首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
16 taxa of gastropods are described from the Lower and Middle Jurassic of Germany and northwestern Poland. They belong to seven genera. Two species (Pommerozygia aspera, Costazygia bilzi) and two genera (Brevizygia, Costazygia) are new. The family Pommerozygiidae is new as well. Compared to the Zygopleuridae, the Pommerozygiidae have a rather short and broad shell with only few teleoconch whorls. The protoconch is broad conical with a rounded apex (because the first whorls are nearly planispiral). From the Zygopleuridae only members of the Zygopleurinae have been found. Most Jurassic species have a smooth protoconch. Within the Zygopleuridae, the development possibly began with protoconchs carrying collabral axial ribs (and spirals) and led to smooth protoconchs. The genera of the Pommerozygiidae are rather similar to each other. The planktotrophic larval shell has a subsutural row of nodes like many species of Triassic Zygopleuridae. Therefore, both families are closely related. The Pommerozygiidae are possibly a separate branch of the Zygopleuroidea without descendants. The main branch is probably the evolutionary line Zygopleuriidae — Janthinoidea.  相似文献   

2.
The history of the study and review of generic and species diversity of Mesozoic rissoid gastropods are provided. The generic composition of Jurassic rissoid gastropods is revised, so that it is proposed to regard them as the family Rissoidae, comprising the genera Bralitzia, Buvignieria, Palaeoceratia, and Palaeorissoina. It is tentatively proposed to assign the genus Hudlestoniella to Rissoidae; this is caused by insufficient morphological knowledge of this genus. The family Palaeorissoidae is regarded as a synonym of Rissoidae. Stratigraphical and geographical distribution of Rissoidae genera is reviewed. From the Jurassic of European Russia, the following species of the genus Buvignieria are described: B. calloviana Gründel, B. imminuera Gründel, B. paucicostata Gründel, B. eichwaldiana (Rouillier), B. choroshovensis Gerasimov, and B. gruendeli sp. nov. The morphological characteristics and stratigraphical distribution of these species are provided. Based on extensive material, the taxonomic significance of particular conchological characters for the establishment of species is discussed.  相似文献   

3.
About 40 type specimens of archostematan beetles from the Jurassic, Lower Cretaceous, and Paleogene of England, named by P. Brodie, J.O. Westwood, C. Giebel, A. Handlirsch, F. Zeuner, P. Whalley, and R. Crowson and stored in the Paleontological Department of the Natural History Museum (London) are redescribed. Nine genera and 11 species are recognized, three genera are assigned to Archostemata for the first time. One new species, Tersus crowsoni (Schizophoridae), is described.  相似文献   

4.
Three new species of fossil snipe flies (Insecta, Diptera, Rhagionidae) from the Daohugou Formation of Chifeng City in Nei Monggol Autonomous Region (= Inner Mongolia), northeastern China are described as Palaeobolbomyia sinica nov. sp., Ussatchovia robusta nov. sp. and Ussatchovia gracilenta nov. sp. They represent the first records of the genera Palaeobolbomyia Kovalev and Ussatchovia Kovalev in China and have implications for stratigraphic correlation of the formations in which they are found. Although the precise age of the Daohugou Formation is currently unresolved, it is most likely Callovian-Oxfordian (latest Middle Jurassic-earliest Late Jurassic) rather than early Middle Jurassic (late Aalenian-early Bajocian) or Early Cretaceous.  相似文献   

