Stratigraphy of the upper cretaceous and lower tertiary strata in the Tethyan Himalayas of Tibet (Tingri area,China)

The 1500-m-thick marine strata of the Tethys Himalaya of the Zhepure Mountain (Tingri, Tibet) comprise the Upper Albian to Eocene and represent the sedimentary development of the passive northern continental margin of the Indian plate. Investigations of foraminifera have led to a detailed biozonation which is compared with the west Tethyan record. Five stratigraphic units can be distinguished: The Gamba group (Upper Albian - Lower Santonian) represents the development from a basin and slope to an outer-shelf environment. In the following Zhepure Shanbei formation (Lower Santonian - Middle Maastrichtian), outer-shelf deposits continue. Pebbles in the top layers point to beginning redeposition on a continental slope. Intensified redeposition continues within the Zhepure Shanpo formation (Middle Maastrichtian - Lower Paleocene). The series is capped by sandstones of the Jidula formation (Danian) deposited from a seaward prograding delta plain. The overall succession of these units represents a sea-level high at the Cenomanian/Turonian boundary followed, from the Turonian to Danian, by an overall shallowing-upward megasequence. This is followed by a final transgression — regression cycle during the Paleocene and Eocene, documented in the Zhepure Shan formation (?Upper Danian - Lutetian) and by Upper Eocene continental deposits. The section represents the narrowing and closure of the Tethys as a result of the convergence between northward-drifting India and Eurasia. The plate collision started in the Lower Maastrichtian and caused rapid changes in sedimentation patterns affected by tectonic subsidence and uplift. Stronger subsidence and deposition took place from the Middle Maastrichtian to the Lower Paleocene. The final closure of remnant Tethys in the Tingri area took place in the Lutetian.     

Late Cretaceous marine fossils and seawater incursion events in the Songliao Basin,NE China

The Songliao Basin is the largest non-marine oil-bearing basin in China. Because of the absence of substantial evidence, the hypothesis of seawater incursion events into the Songliao Basin remains controversial. The presence of marine fossils could provide direct proof to support this supposition. Here, we report new discoveries of foraminifera, calcareous nannofossils, brackish dinoflagellates, and other marine and brackish-water fossils to support the suggestion of seawater incursion events in the Songliao Basin. Relatively abundant benthic and planktonic foraminifera, calcareous nannofossils, marine and brackish-water dinoflagellates, fish, and bivalves have been discovered in Members 1 and 2 of the Nenjiang Formation, a few foraminifera and brackish-water dinoflagellates have been found in the lower Qingshankou Formation, and just a few brackish-water bivalves have been found in the uppermost Qingshankou Fm. Based on the presence of marine molecular fossils and other evidence, we suggest that relatively large seawater incursion events occurred during the sedimentation of the lower Nenjiang Fm., relatively smaller seawater incursions occurred during the deposition of the lower Qingshankou Fm., and possibly a very small seawater incursion occurred during the sedimentation of the uppermost Qingshankou Fm. These seawater incursion events in the Songliao Basin were controlled by regional tectonic activity, evolution of the palaeo Songliao Lake, and global sea level change. These periodic seawater incursions brought marine biota into the palaeo Songliao Lake.     

中国陆相侏罗、白垩系划分对比述评

对我国东北、西南和东南沿海地区目前常用的陆相侏罗、白垩系的划分、对比方案的精度及其与海相标准分阶的对比证据进行了扼要分析和述评 ,指出东北地区陆相白垩系序列可以划分出 13个组 ,其精度已赶上了海相白垩系 12个阶的标准 ,而且许多组已找到了将海陆相地层进行对比的联系化石分子 ,亦具备了陆相地层建阶的条件。同时认为我国中生代陆相地层划分对比表中以往很少表现出地层缺失 ,大多数地区似乎从下向上都存在一个完整的沉积序列 ,这是与陆相地层形成的实际不相符的 ,今后要进一步做工作。     

Inter-regional correlation of transgressions and regressions in the Cretaceous period

