaloolithus oospecies of the Tremp Fm may belong to hadrosaurs, the skeletal remains of which are also abundant in the Tremp Basin.     

Sediment and eggshell interactions: using abrasion to assess transport in fossil eggshell accumulations

Recent excavation at the Late Cretaceous Egg Mountain locality in Montana revealed abundant Spheroolithus eggshell fragments. The depositional history of the fragments is problematic due to the vertical dispersal of eggshell in homogeneous mudstone. The results of previous studies assessing eggshell transport are based on thin, modern eggshell occurring on well-defined horizons. Therefore, the assessment of depositional history required a different method. Chicken (Gallus gallus domesticus) and ostrich (Struthio camelus) eggshells were placed in a tumbler with water and quartz sand for 168–504 h to simulate transport. The resulting wear on these fragments, revealed under scanning electron microscope, was compared to unabraded eggshell. In addition, the modern eggshell was compared to fossil eggshells from a nesting site, crevasse splay and channel deposits, and Egg Mountain. Fossil eggshells from high-energy paleoenvironments display similar edge rounding to modern eggshell placed in the tumbler. In contrast, eggshell from Egg Mountain lacked edge rounding and resembled fossil eggshell from a nesting site and unabraded modern eggshell, suggesting that the Egg Mountain locality represents a parautochthonous assemblage. This study indicates that sediment interaction leaves distinct patterns of abrasion on eggshell, which may be useful for assessing transport of eggshell at fossil localities.     

江西萍乡地区晚白垩世副蜂窝蛋类一新蛋种

依据采自江西省萍乡地区上白垩统周田组的恐龙蛋化石,记述了蜂窝蛋科(Faveoloolithidae)副蜂窝蛋属(Parafaveoloolithus)一新蛋种。材料包括一枚较完整的蛋和若干破碎蛋壳。根据蛋壳弦切面呈蜂窝状结构,径切面蛋壳中、上部蛋壳局部呈现由6~10个以上壳单元成群聚集一起等特征,将其订为一新蛋种——萍乡副蜂窝蛋(Parafaveoloolithus pingxiangensis oosp.nov.)。     

A new peculiar dinosaur egg,Sankofa pyrenaica oogen. nov. oosp. nov. from the Upper Cretaceous coastal deposits of the Aren Formation,south‐central Pyrenees,Lleida, Catalonia,Spain

Abstract: A new type of small, ovoid dinosaur egg, Sankofa pyrenaica oogen. nov. oosp. nov., with a prismatic type eggshell is described from upper Cretaceous (upper Campanian–Maastrichtian) deposits of the Montsec area, South Pyrenean Central Unit, Lleida, Catalonia, Spain. This egg type was sub‐vertically laid in only two rich monospecific sites of a single stratigraphic layer from coastal deposits of the Aren Formation, interpreted as an emerged beach ridge of a barrier island – lagoon depositional system. The size and shape of these eggs with their asymmetric poles are roughly similar to modern hen eggs, which is unusual in the Cretaceous fossil egg record. Its phylogenetic position clusters with bird and Troodontid eggs. A morphospace analysis of egg shapes shows the similarity of the new egg to a Campanian fossil bird egg from Argentina, both being intermediate between modern‐bird eggs and extinct nonavian theropod eggs. However, the eggshell microstructure of Sankofa pyrenaica differs from that of bird eggs in its incipient squamatic texture. It has a peculiar pattern of interlocking small crystals in the middle of the palisade layer, instead of the thick squamatic structure commonly present in modern avian eggshells. This new egg type is attributed to a small theropod, probably with a single oviduct like birds and whose mosaic distribution of features is a combination between that of birds and nonavian theropods. This enhances the arguments supporting the close phylogenetic relationships between both groups.     