5.
《Palaeoworld》2021,30(3):461-494
The paper describes new Lower Jurassic corals from the South-Eastern Pamir Mountains (Tajikistan) and interprets their relationships with contemporaneous West Tethyan corals. Taxonomic similarities with Pliensbachian European and North African faunas indicate a Pliensbachian age for this fauna, which was previously considered to be of Hettangian/Sinemurian age. Together with the taxa earlier described from the Pamirs, this fauna consists of 30 species of 25 genera, including Triassic holdover genera such as Stylophyllopsis, Phacelostylophyllum and Eocomoseris. The bulk of the fauna represents new Jurassic genera: Alichurastrea, Eomicrophyllia, Guembelastreomorpha, Gurumdynia, Pinacomorpha, Protostephanastrea, Psenophyllia, Sedekastrea and Stylimorpha. Earlier coral studies of the region concerned the genera: Archaeosmilia Melnikova, 1975, Archaeosmiliopsis Melnikova, 1975, Cylismilia Roniewicz, 1988, Pachysmilia Melnikova, 1989, and Prodonacosmilia Melnikova in Melnikova and Roniewicz, 1976. Two species that were considered to belong to the genus Cylismilia, are redescribed and reclassified in the genera Psenophyllia, and Archaeosmilia Melnikova, respectively.  相似文献   

6.
Based on the study of more than 300 isophlebiid specimens from several Late Mesozoic sites in eastern Transbaikalia (Ukurei, Tergen’, Glushkovo, and Byankino formations), new genera and species are described: Xeta olovica, Dahurium draco, and Sinitsia sophiae. The insect-bearing deposits are dated Late Jurassic according to analysis of their odonatofauna.  相似文献   

7.

Background

Anomopterellidae was originally classified as a family within the Evanioidea, and later lowered to a subfamily, Anomopterellinae, of Praeaulacidae. Up to date, only Rasnitsyn 1975, with four species, was assigned to Anomopterellinae. Due to their special wing venation and their metasomal attachment similar to those known in Evanioidea, the systematic position of Anomopterellinae in Evanioidea has been in contention.

Principal Findings

Here we report a new fossil genus Synaphopterella gen. nov. and six species from the Middle Jurassic of China and transfer Anomopterella stenocera Rasnitsyn, 1975, from Upper Jurassic of Kazakhstan, to Choristopterella gen. nov. We place these three genera in the restored family Anomopterellidae and provide a key to known genera and species.

Conclusions/Significance

Based on new fossil specimens and phylogenetic analyses, Praeaulacidae has the most basal position in Evanioidea and it is justifiable to restore Anomopterellidae Rasnitsyn, 1975 as a full family. Comparing the size of all described anomopterellids from China, Mongolia and Kazakhstan, we conclude that the species from China have larger bodies and forewings. Diversity of the Praeaulacidae and Anomopterellidae in the late Middle Jurassic of Daohugou suggests that Evanioidea appeared at least before the late Middle Jurassic.  相似文献   

8.
Two new species, Paramesosciophilodes bellus sp. n. and Paramesosciophilodes rarissima sp. n., from the Jiulongshan Formation at Daohugou Village, Inner Mongolia, China, are described in the extinct family Mesosciophilidae. Altogether seven genera with 21 species of mesosciophilids have been described from the Jurassic of Siberia and Kazakhstan, the Lower Cretaceous of Transbaikalia, and the Middle Jurassic of Inner Mongolia. An emended generic diagnosis of Paramesosciophilodes and a list of known taxa of mesosciophilids are provided.  相似文献   

9.
Whereas Middle Jurassic gastropods are very well known in Europe and other regions of the world, these faunas have been much less studied from northern Africa and most contributions available in literature have been based on relatively well-preserved material. Except a little lower Bajocian fauna from the Central High Atlas (Morocco) described at the turn of the 21th century, nothing is known about the Middle Jurassic gastropods of the southwestern Tethyan margin. The present paper aims to update the systematics of two vetigastropod species: Obornella cf. granulata (Sowerby, 1818) and Ambercyclus ornatus (Sowerby, 1819) recently found in the upper Bajocian succession of the Ksour Mountains (Tniet el Klakh Formation) at western Saharan Atlas (northern Algeria). The new Ambercyclus material found in well-preserved conditions confirms the absence of umbilicus in Ambercyclus; thus, we emend the original generic diagnosis. The specimens of Obornella cf. granulata and Ambercyclus ornatus represent the first occurrence of both genera and species in the upper Bajocian marine deposits of the western Saharan Atlas, and provide new taxonomic and palaeobiogeographic information about Middle Jurassic vetigastropods in Algeria.  相似文献   