Well investigated platforms have been selected in each continent, and the history of Cretaceous transgressions and regressions there is concisely reviewed from the available evidence. The factual records have been summarized into a diagram and the timing of the events correlated between distant as well as adjoining areas.On a global scale, major transgressions were stepwise enlarged in space and time from the Neocomian, via Aptian-Albian, to the Late Cretaceous, and the post-Cretaceous regression was very remarkable. Minor cycles of transgression-regression were not always synchronous between different areas. Some of them were, however, nearly synchronous between the areas facing the same ocean.Tectono-eustasy may have been the main cause of the phenomena of transgression-regression, but certain kinds of other tectonic movements which affected even the so-called stable platforms were also responsible for the phenomena. The combined effects of various causes may have been unusual in the Cretaceous, since it was a period of global tectonic activity. The slowing down of this activity followed by readjustments may have been the cause of the global regression at the end of the Cretaceous.     

Mixed marine,brackish water and non-marine microfaunal association in the Inter-trappean beds (Early Palaeocene) of Jhilmili,Chhindwara district,Madhya Pradesh

Except for the east coast of Andhra Pradesh, the Deccan Inter-trappean sedimentary beds of Peninsular India have been long known to yield non-marine microfauna, mainly ostracods. These have been extensively described from different localities of Madhya Pradesh, Maharashtra, Karnataka, Andhra Pradesh, Gujarat and Rajasthan states. Occurrence of mixed microfaunal association of marine, brackish water and non-marine foraminifers and ostracods is being recorded from these beds from Jhilmili, Chhindwara district, Madhya Pradesh. It comprises at least two or more planktonic foraminifer species, and one brackish water and 17 non-marine ostracod species. The brackish water ostracod, Neocyprideis raoi (Jain, 1978) has been previously recorded in great profusion from the Inter-trappean beds of Duddukuru, West Godavari District, Andhra Pradesh, which have been assigned Early Palaeocene age (Khosla and Nagori, 2002). Presence of molt stages of the bulk of non-marine and brackish water ostracods in the Inter-trappean beds of Jhilmili is suggestive that they were inhabitants of low mesohaline inland pool/lake. The planktonic foraminifers were carried to this pool/lake by a marine transgression probably from the east coast of India through the Trans Deccan Straits.     

Moderation of Cretaceous transgressions by block tectonics: An example from the north and north-west of the Paris basin

Cretaceous transgressions in the epicontinental area of western Europe, and in particular in the Paris-London Basin, were controlled, to a large extent, by the eustatic rise of sea-level in direct relation to the creation of mid-oceanic ridges.On a regional and local scale, positive and negative vertical movements of the Earth's crust have moderated the effects of transgression. These variations are revealed by changes in the nature, or thickness, of sediment deposited on the tectonic blocks which form the basin. The method used for the delimitation of blocks is supported by the presentation of paleogeographical maps from various Mesozoic epochs, as well as a NE-SW section from the Boulonnais area to Normandy which displays tectonic control on sedimentation.     

Biostratigraphy and depositional facies of the Cretaceous-Tertiary boundary strata in Amakusa-Shimojima,Kyushu, Western Japan

The Upper Himenoura Subgroup exposed in the island of Amakusa-Shimojima, Kyushu, Japan shows an example of the terminal Cretaceous stratigraphic record in the circum Pacific region. This sequence is a part of the Upper Cretaceous intra-arc basins of southwest Japan. Four cycles of upward coarse-graded facies are recognized. Each cycle consists of a basinal mud facies in the lower part and a tide-dominated shallow marine to brackish coarse clastic facies in the upper part. Biostratigraphic correlation chiefly based on ammonites, inocerami and trigoniids indicates that this sequence is Campanian to Maastrichtian in age. The occurrence of the above three fossils decreases upward and is terminated at the top of the sequence, being replaced by a molluscan assemblage similar to the Danian. This suggests that the sedimentation may have continued to the very end of the Cretaceous period and possibly to the beginning of the Tertiary.     

