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1.
Drewria potomacensis gen. et sp. nov. from the Lower Cretaceous Potomac Group of Virginia (Zone I, probably Aptian) provides the first definite Mesozoic megafossil record of Gnetales. The stems are slender, display no evidence of secondary growth, and show axillary monopodial branching. Attached leaves are opposite and decussate, borne at swollen nodes, and have clasping sheathing bases. Each leaf is oblong, up to 20 mm long, and has a dense network of longitudinally aligned subepidermal fibers. Leaf venation consists of two, or possibly three pairs of longitudinal parallel veins that form a reticulum at the apex and higher-order crossveins that form apically oriented chevrons. Reproductive structures consist of short, loose spikes that are borne in dichasially arranged groups of three. The dichasia are either terminal or lateral in the axil of a leaf. Reproductive units of the lateral spikes in a dichasium contain seeds, each surrounded by at least one pair of opposite, broadly elliptical or ovate bracts. Characters of D. potomacensis that suggest a gnetalean relationship include the opposite bracts surrounding the seeds, the network of subepidermal foliar fibers, and the distinctive leaf venation, which is very similar to that seen in the cotyledons of extant Welwitschia. Other features consistent with a gnetalean relationship include opposite and decussate leaves, swollen nodes, and the dichasial arrangement of the reproductive spikes. Masses of polyplicate gnetalean pollen comparable to that of extant Welwitschia occur in the same bed as the megafossils. The morphology of D. potomacensis indicates that it was an herb or possibly a shrub. The growth habit of D. potomacensis and associated plants, combined with the sedimentary occurrence of the fossils, indicate that this species and perhaps related taxa were important components of early successional vegetation during the mid-Cretaceous.  相似文献   

2.
The characteristic Mesozoic pollen genus Eucommiidites is described from pollen organs and seeds recovered in Cretaceous strata of North America and Europe. The pollen organs are from the lowermost Upper Cretaceous (Cenomanian) of Texas and are referred to Erdtmanitheca texensis gen. et sp. nov. They are spherical heads, composed of numerous, densely crowded, radiating pollen sacs that contain abundant well-preserved pollen. Combined LM, SEM and TEM investigations show that the pollen grains each have a distinct distal colpus flanked by two lateral colpi in an equatorial position. Pollen wall ultrastructure is gymnospermous with a thick lamellate inner layer (endexine) and an outer layer (ektexine) composed of a granular inner part and a homogeneous outer part. The endexine is thickened in the region of the colpi. Small seeds from the Lower Cretaceous (upper Berriasian to Valanginian) of Bornholm, Denmark contain abundant Eucommiidites pollen in their micropyles. The seeds are referred to Erdtmanispermum balticum gen. et sp. nov. They are ovoid, and weakly triangular in transverse section and gradually taper at the apex into an elongated tube. The megaspore membrane is granular and well developed, and apparently surrounded by three separate tissues interpreted as nucellus, a thin inner integument and a sclerified outer envelope. Eucommiidites pollen in the micropyles of the seeds has a laminated endexine and an ektexine comprising two homogeneous parts separated by a granular layer. Réévaluation of other seeds known to contain Eucommiidites pollen indicates that they share significant similarities with Erdlmanispermum and that they may have been produced by closely related plants. Comparison of “Eucommiidites plants” with other seed plants suggests that they are probably most closely related to the anthophytes comprising Bennettitales, Pentoxylales, Gnetales and angiosperms.  相似文献   

3.
Seed cones (Compsostrobus neotericus gen. et sp. nov.), pollen cones, and vegetative remains of coniferophytes occur in Upper Triassic rocks of the Deep River Basin (Pekin Formation) of Central North Carolina. Seed cones have spatulate ovuliferous scales, each with two ovules and subtended by an elongated bract with an attenuate tip. Cuticle of seed cones resembles that of leaves on vegetative axes. Slender leaves are borne along two sides of the axis. Pollen cones have helically arranged microsporophylls, each with two abaxial sporangia bearing pollen grains of the Alisporites type. Seed cones, pollen cones, and vegetative remains suggest a coniferophyte very modern in aspect.  相似文献   