Polar dinosaurs and the question of dinosaur extinction: a brief review

Although the physiology of dinosaurs is still a matter of controversy, there is no doubt that some of them were able to live in environments that were too cold for ectothermic reptiles, as shown by discoveries of Jurassic and Cretaceous polar vertebrate assemblages which contain dinosaurs but lack turtles and crocodiles. This adaptation of dinosaurs to cool climates invalidates hypotheses according to which dinosaur extinction at the end of the Cretaceous was a result of long-term climatic cooling. The pattern seen at the K/T boundary, with the disappearance of dinosaurs and the survival of ectothermic reptiles, is completely different from that seen in Arctic regions during the Late Cretaceous, where ectotherms disappeared, while dinosaurs subsisted, during cooler periods. The idea of an intense and enduring cold spell at the K/T boundary, caused by the Chicxulub impact, is extremely unlikely in view of the pattern of vertebrate extinction (survival of endotherms, extinction of dinosaurs). Models of environmental events following the impact must take this palaeontological constraint into consideration.     

浙江天台晚白垩世巨型长形蛋科一新属及巨型长形蛋科的分类订正

浙江天台盆地上白垩统赤城山组发现的巨型长形蛋类可鉴定为西峡巨型长形蛋(Macroelongatoolithusxi xiaensis)和一新蛋属、新蛋种——桥下巨型纺锤蛋(Megafusoolithus qiaoxiaensis oogen.etoosp.nov.)。西峡巨型长形蛋此前仅发现于河南西峡盆地,其特征为个体巨大(35cm),蛋壳外表面具瘤点状纹饰,蛋壳锥体层与柱状层界线明显,呈波浪形,锥体层与柱状层厚度之比为1:5—1:2。已记述的产自天台的张氏巨型长形蛋(M.zhangi)和产自河南西峡盆地的西峡长圆柱蛋(Longiteresoolithus xixiaensis)均为西峡巨型长形蛋的同物异名。桥下巨型纺锤蛋的特征包括蛋壳中部外表面具有棱脊状纹饰,蛋壳锥体层与柱状层界线不明显,二者厚度之比近1:3,这些特征区别于巨型长形蛋属。目前已知巨型长形蛋科仅包含巨型长形蛋属和巨型纺锤蛋属,订正的科征为:蛋化石巨大,长径大于35cm;蛋长形,两端大致对称,长宽之比约为3:1;蛋化石在蛋窝中一般两枚为一组,呈单层圆环状排列,蛋窝直径近3m;蛋壳外表面具瘤点状或棱脊状纹饰,蛋壳由锥体层与柱状层组成。这些特征明显区别于其他类型的蛋化石,因此它们代表了一个独立的蛋科:巨型长形蛋科(Macroelongatoolithidae)。     

Theropod dinosaurs from the Albian–Cenomanian Wayan Formation of eastern Idaho

The record of terrestrial vertebrates in the upper Albian to Cenomanian Wayan Formation of Idaho is sparse, with most fossils recovered belonging to the small orodromine neornithischian Oryctodromeus cubicularis and the maniraptoran ootaxon Macroelongatoolithus carlylei. Here we report on a diversity of theropod forms now recognised from various isolated teeth, vertebrae, eggs and eggshell. Theropods recognised from isolated teeth include a large possible tyrannosauroid, a small tyrannosauroid, dromaeosaurids, and indeterminate theropods. A possible neovenatorid and indeterminate theropods are recognised from isolated vertebrae. A giant oviraptorosaur is indicated by the presence of rare eggs and common eggshell accumulations referred to Macroelongatoolithus. While these remains are admittedly meager, their presence indicates that a substantial diversity of theropods existed in the Albian to Cenomanian environments of southeastern Idaho. The Wayan theropod assemblage is among the most diverse reported for this time period in North America, and represents a transitional assemblage resembling that of the later Late Cretaceous.     

内蒙古巴音满都呼晚白垩世棱齿龙蛋化石的发现

本文记述的恐龙蛋化石标本,采自内蒙古乌拉特后旗巴音满都呼上白垩统牙道黑达组中。蛋化石在蛋窝中排列的方式和蛋壳的显微结构特征与北美发现的含有可鉴定为棱齿龙胚胎骨骼的蛋化石基本相似,但还有一些差别,如蛋壳外表面不具纵向细纹,柱状层中鱼骨型纹饰不明显等。因此,应为棱齿龙科中另一新的属种代表。     

Fossile Reptil-Eischalen (Chelonia,Crocodilia, Dinosauria) aus dem unteren Barremium von Galve (Provinz Teruel,SE-Spanien)

The Lower Cretaceous vertebrate bearing sediments of Galve (province of Teruel, SE Spain) have yielded some hundred fossil eggshell fragments, all slightly diagenetically altered. Concerning their microstructure, an assignment of the material to different taxa of reptiles was possible. The eggshell assemblage of Galve consists of a-c) three types of chelonian eggshells, one of them probably representing the subfamily Batagurinae, which would extend this taxon back into the Lower Cretaceous, d) the oldest known crocodilian eggshells, with lacunae systems on the outer surface, comparable to Recent taxa, and e-f) two different types of dinosaurian eggshells. In correspondence to the suggested fluviatile paleoenvironment of Galve, the fossil eggshells described herein are fragmented and represent mostly turtles and crocodiles.     

