Pleurotomaria DeFrance, 1826 (Gastropoda,Mollusca) from the Lower Bajocian (Middle Jurassic) sediments of Luxembourg,with considerations on its systematics,evolution and palaeobiogeographical history

Abstract: Pleurotomaria species from lower Bajocian (Middle Jurassic) sediments of south‐western Luxembourg housed in the National Natural History Museum of Luxembourg are described. Seven species are recognized, one of which is new, Pleurotomaria faberi sp. nov. A more detailed definition of the diagnostic characters of the genus is proposed and the morphological continuity between Talantodiscus and Pleurotomaria is demonstrated, suggesting that the former cannot be considered as a distinct taxon. The palaeoecology, evolution and palaeobiogeographical history of Pleurotomaria are outlined. Pleurotomaria presumably first appeared in late Middle Triassic of New Zealand where it underwent a relative diversification up to the Hettangian (Early Jurassic). From early Hettangian, most of its evolutionary history took place in Europe and western Tethys. In the European epicontinental seas, Pleurotomaria experienced two important radiations. The first occurred in the Early Jurassic, with a peak in the late Pliensbachian, and was marked by an expansion of the distribution to the central part of western Tethys. After a collapse in species diversity, probably related to the early Toarcian anoxic event, a second radiation occurred. This culminated in the early Bajocian and was mainly confined in a region encompassing southern England, Paris Basin and southern Germany. Low‐spired species, formerly attributed to Talantodiscus, probably originated independently and iteratively during the history of Pleurotomaria. The facies and associated benthic faunas suggest that Pleurotomaria probably lived on shallow soft bottoms composed of mixed calcareous–siliciclastic sediments. The two main Early Jurassic and early Middle Jurassic radiations of the genus took place in these environments. Records of the genus in Jurassic carbonate platform deposits are very few and concern mainly post‐Bajocian species.     

A revision of the sauropod dinosaur genus ‘Bothriospondylus’ with a redescription of the type material of the Middle Jurassic form ‘B. madagascariensis’

Abstract: The sauropod dinosaur ‘Bothriospondylus’, originally named on the basis of Late Jurassic remains from England, is demonstrated to be invalid, and the characters used to diagnose it are shown to be obsolescent features which are widespread throughout Sauropoda. Material referred to this genus spans a temporal range from the Middle Jurassic until the early Late Cretaceous and has been described from five different countries, across three continents. These remains represent a wide array of sauropod groups, comprising non‐neosauropod eusauropods, a macronarian, titanosauriforms (including at least one definite brachiosaurid) and a rebbachisaurid. The type material of the Middle Jurassic ‘B. madagascariensis’ represents a derived non‐neosauropod eusauropod and possesses two potential autapomorphies. However, as a result of the fragmentary nature of the material and the uncertainty surrounding its association, a new taxon is not erected. Of the numerous specimens referred to ‘Bothriospondylus’, however, several remains are considered diagnostic: Ornithopsis hulkei (Early Cretaceous, UK), Lapparentosaurus madagascariensis (Middle Jurassic, Madagascar) and Nopcsaspondylus alarconensis (early Late Cretaceous, Argentina). At least three types of sauropod were present in the Bathonian (Middle Jurassic) of north‐west Madagascar, with a basal eusauropod (Archaeodontosaurus), a more derived eusauropod (‘B. madagascariensis’) and a titanosauriform (Lapparentosaurus) all approximately contemporaneous. Palaeocontinental reconstructions suggest that Middle Jurassic Madagascan sauropods would still have been capable of global biotic interchange, and this is perhaps reflected in their diverse assemblage. Re‐evaluation of these Malagasy forms has shed new light on this important time period in sauropod evolution.     

