Early Berriasian ammonites from Shal, Talesh region (NW Alborz Mountains, Iran)

An early Berriasian (Berriasella jacobi Zone) ammonite fauna is described for the first time from the Alborz Mountains in northwest Iran. It has been collected from a section located near the village of Shal (Talesh region); in addition to rare phylloceratids, lytoceratids and Neolissoceras, the majority of ammonites belong to the neocomitid subfamily Berriasellinae. With the exception of a new genus and species, Taleshites fuersichi, these taxa are common in European and North African Tethyan successions. Associated calpionellids confirm the early Berriasian age of the ammonite-bearing levels.     

Berriasian Stage of the Crimean Mountains: Zonal subdivisions and correlation

Biostratigraphy of the Berriasian Stage in the Crimean Mountains is specified and substantiated. Fragments of all the standard stage zones (jacobi, occitanica, and boissieri) are distinguished based on the found index species, and position of the Jurassic-Cretaceous boundary is targeted. According to verified distribution of ammonites, the jacobi Zone is divided into the jacobi and grandis subzones crowned by the Malbosiceras chaperi Beds. The Tirnovella occitanica-Retowskiceras retowskyi Beds and overlying Dalmasiceras tauricum Subzone are recognized in deposits of the occitanica Zone. The upward succession of biostratigraphic units established in the boissieri Zone includes the Euthymiceras-Neocosmoceras Beds, Riasanites crassicostatus Subzone, Symphythyris arguinensis and Jabronella sf. paquieri-Berriasella callisto Beds. The last biostratigraphic unit is suggested in this work instead the former Zeillerina baksanensis Beds. Except for the jacobi Zone, the substantiated ammonoid zonation is practically identical to the Berriasian biostratigraphic scale of the northern Caucasus, although the Berriasian-Valanginian boundary has not been defined in the Crimean Mountains based on ammonites. Several marker levels of bivalve mollusks and four biostratigraphic subdivisions of brachiopod scale are distinguishable here. As for the latter, these are (from the base upward) the Tonasirhynchia janini, Belbekella airgulensis-Sellithyris uniplicata, Symphythyris arguinensis, and Zeillerina baksanensis beds.     

Charophytes from the Upper Berriasian of the Western Interior Basin of the United States

A charophyte flora from the Upper Berriasian is described from the Lakota (Black Hills, South Dakota) and Cedar Mountain formations (San Rafael Swell, Utah) of the Western Interior Basin, United States of America. Whereas the latter is dominated by monotonous assemblages of the clavatoracean Nodosoclavator bradleyi (Harris, 1939), found in temporary lakes within palustrine facies, the flora of the Lakota Formation consists of more varied assemblages of the clavatoraceans N. bradleyi (Harris, 1939), Clavator grovesii grovesii Harris 1939, C. bilateralis Peck 1957 and early characeans (Mesochara sp. or Tolypella sp.). This flora was found in deposits related to permanent lakes in fluvial floodplains, i.e. lacustrine marls and limestones that do not show any evidence of subaerial exposure. To date, little is known about C. bilateralis, we provide a new definition on the basis of its particular structure, which shows lateral bract-cell units with a pinnate arrangement. This species appears to be endemic to North America and stratigraphically limited to the earliest Cretaceous. C. grovesii grovesii is part of a long-lasting charophyte lineage, which until now was considered to have originated in the Central Tethyan Archipelago (Europe) during the Early Berriasian, about 145 Ma, and limited to Eurasia until most of the Early Cretaceous. The new data presented here suggest that during the Berriasian this species was very broadly distributed, comprising North America, Europe and China.     

Ammonite <Emphasis Type="Italic">Fauriella boissieri</Emphasis> (Pictet), the index species of the Berriasian upper zone from the Crimean Mountains

Ammonite Fauriella boissieri (Pictet), the index species of the Berriasian upper zone, is described for the first time as taxon occurring in the Crimean Mountains. In the Berriasian sections of the central Crimea and Chatyr-Dag massif, species F. boissieri are encountered only in association with upper Berriasian ammonites. The Berriasian-Valanginian boundary has not been identified based on ammonites in the Crimean Mountains. Consequently, there is no reason to include the otopeta Zone into the boissieri Zone in the rank of its upper subzone.     