10.
Three new genera and five new species of osmylid lacewings are described from the locality Karatau (Kazakhstan, Upper Jurassic): Jurosmylus parvulus sp. nov. (Protosmylinae), Ensiosmylus acutus gen. et sp. nov. (Spilosmylinae), Kolbasinella elongata gen. et sp. nov. (Gumillinae), Arbusella bella gen. et sp. nov. and Jurakempynus arcanus sp. nov. (Kempyninae). Another new osmylid species (Jurakempynus sublimis sp. nov.) is described from the Upper Jurassic of Mongolia (Shar-Teg locality). The quantitative compositions of the osmylid faunas of Karatau and Shar-Teg are discussed.  相似文献   

11.
From specimens collected in the western North Pacific, the early ontogeny ofPsettina iijimae andLaeops kitaharae is described. Diagnostic characters of the genera throughout larval stages are also provided. It is suggested that these species are distributed on continental shelf or at the edge, and that they spawn between July and September.  相似文献   

12.
Small gastropods from the Jurassic deposits of the European Russia, united into the lower Heterobranchia or Allogastropoda, are described. The families of Ampezzanildidae, Cimidae, Cornirostridae, Ebalidae, and Stuoraxidae are distinguished, and a set of taxa is given without reference to a definite family. The family Ampezzanildidae from the Jurassic deposits is described for the first time on the basis of the mass material, ascribed to the new genus Zizipupa gen. nov. with the sole species of Z. costata sp. nov. The family Cimidae includes the genera of Cristalloella, Rotfanella, Urlocella, and Unzhispira gen. nov. with species C. spiralocostata (Gründel, 1998), R. gerasimovi sp. nov., R. reticulata sp. nov., Urlocella undulata sp. nov., and Unzhispira minuta sp. nov. The genus Heteronatica gen. nov. is included into the family Cornirostridae. This genus is the first siphonostomatous representative of the given family including the sole long-living species H. globosa sp. nov., which is subdivided into subspecies H. globosa globosa and H. globosapromota subsp. nov. The family Ebalidae is represented by the genus Ebala, shells of which are distributed from the Middle Oxfordian to the Middle Volgian. The family Stuoraxidae is described based on two genera Stuoraxis and Aneudaronia gen. nov., including species of S. crassa sp. nov. and A. elegans sp. nov. The genus Doggerostra, which fits into different families of Heterobranchia in terms of shell morphology is represented by the species D. riedeli Gründel, 1998, which was previously known from the Bathonian and Callowian deposits in Poland and Germany, as well as form the Upper Jurassic interval in the Russian Plate. The Middle Volgian subspecies D. riedeli affinis subsp. nov. is distinguished in the composition of this species. In addition, the genus Masaevia gen. nov. with the sole species of M. sinistra sp. nov. is described. Due to so specific shell morphology of this genus, its position in the Heterobranchia system is unclear. It is not improbable that we deal with small planktonic gastropods of protoconchs of unknown group of planktonic or benthic gastropods.  相似文献   

13.
Complete, articulated starfish fossils are rare. However, more frequently encountered dissociated skeletal elements (ossicles) permit reliable taxonomic identification, making them a valuable data source for diversity estimates. Nearly 300 asteroid ossicles, collected from the middle Toarcian marls in western France can be assigned to five species. Four species and two genera are described: Comptoniaster vrinensis nov. sp. (Goniasteridae), Poncetaster crateri nov. gen. nov. sp. (Stauranderasteridae), Galbaster recurrans nov. gen. nov. sp. (Goniasteridae) and Pentasteria? liasica nov. sp. (Astropectinidae). The known diversity of Early Jurassic asteroids is increased from 12 to 16 species. These taxa illustrate the diversification of crown-group asteroids early in the Jurassic, following the Permo-Triassic crisis. They also reflect bias of the fossil record, and imply the existence of numerous ghost lineages in the evolutionary trees of extant groups. Variation in asteroid diversity across the “Seuil du Poitou” was driven by ecological constraints. The relative frequency (abundance of ossicles and diversity) of goniasterids and stauranderasterids increases in shallower environments. The Benthopectinidae, represented by Plesiastropecten hallovensis, occurred primarily from deep-shelf sediments. Similar ecological patterns are observed for more recent fossil and extant relatives, which further supports the idea of conservative evolution in post-Palaeozoic starfishes since the Early Jurassic.  相似文献   