A well‐preserved isopod from the Middle Jurassic of southern Germany and implications for the isopod fossil record

A new isopod species, Eonatatolana geisingensis gen. et sp. nov., is described from Middle Jurassic shallow‐water sediments of southern Germany. It shows not only the almost completely preserved dorsal morphology but, in addition, details of the cephalic appendages, the pereiopods, pleopods and uropods. The presence of ambulatory pereiopods I–VII of a wide tridentate mandibular incisor with prominently developed posteriormost tooth and a narrow frontal lamina indicates that the new species belongs to the subfamily Conilerinae of family Cirolanidae within the suborder Cymothoida. It is closer to the species of the modern genus NatatolanaBruce than to any fossil isopod hitherto described. The isopod fossil record as well as current practices of isopod taxonomy in palaeontology are discussed, and the facies distribution and fossilization of isopods is reviewed with examples from the Jurassic.     

Steneosaurus edwardsi (Thalattosuchia: Teleosauridae), the largest known crocodylomorph of the Middle Jurassic

Teleosaurids were a clade of marine crocodylomorphs that were globally distributed during the Jurassic Period. They evolved a wide range of body sizes, from small (～2–3 m) to very large (> 9 m). Until now, the largest known Middle Jurassic teleosaurid was ‘Steneosaurus’ obtusidens, from the Oxford Clay Formation of the UK. Here, we re‐examine a very large Oxford Clay specimen (ilium, ischium, and femur) that had been tentatively attributed to ‘S.’ obtusidens. Based on comparative anatomical study with the ‘S.’ obtusidens holotype and referred specimens of Steneosaurus edwardsi and Steneosaurus leedsi, we conclude that this very large individual actually pertains to S. edwardsi. Based on comparisons with the Machimosaurus mosae neotype (which has a complete femur and skeleton), we estimate a total length in excess of 7 m for this large S. edwardsi individual, making it the largest known Middle Jurassic teleosaurid. Therefore, along with the closely related genus Machimosaurus, this clade of large‐bodied Middle–Late Jurassic teleosaurids were the largest species during the first 100 million years of crocodylomorph evolution. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, ●● , ●●–●●.     

Middle to Late Jurassic radiolarians from Sicily (Italy)

Middle and Upper Jurassic radiolarian faunas from two sections of Sicily are compared with the previously proposed zonations. The ages of the faunas are estimated by correlation with these zonations and by concurrent range zone. The faunas could be assigned to the Bathonian or earlier late Tithonian or early Berriasian. Two new spumellarian species (Bernoullius furcospinus andBernoullius rectispinus) from Middle Jurassic are described.     

Phylogenetic analyses elucidate the inter‐relationships of Pamphilioidea (Hymenoptera,Symphyta)

The phylogeny of the superfamily Pamphilioidea is reconstructed using morphology and DNA sequence data of living and fossil taxa by employing two phylogenetic methods (maximum parsimony and Bayesian inference). Based on our results, the monophyly of Pamphilioidea and Pamphiliidae are corroborated, whereas two extinct families, Xyelydidae and Praesiricidae, are not monophyletic. Because members of Praesiricidae together with Megalodontes form a monophyletic group, we propose that the paraphyletic Praesiricidae is synonymized under Megalodontesidae (syn. nov.). The origin of Pamphilioidea is hypothesized to be as early as the Early Jurassic. To better understand morphological evolution in the early lineages of Pamphilioidea, ancestral states of the first flagellomere and the first and second abdominal terga are reconstructed on the morphology‐based tree. In addition, three new genera (Medilyda, Brevilyda, Strenolyda) with five new species (Medilyda procera, M. distorta, Brevilyda provecta, Strenolyda marginalis and S. retrorsa) are described based on well‐preserved xyelydid fossils from the Middle Jurassic Jiulongshan Formation of north‐eastern China.     

A description of Megalosaurus bucklandii (Dinosauria: Theropoda) from the Bathonian of the UK and the relationships of Middle Jurassic theropods

