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1.
《International Journal of Coal Geology》2007,69(1-2):55-67
Discovery of a permineralized fossil cone in Mesozoic deposits of southern England provides an opportunity to document the first detailed evidence of internal pollen cone anatomy for the extinct conifer family Cheirolepidiaceae. The specimen, described here as Classostrobus crossii sp. nov., occurs in a calcareous nodule recovered from Middle Jurassic marine sediments of the Lower Callovian Sigaloceras calloviense biozone, Kellaways, near Cirencester, England. The cone is 2.0 cm long and 1.8 cm wide. Sporophylls diverge helically from the axis. Each sporophyll displays a narrow stalk and a distal lamina approx. 11 mm long that tapers to a pointed tip. There is also a basal keel that bends inward at the bottom and sides to form a shallow pocket. A single vascular bundle diverges from the cone axis, extends distally into the sporophyll stalk at the contact of two distinctly different histological zones, and further expands into the distal lamina as transfusion tracheids. Several pollen sacs are attached abaxially at the juncture of the sporophyll stalk and keel. Pollen is roughly spheroidal, 26–35 μm in diameter, with unequal polar caps separated by a striated belt with a subequatorial furrow. This specimen helps clarify the range of variation in the morphology of Mesozoic conifer pollen cones. 相似文献
2.
John P. Green Dean R. Lomax 《Proceedings of the Geologists' Association. Geologists' Association》2014
A fragmentary ichthyosaur specimen collected in situ at Castle Top Quarry in Nettleton, Lincolnshire, UK from exposures of the Lower Cretaceous (Berriasian) Spilsby Sandstone Formation (Subcraspedites ?preplicomphalus Zone) is reported. In general, Early Cretaceous ichthyosaurs from the Berriasian to Barremian are poorly understood. Despite the fragmentary nature of the described specimen, it is the first ichthyosaur reported from this specific zone and adds to the literature another rare ichthyosaur from the Berriasian. 相似文献
3.
Jean-Paul Billon-Bruyat Jean-Michel Mazin Joane Pouech 《Swiss Journal of Geoscience》2010,103(2):143-153
The spotty nature of the terrestrial fossil record for the Mesozoic hinders a more complete understanding of dinosaur diversity. For stegosaurs (Ornithischia), the plated dinosaurs, only a few and fragmentary remains are reported from the Early Cretaceous of Europe. A recent revision concluded that only a partial vertebra of the nomen dubium Craterosaurus (?Aptian, England) could be considered as stegosaurian. Here we report on a stegosaur tooth from the Early Cretaceous (Berriasian) Purbeckian deposits of Cherves-de-Cognac (Charente), southwestern France. This tiny tooth was examined in detail using microtomography. Comparisons being limited by the rarity of stegosaur tooth rows material (e.g., from the skull of the holotype of Stegosaurus stenops) and dental material, notably from Europe, we observed new material of cf. Stegosaurus armatus and Hesperosaurus mjosi from the Upper Jurassic Morrison Formation of Wyoming (USA). The tooth shows the most similarities to the Late Jurassic genera Stegosaurus and Hesperosaurus, but differs in having a distinctive downwardly arched (V-shaped) cingulum on the ?lingual face (maxillary tooth hypothesis). It is referred to as Stegosauria indeterminate, a medium-sized quadrupedal herbivore that inhabited an emerged land between the Armorican Massif and the Massif Central. This finding is the first evidence of a stegosaur from the Early Cretaceous of France and a welcome addition to the meagre European record of that time. In addition, it is the second stegosaurian tooth crown reported from Europe. The assemblage of ornithischians of Cherves-de-Cognac shares some similarities with that of the Early Cretaceous (Berriasian) of the Purbeck Limestone Group, southern England. The relative rarity of ornithischian osteological remains in both Purbeckian environments suggests that most of these dinosaurs were mainly inhabitants of inland terrestrial palaeoenvironments. 相似文献
4.
A new species of Elcanidae (Orthoptera: Elcanoidea), Panorpidium yixianensis sp. nov., is described based on two new specimens from the Lower Cretaceous Yixian Formation of northeastern China. It differs from other species in forewing characters and spines on the hind tibiae. In addition, a new specimen Burmelcana sp., is described and figured based on an amber inclusion from the mid-Cretaceous Burmese (Myanmar) amber. P. yixianensis sp. nov. represents the first definite record of Elcanidae in the Early Cretaceous Jehol biota, and Panorpidium is the only genus of Ensifera to be found in the Early Cretaceous faunas of England, Russia and China. 相似文献
5.
