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 31 毫秒
1.
Noriphyllia gen. n. is a distinctive coral representing the Coryphylliidae, a group of Late Triassic scleractinian corals. Coral faunas of this age are poorly known. The new coral is distinguished from related corals belonging to the reimaniphylliids by key features of septal microstructure as discerned in thin sections. This microstructure consists of a straight/wavy midseptal zone and lateral septal stereome organized into thin fascicles of fibres, producing a fine and sharp micromorphology of the septal sides. The solitary genus Noriphyllia gen. n. contains two Early Norian species: N. anatoliensis sp. n. chosen as the type species and N. dachsteinae sp. n., and a Carnian species referred to as N. monotutoensis sp. n. The new genus is widely distributed in the Late Triassic, Early Norian reef facies of the Tethys region (Northern Calcareous Alps, Austria; Taurus Mountains, Turkey) and it also occurs in the Carnian of Timor. Noriphyllia gen. n. is unique and details of its microstructural features add new understanding to the composition of both Late Carnian and Early Norian corals.  相似文献   

2.
A new genus and species of phosphatic‐shelled eolepadid barnacle from the Posidonia Shale (Toarcian, falciferum Zone) of Zell u. Aichelberg, southern Germany, is described as Toarcolepas mutans gen. et sp. nov. Numerous disarticulated individuals, associated with fossil wood, are present in a piece of concretionary limestone, and these are interpreted as having lived epiplanktonically attached to driftwood. The taxonomy of the Late Triassic – Early Cretaceous family Eolepadidae is reviewed, and two further species (T. gaveyi (Withers, 1920) and T. lotharingica (Méchin, 1901)) are referred to Toarcolepas. The chemistry of valve composition of the Carboniferous Praelepas and Triassic–Jurassic eolepadid cirripedes is investigated using X‐ray dispersive analysis, and the ubiquitous presence of abundant phosphorus is taken as evidence that these taxa had a primary phosphatic composition, now preserved as francolite. A significant change in shell chemistry from phosphate to calcium carbonate took place during the evolution of the Thoracica, during the Late Triassic or Early Jurassic. The driving force behind this change may have been related to the reduced predation pressure associated with acquisition of an epiplanktonic mode of life. Calcite is softer, but energetically cheaper to deposit than phosphate mineral phases.  相似文献   

3.
4.
Summary Two characteristic new species and one new genus are described from the Late Triassic of Idaho (Wallowa Terrane):Brochidiella idahoensis n. gen., n. sp. andPtychostoma ornata n. sp.Brochidiella is only known from western North America.Ptychostoma is present in the Carnian of the European Alps (Tethys) and is widespread in the western part of the North American continent (Panthalassa). Late Triassic gastropod faunas from the accreted terranes of North America are poorly known but hold a great potential for future palaeobiogeographic reconstructions.  相似文献   

5.
A new species of the rhynchosaur genus Hyperodapedon, namely H. tikiensis, is described from well‐preserved skeletal elements that were collected from the Upper Triassic Tiki Formation of India. Hyperodapedon tikiensis is diagnosed on the basis of several cranial and postcranial features including longer than wide basipterygoid process, crest‐shaped maxillary cross section lateral to the main longitudinal groove, deeply excavated neural arches of mid‐dorsal vertebrae, long scapular blade, a pronounced deltopectoral crest, proximal humeral end much broader than distal end, iliac length greater than iliac height, equal pre‐ and postacetabular iliac lengths and circular femoral cross section. Two distinct morphotypes of the maxillary tooth plates can be discerned, which are attributed to ontogenetic variations. A maximum‐parsimony analysis was carried out to show that the order Rhynchosauria is characterized by nine cranial and one postcranial character states. The analysis reveals that Otischalkia elderae is invalid and the basal forms, Howesia and Mesosuchus, are closely related. The Mid‐Triassic genus Ammorhynchus is more derived and forms a sister group to the Late Triassic subfamily Hyperodapedontinae. Isalorhynchus and Teyumbaita are basal to the pandemic genus Hyperodapedon. Twenty‐four characters that are not homoplasious document major patterns of skeletal evolution in rhynchosaurs. From laterally oriented scapula and slender propodials, the postcranial skeleton evolved into a more robust form as is evident from nearly vertical scapula and increase in the robustness of the propodials. Shortening of the femur is noted in the derived Late Triassic forms as exemplified in Hyperodapedon gordoni, Hyperodapedon huxleyi and H. tikiensis.  相似文献   