Late Cretaceous marine reptiles (Elasmosauridae and Mosasauridae) of the Chatham Islands, New Zealand

A new marine reptile record for the Upper Cretaceous of the Chatham Islands is described from the Takatika Grit. Incomplete mosasaur and plesiosaur remains represent the first record of marine reptiles from the Chatham Islands and wider New Zealand. Present among the myriad bones are elasmosaurid plesiosaurs and mosasaurine mosasaurs. This assemblage is comparable to the New Zealand marine reptile record and represents apex predators that flourished in a zone of upwelling in a Late Cretaceous southern high-latitude ecosystem.     

Leymeriellidae (Cretaceous ammonites) from the lower Albian of Esfahan and Khur (Central Iran)

Leymeriellid ammonite faunas are described from northeast of Esfahan and the Khur area (Central Iran). The faunas comprise Leymeriella (L.) tardefurcata, L. (L.) germanica and L. (L.) acuticostata? as well as L. (Neoleymeriella) regularis, L. (N.) diabola and L. (Neoleymeriella) pseudoregularis?. The leymeriellids of Iran are closely related to faunas from northwest Europe, the Vocontian Basin and Transcaspia (Mangyschlak) and thus allow for biostratigraphic correlations, indicating the earliest Albian Leymeriella tardefurcata Zone with its superimposed L. acuticostata and L. regularis subzones. We suggest that the sudden appearance of common representatives of the genus Leymeriella in the northern and Central Iranian basins (Leymeriella acme) can be used as a useful proxy marker to define the base of the Albian Stage in Iran.     

华东白垩纪鸭嘴龙类恐龙蛋化石的发现

浙江天台白垩纪地层中最常见的蛋化石类型之一是赤城山组地层（锆石U-Pb法同位素年龄约92Ma）的树枝树枝蛋（Dendroolithus dendriticus）。对比河南西峡含恐龙胚胎的蛋化石,确定其为鸭嘴龙类（Hadrosaurs）恐龙所产。鸭嘴龙类恐龙在系统分类上归鸟脚亚目（Ornithopoda Marsh,1881）鸭嘴龙超科（Hadrosauroidea Cope,1869）鸭嘴龙科（Hadrosauridae Cope,1869）,建议树枝蛋化石也相应归入圆形蛋化石亚目（Spheroolithineae账oosubord．nov．）树枝蛋化石超科（Dendroolithoidea oosuperfam．nov．）树枝蛋化石科（Dendroolithidae Zhaoand Li 1988）,以便对应研究。从已知的鸭嘴龙类恐龙产蛋尺寸推算,浙江天台的树枝树枝蛋（Dendroolithus dendriticus）为身长不超过7m的恐龙所产,个体大小类似东北一蒙古发现的萨哈林日本龙（Nipponosaurus sachaIinensis）、李氏黑龙江龙（Amurosaurus riabinini）和姜氏巴克龙（Bactrosaurus johnsoni）。该蛋在巢穴里,无序放置,至少3层,常超过20枚,蛋壳具韧性,重力作用下呈扁球形。     

Late Albian (Early Cretaceous) ammonites from the Provincial Formation of central Cuba

A late Albian ammonite assemblage from the Provincial Formation of Villa Clara Province, Cuba is described. The Provincial Formation is a lithostratigraphic unit of Albian-Cenomanian age extensively exposed in central Cuba and formed within a part of the Caribbean Tethys that was volcanic during the Cretaceous. The formation is mainly composed of calcareous, terrigenous marine, and volcano-sedimentary deposits characterized by a series of micritic limestones intercalated with marls, sandstones, calcareous conglomerates, ash, and tuffaceous material. A rich assemblage of ammonites recovered from the calcareous biomicrites and marls is of late Albian (Stoliczkaia dispar Zone, Mortoniceras rostratum Subzone) age. The ammonite fauna shows a strong Tethyan affinity, and only a single hoplitid ammonite species was recorded. Although scarce, the first Cuban report of this and other boreal ammonite species now allows precise correlations to be made between Cuba and Albian sediments elsewhere in the world.     