4.
Upatoia barnardii gen. et sp. nov., a conifer pollen cone from the Late Cretaceous (Santonian) Eutaw Formation of Upatoi Creek, Georgia, USA, is known from lignified and fusainised mesofossils that preserve its three-dimensional structure. The cone consists of numerous helically arranged microsporophylls, each composed of a thin stalk and distal lamina. Three elongate pollen sacs are attached to the base of the lamina. Pollen grains isolated from the pollen sacs are relatively large (52 – 75 μm), spheroidal to ellipsoidal in outline, lack sacci, and have a thickened equatorial exine that is often strongly folded. Pollen of Upatoia barnardii indicates a close relationship to extant Araucariaceae. Microsporophylls of U. barnardii confirm suggestions from previous studies of fossil material that some Mesozoic Araucariaceae had only three pollen sacs per microsporophyll, in contrast to extant species that often have more than ten pollen sacs per microsporophyll.  相似文献   

5.
Abstract: A rich, diverse Permian ostracod fauna has been recovered from the red and grey, laminated shales and quartz‐rich shales of the Triassic Lercara Formation. Forty‐seven species have been identified, 13 of which are newly described here; they belong to 26 genera of which three are new: Anahuacia lercaraensis sp. nov., Aurigerites siciliaensis sp. nov., Bairdia portellaensis sp. nov., Cristanaria? katyae sp. nov., Fabalicypris gruendeli sp. nov., Lethiersa salomonensis gen. et sp. nov., Lethiersia sinusoventralis gen. et sp. nov., Portella trapezoida gen. et sp. nov., Siciliella elongata gen. et sp. nov., Siciliella infernespinosa gen. et sp. nov., Siciliella prima gen. et sp. nov., Siciliella quadrata gen. et sp. nov., and Siciliella spinorobusta gen. et sp. nov. The assemblages contain or are composed of palaeopsychrospheric forms, which are regarded as index fossils for deep environments. The bathymetry of the different associations in life is evaluated.  相似文献   

6.
A tetrahedral tetrad of tricolpate, striate pollen from the Upper Cretaceous subcrop sediments of the Bengal Basin has been described under a new generic name, Mulleripollis gen. nov., with the type species Mulleripollis bolpurensis gen. et sp. nov. It has been noticed that this pollen tetrad is restricted to the Upper Cretaceous Bengal Palynological Zone, which is stratigraphically significant. The natural affinity of the pollen could not be established.  相似文献   

7.
Body fossils of caddisfly larvae are described for the first time based on material from the Lower Cretaceous of Siberia (Baissa locality, Neocomian). The material includes a fully grown larva of Baissoplectrum separatum gen. et sp. nov. (Brachycentridae), Creterotesis coprolithica gen. et sp. nov. (Leptoceridae), and Cretolype minuta gen. et sp. nov., a tiny larva probably belonging to an uncertain family of the suborder Annulipalpia (Hydropsychina). C. coprolithica built unusually soft larval cases of pellets; these cases are described as a separate new indusigenus and indusispecies Coprindusia pallida gen. et sp. nov. Bionomics, taxonomy, and evolution of the Mesozoic larvae of Trichoptera are discussed.  相似文献   

8.
A new species, Tanychora loki, sp. nov., and a new genus and species, Megachora sibirica gen. et sp. nov., are described from the Lower Cretaceous of Transbaikalia and Mongolia. The genus Tanychora Townes, 1973 is divided into two genera: Tanychora s. str., composed of T. petiolata Townes, 1973 (type species), T. sinensis Zhang, 1991, and T. loki sp. nov., and Amplicella, gen. nov., composed of A. sessilis (Townes, 1973) (type species), A. exquisite (Zhang et Rasnitsyn, 2003), A. beipiaoensis (Zhang et Rasnitsyn, 2003), and A. spinata (Zhang et Rasnitsyn, 2003). The frequency of occurrence of ichneumonids in the principal Cretaceous localities of central and northern Asia is calculated.  相似文献   

9.

Background

Lacewings (insect order Neuroptera), known in the fossil record since the Early Permian, were most diverse in the Mesozoic. A dramatic variety of forms ranged in that time from large butterfly-like Kalligrammatidae to minute two-winged Dipteromantispidae.