Megalosaurus bucklandii (Dinosauria: Theropoda), the oldest named dinosaur taxon, from the Bathonian (Middle Jurassic) of England, is a valid taxon diagnosed by a unique character combination of the lectotype dentary. Abundant referred material is described and several autapomorphies are identified: ventral surfaces of first and third to fifth sacral centra evenly rounded, ventral surface of second sacral centrum bearing longitudinal, angular ridge; dorsally directed flange around midheight on the scapular blade; an array of posterodorsally inclined grooves on the lateral surface of the median iliac ridge; anteroposteriorly thick ischial apron with an almost flat medial surface; and complementary groove and ridge structures on the articular surfaces between metatarsals II and III. A new phylogenetic analysis focuses on basal tetanurans and includes 41 taxa, six of which have never been included in a cladistic analysis, and 213 characters, 29 of which are new. This is the first phylogenetic analysis to focus on basal tetanuran relationships, and it reveals several new results. Megalosauroidea (= Spinosauroidea) includes two clades, basal to the traditional content of Megalosauridae + Spinosauridae. These comprise Xuanhanosaurus, Marshosaurus, Condorraptor + Piatnitzkysaurus and Chuandongocoelurus + Monolophosaurus. Almost all large‐bodied Middle Jurassic theropods are megalosauroids, but Poekilopleuron is an allosauroid. Megalosauroids show geographical differentiation among clades, indicating the development of endemic theropod faunas across Pangaea during the Middle Jurassic. Notably, megalosaurids are not known from outside of Europe during this epoch. Megalosauroids are less diverse and abundant during the Late Jurassic, when most theropods are neotetanurans and allosauroids dominate the large‐bodied predator niche. This indicates faunal turnover between the Middle and Late Jurassic. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 882–935.     

Dinoflagellate cyst biostratigraphy of the Opalinuston Formation (Middle Jurassic) in the Aalenian type area in southwest Germany and north Switzerland

Feist‐Burkhardt, S. & Pross, J. 2010: Dinoflagellate cyst biostratigraphy of the Opalinuston Formation (Middle Jurassic) in the Aalenian type area in southwest Germany and north Switzerland. Lethaia, Vol. 43, pp. 10–31. In order to provide a detailed dinoflagellate cyst stratigraphy of the Lower Aalenian Opalinuston Formation from the Aalenian type area, 68 samples from four boreholes and one outcrop section were analysed. The sample localities are Hausen an der Fils and Wittnau in southwest Germany, Weiach in north Switzerland and Mont Russelin in the Swiss Jura Mountains. Dinoflagellate cyst assemblages were recovered from the Late Toarcian Aalensis Zone to the Late Aalenian Murchisonae Zone. The samples yielded rich, well‐preserved and diverse assemblages with 51 dinoflagellate cyst taxa identified in total. The dinoflagellate cyst distribution data obtained from this study allow a high‐resolution biostratigraphical subdivision of the lowermost Middle Jurassic Opalinuston Formation into four palynostratigraphical units. First and last occurrences, acmes and consistent presence of the species Batiacasphaera sp. A, Evansia cf. granochagrinata, Kallosphaeridium praussii, Nannoceratopsis triangulata, Phallocysta? frommernensis and Wallodinium laganum were selected as the criteria for defining these units. The obtained high‐resolution palynostratigraphical scheme provides a basis for establishing and further refining early Middle Jurassic biostratigraphy in the Boreal and Tethyan realms. □Aalenian, biostratigraphy, dinoflagellate cysts, Germany, Jurassic, Switzerland, Toarcian.     

Middle Jurassic fossils of the genus Sharasargus from Inner Mongolia, China (Diptera: Archisargidae)

To date, only two species of the genus Sharasargus are known. These Upper Jurassic species were found in Mongolia and Kazakhstan, respectively. We herein describe two new species from the Middle Jurassic, which were found in Inner Mongolia, China. They are the oldest known fossils of this genus. A key to Sharasargus species is given.     

Higher‐level phylogeny and evolutionary history of Pentatomomorpha (Hemiptera: Heteroptera) inferred from mitochondrial genome sequences