Structure of fossil dinosaur eggshell from the Aix Basin,France

At least four types of dinosaur eggshell are distinguished among samples of fossil eggshell from Late Cretaceous deposits of southern France. Recognition is based on shell microstructure, porosity, and shell thickness. Estimated values of water vapour conductance for these dinosaur eggshells are much greather than predicted for avian eggs, suggesting that the eggs were incubated under conditions of high humidity, such as would occur underground.     

A new oospecies of Similifaveoloolithidae from the Xiuning Basin,Late Cretaceous of Anhui,China

Well-preserved dinosaur eggs from the Cretaceous Huizhou Formation in the Xiuning Basin, Anhui Province, China, are analysed in this paper. We describe a new oospecies, Similifaveoloolithus qiyunshanensis, based on several distinct characters of external morphology, size, eggshell thickness, and internal microstructure. Radial sections of this new oospecies show branched eggshell units with a fused layer near the outer surface, while numerous irregular pores and cones constitute a honeycomb pattern in tangential sections. The discovery of S. qiyunshanensis expands the distribution of Similifaveoloolithidae dinosaur eggs in China and provides new fossils for researching dinosaur eggshell formation mechanisms which are different from those of the currently known oofamilies. The dinosaur-egg-bearing strata in the Huizhou Formation have been dated to the early Late Cretaceous (Cenomanian-Turonian) on the basis of a similar dinosaur egg assemblage in the Tiantai Basin in Zhejiang Province. The eggs described in this paper are thought to have been laid in a buried nest while enrichment of trace elements in eggshells may have been caused by their ingestion into the body of the dinosaur producer. We suggest that the paleoclimate of this habitat was semi-arid to arid and that this environment was favourable for the preservation of eggs.http://zoobank.org/LSIDurn:lsid:zoobank.org:pub:9D63A51F-5A4B-4249-901D-42A33E9FA933     

The oldest known avian eggshell,Plagioolithus fukuiensis,from the Lower Cretaceous (upper Barremian) Kitadani Formation,Fukui, Japan

Fossil record of Early Cretaceous birds may be geographically biased, and eggs and eggshells predating the Late Cretaceous were unknown. Here, we report the oldest known bird eggshell (FPDM-V-0009175) collected from the upper Barremian Kitadani Formation in Katsuyama City, Fukui, Japan. The Kitadani Formation likely represents fluvial environments. Thin-section and scanning electron microscope analyses revealed diagnostic characters of FPDM-V-0009175, including thin (0.44 mm) shell, smooth external surface, non-branching and narrow pore canals with relatively constant width, three structural layers, oblique crystal orientation from vertical in the external layer, and mammillary to continuous to external layer thickness ratio of 1:1:0.44. These characters allow assignment of FPDM-V-0009175 to a new oogenus and oospecies, Plagioolithus fukuiensis, and suggest it belonging to a bird. The three-layered eggshell structure is seen in extant and extinct birds, Plagioolithus fukuiensis, and non-avian theropods. Therefore, such structure may be plesiomorphic among theropods, appearing in the late Barremian or earlier. As the first bird body fossil from the Mesozoic of Japan, Plagioohlithus fukuiensis suggests extensive distribution and abundance of birds in the Barremian East Asia. Plagioolithus fukuiensis indicates that the late-Barremian birds inhabited and reproduced in the fluvial environments within a basin located along the eastern margin of the Asian continent.http://www.zoobank.org/urn:lsid:zoobank.org:pub:90A8CCE8-57F7-473C-855C-B2CCE2BBD1A2     

Eggshell permeability: a standard technique for determining interspecific rates of water vapor conductance