We re-define the Cretaceous bony fish genus Rhinconichthys by re-describing the type species, R. taylori, and defining two new species; R. purgatorensis sp. nov. from the lowermost Carlile Shale (middle Turonian), southeastern Colorado, United States, and R. uyenoi sp. nov. from the Mikasa Formation (Cenomanian), Middle Yezo Group, Hokkaido, Japan. Rhinconichthys purgatoirensis sp. nov. is designated on a newly discovered specimen consisting of a nearly complete skull with pectoral elements. Only known previously by two Cenomanian age specimens from England and Japan, the North American specimen significantly extends the geographic and stratigraphic range of Rhinconichthys. The skull of Rhinconichthys is elongate, including an expansive gill basket, and estimated maximum body length ranges between 2.0 and 2.7 m. Rhinconichthys was likely an obligate suspension-feeder due to its derived cranial morphology, characterized by a remarkably large and elongate hyomandibula. The hyomandibula mechanically acts as a lever to thrust the jaw articulation and hyoid arch both ventrally and anterolaterally during protraction, thus creating a massive buccal space to maximize filtering of planktonic prey items. Cladistic analysis supports a monophyly of suspension-feeding pachycormids including Rhinconichthys, but further resolution within this clade will require more information through additional fossil specimens. 相似文献
6.
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. 相似文献
7.
Seven specimens of fossil scorpionflies (Mecoptera) not assignable to any known family were discovered in the Wealden Supergroup (Lower Cretaceous) of southern England. They were found at Rudgwick Brickworks, West Sussex and Smokejacks Brickworks, Surrey and came from the Upper Weald Clay Formation, dated as Barremian (∼129.4–125 Ma). A new family – Englathaumatidae fam. nov., new genus – Englathauma gen. nov. and two new species E. crabbi sp. nov. and E. mellishae sp. nov. are described. A discussion of systematic position of these new taxa within the order Mecoptera is given. Englathaumatidae fam. nov. has been a nomen nudum since the year 2002, due to the first author's untimely death. 相似文献
8.
Axelrodichthys megadromos sp. nov. is a coelacanth described based on a single specimen collected in the lower Campanian site of Ventabren motorway, Southern France. The new species is referred to the mawsoniids because of the ornamentation of the skull roof and of the proportionally wide supraorbital series. The specimen belongs to the Mawsonia-Axelrodichthys complex based on features present on the lower jaw and on the basisphenoid. The new species is referred to the genus Axelrodichthys because of proportions of its parietonasal shield and because of the arrangement of the posterior parietals relative to the supraorbitals. Autapomorphic characters, in particular on the parasphenoid, justify the inclusion of the specimen in a new species. The occurrence of a mawsoniid in the Ibero-Amorican Island that formed part of the European Archipelago in the terminal Cretaceous is an evidence of a dispersal event from the southern land masses. The occurrence of A. megadromos in the Campanian-Maastrichtian represents the last occurrence of mawsoniids worldwide, after a gap in the fossil record of about 30 million years. This belated occurrence of Axelrodichthys extends the time range of this genus to approximately 40 myr and suggests that this genus, together with its sister genus Mawsonia, were organisms with a slow morphologic evolution. 相似文献
9.
During fieldwork carried out in January 2009 at Aurora do Tocantins (Tocantins State, northern Brazil), we recovered a fragmentary right maxilla (UNIRIO-PM 1006) of Catagonus stenocephalus from a sedimentary deposit of presumed late Pleistocene age in a karstic cave. This paper aims to: (1) provide the first record of C. stenocephalus in the northern region of Brazil (and consequently, also the northernmost one); (2) update the geographic distribution of C. stenocephalus; (3) present a date for the specimen; and (4) discuss the palaeoenvironmental and palaeobiogeographical implications of the finding. The species C. stenocephalus (Lund) is known from the Bonaerian (middle Pleistocene) and Lujanian (late Pleistocene to earliest Holocene) ages in Argentina, Uruguay, Brazil and Bolivia. The new record presented here extends the geographical distribution of C. stenocephalus more than 1000 km north from the former northernmost record (caves of Lagoa Santa region). Peccaries of the genus Catagonus have several morphological features associated with cursorial habits in relatively open and dry environments. The new distributional range of C. stenocephalus is coincident with the Chacoan subregion, characterized by dry climates and open areas. As the studied material comes from the top of the carbonate layer, this may suggest that the deposition of the C. stenocephalus remains described here is synchronous with the onset of a wetter climate phase. This argument is also in accordance with the datation results, around 20 ky BP, just after the last glacial maximum. This increasingly wet climate, which may also be related to the climatic changes that occurred during the late Pleistocene/early Holocene, could be a factor in the extinction of C. stenocephalus in South America. 相似文献
10.