6.
The tetrapod faunas from the terrestrial Middle–Late Triassic basins of Africa and South America are among the richest in the world, especially in non‐mammalian cynodonts. Despite the great abundance of cynodont specimens found in these basins, there are few known taxa that exhibit interbasinal distributions. Here we describe a new species of traversodontid cynodont of the genus Scalenodon from the Triassic Dinodontosaurus Assemblage Zone of the Santa Maria Supersequence, from the state of Rio Grande do Sul, Brazil. Scalenodon ribeiroae sp. nov. is based on a partial skull that possesses a combination of features not observed in any other South American traversodontid: ellipsoid upper postcanines with the transverse crest formed by three cusps, lacking a mesiobuccal accessory cusp, and with lingual cusp projected lingually creating a concave lingual surface on the upper postcanines; the paracanine fossa is positioned medially to the upper canine, and jugal lacks a suborbital process. A phylogenetic analysis places the new taxon in a basal position within the Family Traversodontidae, with the African Scalenodon angustifrons as sister‐taxon. The new specimen of Scalenodon represents the first record of this genus outside of the Manda Beds of Tanzania, and reinforces the biostratigraphical and biogeographical connection between Gondwanan Middle–Late Triassic tetrapod faunas. Although recent advances have been made, our current knowledge of these faunas is limited by the lack of absolute dates for most units and by uncertainties in the taxonomy and stratigraphical provenance of key fossils.  相似文献   

7.
Tertiary cormorant fossils (Aves: Phalacrocoracidae) from Late Oligocene deposits in Australia are described. They derive from the Late Oligocene – Early Miocene (26–24 Mya) Etadunna and Namba Formations in the Lake Eyre and Lake Frome Basins, South Australia, respectively. A new genus, Nambashag gen. nov. , with two new species ( Nambashag billerooensis sp. nov. , 30 specimens; Nambashag microglaucus sp. nov. , 14 specimens), has been established. Phylogenetic analyses based on 113 morphological and two integumentary characters indicated that Nambashag is the sister taxon to the Early Miocene Nectornis miocaenus of Europe and all extant phalacrocoracids. As Nambashag, Nectornis, and extant phalacrocoracids constitute a strongly supported clade sister to Anhinga species, the fossil taxa have been referred to Phalacrocoracidae. Sulids and Fregata were successive sister taxa to the Phalacrocoracoidea, i.e. phalacrocoracids + Anhinga. As phalacrocoracids lived in both Europe and Australia during the Late Oligocene and no older phalacrocoracid taxa are known, the biogeographical origin of cormorants remains unanswered. The phylogenetic relationships of extant taxa were not wholly resolved, but contrary to previous morphological analyses, considerable concordance was found with relationships recovered by recent molecular analyses. Microcarbo is sister to all other extant phalacrocoracids, and all Leucocarbo species form a well‐supported clade. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 277–314.  相似文献   

8.
A new prolacertilian species and genus, Augustaburiania vatagini gen. et sp. nov. (Reptilia: Archosauromorpha), from the Lower Triassic of the Don River Basin is described. It is the first representative of the Tanystropheidae in the Eastern Europe and the world oldest member of this family. Another new genus (Protanystropheus gen. nov.) from Central and Western Europe is also established. The diversity, systematics, phylogeny, evolution, and stratigraphic and geographical distribution of prolacertilians are discussed. The ecological role of prolacertilians in Early Triassic communities and adaptation to marine environments are analyzed.  相似文献   

9.
Rhynchosauria was an important clade of herbivorous archosauromorph reptiles during the Triassic, with a worldwide distribution. We describe a new genus and species of early rhynchosaur, E ohyosaurus wolvaardti gen. et sp. nov. , from the early Middle Triassic (early Anisian) Cynognathus Assemblage Zone (Subzone B) of the Karoo Supergroup, South Africa. Eohyosaurus wolvaardti is known from a single skull, and is recovered as the sister taxon of Rhynchosauridae in a new phylogenetic analysis. Cynognathus Subzone B has previously yielded the stratigraphically oldest well‐understood rhynchosaur species, Mesosuchus browni and Howesia browni. Eohyosaurus wolvaardti increases the rhynchosaur diversity within this stratigraphical horizon to three species. Intriguingly, all currently confirmed rhynchosaur occurrences from the Early Triassic to earliest Middle Triassic are from South Africa. This may suggest a relatively restricted palaeogeographical distribution for early rhynchosaurs, followed by a global dispersal of rhynchosaurids during the Middle Triassic. © 2015 The Linnean Society of London  相似文献   