New insight on the genus Nolaniceras Casey, 1961 (Ammonoidea,Cretaceous) and its consequences on the biostratigraphy of the Aptian Stage

Nolaniceras nolani ( Seunes, 1887) has been widely quoted in the Upper Aptian literature over the years. Re-examination of the holotype of the species shows that it has always been misidentified and that this taxon is represented by a single specimen, the holotype, of uncertain age. As a consequence, its use as an index species for the Upper Aptian should be reconsidered and abandoned.     

The Olduvai buffalo Pelorovis and the origin of Bos

The origin of the genus Bos is a debated issue. From ∼ 0.5 Ma until historic times, the genus is well known in the Eurasian large mammal assemblages, where it is represented by Bos primigenius. This species has a highly derived cranial anatomy that shows important morphological differences from other Plio-Pleistocene Eurasian genera of the tribe Bovini such as Leptobos, Bison, Proamphibos-Hemibos, and Bubalus. The oldest clear evidence of Bos is the skull fragment ASB-198-1 from the middle Pleistocene (∼ 0.6-0.8 Ma) site of Asbole (Lower Awash Valley, Ethiopia). The first appearance of Bos in Europe is at the site of Venosa-Notarchirico, Italy (∼ 0.5-0.6 Ma). Although the origin of Bos has traditionally been connected with Leptobos and Bison, after a detailed anatomical and morphometric study we propose here a different origin, connecting the middle Pleistocene Eurasian forms of B. primigenius with the African Late Pliocene and early Pleistocene large size member of the tribe Bovini Pelorovis sensu stricto. The dispersal of the Bos lineage in Western Europe during middle Pleistocene times seems to coincide with the arrival of the Acheulean tool technology in this continent.     

Representatives of the Neocosmoceras (Neocomitidae, Ammonoidea) genus from the Berriasian of the Crimean Mountains and their stratigraphic significance

The genus Euthymiceras is considered as the junior synonym of the genus Neocosmoceras. Four species N. euthymi, N. cf. transfigurabilis, N. minutus sp. nov., and N. giganteus sp. nov. from the Berriasian deposits of the Crimean Mountains are described for the first time. The biostratigraphic unit formerly termed the “Euthymiceras-Neocosmoceras Beds” is ranked now as the Neocosmoceras euthymi Subzone with a synonymous index species. The subzone is correlated to the following biostratigraphic units: the synonymous subzone of the northern Caucasus, the Neocosmoceras-Septaliphoria semenovi (upper part) and Buchia volgensis local zones of Mangyshlak, the upper part of the Riasanites rjasanensis Zone in the East European platform, and the paramimounum Subzone of the boissieri Zone in the standard zonation of the Tethyan ammonites.     

New Cretaceous caddisflies from Burmese amber (Insecta,Trichoptera)

Three new caddisflies species are described and illustrated from the mid-Cretaceous Burmese amber: Wormaldia cretacea sp. nov., W. resina sp. nov. (Philopotamidae) and Neureclipsis burmanica sp. nov. (Polycentropodidae). Palerasnitsynus ohlhoffi (Psychomyiidae) is re-described based on new fossils. Wormaldia are common in Burmese amber, and its diversity shows that this genus had very ancient origin and diversified at least during the mid-Cretaceous. N. burmanica sp. nov. is the oldest record of Neureclipsis, revealing this genus originated at least in the mid-Cretaceous. So far, six extinct species representing the small Order Trichoptera have been found in Burmese amber.     

Representatives of genera <Emphasis Type="Italic">Malbosiceras</Emphasis> and <Emphasis Type="Italic">Pomeliceras</Emphasis> (Neocomitidae,Ammonoidea) from the Berriasian of the Crimean Mountains

The revised representatives of ammonite genera Malbosiceras and Pomeliceras from the Berriasian of the Crimean Mountains are classed with seven species, four of the first genus [M. malbosi (Pictet), M. chaperi (Pictet), M. broussei (Mazenot), M. pictetiforme Tavera] and three of the second one [P. aff. boisseti Nikolov, P. breveti (Pomel), P. (?) funduklense Lysenko et Arkadiev sp. nov.]. The identified species are described. The genus Mazenoticeras is considered as synonym of Malbosiceras. The above species prove that all the Berriasian zones (jacobi, occitanica and boissieri) are characteristic of corresponding deposits in the Crimean Mountains.     