14.
Hispaniastraea Turnšek et Geyer, 1975 is a unique coral genus from the Early Jurassic Epoch (Liassic). Corals of this genus are characterised by a highly dominant major septum and a set of eleven minor septa that are very short or even abortive. Initially discovered in Spain, new samples of this genus were depicted from Morocco by Beauvais in 1980; however, this genus was interpreted as a synonym of Pseudoseptifer Fischer, 1970, a chaetetid sponge (i.e., a sponge with siliceous spicules embedded in a calcareous skeleton). The skeleton of Pseudoseptifer is composed of adjacent tubules that increase by fissiparity by means of a pseudoseptum. Based on the study of new material sampled from the Lower Jurassic of Morocco and Southern France, we highlight the coexistence and legitimacy of both genera (i.e., Pseudoseptifer and Hispaniastraea), which therefore constitutes a fine example of morphological convergence between separate phyla. Although the living tissues and microstructures of the skeleton differ between the sponge and coral genera, the distinction from fossil material is challenging, especially if material is diagenetically altered. Herein, we recommend a set of key characters to distinguish these genera and propose a systematic revision of the genus Hispaniastraea. The synonymy between the two original species, Hispaniastraea murciana and H. ramosa is established and a new species, Hispaniastraea ousriorum, is described. Finally, a new family, the Hispaniastraeidae (Order Hexanthiniaria?), is erected for these distinctive corals, which are unique in the history of this group.  相似文献   

15.
A comparison of some genera of the Condaminecae (Rubiaceae) with a few taxa of closely related tribes (Rondeletieae, Calycophylleae, and Cinchoneae) revealed that some species ofChimarrhis (Condamineeae s. 1.),Bathysa (Rondeletieae), andCalycophyllum (Calycophylleae) are often misassigned to genera. The taxonomic significance of calycophylls is discussed; the generic boundaries ofChimarrhis, Bathysa, andCalycophyllum are reevaluated; and their similarities and differences are discussed. As a result, a new calycophyllous species ofChimarrhis from the Amazon,C. gentryana, is described, two of its species are transferred toBathysa (B. Bathysoides, B. perijaënsis), and one species ofBathysa (B. difformis) is reduced to synonymy underChimarrhis (C. turbinata).  相似文献   

16.
The data on the genus Peronopsis, including 116 species and subspecies, that is, at least half of Middle Cambrian agnostians, are completely revised. The revision is based on the order of the formation of pygidial characters in ontogeny. A convenient taxonomic system of abundant species of this genus is proposed. It is shown that the sequence of the formation of characters in ontogeny generally corresponds to the chronological sequence of the appearance of species with appropriate morphology. The study of the genus Peronopsis resulted in a revision of the species composition of some other genera of the family Peronopsidae, clarification of the periods of existence of the majority of genera of this family. New diagnoses of genera and subgenera of the family Peronopsidae are provided.  相似文献   

17.
《Comptes Rendus Palevol》2018,17(6):346-350
A new campterophlebiid damsel-dragonfly, Honghea xui gen. et sp. nov., is described from the Lower Jurassic Badaowan Formation of the Junggar Basin, NW China. This is the second Chinese Campterophlebiidae recorded for the earliest Jurassic, reflecting the quick diversification and radiation of the damsel-dragonflies during this period. Hnouveau onghea gen. nov. is closely related to Chinese genera Zygokaratawia and Ctenogampsophlebia, both from the Middle Jurassic of the Daohugou Biota; but differs from these genera in having a larger wing size, RP2 slightly distal of Sn, and a narrower area between IR2 and RP3/4.  相似文献   

