Sedimentology and palynology of the Calafate Formation (Maastrichtian), Austral Basin, Southern Patagonia, Argentina     

S. Marenssi  V. Guler  S. Casadío  R. Guerstein  O. Papú 《Cretaceous Research》2004,25(6):907-918

The Calafate Formation crops out in south-western Santa Cruz Province, Argentina, and displays a stacking of asymmetrical coarsening–fining-upward cycles. These cycles are interpreted as the product of short-lived transgressive-regressive events in which the coarsening upward part represents sedimentary aggradation with a stable or decreasing sea level. Sedimentological and palynological analyses indicate nearshore marine conditions. Even though the existence of an estuary or incised valley cannot be determined, this is the most probable palaeogeographic model. Based on dinoflagellate cysts, the base of the section is considered to be not older than Maastrichtian. The presence of the oyster Ambigostrea clarae (Ihering) occurring together with the dinoflagellate cyst species Manumiella druggii (Stover) Bujak and Davies and Eisenackia circumtabulata Drugg in the middle part of the section indicates an age no older than late Maastrichtian. According to sedimentological data, deposits representing the Cretaceous–Palaeogene transition would have been eroded, which is confirmed by the presence of Grapnelispora loncochensis Papú. This megaspore is a consistent component of the Maastrichtian assemblages from Patagonia.  相似文献   

Middle Campanian–lowermost Maastrichtian nannofossil and foraminiferal biostratigraphy of the northwestern Australian margin     

Robert J. Campbell  Richard W. Howe  John P. Rexilius   《Cretaceous Research》2004,25(6):827-864

The middle–late Campanian was marked by an increase in the bioprovinciality of calcareous microfossil assemblages into distinct Tethyan, Transitional, and Austral Provinces that persisted to the end of the Maastrichtian. The northwestern Australian margin belonged to the Transitional Province and the absence of key Tethyan marker species such as Radotruncana calcarata and Gansserina gansseri has led petroleum companies operating in the area to use the locally developed KCCM integrated calcareous microfossil zonation scheme. The KCCM zonation is a composite scheme comprising calcareous nannofossil (KCN), planktonic foraminiferal (KPF) and benthonic foraminiferal (KBF) zones. This paper presents the definitions and revisions of Zones KCCM8–19, from the highest occurrence (HO) of Aspidolithus parcus constrictus to the lowest occurrence (LO) of Ceratolithoides aculeus, and builds on our previous early–late Maastrichtian study. The presence of a middle–upper Campanian disconformity is confirmed by microfossil evidence from the Vulcan Sub-basin, Exmouth and Wombat plateaus, and the Southern Carnarvon Platform. In the Vulcan Sub-basin and on the Exmouth Plateau (ODP Hole 762C) the hiatus extends from slightly above the LO of common Rugoglobigerina rugosa to above the LO of Quadrum gothicum. On the Wombat Plateau (ODP Hole 761B) it spans from above the LO of Heterohelix semicostata to above the LO of Quadrum gothicum; and in the Southern Carnarvon Platform the disconformity has its longest duration from above the HO of Heterohelix semicostata to above the LO of Quadrum sissinghii. A significant revision of the events which define Zones KCCM18 and 19 was necessary owing to the observation that the LO of Ceratolithoides aculeus occurs below the HOs of Archaeoglobigerina cretacea and Stensioeina granulata incondita and the LO of common Rugoglobigerina rugosa. In the original zonation these events were considered to be coincident.  相似文献   

Contribution to knowledge of the last dinosaur footprints in Europe. Persistence of ornithopods in the upper Maastrichtian of SE Spain     

《Cretaceous Research》2016

In the locality of Rambla de los Gavilanes (Betic Chain Murcia, Spain), six new outcrops with dinosaur footprints are reported from an uppermost Cretaceous succession of coastal marine deposits. Four of these sites are found in the upper part of the lower Maastrichtian and the other two in the upper Maastrichtian, these latter located only a few meters below the Cretaceous-Paleocene boundary (K/Pg). Traces appear as impressions or as natural casts, on tabular limestone beds consisting of micritic carbonate facies, these deposited in coastal marine areas that include a variety of environments (coastal lakes, tidal flats, salt marshes, and shallow coastal lakes). Two main types of traces have been recognized, respectively attributed to sauropod footprints and large ornithopod footprints with remarkable pointed hoof marks. The Maastrichtian sites with large ornithopod footprints in Europe are reported from Spain, Poland and Romania. Sauropod (titanosaurian), theropod (Irenesauripus and other undetermined theropods), and ornithopod footprints have been found at sites located up to 20 m below the K/Pg boundary. The Spanish dinosaur ichnites known closest to the K/Pg boundary are in the Pyrenean upper Maastrichtian, and are tridactyl, theropod and ornithopod (Hadrosauropodus and Amblydactylus) footprints. In this work, the assignation of the Rambla de los Gavilanes ornithopod footprints has been made following the recommended synthesis in several recent papers which reduce the large ornithopod ichnogenus to four.  相似文献   