10.
Saurichthys, characterized by a long slender body and an elongated rostrum, is one of the most iconic genera of Late Paleozoic–Early Mesozoic fishes. The genus was particularly speciose in the Triassic, with a global distribution in both marine and freshwater habitats. Here, we describe two new species from the Middle Triassic Besano Formation of Monte San Giorgio, Switzerland, Saurichthys breviabdominalis sp. nov. and Saurichthys rieppeli sp. nov. S. breviabdominalis is characterized by a proportionately long operculum, short abdominal region and rib‐like mid‐lateral scales, whereas S. rieppeli is divergent from other Middle Triassic saurichthyids in the block‐like haemal arches, fringing fulcra on the pelvic and unpaired fins, and reduction of the squamation to a single row in the abdominal region. Phylogenetic analysis places S. rieppeli in a basal position relative to congeners from the Alpine Triassic, and supports previous hypotheses regarding the convergent evolution of reduced squamation within saurichthyids. S. breviabdominalis forms a monophyletic group with species from the same locality, suggesting divergence in sympatry. This finding has implications for our understanding of disparity and character evolution in saurichthyid fishes, as well as ecomorphological divergence and resource partitioning between closely related fishes in Triassic marine ecosystems. © 2015 The Linnean Society of London  相似文献   

11.
FRANK STILLER 《Palaeontology》2011,54(6):1415-1433
Abstract: The isocrinid sea lily Tyrolecrinus wugangi sp. nov. from uppermost middle to lowermost upper Anisian (lower Middle Triassic) strata of Leidapo near Qingyan, Guizhou Province, south‐west China, provides new data on the early phylogeny of the order Isocrinida. The new species is the earliest unequivocal representative of the family Isocrinidae. It predates all other known species of the genus Tyrolecrinus that come from upper Ladinian to Rhaetian strata and also all other known taxa of the Isocrinidae. Nevertheless, its stem is of fully developed isocrinid type and is characteristic of the genus, with consistently synostosial, rarely cryptosymplectial, distal nodal articular facets. These findings indicate that the Isocrinidae evolved prior to the late middle Anisian in the far‐eastern part of the Palaeotethys ocean, perhaps in the region forming today’s south‐west China, and spread to various other regions later in the Middle and Late Triassic. The genus Tyrolecrinus is revised and the new genus Bakonycrinus gen. nov. is erected.  相似文献   

12.
Until now the Doswelliidae was considered a monospecific family including Doswellia kaltenbachi from the Late Triassic of North America. The phylogenetic position of this taxon remained enigmatic until recently, when a sister‐group relationship with the Proterochampsidae was suggested. In the present contribution we describe the new doswelliid species Archeopelta arborensis gen. et sp. nov. from the Middle–Late Triassic of Brazil. A cladistic analysis recovered Archeopelta, Doswellia, and Tarjadia within a monophyletic group of basal archosauriforms, the Doswelliidae. The monophyly of this family is supported by the presence of osteoderm ornamentation that is coarse, incised, and composed of regular pits and the presence of an unornamented anterior articular lamina. Archeopelta is more closely related to Doswellia than to other archosauriforms by the presence of basipterygoid processes anterolaterally orientated, dorsal centra with a convex surface, width of the neural arch plus ribs of the first primordial sacral that are three times the length of the neural arch, and iliac blade laterally deflected, with strongly convex dorsal margin, and a length less than three times its height. The phylogenetic analysis indicates that Doswellidae is the closest large monophyletic entity to Archosauria, which achieved a wide palaeolatitudinal distribution during the late Middle and Late Triassic time span. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161 , 839–871.  相似文献   