Report on the 5th International Meeting of the IUGS Lower Cretaceous Ammonite Working Group,the Kilian Group (Ankara,Turkey, 31st August 2013)

The 5th meeting of the IUGS Lower Cretaceous Ammonite Working Group (the Kilian Group) held in Ankara, Turkey, 31st August 2013, discussed the Mediterranean ammonite zonation, and its calibration with different ammonite zonal schemes of the Boreal, Austral and Central Atlantic realms. Concerning the standard zonation, that corresponds to the zonal scheme of the West Mediterranean province, some changes have been made on two stages. For the Valanginian, the Busnardoites campylotoxus Zone was abandoned; the upper part of the lower Valanginian is now characterised by the Neocomites neocomiensiformis and Karakaschiceras inostranzewi zones. For the upper Barremian, the former Imerites giraudi Zone is here subdivided into two zones, a lower I. giraudi Zone and an upper Martellites sarasini Zone. The I. giraudi Zone is now subdivided into the I. giraudi and Heteroceras emerici subzones, previously considered as horizons. The current M. sarasini and Pseudocrioceras waagenoides subzones correspond to the lower and upper parts of the M. sarasini Zone, respectively. The Anglesites puzosianum Horizon is kept. The Berriasian, Hauterivian, Aptian and Albian zonal schemes have been discussed but no change was made. The upper Hauterivian zonal scheme of the Georgian (Caucasus) region (East Mediterranean province) has been compared with the standard zonation. Discussions and some attempts at correlations are presented here between the standard zonation and the zonal schemes of different palaeobiogeographical provinces: the North-West European area for the Valanginian and Hauterivian, the Argentinean region for the Berriasian, Valanginian and Hauterivian, and the Mexican area for the Valanginian–Hauterivian and Aptian–lower Albian. The report concludes with some proposals for future work.     

Broeckina gassoensis sp. nov., a larger foraminiferal index fossil for the middle Coniacian shallow-water deposits of the Pyrenean Basin (NE Spain)

The Upper Cretaceous shallow-water carbonates of the Pyrenean Basin (NE Spain) host rich and diverse larger foraminiferal associations which witness the recovery of this group of protozoans after the dramatic extinction of the Cenomanian–Turonian boundary interval. In this paper a new, large discoidal porcelaneous foraminifer, Broeckina gassoensis sp. nov., is described from the middle Coniacian shallow-water deposits of the Collada Gassó Formation, in the Bóixols Thrust Sheet. This is the first complex porcelaneous larger foraminifer of the Late Cretaceous global community maturation cycle recorded in the Pyrenean bioprovince. It differs from the late Santonian–early Campanian B. dufrenoyi for its smaller size in A and B generations and the less developed endoskeleton, which shows short septula. Broeckina gassoensis sp. nov. has been widely employed as a stratigraphic marker in the regional geological literature, under the name of “Broeckina”, but its age was so far controversial. Its middle Coniacian age (lowermost part of the Peroniceras tridorsatum ammonite zone), established in this paper by strontium isotope stratigraphy, indicates that it took about 5 My after the Cenomanian–Turonian boundary crisis to re-evolve the complex test architecture of larger foraminifera, which is functional to their relation with photosymbiotic algae and K-strategy.     

Origin and evolutionary history of Anglonautilus (Nautilida,Cymatoceratidae) and a new species from the lower Aptian of Spain

The cymatoceratid nautilid genus Anglonautilus is distinguished from most other post-Triassic nautiloids by the occurrence of pronounced fold-like undulating ribs on the phragmocone and early body chamber. Anglonautilus praeundulatus n. sp. is described from the lower Aptian of eastern Spain. It is the first record of this genus from Spain and constitutes the oldest definite representative of the genus. This places the new species at the base of the evolutionary history of Anglonautilus. Its ornamental features confirm the previously assumed close relationship between Anglonautilus and Cymatoceras. An analysis of the ornamental pattern of all species hitherto referred to Anglonautilus indicates that there is an evolutionary lineage leading to the type species of the genus, A. undulatus, and a single successor (A. subalbensis). Several Late Cretaceous species hitherto identified as Anglonautilus (A. japonicus, A. mamiyai, A. suciensis) bear fold-like ribs superficially similar to typical representatives of Anglonautilus. The pattern of ornament in these taxa is very different at closer inspection, though. This suggests that these species developed independently from Cymatoceras. The undulations present in these taxa are interpreted here as a result of convergent evolution. They are therefore excluded from the genus Anglonautilus and provisionally referred to as “Anglonautilus” spp.     