Upper Maastrichtian shallow marine environments and neoselachian assemblages in North Iberian palaeomargin (Castilian Ramp,Spain)     

《Cretaceous Research》2016

Upper Maastrichtian deposits formed in a nearshore subtidal environment within the Valdenoceda Formation (Castilian Ramp, North Iberian margin) are described together with two recently found selachian assemblages. Rare earth element concentrations (REE) have been used to assess the degree of taphonomic mixing and reworking, observing that it is minor or non-existent, and differences in degree of preservation and ecologic mixing can be explained by biostratinomic processes. The patterns of REE also helped to obtain a better understanding of the depositional environment, including the diagenetic history from burial to final degree of bone preservation.The fossil assemblages here described are close to that of the late Maastrichtian of Albaina (in the enclave of Condado de Treviño, Burgos), both in the Basque-Cantabrian Region, but their age may be slightly older (early late Maastrichtian). In total, the new assemblages consist of 17 taxa, assigned to 11 genera of shallow-water dwellers combined with individuals from the outer shelf. They represent cosmopolitan taxa (Squalicorax pristodontus, Serratolamna serrata and Rhombodus binkhorsti) together with local species (Rhinobatos echavei, Rhinobatos ibericus). Although there are not significant differences between Albaina and Quintanilla la Ojada faunas, the new assemblages add interesting taphonomic and geochemical information to the few existing uppermost Cretaceous deposits with fossil sharks in southwestern Europe.  相似文献   

Magnetostratigraphy of the Maastrichtian continental record in the Upper Aude Valley (northern Pyrenees,France): Placing age constraints on the succession of dinosaur-bearing sites     

《Cretaceous Research》2016

The first detailed stratigraphic succession of the Upper Cretaceous continental record from the Upper Aude Valley (southern France) is presented together with a magnetostratigraphic study. The combined stratigraphy and magnetostratigraphy of the Marnes rouges inférieures Fm (Lower Red Marls), constrained by biochronological markers such as charophyte occurrence and revised dinosaur eggshells, results in a succession of fluvial red beds dated from chron C32n to the top of chron C31r. It implies an earliest Maastrichtian age close to the C32n.1n-C31r reversal for the majority of the dinosaur sites including Bellevue. In contrast, the upper Maastrichtian is likely represented by a short interval within the lacustrine-palustrine Calcaires et argiles de Vignevieille Fm (Vignevieille Limestones), or it might even not be recorded. The proposed age indicates that the marine to continental transition, as a result of the Late Cretaceous transgression, took place earlier in the north Pyrenean basin than in the southern area.  相似文献   

The Molí del Baró-1 site,a diverse fossil assemblage from the uppermost Maastrichtian of the southern Pyrenees (north-eastern Iberia)     

《Cretaceous Research》2016

The Molí del Baró-1 site (north-eastern Iberia) has yielded one of the richest fossil assemblages of the continental upper Maastrichtian from western Europe. It includes abundant plant (charophytes, sporomorphs, angiosperm leaves, seeds and logs), invertebrate (mollusc shells, partial insect exoskeletons and eggs) and vertebrate (teeth, bones, eggshells) fossils. The fossil assemblage is composed of both parautochthonous and allochthonous remains that mostly deposited in a pool formed at the edge of a meandering river. Plant megafossil evidence suggest that at least three angiosperm species (a willow-like dicot, palms and a likely typhacean monocot) formed the plant community growing in this fluvial environment. Tooth remains indicate that crocodylomorphs were diverse (including atoposaurids, ziphosuchians and eusuchians) which together with small theropod dinosaurs likely consumed prey carcasses or scavenged near the depositional setting. Prismatoolithid eggshells also suggest the presence of nearby nesting area of theropods. On the other hand, hadrosauroids apparently dominated phytophagous faunas including lambeosaurines as well as more basal forms. The taxonomic composition of the Molí del Baró-1 site matches the expected for the timespan and environment and represents a relevant locality to know the diversity of the latest Cretaceous terrestrial ecosystems in south western Europe.  相似文献   

Late Cretaceous (Maastrichtian) amphibians and squamates from northeastern Iberia     

《Cretaceous Research》2016

Maastrichtian biodiversity of medium- and large-sized terrestrial vertebrates is well known in Europe and, specifically, in the Iberian Peninsula. Regarding small-sized herpetofaunas (lissamphibians and squamates), only a few European sites have yielded a significant amount of fossils, and they are still poorly known from the Iberian Peninsula. Recent fieldwork carried out at several sites exposing the Tremp Formation (Southern Pyrenees) has revealed four new localities yielding microvertebrates. Two of them (L'Espinau and Serrat del Rostiar-1) are relatively diverse in herpetofauna, containing albanerpetontids, four different anurans (two different alytids, a pelobatid or gobiatid and a palaeobatrachid), as well as six types of squamates (including scincomorphs, iguanids, anguids and probably gekkotans). Most of these groups are shared with other Campanian-Maastrichtian localities from eastern Iberia although, in some cases, morphological differences might suggest the presence of new lower-level taxa (i.e., genera or species). Also remarkable is the presence of alytines and likely gekkotans that would represent the oldest records of these taxa in Europe and in the Iberian Peninsula, respectively. Taxa of Laurasian origin are common at the Serrat del Rostiar-1 and L'Espinau localities, while Gondwanan taxa are lacking in all cases. Evidence for Asian immigrants (i.e., alytines) is found amongst anurans. Some differences regarding the faunal composition could be explained by environmental factors (i.e., coastal wetlands vs. fluvial settings), although the possibility of taphonomic biases cannot be ruled out.  相似文献   