Principal Findings

We describe the intriguing new neuropteran family Parakseneuridae fam. nov. with three new genera and 15 new species from the Middle Jurassic of Daohugou (Inner Mongolia, China) and the Early/Middle Jurassic of Sai-Sagul (Kyrgyzstan): Parakseneura undula gen. et sp. nov., P. albomacula gen. et sp. nov., P. curvivenis gen. et sp. nov., P. nigromacula gen. et sp. nov., P. nigrolinea gen. et sp. nov., P. albadelta gen. et sp. nov., P. cavomaculata gen. et sp. nov., P. inflata gen. et sp. nov., P. metallica gen. et sp. nov., P. emarginata gen. et sp. nov., P. directa gen. et sp. nov., Pseudorapisma jurassicum gen. et sp. nov., P. angustipenne gen. et sp. nov., P. maculatum gen. et sp. nov. (Daohugou); Shuraboneura ovata gen. et sp. nov. (Sai-Sagul). The family comprises large neuropterans with most primitive wing venation in the order indicated by the presence of ScA and AA1+2, and the dichotomous branching of MP, CuA, CuP, AA3+4, AP1+2. The phylogenetic position of Parakseneuridae was investigated using a phylogenetic analysis of morphological scoring for 33 families of extinct and extant Neuropterida combined with DNA sequence data for representatives of all extant families. Parakseneuridae were recovered in a clade with Osmylopsychopidae, Prohemerobiidae, and Ithonidae.

Conclusions/Significance

The presence of the presumed AA1+2 in wings of Parakseneuridae is a unique plesiomorphic condition hitherto unknown in Neuropterida, the clade comprising Neuroptera, Megaloptera, Raphidioptera. The relative uncertainty of phylogenetic position of Parakseneuridae and the majority of other families of Neuroptera reflects deficient paleontological data, especially from critical important periods for the order, earliest Triassic and latest Triassic/earliest Jurassic.  相似文献   

10.
The Anjihaihe Formation in the southern edge of the Junggar Basin was previously considered a series of freshwater lacustrine depositions. However, abundant marine dinoflagellate cysts were recently recovered from the middle to upper part of the middle member of the formation. Two new genera, six new species and one new subspecies among the abundant dinoflagellate cysts are described and illustrated, i.e. Circulodinium? laeve sp. nov., Kaiwaradinium abbreviatum sp. nov., Spiniferites adnatus subsp. latispinus subsp. nov., Oligosphaeropsis accreta gen. et. sp. nov., Oligosphaeropsis complex gen. et. sp. nov., Oligosphaeropsis megaprocessa gen. et. sp. nov. and Tianshandinium biconicum gen. et. sp. nov. They are rare to common constituents of the dinoflagellate assemblage in the Anjihaihe Formation and may prove useful for regional biostratigraphic correlation and palaeoenvironment re-establishment.  相似文献   

11.
Ediea homevalensis H. Nishida, Kudo, Pigg & Rigby gen. et sp. nov. is proposed for permineralized pollen-bearing structures from the Late Permian Homevale Station locality of the Bowen Basin, Queensland, Australia. The taxon represents unisexual fertile shoots bearing helically arranged leaves on a central axis. The more apical leaves are fertile microsporophylls bearing a pair of multi-branched stalks on their adaxial surfaces that each supports a cluster of terminally borne pollen sacs. Proximal to the fertile leaves there are several rows of sterile scale-like leaves. The pollen sacs (microsporangia) have thickened and dark, striate walls that are typical of the Arberiella type found in most pollen organs presumed to be of glossopterid affinity. An examination of pollen organs at several developmental stages, including those containing in situ pollen of the Protohaploxypinus type, provides the basis for a detailed analysis of these types of structures, which bear similarities to both compression/impression Eretmonia-type glossopterid microsporangiate organs and permineralized Eretmonia macloughlinii from Antarctica. These fossils demonstrate that at least some Late Permian pollen organs were simple microsporophyll-bearing shoot systems and not borne directly on Glossopteris leaves.  相似文献   

12.
One new genus and four new species of ichneumon wasps are described from the Lower Cretaceous of Buryatia (Khasurty locality): Amplicella mininae, sp. nov., A. shcherbakovi, sp. nov., A. bashkuyevi, sp. nov., Khasurtella buriatica, gen. et sp. nov. The species Tanychora sinensis Zhang, 1991 is transferred to the new genus Khasurtella. Similarity of the ichneumonid faunas of Khasurty and the Chinese localities Yixian and Laiyang indicates the age similarity between these localities. Identification key to genera and species of Tanychorinae is given.  相似文献   

