Late Cretaceous Deposits Research Articles

New specimens ofAllodaposuchus precedensfrom France: intraspecific variability and the diversity of European Late Cretaceous eusuchians

A series of cranial remains as well as a few postcranial elements attributed to the basal eusuchian Allodaposuchus precedens are described from Velaux-La Bastide Neuve, a Late Cretaceous continental locality in southern France. Four skulls of different size represent an ontogenetic series and permit an evaluation of the morphological variability in this species. On this basis, recent proposals that different species of Allodaposuchus inhabited the European archipelago are questioned and A. precedens is recognized from other Late Cretaceous deposits of France and Romania. A dentary bone is described for the first time in A. precedens and provides a basis to reconsider the validity of two taxa, Ischyrochampsa meridionalis and Musturzabalsuchus buffetauti, which are interpreted as possible junior synonyms of Allodaposuchus. These results allow the diversity of Late Cretaceous eusuchians from Europe to be refined and recognize a basal stock known as the Hylaeochampsidae sharing an absence of external mandibular fenestrae. Within this family, Allodaposuchus occupies a basal position relative to Acynodon, Iharkutosuchus and Hylaeochampsa. © 2015 The Linnean Society of London

Mesozoic and Early Cenozoic sediment influx and morphology of the Mozambique Basin

The Mozambique Basin is one of the oldest extensional sedimentary basins developed along the eastern African margin. The basin hosts a continuous record of sediments since the Jurassic separation of Antarctica from Africa. The objectives of this study were to extend the regional stratigraphic framework north of the Zambezi Delta into the deep abyssal plains and review the early evolution of the Mozambique Basin using nine multi-channel seismic reflection profiles.We identify six major stratigraphic units that were deposited in Jurassic, Early Cretaceous, Late Cretaceous, Paleogene, Neogene and Quaternary times. Mesozoic sedimentation rates of 5–10 cm/kyr and 1–3 cm/kyr during the Paleogene are calculated in the deeper basin. The presence of shales in neighbouring wells on the shelf implies an euxinic environment in the rapidly subsiding basin until Early Cretaceous times. The Mesozoic sediments have a high seismic velocity that exceeds 4.5 km/s, except in a distinct Early Cretaceous low-velocity (3.7 km/s) zone that may indicate the presence of undercompacted, overpressured shales. In spite of the fact that the Zambezi catchment was much smaller in pre-Miocene times, the high Late Cretaceous sedimentation rates can be attributed to rapid denudation of the African continent after a major tectonic uplift episode at approximately 90 Ma. Increased sediment influx into the basin from the Zambezi in Late Cretaceous times resulted in the formation of an elongated submarine fan lobe into the Mozambique Channel north of Beira High. Strong north-south bottom currents commenced within the channel in Late Cretaceous times, forcing the aggradation of sediments on the southern flank of the lobe. In addition, we observe several current-controlled sediment deposits in the deeper basin that are influenced by north-south bottom currents. Low Paleogene sedimentation rates are attributed to a sediment-starved basin during a relative quiet tectonic phase onshore.

A new Late Cretaceous (late Campanian to early Maastrichtian) wood flora from southern Patagonia

