Upper Aptian–albian Rudist Bivalves from Northern Sinai, Egypt

Rudist bivalves are described from two Upper Aptian–Albian sections in northern Sinai, Egypt. Independent stratigraphical evidence is provided by orbitolinid foraminifera and sequence stratigraphic correlation with other, ammonite–bearing sections of the region. With the exception of Eoradiolites liratus (Conrad) and Sellaea, this is the first record of Lower Cretaceous rudists from Egypt. A rather continuous occurrence of rudists is recorded in the more open marine deposit at Rizan Aneiza, but they occur only in the Middle–Upper Albian at Gebel Raghawi to the south–west. In the uppermost Aptian to basal Middle Albian at Rizan Aneiza, the succession of Eoradiolites plicatus–E. murgensis–E. liratus is interpreted as a lineage of chronospecies. Of particular interest is the presence of canaliculate rudists in the Upper Albian of both sections, as there exists a large gap, spanning the Upper Aptian and most parts of the Albian, in the fossil record of the Caprininae d’Orbigny. Neocaprina raghawiensis sp. nov. and Neocaprina? sp. are recognized as ancestors of Cenomanian species of Neocaprina Pleni?ar and Caprinula d’Orbigny. The inclusion of these genera in the Caprininae d’Orbigny is questioned and the phylogenetic descent from an unidentified Albian taxon with well–developed myophoral cavities is suggested.     

吉林榆树榆-302孔阿尔布期孢粉组合 --兼论松辽盆地登楼库组的地质时代

榆-302孔位于松辽盆地东部边缘,钻深899．30m,顶部3．15m为第四系,上部683,65m以砂岩为主,夹少量泥岩,下部212．50m以灰色泥岩为主,夹砂岩及少量凝灰岩。以盆地内岩石地层比较,其上部应属登楼库组3段,下部为登楼库组2段,剖面缺失登楼库组4段,未钻及登楼库组1段。整个剖面上的孢粉组合面貌基本一致,共有苔藓、蕨类植物孢子40属70余种、裸子植物花粉19属28种、被子植物花粉2属3种、藻类及疑源类6属8种。组合中的绝大部分属种都是我国北方早白垩世孢粉植物群的常见分子,如Cicatricosisporites(约占组合的7％-35％),Appendicisporites,Impardecispora,Pilosisporites,Aequitriradites,Kuylisporites,Triporoletes等。特别有意义的是自登楼库组2段开始即已出现大孢子Balmeisporites holodictyus,被子植物花粉Polyporites debilis,Retitricolpites sp．和沟鞭藻Vesperopsis zhaodongensis。登楼库组3段出现曾见于阿尔布期的Scopusporis lautus及晚白垩世的Scopusporis verrucosus,Trochicola scollardiana,Verrucosisporites fuyuensis等,证明其时代属早-中阿尔布期。榆-302孔的孢粉证据表明登楼库组至少自登楼库组2段起已进入阿尔布期,至于登楼库组1段因无更多新的资料佐证。阿普特期的时代定位可暂予保留。文中描述一新种Verrucosisporites fuyuensis sp．nov．和一新联合种Scopusporis uerrucosus(Chlonova)comb．nov．。     

黑龙江省东北部绥滨地区东荣组最上部的沟鞭藻组合--兼论该地区侏罗-白垩系界线

黑龙江省东北部绥滨地区海相东荣组最上部产丰富或较丰富的沟鞭藻类,经鉴定达20属30余种,其中有些在我国为首次发现,包括一新种Leberidocysta suibinensis sp．nov.。文中详细地讨论沟鞭藻Oligosphae-ridium pulcherrimum组合的特征及其地质时代,包括侏罗-白垩系界线等;认为该组合的时代为Berriasian—Valanginian期。这一组合是我国白垩纪最早期的海相沉积,也是白垩系底部的第一个化石组合;首次提出黑龙江省东北部绥滨地区侏罗-白垩系界线应置于Tithonian阶的沟鞭藻Amphorula delicata组合与Berriasian-Valanginian阶的Oligosphaeridium pulcherrimum组合之间,即岩石地层上的东荣组上部与最上部之间。这条沟鞭藻类生物地层界线与双壳类的下、中伏尔加阶的Buchiamosquensis-B．rugosa带与上伏尔加阶的B．fischeriana带之间的分界完全吻合,与目前国际地科联地层委员会建议的侏罗-白垩系界线位于中伏尔加阶与上伏尔加阶之间亦完全一致。     

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.     

Echinoderm faunas from the Lower Cretaceous (Aptian–Albian) of Alexander Island,Antarctica

Abstract: Strata assigned to the Fossil Bluff Group on Alexander Island, Antarctica, contain Aptian to Albian high‐latitude echinoderm faunas that lived at palaeolatitudes greater than 60 degrees south. The Pluto Glacier Formation, of essentially Aptian age, yields a deep‐water assemblage that includes two ophiuroids, an ophiacanthid and a representative of the ophiolepidid genus Mesophiomusium, both represented by partially articulated specimens. The echinoid fauna includes a new genus of diadematoid, Australidiadema, and a new genus of disasteroid, Notidisaster, which extend the record of both groups into the southern hemisphere. The overlying Neptune Glacier Formation, of late Albian age, yields only spatangoids which are common but rarely well enough preserved to be identified even to genus level, although at least some belong to the genus Hemiaster.     