13.
A new scanilepiform, Beishanichthys brevicaudalis gen. et sp. nov. , is named and described based on fossils from the Lower Triassic lake deposits exposed in Beishan area, Gansu Province, China. The discovery documents a new record of this group, which is significantly older than other known scanilepiforms from China, and is slightly younger than Evenkia from the Lowest Triassic of Central Siberia. Although the Beishan beds were previously interpreted as Late Permian in age, based on megaplant fossils, this new discovery supports the reinterpretation of the deposits as Early Triassic in age, based on vertebrate fossils from the same locality and horizon. Phylogenetic analysis was conducted to resolve the relationships of Scanilepiformes with other actinopterygian clades, and the inter‐relationships within Scanilepiformes. Contrary to previous thought that scanilepiforms are closely related to the Amiidae, the phylogenetic results of this study recognize the Scanilepiformes as stem‐group neopterygians. Relationships of the Scanilepiformes and Australosomus with other neopterygians remain unresolved. With a characteristic long‐based dorsal fin, scanilepiforms represent a small group that emerged in Early Triassic freshwater environments, inhabited Eurasia and North America during the Middle–Late Triassic, briefly invaded the marine environment by the Late Triassic in Europe, and became extinct at the end of Triassic. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161 , 595–612.  相似文献   

14.
Otozamites is a representative fossil leaf morphogenus of the extinct Bennettitales, with an extensive distribution during the Mesozoic, especially in China. Understanding the fossil diversity variation and distribution pattern of Otozamites in China will provide information on biodiversity of bennettitalean plants as well as for reconstruction of palaeogeography and palaeoclimate conditions during the Mesozoic. So far, 46 species of this genus have been described in China, excluding unspecified species. The results show that the fossils of Otozamites are extensively recorded in the Late Triassic, and then reach their maximum development in the Early Jurassic, followed by a reduction in diversity in the Middle and Late Jurassic, and finally become extinct at the end of Early Cretaceous. Geographically, they occur in both Northern and Southern Floristic Provinces in the Mesozoic of China, with a relatively higher abundance in the Southern Floristic Province. It implies that the diversity variation and distribution of Otozamites are closely related to the change of the palaeoclimatic conditions. The warm and humid climate prevailed in the Late Triassic and Early Jurassic in South China, propitious to the development of Otozamites. After the Middle Jurassic, dry and hot climate may have caused the lower diversity level and blocked the development of Otozamites; finally at the end of the Early Cretaceous, the frequent arid climate may be a major cause for the extinction of Otozamites.  相似文献   

15.
A diverse Late Triassic (Late Norian) gastropod fauna is described from the Mission Creek Limestone of the Wallowa terrane (Idaho, USA). Sample standardization by rarefaction analysis indicates that the fauna is even more diverse than the Late Triassic gastropod fauna from the Pucara Formation (Peru) which represents the most diverse gastropod fauna from South America. The gastropod fauna consists of 66 species; several genera are reported for the first time from North America. A high percentage of the species are highly ornamented and several have distinct siphonal canals. This suggests that the appearance of truly Mesozoic elements among the gastropods began before the Mesozoic Marine Revolution in other clades. The fauna is dominated by high-spired strongly ornamented procerithiids, a group more characteristic for the Jurassic. Comparison of the present fauna and the Iranian Nayband Formation gastropod fauna show that the procerithiids underwent a first global radiation in the Late Triassic. The high number of new species in this fauna suggests that sampling of Late Triassic gastropod faunas is still incomplete and hinders palaeobiogeographic considerations. Previous suggesions that gastropod faunas from the Wallowa and Wrangellia terranes resemble each other and are distinct from those of Alexander, Chulitna, and Farewell terranes are basically corroborated. The gastropod fauna of the Mission Creek Limestone differs considerably from that of the western and central Tethys but shares several taxa with the Late Triassic gastropod fauna of the Pucara Formation in Peru. Thus, the Hispanic corridor was probably not present in the Norian but opened only in the Early Jurassic. The subfamily Andangulariinae is introduced and placed in the Zygopleuridae. The generaSpiniomphalus, Nodoconus, Gudrunella, Blodgettella, Idahospira, andSiphonilda and the subgenusCryptaulax (Wallowax) are introduced. 27 species are erected. A lectotype is designated forCryptaulax rhabdocolpoides Haas, 1953.   相似文献   