The Cerro Fortaleza Formation, in southernmost Patagonia (Argentina), contains a unique Late Cretaceous (Campanian) flora and fauna. This formation is characterized by lithified fluvial sands, overbank mud deposits, and paleosols deposited in fluvial, fluvial–palustrine, and coastal plain environments from the northeastern margin of the Austral (Magellanes) Basin. The overlying and underlying formations have been dated as Campanian and Maastrichtian, respectively. Therefore, the Cerro Fortaleza Formation putatively falls within the late Campanian–Maastrichtian. This formation is known for its diverse fauna including dinosaurs, fishes, and turtles. Furthermore, poorly preserved leaf impressions from indeterminate conifers and cycads have also been discovered but not yet described.Fossil wood taxa from the Cerro Fortaleza Formation yields a diverse flora of gymnosperm wood but only two genera of angiosperm wood. Gymnosperm genera identified in this study include Agathoxylon, Planoxylon, Taxodioxylon, Cupressinoxylon, and Podocarpoxylon; and angiosperm genera identified include Hedycaryoxylon and Nothofagoxylon. This is the first record of Planoxylon, Taxodioxylon, Cupressinoxylon, and Hedycaryoxylon from Argentina. Additionally, this is the oldest occurrence of Nothofagoxylon in Argentina. Both the angiosperm and gymnosperm wood samples possess distinct growth rings, providing strong evidence for seasonal growth regimes in the region. All of the wood genera from the Cerro Fortaleza Formation, except Planoxylon, have also been described from Late Cretaceous sediments of the Antarctic Peninsula. Thus, the presence of these taxa in both regions supports Late Cretaceous plant dispersal between them. Despite sharing the same taxa, the floras from the Cerro Fortaleza Formation and the Antarctic Peninsula exhibit strikingly different relative abundances. The ratio of gymnosperm to angiosperm wood in the Cerro Fortaleza Formation is 75:25; whereas coeval floras from the Antarctic Peninsula are ~25:75. The floral differences between these locations may be a relict from a widespread older flora that included Antarctica, regional floristic variations or a result of different depositional and/or taphonomic controls in discrete paleoenvironments.

Chemistry of groundwater from mud volcanoes in parts of Upper Benue Trough, northeastern Nigeria

Mud volcanoes grouped into 14 fields are found in southern Gombe, part of the Cretaceous Upper Benue Trough filled with Early Cretaceous continental deposits and Late Cretaceous marine deposits, having a history of magmatism dating from Albian to Pleistocene. They are mostly of small sizes, having cones not exceeding one and half metres in height and diameters ranging from 0.5 to 8 m at base, as well as pools with muddy water and mudflows were encountered. Results of the study show that the cationic and anionic concentration varies as follows: Ca2+ (8.26–46.4 mg/l), Mg2+ (1.16–20 mg/l), Na+(18.6–4789 mg/l), K+ (9.4–134 mg/l), Fe (0.02–5.74 mg/l), HC 3 − (126–3111 mg/l), Cl– (5–2625 mg/l), SO 4 2– (12.5–16.9 mg/l), CO 3 2– (3–2040 mg/l) and SiO2 (7–45.6 mg/l). The study also reveals that the water issuing from the mud volcanoes, in most cases, is highly alkaline (pH ranges from 7.94 to 8.99), saline (TDS varies from 140 to 1620 mg/l), very hard (TH varies from 102 to 1180 mg/l) and belongs to five hydrochemical facies, namely: Na–HCO3, Na–HCO3–Cl, Na–Ca–HCO3, Na–Cl–CO3–HCO3 and Ca–Na–HCO3. The dominant hydrochemical facies is Na–HCO3 while Ca–Na–HCO3 is the minor water type. Statistical correlation reveals positive correlation between most of the parameters. With the exception of Ca2+, Mg2+ and SO 4 2− , all other parameters are far above the World Health Organisation standards for drinking water. These waters are mineralised and are not considered to be suitable for drinking and domestic purposes, but may be considered for therapeutic purposes.

Fossocytheridea Swain & Brown and Perissocytheridea Stephenson (Ostracoda): insights into paleosalinity gradients of Late Cretaceous deposits from Brazil and Portugal

Fossocytheridea Swain & Brown and Perissocytheridea Stephenson are genera characteristic of brackish water environments. In 51 samples from the Santonian-Campanian, from the well 9-MO-13-RN, Potiguar Basin, Brazil, Fossocytheridea potiguarensis Piovesan, Cabral & Colin, Fossocytheridea POT 1 Piovesan, Cabral & Colin and Perissocytheridea jandairensis Piovesan, Cabral & Colin have been identified. In the Sao Joao das Lampas section (middle Cenomanian), Lusitanian Basin, Portugal, 25 samples were studied and Fossocytheridea merlensis (Babinot & Colin) and Perissocytheridea estribeirensis Andreu have been recognized. The distributional pattern of the Fossocytheridea-Perissocytheridea assemblage, combined with analysis of the abundance and diversity of marine ostracodes, suggests that in the Late Cretaceous Fossocytheridea and Perissocytheridea were euryhaline genera, and that the tolerance to salinity gradients is related to the ecology of each species and not strictly to that of the genus.