Towards an Aptian (Lower Cretaceous) ammonite biostratigraphy of the Mina Texali section,Central Atlantic province (Puebla State,Central Mexico)

This work is a study of the ammonite record of a new stratigraphic section of Aptian age, at the Mina Texali (Puebla State, Central Mexico). A detailed biostratigraphic analysis was carried out on 309 specimens systematically sampled on a bed-by-bed basis. An Aptian ammonite zonation is proposed for the Mina Texali (= MT) section with two interval zones, Dufrenoyia justinae and Caseyella sp., and one informal biostratigraphic unit represented by the Huastecoceras trispinosoides beds. We also analyze the taxonomic composition, paleoecology and some systematic issues of the ammonite record of the MT section. The first record in Mexico of the genera Pseudosaynella, Xerticeras and the nautiloid Heminautilus is identified in this section. The ammonite assemblage is assigned to the proximal part of the outer neritic region of the continental shelf. The ammonite record of the studied section is diagnostic in establishing the lower-upper Aptian transition, and the local zonation of the MT provides important data for the development of an Aptian standard ammonite zonation for the Central Atlantic province.     

A Basal Titanosauriform from the Early Cretaceous of Guangxi, China

Based on a partial postcranial skeleton collected from the Lower Cretaceous Napai Formation of Guangxi, China, we erect a new sauropod taxon, Fusuisaurus zhaoi gen. et sp. nov. The holotype specimen consists of the left ilium, left pubis, anterior caudals, most of the dorsal ribs and distal end of the left femur. Fusuisaurus zhaoi is diagnosed by a unique combination of character states among the known sauropods. It displays several synapomorphies of Titanosauriformes but lacks many derived features seen in other titanosauriforms, suggesting that the new taxon represents the basalmost known titanosauriform and providing new evidence that Titanosauriformes originated from Asia. A size comparison suggests that Fusuisaurus zhaoi is among the largest Early Cretaceous sauropods, providing an important addition to the Early Cretaceous Chinese sauropod diversity.     

Variation on Foraminiferal Composition in Cretaceous Black-Gray-Red Bed Sequence of Southern Tibet, China

An Upper Cretaceous black-gray-red bed sequence was deposited in the Tethys-Himalayan Sea where abundant foraminifera, especially planktons, were yielded. In the shallow shelf to the upper slope on the north margin of Indian plate was recorded an extinction-recovery-radiation cycle of foraminiferal fauna highly sensitive to paleoceanographical changes. The black unit, consisting of the Late Cenomanian-earliest Turonian beds, displays a major extinction, with keeled planktonic and many benthic species as the principal victims at the end of the Cenomanian when existed only low diversity, sin-face water-dwelling foraminifera. The gray unit spans a long-term recovery interval from the Turonian to the early Santonian with keeled planktonic foraminifera returning stepwise to the water colunm. The planktonic biota in the red unit, extremely abundant, indicate a biotic radiation during the Late Santonian and the Early Campanian, implying that the high oxygen levels had returned to all the oceanic depth levels,and that the water stratification disappeared, followed by the radiation of all depth-dwellers. The variation on foraminiferal faunas from the whole sequence refers to the extreme warm climate that appeared in the Middle Cretaceous and to the declined temperature toward the late epoch. Substantial deposits for this warming and cooling zones represent the black shales in the Middle Cretaceous and the red beds in the later period of the southern Tibet. The change in the foraminiferal composition corresponded to the formation of dysaerobic facies and to the development of high-oxidized circumstances.     

A Late Cretaceous theropod caudal vertebra from the Sultanate of Oman

A caudal vertebra collected from conglomerates of the Al-Khod Formation (Late Cretaceous) in the Al-Khod area, Sultanate of Oman, is assigned to a medium-sized theropod dinosaur. The Al-Khod discovery represents one of the very few dinosaur records from the Middle East.     