The higher‐level phylogeny of Pentatomomorpha, the second largest infraorder of true bugs (Hemiptera: Heteroptera), which includes many important agriculture and forestry pests, has been debated for decades. To investigate the phylogeny and evolutionary history of Pentatomomorpha, we assembled new mitochondrial genomes for 46 species through next‐generation sequencing of pooled genomic DNA. Based on a much broader taxon sampling than available previously, Bayesian analyses using a site‐heterogeneous mixture model (CAT+GTR) resolved the higher‐level phylogeny of Pentatomomorpha as (Aradoidea + (Pentatomoidea + (Coreoidea + (Lygaeoidea + Pyrrhocoroidea)))). There was a transition from trnT/trnP to trnP/trnT in the common ancestor of Pyrrhocoroidea, which indicates that this gene rearrangement could be an autapomorphy for Pyrrhocoroidea. Divergence time analyses estimated that Pentatomomorpha originated c. 242 Ma in the Middle Triassic, and most of the recognized superfamilies originated during the Middle Jurassic to Early Cretaceous. The diversification of families within Pentatomomorpha largely coincided with the radiation of angiosperms during the Early Cretaceous.     

Quantitative assessments and taxonomic revision of the genus Archirhagio with a new species from Daohugou,China (Diptera: Archisargidae)

A new species, Archirhagio gracilentus sp.n. , is described from the Middle Jurassic Jiulongshan Formation of Daohugou, Inner Mongolia in China. The ground plan of genital structures of Archirhagio is described according to the well‐preserved male and female genitalia in this new species. Based on venational patterns of five species of the Archirhagio, we conducted the geometric morphometric analysis to quantitatively review and revise the taxonomy of Archirhagio. The results indicate that most species of the genus, with one exception, have distinctive interspecific variances to support their taxonomy. Therefore, we propose Archirhagio mostovskii as a new synonym for Archirhagio zhangi according to both morphological characters and quantitative analyses. Furthermore, a traditional key character, the position of m‐cu, is too unstable to be used as a specific diagnosis. A key to all species of the Archirhagio is also provided. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:112F5E51-42AB-4438-9512-32E19E1CF5E3 .     

Two new species of Ginkgoales from the Middle Jurassic of Mexico

This paper reports two new species of Ginkgoales collected from the Cañada Alejandro and Río Ñumi (Zorrillo and Zorrillo–Taberna Undifferentiated Formations, Middle Jurassic). Thirty-one fossils were selected and compared with 14 species from different localities. A numerical taxonomy analysis was performed through a data matrix formed by 15 characters. Results indicate an important speciation process of the Ginkgoales during the Jurassic in the southeast of Mexico. New evidence suggests the existence of eight species from the Ginkgoidium Yokoyama, 1889 and Sphenobaiera (Florin) Harris and Millington, 1974 genera and two new species Ginkgoidiumnundichii Velasco-de León, Lozano-Carmona, Flores, Martínez and Silva and Sphenobaieramixteca Velasco-de León, Lozano-Carmona, Flores, Martínez and Silva     

New Jurassic Cercopoidea from China and their evolutionary significance (Insecta: Hemiptera)

Abstract: A new family, Sinoalidae Wang and Szwedo fam. nov., is described from the Middle Jurassic Daohugou Biota (Inner Mongolia, China). Two new genera with three new species (Sinoala parallelivena Wang and Szwedo gen. et sp. nov., Jiania crebra Wang and Szwedo gen. et sp. nov., and Jiania gracila Wang and Szwedo sp. nov.) are erected based on well‐preserved whole‐bodied specimens. The morphological characters of Procercopidae and the new family are given, and a key to the species of Sinoalidae is presented. The genera Luanpingia Hong, 1983 and Huabeicercopis Hong, 1983 are revised and attributed to Sinoalidae. The genera Mesocercopis Hong, 1983 and Sinotettegarcta Hong, 1986 are considered junior synonyms of Anthoscytina Hong, 1983. Taxa assigned to Sinoalidae fam. nov. cannot be attributed to any previously known family, but share some general (plesiomorphic) characters with ancient Clypeata, for example, postclypeus distinctly swollen, transversely wrinkled, antenna with a flagellum of a few elongate segments, frons with median ocellus and lateral ocelli on crown. Moreover, the new family is closely related to Procercopidae (Cercopoidea) based on a pronotum with a median incision at the hind margin; tegmen slender, partly punctuate, basal portion of Sc not exceeding apex of basal cell, and hind legs with lateral spines. It has a mixture of ancestral characters shared with Hylicelloidea and Jurassic Procercopidae and some derived characters. Therefore, it is tentatively placed in Cercopoidea. A preliminary phylogram of Clypeata is presented based on the combination of fossil and morphological data.     