Late Cretaceous nautilid juveniles of Cymatoceras reussi and Eutrephoceras aff. sublaevigatum – scarce fossils under risk of pyrite degradation

Late Cretaceous nautilid juveniles of Cymatoceras reussi and Eutrephoceras aff. sublaevigatum – scarce fossils under risk of pyrite degradation

Extensional basin development and subsequent inversion in Greymouth Coalfield

The validity of the history of basin development in the east of Greymouth Coalfield, as broadly accepted for the past 60 years, is examined through reinterpretation of the structure and stratigraphy. Rather than a Late Cretaceous–Paleocene fault-angle basin (extensional half-graben) west from the Mount Davy Fault Zone, a downwarping basin extended across the location of that future fault zone. This basin developed within regionally extensive deposition of Late Cretaceous sediments. Uplift and erosion in the east was followed by the development of an Eocene fault-angle basin extending from the Montgomerie Fault west across the developing Mount Davy Fault Zone. A thick Miocene sequence accumulated in the Grey Valley Trough to the east, and a thinner sequence is inferred to have covered the whole coalfield. Inversion in the coalfield, rather than being intermittent throughout the whole Palaeogene, began c. 4.5 Ma ago with development of the Brunner Anticline and reversal of movement on both the Mount Davy Fault Zone and the Montgomerie Fault.

The skeletal morphology of the solemydid turtle Naomichelys speciosa from the Early Cretaceous of Texas

The fossil record of solemydid turtles is primarily based on isolated fragments collected from Late Jurassic to Late Cretaceous sediments throughout North America and Europe and little is therefore known about the morphology and evolutionary history of the group. We here provide a detailed description of the only known near-complete solemydid skeleton, which was collected from the Lower Cretaceous (Aptian–Albian) Antlers Formation of Texas during the mid-twentieth century, but essentially remains undescribed to date. Though comparison is limited, the skeleton is referred to Naomichelys speciosa, which is based on an isolated entoplastron from the Lower Cretaceous (Aptian–Albian) Kootenai (Cloverly) Formation of Montana. The absence of temporal emarginations, contribution of the jugals to the orbits, and a clear subdivision of the middle and inner cavities, and the presence of elongate postorbitals, posteriorly expanded squamosals, a triangular fossa at the posterior margin of the squamosals, an additional pair of tubercula basioccipitale that is formed by the pterygoids, foramina pro ramo nervi vidiani (VII) that are visible in ventral view, shell sculpturing consisting of high tubercles, a large entoplastron with entoplastral scute, V-shaped anterior peripherals, and limb osteoderms with tubercular sculpture diagnose Naomichelys speciosa as a representative of Solemydidae. The full visibility of the parabasisphenoid complex in ventral view, the presence of an expanded symphyseal shelf, and the unusual ventromedial folding of the coronoid process are the primary characteristics that distinguish Naomichelys speciosa from the near-coeval European taxon Helochelydra nopcsai.

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.

Shell Microstructure of Late Cretaceous (Maastrichtian) Oysters from Ariyalur, Tamil Nadu

Abstract The micro-morphological shell characters (both in optical microscope and SEM) have been used to discriminate in between oyster’s sub-families Pycnodonteinae Stenzel 1959, Exogyrinae Vyalov 1936, Ostreinae Refinesque 1815 and Lophinae Vyalov 1936. These sub-families are represented by six constituent genera Phygraea (Phygarea) vesicularis (Lamarck 1806), Hyotissa semiplana (Sowerby1813), Curvostrea rouvellei (Coquand 1862), Ceratostreon pliciferum (Dujardin 1837), Agerostrea ungulata (Schlotheim 1813) and Rastellum (Arctostrea) pectinatum (Lamarck 1810) in the late Cretaceous (Maastrichtian) sediments of the Ariyalur area of Tamil Nadu, south India. The optical microscopic observations and SEM studies of the shells of these six genera clearly indicate that all the four sub-families consist of distinctive set of shell-microstructures. Sub-family Pycnodonteinae is characterized by predominance of vesicular, exogyrinae by prismatic, Ostreinae by cross foliated and Lophinae by foliated shell microstructures. Besides their characteristic shell microstructures, some additional microstructures are also visible in the shells of some of the genera of these four sub-families.