U–Pb Zircon Ages of Early Cretaceous Volcanic Rocks in the Tethyan Himalaya at Yangzuoyong Co Lake,Nagarze, Southern Tibet,and Implications for the Jurassic/Cretaceous Boundary

Upper Jurassic–Lower Cretaceous transitional successions are widely distributed in the Tethyan Himalaya, southeast of Yangzuoyong Co Lake, southern Tibet. In ascending order, these include the Weimei (J₃, Tithonian), Sangxiu/Jiabula formations (K₁, Berriasian). The J/K boundary is located between the Weimei Formation and Sangxiu/Jiabula Formations. Ammonites found in J/K boundary sections in the research area have been classified into three assemblages: Valanginites–Phyllopachyceras assemblage zone (Valanginian), Spiticeras–Thurmanniceras assemblage zone (Berriasian) and Haplophylloceras–Blanfordiceras–Himalayites assemblage zone (Tithonian). Six nannofossil zones: Calcicalathina oblongata assemblage zone, Speetonia colligate zone, N. st. steinmannii zone, N. st. minor zone, P. beckmanni–N. st. minor interval zone, Conusphaera–Polycostella–Nannoconus–Watznaueria assemblage zone were recognized as well.On the basis of lithology, biostratigraphy and geochronology of the J/K transitional deposition succession, this study suggests that the J/K boundary, in southern Tibet, is located on the bottom of P. beckmanni–N. st. minor interval zone, which is further definited as and disappear of Polycostella beckmanni. To address the paucity of previously reported reliable ages for the J/K boundary, this study reports four U–Pb zircon ages (140–142 Ma) obtained with Secondary Ion Mass Spectrometry (SIMS) from the volcanic rocks interbedded in the lower Sangxiu Formation, which is expected to provides a direct date reference for the J/K boundary in the Tethyan Himalaya, southern Tibet. From integration of our new (SIMS) U–Pb zircon ages with calcareous nannofossils and ammonites, the age of the N. st. minor zone (NK-D) directly above the P. beckmanni-N. st. minor interval zone (NJK-C) of the basal Berriasian in the Tethyan realm is estimated to be 141–142 Ma. This research is not only helpful to improve the isotopic determination of absolute age for the J/K boundary, but also implies that the Tethyan Himalaya of southern Tibet may be an ideal location in which to explore the J/K boundary in both biostratigraphy and geochronology in future.     

First record of Bison antiquus from the Late Pleistocene of southern Mexico

In Mexico, just 54% of the reported Pleistocene Bison material has been identified to species. Current paleontological research in northwestern Oaxaca, southern Mexico, has allowed collection of several specimens of Bison antiquus that are part of the Viko Vijin Local Fauna. B. antiquus had a very wide geographic distribution, from lowlands to mountainous landscapes of North and Central America. The B. antiquus record from southern Mexico links their former records from central Mexico and middle Central America and confirms this wide geographic distribution. The univariate mesowear score of the B. antiquus specimens from Oaxaca is in the lower extreme of grazers and the upper end of mixed-feeders, suggesting that they had a less abrasive diet than the modern plains Bison, as has been observed in other samples of this species from diverse parts of North America. The presence of B. antiquus in the Viko Vijin L. F. constrains the age of this fossil assemblage within a range from 60 Ka to 11.7 Ka.     

Notes on the divergence time of the fern genus Asplenium from fossil and molecular evidence

The extant fern genus Asplenium Linnaeus, 1753 is widely distributed in tropical-temperate regions and shows a high diversity. The oldest fossils assigned to it comprise fronds and spores preserved in situ from the Lower Cretaceous of northeast Asia. However, molecular dating suggests that Asplenium diverged during the Paleocene (∼57.7 Ma). Here we present some explanations for the disparity in fossil and molecular age estimates, and new insights into the origin and evolution of the genus. We suggest that Cretaceous Asplenium most likely represents a stem-group member, and that lineage extinction during the early evolutionary stages of the genus resulted in missing nodes.     