18.
Germanasterias amplipapularia andHystrixasterias hettangiurnus are new genera and species of Asteriidae (Asteroidea: Forcipulatida) described from the Hettangian (lowest Jurassic) of southern Germany. They are among the oldest known relatively complete asteroids assignable to surviving families, yet they are remarkably similar to certain living species. Modern asteriids are efficient predators of sessile and slow-moving stoutly-armored mullusks, however much asteriid morphology is suggested to have originated with suspension-feeding habits. The lineage leading to the modern Forcipulatacea might have separated from that of the remainder of the modern asteroids as early as the Carboniferous.  相似文献   

19.
The Lower Jurassic Misone Limestone of the Trento Platform (Southern Alps, Italy) contains a siliceous sponge fauna which is here described. Besides the well-known Moroccan sponge carbonates, these Lower Jurassic spongioliths from the Trento Platform are presently the second mass occurrence of siliceous sponges, which is known from the southern margin of the Tethys. They differ from each other in regard of the composition of the sponge fauna and the absence of microbial crusts in the spongioliths of the Trento Platform. There, hexactinosans and lithistid demosponges occur in equal proportions. Sphinctozoans are another very characteristic element. Because of the richness in both sphinctozoans and siliceous sponges, the Trento occurrences may be considered as a transitional fauna between the late Palaeozoic-Triassic sponge fauna dominated by sphinctozoans and the post-Liassic sponge fauna dominated by more modern groups of siliceous sponges. Two new siliceous sponge genera with their species are established:Misonia baldensis n. gen. n. sp. (Hexactinosa) andBenacia princeps n. gen. n. sp. (lithistid Demospongiae). The rarity of siliceous sponge dominated spongioliths in the Early Jurassic is due to the restricted occurrence of low energy, deeper shelf areas.  相似文献   

20.
The taxonomy of the Late Jurassic pterodactyloid pterosaur Pterodactylus scolopaciceps Meyer, 1860 from the Solnhofen Limestone Formation of Bavaria, Germany is reviewed. Its nomenclatural history is long and complex, having been synonymised with both P. kochi (Wagner, 1837), and P. antiquus (Sömmerring, 1812). The majority of pterosaur species from the Solnhofen Limestone, including P. scolopaciceps are represented by juveniles. Consequently, specimens can appear remarkably similar due to juvenile characteristics detracting from taxonomic differences that are exaggerated in later ontogeny. Previous morphological and morphometric analyses have failed to separate species or even genera due to this problem, and as a result many species have been subsumed into a single taxon. A hypodigm for P. scolopaciceps, comprising of the holotype (BSP AS V 29 a/b) and material Broili referred to the taxon is described. P. scolopaciceps is found to be a valid taxon, but placement within Pterodactylus is inappropriate. Consequently, the new genus Aerodactylus is erected to accommodate it. Aerodactylus can be diagnosed on account of a unique suite of characters including jaws containing 16 teeth per-jaw, per-side, which are more sparsely distributed caudally and terminate rostral to the nasoantorbital fenestra; dorsal surface of the skull is subtly depressed rostral of the cranial table; rostrum very elongate (RI = ∼7), terminating in a point; orbits correspondingly low and elongate; elongate cervical vertebrae (approximately three times the length of their width); wing-metacarpal elongate, but still shorter than the ulna and first wing-phalanx; and pteroid approximately 65% of the total length of the ulna, straight and extremely thin (less than one third the width of the ulna). A cladistic analysis demonstrates that Aerodactylus is distinct from Pterodactylus, but close to Cycnorhamphus Seeley, 1870, Ardeadactylus Bennett, 2013a and Aurorazhdarcho Frey, Meyer and Tischlinger, 2011, consequently we erect the inclusive taxon Aurorazhdarchidae for their reception.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号