Calcareous nannofossils from Late Cretaceous deposits in Mojen section (NE Iran)

A biostratigraphic study of calcareous nannofossils from the Mojen of the NE Iran has allowed the recognition of seven calcareous nannofossil biozones by Sissingh (Geol En Minjbouw 56: 37–65, 1977), CC20–CC26 in Mojen section. According to these biozones, the age of the studied sections in Mojen is Late Early Campanian–Late Maastrichtian. In this study, 38 samples of Mojen were taken and prepared with smear slide. As a result of this study, 23 genera and 41 species of nannofossils in Mojen section have been identified. On the base of paleoecological interpretation, the last layers related to the Cretaceous deposits in this section were deposited in shallow marine environment in relatively low latitude, and the depth of the basin from Cretaceous deposits toward Fajan Formation decreased.

Paleoclimate estimates and fire ecology immediately prior to the end-Cretaceous mass extinction in the Frenchman Formation (66 Ma), Saskatchewan, Canada

The fossil-rich deposits of the uppermost Maastrichtian (66Ma) Frenchman Formation of southern Saskatchewan, Canada provide a detailed, continuous record of terrestrial ecosystem dynamics during the last half-million years leading up to the end-Cretaceous mass extinction. Paleoenvironmental interpretations for the Frenchman Formation are here refined by the first absolute paleoclimate estimates for the Late Cretaceous of Saskatchewan, and by the placement of these climate estimates within a North American context. Climate estimates were calculated using Leaf Margin Analysis and the Climate Leaf Analysis Multivariate Program (CLAMP), derived from two independent plant macrofossil assemblages collected from the Frenchman Formation. Climate parameter estimates indicate that the Maastrichtian climate of southern Saskatchewan was subtropical to warm-temperate, with mean annual temperatures between 12°C and 14°C, and with marked seasonality. These results are comparable with estimates derived from other late Campanian and Maastrichtian paleofloras in the Western Interior Basin, although small variations among coeval localities were noted or determined. Overall, the plant fossil assemblages from the two study localities support the paleoenvironmental interpretation of the Frenchman Formation as a swampy to lowland forest system with canopy-forming deciduous conifers and a diverse, angiosperm-dominated mid-canopy and understory. An unexpected, marked disparity in plant diversity was found between the two paleofloras, despite the plant assemblages returning similar paleoclimate parameter estimates. Abundant in situ inertinite (fossil charcoal) deposits were found in association with the less diverse paleofloral site, which contained only angiosperm fossils. Inertinite was absent from the deposits containing the more diverse paleoflora, which contained a different composition of angiosperm and gymnosperm fossils. Fire is known to be a prevalent feature of Late Cretaceous deposits worldwide, and modern angiosperm plants typically are the first to recover following fire disturbances. We suggest that the two Frenchman Formation paleofloras represent different stages of secondary ecological succession following a disturbance by fire. The identification of fire ecology in the fossil record may have important implications for understanding biodiversity patterns on small spatial and temporal scales immediately prior to the Cretaceous mass extinction.