Snipe flies (Diptera: Rhagionidae) from the Daohugou Formation (Jurassic), Inner Mongolia,and the systematic position of related records in China

Abstract: Four new species referred to three new genera and one known genus of fossil snipe flies (Family Rhagionidae) from the Daohugou Formation of Chifeng City in Inner Mongolia, north‐eastern China, are described as Daohugorhagio elongatus gen. et sp. nov., Parachrysopilus jurassicus gen. et sp. nov., Sinorhagio sinuatus sp. nov. and Trichorhagio gregarius gen. et sp. nov. These taxa represent only a fraction of the rhagionid assemblage in the Daohugou biota. They contribute towards the high diversity and abundance of snipe flies during the latest Middle Jurassic – earliest Late Jurassic. The diagnosis of Sinorhagio K. Zhang, Yang and Ren, 2006 is revised based on the new results. Many genera and species from the Lower Cretaceous of China have been assigned to Rhagionidae. Most of these do not actually belong to this family: specifically Mesorhagiophryne incerta Hong and Wang, 1990, M. robusta Hong and Wang, 1990, Mesostratiomyia laiyangensis Hong and Wang, 1990, Stratiomyopsis robusta Hong and Wang, 1990, Longhuaia orientalis Hong, Wang and Sun, 1992, Basilorhagio venusius Ren, 1995. Pauromyia oresbia Ren, 1998 is transferred to an archisargid genus as Sharasargus oresbius (Ren, 1998) comb. nov.     

Mesozoic Trachypachidae (Insecta: Coleoptera) from China

Abstract: Four well‐preserved beetles, attributed to Eodromeinae within Trachypachidae, are described from the Mesozoic of Inner Mongolia, China. Eodromeus robustus sp. nov., E. daohugouensis sp. nov. and Unda chifengensis sp. nov. are from the Middle Jurassic of Daohugou. The diagnostic characters for the two genera are revised, and all species of these genera are keyed. A new genus and species, Sinodromeus liutiaogouensis gen. nov., sp. nov., is described from the Lower Cretaceous Yixian Formation of Liutiaogou. The current fossil records of Trachypachidae from China are reviewed, and only five species (four described here) can be convincingly attributed to this family. The morphological disparity of Mesozoic Eodromeinae suggests that they evolved a broad spectrum of locomotory lifestyles.     

The palaeoxylological record of Metapodocarpoxylon libanoticum (Edwards) Dupéron-Laudoueneix et Pons and the Gondwana Late Jurassic–Early Cretaceous continental biogeography

Aim Vertebrates, palynomorphs and leaf floras each give a different picture of continental biogeography of Northern Gondwana during the Middle Jurassic–Early Cretaceous interval. A new biogeographical marker is required to get a clearer picture. Location Northern part of the Gondwana during the Middle Jurassic–Early Cretaceous interval. Methods Comparisons and correlations of wood data from the literature and new material. Results We have selected Metapodocarpoxylon Dupéron‐Laudoueneix et Pons because it has a restricted distribution, temporally and geographically; it is a well‐defined Mesozoic fossil wood monospecific genus, and there are wide‐ranging data on its distribution. Conclusions Metapodocarpoxylon distribution draws a clear latitudinal belt extending from Lebanon westward to Peru. Climate being the main factor of plant distribution at a global scale, the Metapodocarpoxylon area probably underlines a climatic belt. This has several implications, for example, choosing among different Global Circulation Models or discussing dinosaur distribution.     