11.
Fabrizio Cecca Kazem Seyed-EmamiJohann Schnyder Mohamed BenzaggaghMahmoud Reza Majidifard Mohammed Mohammadi Monfared 《Cretaceous Research》2012,33(1):106-115
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. 相似文献
12.
A gypsum quarry at Cherves-de-Cognac in south-western France exposes a large section of Berriasian (basal Cretaceous) sediments deposited in a lagoonal environment. The sediments have yielded rich vertebrate faunas, but only two species of selachians are present; the lonchidiid hybodont Parvodus celsucuspus sp. nov. and the batoid Belemnobatis variabilis. The composition of the fauna, including only a single, seemingly endemic, hybodont species from a time when hybodont faunas are relatively well investigated in Europe, indicate that small hybodonts were not able to migrate longer distances. The recorded batoid species also occurs in southern England, demonstrating that these batoids were primarily marine fishes that regularly explored areas with reduced salinity. 相似文献
13.
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. 相似文献
14.
Berriasella jacobi is a key ammonite taxon that has been widely used for the definition of the Tithonian/Berriasian boundary and has been widely quoted in the literature as the index species for the lowest zone of the Berriasian Stage. The taxonomic revision of B. jacobi shows that it should be excluded from the genus Berriasella and transferred to the genus Strambergella. Analysis of the literature has convinced us that most specimens illustrated as B. jacobi have been misidentified. New collection at Le Font de Saint Bertrand (Les Combes, Glandage, Drôme, France) shows us the type series corresponds to the microconch form of a dimorphic pair. New integrated data on its stratigraphic distribution causes us to question its value as an index species for the base of the Berriasian. 相似文献
15.
Late Jurassic and Early Cretaceous charophyte assemblages from the northern part of the Aquitaine Basin in south-west France are reviewed here to understand their palaeoecological, palaeobiogeographical and biostratigraphic features. Three sites were studied: the Tithonian-lower Berriasian of Chassiron, and the Berriasian of Cherves-de-Cognac and Angeac-Charente. Abundant porocharaceans, less abundant clavatoraceans and scarce characeans recorded in Cherves-de-Cognac and Angeac-Charente indicate that brackish water environments were substituted by freshwater environments eastwards. The occurrence of Clavator grovesii var. grovesii and morphotypes intermediate with C. grovesii var. discordis in the same areas is significant from a biostratigraphic viewpoint, since these species belong to the Maillardii, Incrassatus and Nurrensis European charophyte biozones, representing the Berriasian. This observation refutes a previous dating of the Angeac-Charente site and highlights the absence of Hauterivian–Barremian records in northern Aquitaine, which is in contrast to the more complete Lower Cretaceous record in southern Aquitaine. These contrasting records could be due to differences in the available sedimentary space produced by the opening of the Bay of Biscay during the Barremian. 相似文献
16.
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. 相似文献
17.
Andrew T. McDonald 《Cretaceous Research》2012,33(1):1-6
Dollodon bampingi was recently named based upon a specimen from the Bernissart Quarry that had previously been referred to Mantellisaurus atherfieldensis. The initial diagnosis of Dollodon did not adequately distinguish it from Mantellisaurus or from other basal iguanodonts, necessitating a reassessment of the material. Firsthand examination of the holotypes of the two taxa and numerous other basal iguanodont specimens, as well as a principal components analysis of basal iguanodont dentaries, did not find any morphological features to justify the distinction of Dollodon from Mantellisaurus. D. bampingi is thus best considered a junior synonym of M. atherfieldensis. Furthermore, the recent referral of the species Iguanodon seelyi to the genus Dollodon is not supported; I. seelyi is indistinguishable from Iguanodon bernissartensis, and is considered a junior synonym of that species. Finally, the recently named taxon Proplanicoxa galtoni, also based upon a specimen formerly attributed to M. atherfieldensis, is considered a nomen dubium and probable junior synonym of M. atherfieldensis. Thus, only two species of large-bodied basal iguanodont should be recognized from the Barremian-Aptian of England and Belgium: M. atherfieldensis and I. bernissartensis. 相似文献
18.