Introduction to calcareous algae in Esfiyukh Mountain

In this research the biostratigraphy in Esfiyukh Mountain (5km of North-east of Torbat-e-Heydarieh) is studied for the first time. Thedeposits in this section are about 175 meters thickness; lithology consists ofalternative layers of medium bedded to very thick bedded limestone. This partoverlies on brown-dark red sandstone & Jurassic deposits with angularunconformity and is overlain by late Cretaceous sediments with unconformablecontact. The first study of benthic foraminifera and calcareous algaeidentification is the survey of paleoecology condition of benthic foraminifera,that 60 thin sections were studied. In this study ten genera and species ofcalcareous algae Salpingoporella cf. parapiriniae (Carras et al., 2006),Cylindroporella sp. (Elliot, 1979), Rajkella sp. (Dragastan & Bucur, 1993),Neomeris cretaceous (Stewmann, 1978), Triploporella sp. (SRIVASTAVA, 1978),(BUCUR, 1993), (Granier et al., 2000), Terquemella sp. (Radoicic, 1978),Boueina sp., Macroporella sp., Falsolikanella danilovae, (Radiocic ex1982), (Berger,1992)ag.,Actinoporellageredeensis, (CONRAD,1970), Salpingoporella aff. hasi, ,(Carras et al, 2006) has been known. With view to association ofbenthic foraminifera the age of the studied section Barremian t-Aptian isdetermined.

Род Trochodendroides Berry в чинганджинской флоре Северо-Востока России

Three species of Trochodendroides were described fr om the Late Cretaceous deposits of the Chingandzha Formation. Two of them (T. tumanensis Yudova, sp. nov. and T. deminii Yudova et Golovn., sp. nov.) were described as new species, and one was described as Trochodendroides sp. Comparison of new species of the genus Trochodendroides of the Chingandzha flora with representatives of this genus in other Late Cretaceous floras of Northeastern Russia shows that they were presented in composition of the Coniacian Tylpegyrgynai flora of the Pekulnei ridge too, wh ere they were described with other species names (Trochodendroides arctica (Heer) Berry, and Zizyphus smilacifolia Budants.). The presence of the same species shows a similarity of the Chingandzha with Tylpegyrgynai flora and confirms the Coniacian age of the Chingandzha flora.

Aquilapollenites and other triprojectate pollen from the Late Cretaceous to Early Paleocene Deccan intertrappean deposits of India

Palynological investigations of Deccan volcanic-associated intertrappean deposits of the Late Cretaceous–Early Paleocene of central and western India were carried out. The study shows the presence of abundant triprojectate pollen grains, particularly Aquilapollenites Rouse 1957, Jiangsupollis Song 1980in Song et al. 1980 and Farabeipollis Nandi & Chattopadhyay 2002. The data on the triprojectate group from the Indian subcontinent shows that Aquilapollenites spp. were widely distributed in the Late Cretaceous (Maastrichtian) sediments, and Farabeipollis and Jiangsupollis are less common. The post-Cretaceous record of triprojectate pollen from the Indian subcontinent is poor, and only a few species of Aquilapollenites survived the Cretaceous–Paleocene transition.

Lithofacies architecture and depositional environment of Late Cretaceous Lameta Formation, central India

Establishment of lithofacies and interpretation of depositional environment of the Lameta Formation have been carried out for a new area having three nearby exposures. Overall, the successions are broadly differentiable into three major units, i.e. arenaceous in the lower part, argillaceous in middle and calcareous at the top, which more or less serve as three lithofacies associations. Each association consists of various lithofacies which are identified and established on the basis of field observations, added with significant petrological details. The arenaceous association includes five lithofacies, viz. massive sandstone lithofacies; green sandstone lithofacies; thinly bedded, yellowish orange and greyish brown sandstone lithofacies; coarse-grained sandstone lithofacies and dark brown bioturbated sandstone lithofacies. The argillaceous lithofacies association consists of yellowish-brownish-greenish clay–siltstone lithofacies and light grey silty–clay with concretions lithofacies, whereas the calcareous lithofacies association is represented by calcrete lithofacies, nodular limestone lithofacies, chertified limestone lithofacies and intraformational breccia lithofacies. The facies analysis reveals that the deposition of Late Cretaceous Lameta sediments took place in fluvial–lacustrine environments in semi arid condition.