Typically, eggshell water vapor conductance is measured on whole eggs, freshly collected at the commencement of a study. At times, however, it may not be possible to obtain whole fresh eggs but rather egg fragments or previously blown eggs. Here we evaluate and describe in detail a technique for modern laboratory analysis of eggshell conductance that uses fragments from fresh and museum eggs to determine eggshell water vapor conductance. We used fresh unincubated eggs of domesticated chickens (Gallus gallus domesticus), ducks (Anas platyrhynchos domesticus), and guinea fowl (Numida meleagris) to investigate the reliability, validity, and repeatability of the technique. To assess the suitability of museum samples, museum and freshly collected black-headed gull eggs (Larus ridibundus) were used. Fragments were cut out of the eggshell from the blunt end (B), equator (E), and pointy end (P). Eggshell fragments were glued to the top of a 0.25-mL micro test tube (Eppendorf) filled with 200 μL of distilled water and placed in a desiccator at 25°C. Eppendorfs were weighed three times at 24-h intervals, and mass loss was assumed to be a result of water evaporation. We report the following results: (1) mass loss between weighing sessions was highly repeatable and consistent in all species; (2) the majority of intraspecific variability in eggshell water vapor conductance between different eggs of the same species was explained through the differences in water vapor conductance between the three eggshell parts of the same egg (B, E, and P); (3) the technique was sensitive enough to detect significant differences between the three domestic species; (4) there was no overall significant difference between water vapor conductance of museum and fresh black-headed gull eggs; (5) there was no significant difference in water vapor conductance for egg fragments taken from the same egg both between different trials and within the same trial. We conclude, therefore, that this technique is an effective way of measuring interspecific water vapor conductance from eggshell fragments and that museum eggs are a suitable resource for such work.     

浙江天台盆地晚白垩世网形蛋类新类型及网形蛋类的分类订正(英文)

记述了产自浙江省天台盆地的网形蛋类新材料,建立一新蛋属——拟网形蛋属(Paradictyoo lithusoogen.nov.),两个新蛋种:庒前拟网形蛋(Paradictyoolithus zhuangqianensis oogen.etoosp.nov.)和下西山拟网形蛋(P.xiaxishanensis oogen.et oosp.nov.)。在此基础上,重新系统描述其他已知4种网形蛋属成员的结构特征,并对网形蛋类的分类进行了订正:网形蛋属(Dictyoolithus)仅保留红坡网形蛋(D.hongpoensis Zhao,1994)一个蛋种;建立一新蛋属:原网形蛋属(Protodictyoolithus oogen.nov.),将发现于河南西峡盆地的内乡网形蛋(D.neixiangensis Zhao,1994)和发现于山东莱阳盆地的蒋氏网形蛋(D.jiangi Liu&Zhao,2004)分别修订为:内乡原网形蛋(修订种)(Protodictyoolithus neixiangensis(Zhao,1994)comb.nov.)和蒋氏原网形蛋(修订种)(P.jiangi(Liu&Zhao,2004)comb.nov.);此外,发现于吉林公主岭早白垩世的公主岭网形蛋(D.gongzhulingensis Wang et al.,2006)并不属于网形蛋类,而应归入似蜂窝蛋类(Similifaveoolithus),将其修订为公主岭似蜂窝蛋(修订种)(Similifaveoolithus gongzhulingensis(Wangetal.2006)comb.nov.)。     

Microstructural organization of the central nervous system in the harvestman Leiobunum japonicum (Arachnida: Opiliones)

Although the order Opiliones constitutes the third‐largest group of arachnids, this creature is still mysterious and has a rich unexplored field compared to what is known about insects and crustaceans. The order Opiliones is traditionally regarded as a close relative of mites, mainly because of morphological similarities in external body structure; however microstructural organization of the ganglionic neurons and nerves in the harvestman Leiobunum japonicum is quite similar to the central nervous system (CNS) in all extant arachnids. The CNS consists of a large neural cluster with paired appendicular nerves. The esophagus passes through the neural cluster and divides it into the upper supraesophageal ganglion (SpG) and the lower subesophageal ganglion (SbG). The dorsal part of the SpG has a quite condensed cell body compared with other parts of the CNS and has two main components, the protocerebrum and the cheliceral ganglion. The protocerebrum receives the optic nerves and has four main groups of neuropiles from the optic lobes, the superior central body, the lateral neuropils (corpora pedunculata) and the inferior neuropil. However, a pair of pedipalpal and four pairs of appendage nerves including several pairs of abdominal nerves arise from the nerve masses of the SbG.     