《Cretaceous Research》2012,33(6):774-780
Rebbachisauridae is a poorly understood clade of diplodocoid sauropod dinosaurs, currently known only from the Cretaceous of Africa, Europe and South America. European representatives are particularly rare and fragmentary. Here, we report an anterior caudal vertebra from the Barremian (Early Cretaceous) Wessex Formation of the Isle of Wight, off the southern coast of England. This specimen possesses several features known only in rebbachisaurids and shares two synapomorphies with the Afro-European taxa Demandasaurus darwini and Nigersaurus taqueti, both pertaining to the morphology of the neural spine. These features are the development of triangular lateral processes and the presence of an elliptical fossa on the lateral surface, bounded by the lateral lamina and postspinal rugosity. The Isle of Wight specimen also shares several features solely with Demandasaurus, indicating a close relationship with the Spanish taxon. These include the presence of a hyposphenal ridge, as well as an anteriorly excavated caudal rib that is restricted almost entirely to the neural arch. However, it differs from Demandasaurus in a number of ways, including the lack of excavation on the posterior surface of the caudal rib, the orientation of the neural spine, and the composition and morphology of the lateral lamina. In addition, the Isle of Wight vertebra possesses one potential autapomorphy: bifurcation of the elliptical fossa on the neural spine. However, because of the fragmentary nature of the material, a new name is not erected. Along with Demandasaurus and Histriasaurus boscarollii, this caudal vertebra indicates the presence of at least three European rebbachisaurid taxa and provides new anatomical information on this enigmatic clade of sauropod dinosaurs. 相似文献
19.
《Proceedings of the Geologists' Association. Geologists' Association》2022,133(6):491-500
Pterosaurs are a rare component of the Early Cretaceous (Albian) Gault Formation of southern England. The only named taxon reported, ‘Pterodactylus’ daviesii Owen, 1874, is widely regarded as a nomen dubium or as Pterodactyloidea incertae sedis, while most other material can be referred to Pterodactyloidea indet. Here we describe a fragmentary humerus and elongate mid-series cervical vertebra both from the Gault Formation of Kent, southeast England that can be referred to the edentulous pterodactyloid clade Azhdarchoidea. The cervical vertebra is identified as being from a non-tapejaromorph azhdarchoid on account of its reduced neural spine, a neural arch confluent with the centrum, a neural canal that is subsumed into the centrum and the lack of foramina on the lateral surfaces of the centrum. The humerus is referred to Azhdarchoidea on account of its sub-rectangular distal end. 相似文献
20.
Yabeinosaurus was the first lizard genus described from the Early Cretaceous Jehol Biota of China. The holotype of the type species, Y. tenuis, is an immature skeleton but it has been lost for decades. A second species, Y. youngi, was erected based on another immature skeleton and is distinguished by its longer, more gracile limbs. In 2001, a juvenile skeleton from the Jingangshan locality of Liaoning was designated as the neotype for Y. tenuis. Subsequently, several further specimens from other localities, juvenile and adult, have been attributed to this species. Here we describe a second lizard specimen from the neotype locality. In anterior tooth shape, finger-like mandibular angular process, cranial sculpture, maxilla shape, and short, robust humerus, the new specimen resembles adult and subadult material currently attributed to Y. tenuis, but it differs in having bicuspid posterior teeth and a straight rather than a hooked angular process of the mandible. We propose a new species (Y. bicuspidens sp. nov.) for this specimen which represents the first occurrence of bicuspid teeth in an Early Cretaceous lizard from China. However, the recognition of a second species at the neotype locality raises a taxonomic problem. Due to the immaturity of the designated holotype and neotype of Y. tenuis, they cannot be coded for the jaw and dental characters that distinguish the two robust-limbed species. This renders Yabeinosaurus tenuis a nomen dubium. Here we propose that Yabeinosaurus tenuis should be treated as a historic taxon, permitting retention of the generic name under ICZN rules, and erect a second new species (Y. robustus sp. nov.) for the principal robust-limbed morphotype in the Jehol Biota with monocuspid posterior teeth and a hooked angular process. 相似文献