Further evidence of marine Cenomanian,lower Turonian and Maastrichtian in the Upper Benue basin of Nigeria (West Africa)

Field investigations in the Upper Benue rift basin of Nigeria highlight the necessity for a review of the Cenomanian-Turonian biostratigraphy of the area. Three ammonite zones of Vascoceras bulbosum (Reyment), Paravascoceras costatum (Reyment) and Pseudotissotia (Bauchioceras) nigeriensis (Woods) have been recognized at sections exposed at the quarry of the cement factory near the village of Ashaka. The sediments within the Vascoceras bulbosum zone also contain specimens of Exogyra olisiponensis (Sharpe), Kanabiceras septemseriatum (Cragin) and Epengonoceras dumbli (Cragin). These are all indicative of an uppermost Cenomanian age and reveal that at least the lower portion of the Gongila Formation as exposed at Ashaka is faunistically equivalent to the Pindiga Formation as exposed in the type section at Pindiga.The shales in the Gombe region in which Libycoceras ismaeli (Zittel) was found are probably part of the Maastrichtian Fika shales outcropping extensively in the northern part of the area. The discovery of Cyclolithes nov. sp. within Gombe sandstones at Dakiti near Kumo confirm that they are at least partially marine in origin and Maastrichtian in age. This could be considered as an additional evidence in favour of the presence of marine waters in the Upper Benue during the last part of the Cretaceous.     

Cretaceous transgressions and regressions on the Russian Platform, in Crimea and Central Asia

This paper is a brief explanation of the diagrams of the Cretaceous transgressions and regressions on the Russian Platform, in the Crimea (Figures 1–3) and some regions of central Asia—the western flanks of the Tien Shan mountains, the Fergana basin, the Zeravshan-Gissar and Alaj mountains, and the Northern Pamirs (Figures 5–7).Internationally recognized stages are employed. They are interpreted by Sasonova (1967) for the Lower Cretaceous (K₁) of the Russian Platform, by Naidin (1977) for the Upper Cretaceous (K₂) of the Platform and the Crimea, by Djalilov (1971) and Pojarkova (1976) for the Upper Cretaceous of central Asia. General data on the stratigraphy of the Cretaceous of central Asia may be found in Anon 1977.     

First false jewel beetle (Coleoptera: Schizopodidae) from the Lower Cretaceous of China

A new false jewel beetle, Mesoschizopus elegans n. gen. n. sp., is described and illustrated based on a well-preserved impression fossil from the Lower Cretaceous Yixian Formation of China. It represents a definitive Mesozoic fossil belonging to the recent small buprestoid family Schizopodidae, which is now endemic to the western North America. Mesoschizopus is placed in Schizopodidae based on its overall body shape and size, short prosternum in front of procoxae, wide metanepisternum, and wing venation. The discovery of the first schizopodid from the Early Cretaceous not only highlights the antiquity of the small family, but also provides an example of a now narrowly distributed group whose ancestral groups were probably more widespread in the Mesozoic.     

A new, large tyrannosaurine theropod from the Upper Cretaceous of China

Tyrannosaurids are primarily gigantic, predatory theropod dinosaurs of the Cretaceous. Here we report a new member of the tyrannosaurid clade Tyrannosaurinae from the Upper Cretaceous Wangshi Group of Zhucheng, Shandong Province, China, based on a maxilla and associated dentary. The discovery of this animal, here named Zhuchengtyrannus magnus gen. et sp. nov., adds to the known diversity of tyrannosaurids in Asia. Z. magnus can be identified by a horizontal shelf on the lateral surface of the base of the ascending process, and a rounded notch in the anterior margin of the maxillary fenestra. Several additional features contribute to a unique combination of character states that serves to further distinguish Z. magnus from other taxa. Comparisons with other tyrannosaurids suggest that Zhuchengtyrannus was a very large theropod, comparable in size to both Tarbosaurus and Tyrannosaurus.