Crocodilian Nest in a Late Cretaceous Sauropod Hatchery from the Type Lameta Ghat Locality,Jabalpur, India

The well-known Late Cretaceous Lameta Ghat locality (Jabalpur, India) provides a window of opportunity to study a large stable, near shore sandy beach, which was widely used by sauropod dinosaurs as a hatchery. In this paper, we revisit the eggs and eggshell fragments previously assigned to lizards from this locality and reassign them to crocodylomorphs. Several features point to a crocodilian affinity, including a subspherical to ellipsoidal shape, smooth, uneven external surface, discrete trapezoid shaped shell units with wide top and narrow base, basal knobs and wedge shaped crystallites showing typical inverted triangular extinction under crossed nicols. The crocodylomorph eggshell material presented in this paper adds to the skeletal data of these most probably Cretaceous-Eocene dryosaurid crocodiles.     

The proteome of the insoluble Schistosoma mansoni eggshell skeleton

In schistosomiasis, the majority of symptoms of the disease is caused by the eggs that are trapped in the liver. These eggs elicit an immune reaction that leads to the formation of granulomas. The eggshell, which is a rigid insoluble structure built from cross-linked proteins, is the site of direct interaction between the egg and the immune system. However, the exact protein composition of the insoluble eggshell was previously unknown. To identify the proteins of the eggshell of Schistosoma mansoni we performed LC-MS/MS analysis, immunostaining and amino acid analysis on eggshell fragments. For this, eggshell protein skeleton was prepared by thoroughly cleaning eggshells in a four-step stripping procedure of increasing strength including urea and SDS to remove all material that is not covalently linked to the eggshell itself, but is part of the inside of the egg, such as Reynold’s layer, von Lichtenberg’s envelope and the miracidium. We identified 45 proteins of which the majority are non-structural proteins and non-specific for eggs, but are house-keeping proteins that are present in large quantities in worms and miracidia. Some of these proteins are known to be immunogenic, such as HSP70, GST and enolase. In addition, a number of schistosome-specific proteins with unknown function and no homology to any known annotated protein were found to be incorporated in the eggshell. Schistosome-specific glycoconjugates were also shown to be present on the eggshell protein skeleton. This study also confirmed that the putative eggshell protein p14 contributes largely to the eggshell. Together, these results give new insights into eggshell composition as well as eggshell formation. Those proteins that are present at the site and time of eggshell formation are incorporated in the cross-linked eggshell and this cross-linking does no longer occur when the miracidium starts secreting proteins.     

Crocodylomorph eggs and eggshells from the Adamantina Formation (Bauru Group), Upper Cretaceous of Brazil

Abstract: Compared with crocodylomorph body fossils, the record of fossil crocodiloid eggs is scarce and poorly understood, a gap partially attributed to their typically thin eggshell, which is not conducive to preservation. A remarkable new association of well‐preserved eggs and eggshells from the Adamantina Formation (Bauru Group, Upper Cretaceous) is described and compared to other known materials, while the significance of their unique oological features is discussed. These eggs constitute a new ootaxon, Bauruoolithus fragilis oogen. et oosp. nov., diagnosed by the following characteristics: elongate and elliptical egg with blunt ends; length‐to‐diameter ratio of 1:0.55; outer surface slightly undulating; shell thickness ranging from 0.15 to 0.25 mm; pore openings elliptical or teardrop‐shaped, ranging from 30 to 80 μm in diameter; and shell units wider than higher, with the interstices forming an obtuse triangle. Specimens of Bauruoolithus also show only slight signs of extrinsic degradation that, coupled with the evidence that some of them constitute hatched eggs, suggests that the egg‐laying taxon had a different pattern of egg incubation, in which the hatchling could break through the rather thin eggshell relatively easily and that the extrinsic degradation of the eggshell was not necessary. This contrasts with the pattern of incubation for all other known crocodylomorphs and crocodiloid eggs, where extrinsic degradation is a key component of the hatching process.