16.
The lagerstätten in the Monte San Giorgio have provided excellent fossils representing one of the most important windows to the marine life during the Triassic. Among these fossils, fishes are abundant and extraordinarily well preserved. Most of these fishes represent extinct lineages and were difficult to understand and classify during the early years after discovery. These difficulties usually led to a mixture of species under the same taxonomic name. This is the case of fishes referred to the genus Archaeosemionotus. The name bearing type of A. connectens, the type species of this genus, represents a basal halecomorph, but most other fishes referred to this genus represent basal ginglymodians. Therefore, we conducted this study to clarify the taxonomic status and phylogenetic relationships of A. connectens, which is a member of the family Furidae (Halecomorphi, Ionoscopiformes) representing the second cladistically supported evidence of ionoscopiforms in the Triassic and it is thus one of the two oldest reliable records of this group. Ionoscopiforms have a long stratigraphic range, though their fossil record is rather patchy. In our analysis, the sister taxon of Archaeosemionotus is Robustichthys from the Anisian of China, and they together form a clade with Furo, which is known from several localities ranging from the Early to the Late Jurassic. Other ionoscopiforms are so far known from the Kimmeridgian to the Albian and it is thus evident that recent efforts have concentrated on the later history of the group (Late Jurassic to Cretaceous). The phylogenetic relationships obtained for the Ionoscopiformes do not show a clear palaeobiogeographic pattern, but give important new insights into the origin, divergence date and early history of this clade.  相似文献   

17.
18.
Two new bryozoan species of the trepostome family Dyscritellidae,Dyscritellopsis thaynesianus n. sp. andDyscritellopsis montelloensis n. sp., are described from the Early Triassic (Smithian/Spathian) Thaynes Limestone, Nevada (USA). The bryozoan fauna documents the survival of Paleozoic lineages into the earliest Triassic on northern open shelves outside the tropics. The fauna holds paleobiogeo-graphic connections to the Early Triassic bryozoan faunas of Spitsbergen.   相似文献   

19.
Three wasp (Hymenoptera: Vespidae) fossils in Cretaceous amber (Late Albian) of northern Myanmar are described. Two are new species of the Mesozoic genus Curiosivespa (Rasnitsyn): C. zigrasi sp.n. and C. striata sp.n. The third species, Protovespa haxairei gen.n. et sp.n. , has a combination of features unique among Mesozoic Priorvespinae and the extant subfamilies. These well preserved fossils provide new morphological data for a cladistic analysis of the basal lineages of Vespidae. Results suggest that Euparagiinae is the sister group of all other Vespidae. The new genus Protovespa appears more closely related to extant Masarinae, Eumeninae and social wasps than to Priorvespinae. We assign it to a new subfamily: Protovespinae. Finally, fossil information combined with a phylogenetic tree shows that the main groups of Vespidae probably evolved during the Early Cretaceous. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:1E7E4796‐6E70‐4D81‐BB34‐0FEEA765DC25 .  相似文献   

20.
In this contribution, new specimens of the tritheledontid eucynodont Irajatherium hernandezi, from the Late Triassic (Caturrita Formation) of southern Brazil, are analyzed. The new material provides significant information about incisor count, canine size and shape, basicranial morphology, and other previously unknown aspects of skull and dentition. A cladistic analysis with inclusion of the new data supports the assignment of Irajatherium to Tritheledontidae, basal to Chalimininae and Pachygenelinae. Previously unknown characters of Irajatherium revealed by the new material include: the presence of three lower incisors; the first lower incisor is enlarged; the presence of large upper and lower canines with deep paracanine fossa on the maxilla; almost complete upper and lower postcanine tooth row with a pattern similar to that of other tritheledontids (e.g. Pachygenelus and Chaliminia); there is a conspicuous crest on the inner surface of the maxilla for the attachment of the inferred maxillary turbinates; partially confluent jugular foramen and fenestra rotunda within the jugular fossa, separated by a finger-like projection of the posterolateral wall of the opisthotic; and hypoglossal foramina located outside the jugular fossa. Irajatherium is a key taxon for understanding the early evolution of ictidosaurs, a group of cynodonts closely related to mammaliaforms, during the cynodont–mammal transition from the Late Triassic to Early Jurassic.  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