粤西怀集盆地白垩系马屋组的介形类化石

依据闸岗剖面地表及钻井样品的分析鉴定,粤西怀集盆地白垩纪闸岗群马屋组产介形类化石10属17种,本文描述其中9属14种,包括1新种。介形类组合以Eucypris最繁盛,次为Ziziphocypris和Darwinula,称Eucypris hubeiensis-Ziziphocypris simakovi-Darwinula leguminella组合。马屋组与湖北贾店组的介形类组合面貌非常相似,可以进行对比,层位大体相当,其时代应属早白垩世最晚期(Albian)-晚白垩世早期(Cenomanian)。     

Reappraisal of the latest Albian (Mortoniceras fallax Zone) cephalopod fauna from the classical Salazac locality (Gard,southeastern France)

The Salazac locality (Gard, southeastern France) is renowned for the richness of its cephalopod fauna (especially ammonites) from the Mortoniceras fallax Zone (uppermost Albian, Lower Cretaceous). However, most ammonite species have paradoxically been scarcely illustrated up to now. Furthermore, the rare assessments of ammonite taxonomic diversity are presumably inaccurate, as they either result from a drastic typological approach or could not benefit from the most recent advances in modern concepts of ammonoid intraspecific and ontogenetic variations. In this work, we document an original cephalopod assemblage from Salazac represented by abundant, well-preserved specimens (564 studied ammonites, including ca. 50% of heteromorphs) constituting a high diversity. The sample size and quality of this new material allowed some extensive morphological and biometric analyses whenever possible (i.e., for subdatasets in which a significant number of measurements is available) and to thoroughly assess intraspecific and ontogenetic variations for a few species. This led to determine the diagnostic value of various shell characters commonly used to characterize both well-documented and poorly-defined species. In particular, we show that a significant part of the variation in the number of ribs per whorl within the heteromorphic genera Mariella and Turrilitoides is directly related to shell size and that the strength of tubercles covaries negatively with the number of ribs in Mariella, therefore challenging the diagnostic value of these characters. We further suggest that rib density covaries with whorl shape in Mariella, following Buckman’s first rule of covariation. In total, one species of nautilid and 38 taxa (25 genera) of ammonites are described, among which five species are documented from Salazac for the first time. In turn, this study provides valuable data for future phylogenetic, biostratigraphical, biogeographical and broad-scale diversity studies.     

Les gastéropodes et le bivalve Pinna (Pinna) cretacea cretacea (Schlotheim) des dépôts albiens des Rides sud-rifaines (région de Moulay Idriss Zerhoun,nord Maroc)

The « Marnes et calcaires lumachelles à huîtres » Formation (late Albian–early Cenomanian) of the South Riffian Ridges, rich in bivalves, yielded in levels of upper Albian some gastropod specimens including: Ampullina aff. uchauxiensis Cossmann, Ampullina indet., Aporrhaidae indet., Calliomphalus cf. orientalis (Douvillé), Cerithioidea indet., Mrhilaia indet.,?Neogastropoda indet., Pleurotomaria indet., Pseudamaura subbulbiformis (d’Orbigny), Tylostoma aff. globosum Sharpe, and a rare bivalve, Pinna (Pinna) cretacea cretacea (Schlotheim). The two underlying formations « Conglomérat et marnes sableuses » and « Calcaires gréseux » (early to middle Albian?), poor in macrofauna, yielded rare Nerineopsis aff. excavata (Brongniart) and Turritella indet. These species are reported for the first time in the Moroccan Cretaceous deposits.     

Échinides irréguliers de l’Albien supérieur de la Formation d’El Mizab (Bassin de Talerhza,Rides sud-rifaines,nord Maroc)

The El Mizab Formation of the Talerhza Basin (South-Riffian Rides) in the Moulay Idriss Zerhoun area, provided sixteen irregular echinoid specimens from stratigraphic levels dated by ammonites of Upper Albian (Dipoloceras cristatum-Mortoniceras (M.) inflatum zones). It consists of Coenholectypus neocomiensis (Gras, 1848), Coenholectypus sp. and Macraster aff. vatonnei (Coquand, 1862). The latter species, more abundant (14 specimens), is represented by three varieties. These echinoid species, studied and illustrated, are reported for the first time for the late Albian of the South Riffian Ridges and of Morocco. On the paleo-environmental pattern, echinofauna, associated macrofauna and lithofacies evoke for the studied stratigraphic sequence a shallow, calm and oxygenated proximal platform rich in organic material and subject to the pelagic influence.