13.
New taxa of Achilini (Achilidae) are described from Baltic amber: Paratesum rasnitsyni gen. et sp. nov., Protomenocria notata gen. et sp. nov., Psycheona variegata gen. et sp. nov., P. striata sp. nov. Protepiptera kaweckii Usinger, 1939 (= Cixidia christinae Lefebvre, Bourgoin et Nel, 2007, syn. nov.) is redescribed with designation of a neotype. “Cixius” testudinarius Germar et Berendt, 1856, “C.” longirostris Germar et Berendt, 1856 and “Oliarus” oligocenus Cockerell, 1910 are transferred to Achilini. A key to the genera of Achilidae known from Baltic amber is provided.  相似文献   

14.
Late Jurassic Mammals from Tendaguru, Tanzania, East Africa   总被引:1,自引:0,他引:1  
Records of Mesozoic mammals are extremely rare in Africa. The only previous record from the Upper Jurassic of Africa is a fragmentary mandible without teeth of Brancatherulum tendagurense. Here I report the discovery of two new mammals from the Upper Jurassic of Tendaguru, Tanzania. The fossils were recovered from the Middle Saurian Bed of the Tendaguru Series. A lower molar of a triconodontid mammal is described as Tendagurodon janenschi gen. et sp. nov., and a fragmentary dentary of a eupantothere as Tendagurutherium dietrichi gen. et sp. nov. The eupantothere in particular contributes to documenting the evolution of mammals during the Mesozoic. The posterior portion of the mandible of Tendagurutherium dietrichi gen. et sp. nov. shows that the angular (tympanic) bone was not yet completely separated from the dentary, a previously undocumented stage of eupantotherian middle ear evolution.  相似文献   

15.
Abstract: Palaeoscolecidan worms are rare, Early Palaeozoic fossils with uncertain affinities within the Ecdysozoa. They are locally abundant in the Cambrian and scattered in the Early Ordovician, but very sparse thereafter. Forty‐four specimens have been collected from the Middle Ordovician of the Builth‐Llandrindod Inlier of Mid Wales and include well‐preserved material assigned to seven new genera, with four additional species in open nomenclature. An additional specimen from the Arenig Pontyfenni Formation of South Wales is also described in open nomenclature. The total demonstrates much greater palaeoscolecid diversity than hitherto suspected for this time. The specimens are preserved as cuticle fragments in shales and siltstones, often of submillimetre size but in many cases with excellent preservation. The level of detail preserved in some is equal to that found in Cambrian phosphatized faunas. The new approach to collecting, and the recognition that this material can yield taxonomically useful information, opens new avenues for palaeoscolecidan research in siliciclastic environments. The new taxa are the following: Radnorscolex bwlchi gen. et sp. nov., Aggerscolex murchisoni gen. et sp. nov., Bullascolex inserere gen. et sp. nov., Wernia eximia gen. et sp. nov., Ulexiscolex ormrodi gen. et sp. nov., Pluoscolex linearis gen. et sp. nov. and Loriciscolex cuspidus gen. et sp. nov. The high diversity, and the taxonomic separation from known groups described primarily from Cambrian carbonates, implies that palaeoscolecidans either diversified significantly during the Ordovician or were taxonomically segregated between carbonate and siliciclastic settings. Palaeobiological findings also include confirmation that some palaeoscolecid basal cuticles were solid and others reticulate, plates (and platelets) could form by lateral accretion, plates were in part primarily phosphatic and in part organic and that in at least some groups, platelet secretion occurred external to plate secretion.  相似文献   