A primitive euhadrosaurian dinosaur from the uppermost Cretaceous of the Ager syncline (southern Pyrenees,Catalonia)     

Casanovas  M.L.  Pereda Suberbiola  X.  Santafé  J.V.  Weishampel  D.B. 《Geologie en Mijnbouw》1999,78(3-4):345-356

New hadrosaurid material is recorded from Fontllonga (Ager syncline, province of Lleida), in the Catalonian Pyrenees, comprising a dentary with part of the dental battery, recovered from Late Maastrichtian strata (Tremp Formation), close to the presumed Cretaceous/Tertiary boundary. This hadrosaurid is more derived than is Telmatosaurus transsylvanicus from the Haeg Basin (Romania), but lacks a number of features that diagnose the clade Hadrosaurinae plus Lambeosaurinae. It is attributed to the Euhadrosauria on the basis of the following synapomorphies: dentary teeth not recurved distally, narrow dentary crowns, and denticles not supported by subsidiary ridges. The phylogenetic relationships of the best-known iguanodontids and hadrosauroids are evaluated using mandibular and dentary tooth characters. On the basis of a cladistic analysis, the family of Hadrosauridae is diagnosed by more than 29 dentary tooth positions, parallel-sided vertical furrows formed by dentary alveoli, and absence of caudal secondary ridges. Within Hadrosauridae, successive sister-groups of Hadrosaurinae plus Lambeosaurinae are the Fontllonga taxon and Telmatosaurus. The clade Hadrosaurinae plus Lambeosaurinae is characterised mainly by a coronoid process inclined rostrally and by the absence of secondary ridges on dentary crowns. The Fontllonga find suggests the diversity of European hadrosaurids at the end of the Cretaceous to have been greater than previously thought. Moreover, the primitive character of European hadrosaurids as compared to western North American and Asian relatives may be explained in terms of geographical isolation during the Late Cretaceous.  相似文献   

Marine connections in North America during the late Maastrichtian: palaeogeographic and palaeobiogeographic significance ofJeletzkytes nebrascensisZone cephalopod fauna from the Elk Butte Member of the Pierre Shale, SE South Dakota and NE Nebraska     

W.J. Kennedy  N.H. Landman  W.K. Christensen  W.A. Cobban  J.M. Hancock 《Cretaceous Research》1998,19(6):745-775

The Elk Butte Member of the Pierre Shale of southeast South Dakota and northeast Nebraska yields a late Maastrichtian cephalopod fauna of nautiloids, belemnites and ammonites of theFeletzkytes nebrascensisZone, best known from the near-shore facies of the Fox Hills Formation. ThenebrascensisZone is the highest distinct marine assemblage that can be recognised in the Western Interior, although ammonites occur as rarities high in the Lance Formation in Wyoming. Elements of the fauna occur in the Gulf Coast and Atlantic Seaboard, and extend into the highest Maastrichtian nannofossil Subzone CC26b, ofMicula prinsii, in Texas. These occurrences point to the existence of a southerly marine route for migration into and out of the northern Interior during the late late Maastrichtian. An analysis of Maastrichtian ammonite occurrences in West Greenland reveals no evidence for a marine link to the western Interior at this time, but rather indicates an open marine link to the North Atlantic region.The presence of upper upper Maastrichtian Pierre Shale in southeast South Dakota and northeast Nebraska, deposited in water depths that are conservatively estimated at 100-200 m, suggests that marine conditions (evidence for which has been removed by post-Cretceous erosion) may have extended well to the north of the shoreline position indicated in recent palaeogeographic reconstructions.  相似文献   

Relative sea-level, tectono-eustasy, geoidal-eustasy and geodynamics during the Cretaceous     

N. -A. Mrner 《Cretaceous Research》1980,1(4):329-340

A priori, the recorded relative sea-level changes during the Cretaceous must be the combined effect of tectono-eustasy, geoidal-eustasy and various crustal level changes. To this we must add the human factor of differences and errors in interpretations.A posteriori, it is claimed that geoidal-eustasy dominated during the Hauterivian, Barremian, Turonian, Santonian and Maastrichtian, that tectono-eustasy dominated during the Albian, Cenomanian, Campanian and at the Maastrichtian/Danian boundary, and that local influences of sea-floor spreading are identified from the Albian/Cenomanian boundary onwards. To this we must add the local differential crustal movements modulating the global and regional ocean level changes. Geoidal-eustasy is mainly expressed as a latitudinal differentiation of the sea-level with out-of-phase changes between the hemispheres or the both high latitude regions. Furthermore, sedimentological records seem to record short-period geoidal-eustatic cycles.  相似文献