Growth trajectories of some major ammonoid sub‐clades revealed by serial grinding tomography data

Molluscs such as ammonoids record their growth in their accretionary shells, making them ideal for the study of evolutionary changes in ontogeny through time. Standard methods usually focus on two‐dimensional data and do not quantify empirical changes in shell and chamber volumes through ontogeny, which can possibly be important to disentangle phylogeny, interspecific variation and palaeobiology of these extinct cephalopods. Tomographic and computational methods offer the opportunity to empirically study volumetric changes in shell and chamber volumes through ontogeny of major ammonoid sub‐clades in three dimensions (3‐D). Here, we document (1) the growth of chamber and septal volumes through ontogeny and (2) differences in ontogenetic changes between species from each of three major sub‐clades of Palaeozoic ammonoids throughout their early phylogeny. The data used are three‐dimensional reconstructions of specimens that have been subjected to grinding tomography. The following species were studied: the agoniatitid Fidelites clariondi and anarcestid Diallagites lenticulifer (Middle Devonian) and the Early Carboniferous goniatitid Goniatites multiliratus. Chamber and septum volumes were plotted against the septum number and the shell diameter (proxies for growth) in the three species; although differences are small, the trajectories are more similar among the most derived Diallagites and Goniatites compared with the more widely umbilicate Fidelites. Our comparisons show a good correlation between the 3‐D and the 2‐D measurements. In all three species, both volumes follow exponential trends with deviations in very early ontogeny (resolution artefacts) and near maturity (mature modifications in shell growth). Additionally, we analyse the intraspecific differences in the volume data between two specimens of Normannites (Middle Jurassic).     

A specialized new species of Ashicaulis (Osmundaceae,Filicales) from the Jurassic of Liaoning,NE China

A new species of structurally preserved fern rhizome, Ashicaulis plumites (Osmundaceae, Filicales), is described from the Middle Jurassic Tiaojishan Formation in western Liaoning Province, NE China. The new species is characterized by a peculiar sclerenchyma mass in the petiolar vascular bundle concavity. This sclerenchyma mass varies from a linear-shape to a mushroom-like shape with a remarkable outward protuberance, which distinguishes the present new species from other Ashicaulis species. Such a protuberance is very rare among osmundaceous ferns, and should represent a unique type for sclerenchymatous tissue in the osmundaceous vascular bundle concavity. Recognition of the peculiar structure of this new fossil species enriches anatomical diversity of permineralized osmundaceous ferns, indicating that the family Osmundaceae might have experienced a remarkable diversification during the Middle Jurassic in NE China. The new species show anatomical similarities to Osmunda pluma Miller from the Palaeocene of North America. The occurrence of A. plumites in the Middle Jurassic of China provides a new clue for understanding the evolution of some members of the living subgenus Osmunda.     

The ‘Giant of Ksour’, a Middle Jurassic sauropod dinosaur from Algeria

Continental strata of Early and Middle Jurassic age are seldom-exposed, and little is known of the history of sauropod dinosaurs prior to the neosauropod radiation of the end of the Middle Jurassic. Here, we report, in the Middle Jurassic of the Occidental Saharan Atlas (Algerian High Atlas), the discovery of a skeleton, including cranial material, of a new cetiosaurid sauropod. Chebsaurus algeriensis n. g., n. sp. represents the most complete Algerian sauropod available to date, only few remains were found before. To cite this article: F. Mahammed et al., C. R. Palevol 4 (2005).     

Una nueva especie de Weltrichia (Bennettitales) del Jurásico Medio de la Formación Tecomazuchil (Oaxaca, México)

A new species of Weltrichia (Williamsoniaceae: Bennettitales) is described from the Middle Jurassic of Oaxaca. The specimens come from the Tecomazuchil Formation in the Ayuquila region, at the border between the Oaxaca and Puebla states. Fossils are preserved as impressions and compressions, in a fine-grained sublitharenite sequence deposited in a fluvial environment. Preserved diagnostic characters include: large size; a cup-shaped receptacle showing seven radially arranged and basically fused microsporophylls bearing synangia. Microsporophylls are ornamented with longitudinal striations and fine brittled hairs on the edge of their wide base, and taper into a narrow distal tip. In the adaxial part of the microsporophylls seven to nine synangia are observed. These characters differentiate the new species Weltrichia mixtequensis from all previously recorded species from Mexico or elsewhere. The presence of this new species in the Middle Jurassic strata of the Ayuquila region add to the scarce fossil record of microsporangiate structures in the Jurassic flora of Mexico.