16.
Neoselachian sharks and rays from the British Bathonian (Middle Jurassic)   总被引:2,自引:1,他引:1  
Extensive sampling of Bathonian sediments from localities across southern and central England has produced over 8000 neoselachian teeth. These comprise diverse faunas, with over 25 species being represented in total, most of them previously undescribed. Seventeen new species and seven new genera are named: Palaeoscyllium tenuidens sp. nov., Praeproscyllium oxoniensis gen. et sp. nov., Eypea leesi gen. et sp. nov., Proheterodontus sylvestris gen. et sp. nov., Paracestracion bellis sp. nov., Palaeobrachaelurus mussetti sp. nov., Heterophorcynus microdon gen. et sp. nov., Dorsetoscyllium terraefullonicum gen. et sp. nov., Ornatoscyllium freemani gen. et sp. nov., Pseudonotidanus semirugosus gen. et sp. nov., Synechodus duffini sp. nov., Protospinax magnus sp. nov., P. bilobatus sp. nov., P. carvalhoi sp. nov., Belemnobatis kermacki sp. nov., B. stahli sp. nov. and Spathobatis delsatei sp. nov. In addition, a new family, the Pseudonotidanidae fam. nov., is defined and the status of Paranotidanus Ward and Thies, 1987, Hybodus levis Woodward, 1889 and Breviacanthus brevis (Phillips, 1871) are discussed. These taxa show strong facies specificity, with different species being restricted to different palaeoenvironments.  相似文献   

17.
Abstract:  Three new genera and four new species of the extinct mantidfly subfamily Mesomantispinae (Insecta: Neuroptera: Mantispidae) are described from the Lower Cretaceous Yixian Formation of Liaoning and the Middle Jurassic Jiulongshan Formation of Inner Mongolia: Archaeodrepanicus nuddsi gen. et sp. nov., A. acutus gen. et sp. nov., Sinomesomantispa microdentata gen. et sp. nov., (Yixian Formation) and Clavifemora rotundata gen. et sp. nov. (Jiulongshan Formation). The specimens described herein represent the first Mesozoic mantidfly compression fossils to have body parts preserved, including the specialized raptorial forelegs articulated to the prothorax anteriorly, an autapomorphy of the family. These new taxa further confirm the placement of the subfamily Mesomantispinae within the family Mantispidae; however, the monophyly of Mesomantispinae has not been confirmed, and it is likely that it will prove to be paraphyletic.  相似文献   

18.
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.  相似文献   

19.
Abstract: Bulk sampling of upper Campanian to lower–middle Maastrichtian coastal and lagoonal deposits in five sections of the Tremp Formation in the south‐central Pyrenees yielded numerous neoselachian teeth. The fauna comprises nine taxa of which three species and one genus are new: Hemiscyllium sp., Lamniformes indet., Paratrygonorrhina amblysoda gen. et sp. nov., Coupatezia trempina sp. nov., Coupatezia sp., Coupatezia? sp., Rhombodus ibericus sp. nov. and Igdabatis indicus. The neoselachian fauna is dominated by small nectobenthic rays. This composition resembles assemblages known from the marine Upper Cretaceous, but differs from nearby localities of the Basque‐Cantabrian region and continental selachian associations of the French Pyrenees. The results indicate that Rhombodus might not be a reliable biostratigraphic marker for the Maastrichtian. The faunal composition suggests a shallow trans‐Tethyan connection between Eurasia and India at the end of the Cretaceous Period.  相似文献   

20.
Gram-negative, facultatively anaerobic bacteria were isolated from symptomatic oak tissue in the UK and USA. Partial gyrB sequencing placed ten strains in the genus Brenneria, with B. goodwinii as the closest phylogenetic relative. The strains were investigated further using a polyphasic approach including MLSA (based on partial gyrB, rpoB, infB and atpD gene sequences), 16S rRNA gene sequencing, DNA–DNA relatedness studies and both phenotypic and chemotaxonomic assays. The MLSA and 16S rRNA gene analyses separated the strains into two groups based on origin, suggesting that they belong to Brenneria as two novel species. However, the DNA–DNA relatedness values revealed a closer relationship between the groups and indicated that they should belong to the same species. As the two groups of strains from the UK and USA can be differentiated from each other phenotypically and by ERIC PCR fingerprints, it is proposed to classify them as novel subspecies of a novel Brenneria species. The name Brenneria roseae sp. nov. (FRB 222T = LMG 27714T = NCPPB 4581T) is proposed, with Brenneria roseae subsp. roseae ssp. nov. (FRB 222T = LMG 27714T = NCPPB 4581T) for the strains from the UK and Brenneria roseae subsp. americana ssp. nov. (FRB 223T = LMG 27715T = NCPPB 4582T) for the strains from the USA.  相似文献   

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