PALEOVARSOVIELLA AND PALEOVARSOVIELLINAE, NEW NAMES FOR THE FORAMINIFERAL GENUS VARSOVIELLA GAWOR-BIEDOWA, 1987, AND SUBFAMILY VARSOVIELLINAE GAWOR-BIEDOWA, 1987

More than two decades ago, Gawor-Biedowa (1987) described a number of benthic foraminifers from Late Cretaceous deposits in Poland. At that time she proposed a new genus Varsoviella , although this name was already preoccupied by the validly named rhabdocoel flatworm Varsoviella Gieysztor and Wiszniewski, 1947. The foraminifer Varsoviella Gawor-Biedowa, 1987 …

Morphology and size variation of a portunoid crab from the Maastrichtian of the Americas

The portunoid crab OphthalmoplaxRathbun, 1935, is known from late Cretaceous deposits of Africa and the Americas. A review of 76 specimens from many localities in North and South America reveals that the genus is represented by only two species — one in Africa (recently described) and the other in the Americas. Ophthalmoplax brasiliana (Maury, 1930) was distributed along the Atlantic and Gulf coasts of the Americas throughout the Maastrichtian — from Brazil to North Carolina. In early Maastrichtian deposits of North America (∼69.0 Ma), the species is represented by local populations of medium-sized individuals, and by the late Maastrichtian (∼67.0 Ma), populations of larger individuals became abundant. This size increase may be related to a decrease in ocean water temperatures. Populations of medium-sized individuals are found again in the latest Maastrichtian (∼66.2 Ma), below strata with ejecta deposits in Coahuila, Mexico, and in the uppermost Owl Creek Formation, Mississippi. This size decrease is possibly linked to an increase in seawater temperature occurring just below the K/P boundary, when Ophthalmoplax became extinct.

Description of Pseudosabinia klinghardti and some species of Pseudopolyconites (rudist bivalves) from the Late Cretaceous shallow-marine deposits from the Roşia Basin, Apuseni Mountains, Romania: Systematic palaeontology, biostratigraphy, and palaeobiogeography

The shallow-marine, mixed siliciclastic-calcareous Late Cretaceous deposits from the Apuseni Mountains have been extensively studied and compared to coeval deposits from the Alpine Gosau. The former are mainly represented by conglomerates, sandstones, marls, and limestones with rudists that unconformably overlie the crystalline basement and its Permo-Mesozoic cover. Our new, detailed investigations on the rudist fauna from Măgura Hill, the type locality of Pseudopolyconites hirsutus (Patrulius) and Miseia costulata Patrulius, indicate a Late Santonian–Early Campanian age for these deposits instead of an Early Santonian one as previously suggested (Patrulius, 1974). This study also mentions for the first time the occurrences of Pseudosabinia klinghardti (Böhm) and Pseudopolyconites parvus Milovanović in the rudist-bearing deposits from the Apuseni Mountains. We include their palaeontological features, as well as the ones for Pseudopolyconites hirsutus. Based on new biostratigraphic data, our study expand the stratigraphic range of Pseudosabinia klinghardti and Pseudopolyconites parvus – previously considered characteristic for the Early Campanian–Maastrichtian interval. Also we add new information on their palaeobiogeographic distribution within the central-eastern Mediterranean area during the Late Cretaceous.

Osteology of Khaan mckennai (Oviraptorosauria: Theropoda)

The monophyly of Oviraptoridae, a group of theropod dinosaurs, which share a uniquely bizarre morphology, has never been called into question due in large part to their unusual complex of characters. Despite a vivid recent history of discovery and broad public appeal the nature of their morphological diversity has not been explored extensively. Many previous descriptions of oviraptorid taxa are lost in the obscurity of hard-to-find journals, and many lack illustrations of what are now recognized as phylogenetically important characters. The primary goal of this paper is to provide a relatively comprehensive descriptive morphology and illustrations for one member of Oviraptoridae, namely Khaan mckennai, with an emphasis on characters that can be used to establish a phylogenetic hypothesis for the taxon and group as a whole. K. mckennai is a small-bodied, crestless oviraptorid that is known from pristine material that has been collected from the Late Cretaceous sediments of Mongolia. Similar to other oviraptorids, it shares a wide number of features in common with extant birds. However, when these characters are put in the context of Oviraptorosauria, including relatively new, more basal forms like Incisivosaurus gauthieri and Caudipteryx zoui, character states such as extreme pneumatization of the skull or the reduction in the number of caudal vertebrae are found to be either homoplastic for the two groups or plesiomorphic for a more inclusive clade.