A possible azhdarchid pterosaur (Pterosauria,Azhdarchidae) in the Durlston Formation (Early Cretaceous,Berriasian) of southern England

A new specimen of pterosaurian metacarpal IV from the Early Cretaceous (Berriasian) Durlston Formation of Dorset, southern England, closely resembles those of the Chinese dsungaripterid Dsungaripterus weii Young, 1964 and the Central Asian azhdarchid Azhdarcho lancicollis Nessov, 1984. However, the new specimen lacks the thickened bony wall typical of Dsungaripteridae and is therefore regarded as azhdarchoid. An mcIV with a markedly offset distal condyle with well-developed diaphyseal constriction behind the distal condyle and asymmetrical condylar margins may be an autapomorphy of Dsungaripteridae + Azhdarchoidea, while the same condition with bone thickening may typify Dsungaripteridae. The new specimen also provides osteological evidence supporting claims for large wing-spanned pterosaurs in the Berriasian of southern England based previously only on ichnological finds. The new specimen suggests a wingspan of between 2.9 and 3.7 m and represents the largest pterosaur from the Berriasian.     

Cranial anatomy of Pholidosaurus purbeckensis from the Lower Cretaceous of France and its bearing on pholidosaurid affinities

New and nearly complete cranial remains of Pholidosaurus purbeckensis are described on the basis of specimens recovered from the Berriasian locality of Cherves-de-Cognac, France. Two skulls, associated mandibles and a set of dorsal osteoderms are available and allow a refinement of the anatomy of the genus, known otherwise from coeval deposits in Germany and England. Because of its longirostrine morphology, convergent with other crocodylomorph lineages, the phylogenetic relationships of Pholidosaurus are likely to be affected by Long Branch Attraction problems. Various tests of removing/excluding longirostrine lineages confirm that Dyrosauridae have a labile position and that their affinities with Pholidosauridae are weakly supported. Results from comparative anatomy and phylogenetic analyses recover Pholidosaurus as the basalmost member of Pholidosauridae, a group closely related to Goniopholididae. Pholidosaurus is recovered together with abundant remains of Goniopholis and with more limited remains of Theriosuchus. The paleoecology of Pholidosaurus and more generally, of Pholidosauridae, is discussed.     

Evolution of the Cretaceous calcareous nannofossil genus Eiffellithus and its biostratigraphic significance

The calcareous nannofossil genus Eiffellithus is an important taxon of mid- to Upper Cretaceous marine sediments in biostratigraphy and paleoceanography. The definition of species within Eiffellithus have been both broadly interpreted and variably applied by nannofossil workers. This is particularly true for the Eiffellithus eximius plexus. While the taxonomy of mid-Cretaceous Eiffellithus species has recently been well-defined, the remaining 35 m.y. history of the genus has not been closely examined. Our investigation of Cenomanian to Maastrichtian sediments from the Western Interior Seaway, Gulf of Mexico, and Western Atlantic gives rise to six new species of Eiffellithus that can be reliably differentiated. In this paper the hitherto used biostratigraphic markers (E. turriseiffelii and E. eximius) have been redefined in a more restricted sense to increase their utility. These refinements in taxonomy reveal an obvious shift in abundance both within the genus and within the nannofossil assemblage as a whole through the Late Cretaceous. In the Cenomanian and Maastrichtian the genus is composed exclusively of coccoliths bearing an X-shaped central cross, such as E. turriseiffelii, while in the Coniacian through Campanian axial-cross forms such as E. eximius comprise more than 60% of the genus. Within the nannofossil assemblage the genus has low abundances in the Cenomanian but increases to >15% of the assemblage in well-preserved samples in the Santonian. In addition, the pattern of diversification of this genus, whereby a x-shaped, diagonal cross repeatedly gives rise to an axial cross by rotation about the central axis, is an excellent example of iterative evolution that may be related to repetitive shifts in Late Cretaceous climatic and paleoceanographic regimes.     

Detecting recent changes in the demographic parameters of drosophilid populations from western and central Africa

Previous genetic studies showing evidence of past demographic changes in African drosophilids suggested that these populations had strongly responded to Quaternary climate changes. We surveyed nine species of Zaprionus, a drosophilid genus mostly present in Africa, in forests located between southern Senegal and Gabon. The mitochondrial COI gene showed contrasted levels of sequence variation across species. Populations of the only cosmopolitan species of the genus, Z. indianus, and of its closely related sibling species, Z. africanus, are highly polymorphic and appear to have undergone a continuous population expansion beginning about 130,000 years ago. Five less variable species probably underwent a population expansion beginning only about 20,000–30,000 years ago. One of them, Z. taronus, was significantly structured between forest blocks. The last two species were nearly monomorphic, probably due to infection by Wolbachia. These results are similar to those obtained in three species from the melanogaster subgroup, and may be typical of the responses of African drosophilid populations to glacial cycles.