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1.
2.
A new species of Eastmanosteus Obruchev is described from the Upper Devonian Gogo Formation of Western Australia as E. calliaspis sp. nov. It is at the pachyosteomorph level of organization having no contact between the plates of the flank and those of the ventral shield behind the pectoral fin. Well preserved material of the parasphenoid and scapulocoracoid throws further light on the structure of these elements in arthrodires. The genus Eastmanosteus is reviewed.  相似文献   

3.
New bryozoans Saffordotaxis altaicus sp. nov. from the Givetian Stage (Middle Devonian) and Cyphotrypa olgae sp. nov. and Crustopora aliena sp. nov. from the Famennian Stage (Upper Devonian) are described from the Devonian of Gorny Altai.  相似文献   

4.
Two bryozoan species are described from the Geirud Formation (Upper Devonian/Lower Carboniferous) of Central Alborz (Iran). Trepostome Schulgina mutabilis Troizkaya, 1975 is known from the Upper Devonian (Famennian) of Central Kazakhstan. The new species Ascopora geirudensis n. sp. is the earliest known representative of the rhabdomesine genus Ascopora Trautschold, 1876.  相似文献   

5.
Two monotypic genera of tubular-snouted eubrachythoracid arthrodires are described from the Upper Devonian Gogo Formation of Western Australia as Rolfosteur gen nov. and Tubonnsus gen. nov. They are most closely related to Camuropiscis Dennis & Miles, also from the Gogo Formation, and all three are therefore placed in the family Camuropiscidae nov. Rolfosteus and Tubonasus are jointly the sister-group of Camuropiscis .  相似文献   

6.
A primitive eubrachythoracid arthrodire from Gogo, Western Australia   总被引:2,自引:0,他引:2  
A new eubrachythoracid arthrodire, Hanytoombsia elegans gen. et sp. nov., is described from the Upper Devonian Gogo formation of Western Australia. Its structure and relationships are discussed within the framework provided by a new sketch cladogram for arthrodires. H. elegans is morphologically similar to Coccosteus cuspidatus , but its relationships among primitive eubrachythoracids are unknown.  相似文献   

7.
A new genus of long-snouted, eubrachythoracid arthrodire, Camuropiscis gen. nov., is described from the Upper Devonian Gogo formation of Western Australia. It is represented by two species, the type C. concinnus sp. nov. and C. laidlawi sp. nov. These species are interchangeable with Coccosteus spp. in a sketch cladograin for arthrodires; their phylogenetic relationships are not known in any detail. C. concinnus has a well-preserved pelvic girdle and throws new light on the structure of this element in arthrodires.  相似文献   

8.
Biomechanical models offer a powerful set of tools for quantifying the diversity of function across fossil taxa. A computer‐based four‐bar linkage model previously developed to describe the potential feeding kinematics of Dunkleosteus terrelli is applied here to several other arthrodire placoderm taxa from different lineages. Arthrodire placoderms are a group of basal gnathostomes showing one of the earliest diversifications of jaw structures. The linkage model allows biomechanical variation to be compared across taxa, identify trends in skull morphology among arthrodires that potentially influence function and explore the role of linkage systems in the early evolution of jaw structures. The linkage model calculates various kinematic metrics including gape angle, effective mechanical advantage, and kinematic transmission coefficients. Results indicate that the arthrodire feeding system may be more diverse and complex than previously thought. A range of potential kinematic profiles among arthrodire taxa illustrate a diversity of feeding function comparable with modern teleost fishes. Previous estimates of bite force in Dunkleosteus are revised based on new morphological data. High levels of kinematic transmission among arthrodires suggest the potential for rapid gape expansion and possible suction feeding. Morphological comparisons indicate that there were several morphological solutions for obtaining these fast kinematics, which allowed different taxa to achieve similar kinematic profiles while varying other aspects of the feeding apparatus. Mapping of key morphological components of the linkage system on a general placoderm phylogeny illustrates the potential importance of four‐bar systems to the early evolution of jaw structures. J. Morphol. 271:990–1005, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   

9.
We describe a new ammonoid fauna from the Taurus Mountains of southern Turkey. The Carnian ammonoid fauna from A?a?iyaylabel is presented for the first time. Ammonoids were obtained from limestone to marl beds of an approximately 35‐m‐thick section, which presents the rare opportunity to investigate ammonoid faunas across the Lower–Upper Carnian boundary. Intense sampling near the village of A?a?iyaylabel led to the recognition of a new Lower Carnian (Julian 2) to Upper Carnian (Tuvalian 1) ammonoid fauna from the Kasimlar Formation. The genus Kasimlarceltites gen. nov. is reported for the first time from the Taurus Mountains, which represents the main faunal element and occurs as huge mass occurrence (n ? 1 million). Kasimlarceltites krystyni gen. et sp. nov., Klipsteinia disciformis sp. nov. and Anasirenites crassicrenulatus sp. nov. occur within the Lower Carnian Carbonate member (Units A–B) of the Kasimlar Formation from the Taurus Platform Units. Ammonoids described from the marls of the Tuvalian Marlstone member were deposited during a major, Tethyan‐wide climate crisis – the so‐called Carnian crisis – characterized by a demise of carbonate platforms. Based on the biostratigraphic relevance of certain ammonoid taxa described herein, the age of the analysed parts of the Kasimlar Formation is Julian 2 to Tuvalian 1. The discovery of the new ammonoid assemblages from A?a?iyaylabel substantiates the significance of Upper Triassic faunas within the Taurus Mountains and facilitates the correlation with faunal assemblages from other regions in the Tethyan Realm. The ammonoid fauna and facies indicate a general deepening from open‐platform margins, over deeper shelf settings down to an open marine‐influenced basinal environment. The tentative habitat for Kasimlarceltites gen. nov. is a shallow platform environment to upper mid‐ramp.  相似文献   

10.
Two new strophomenid species, Leptagonia barunkhuraica sp. nov. (Famennian) and Floweria mongolica sp. nov. (Frasnian), from the Upper Devonian of the Barunkhurai Depression of southern Mongolia are described.  相似文献   

11.
Heintzichthys gouldii is redescribed based on new material from the Interstate 71 Paleontological Salvage Project (Cleveland Museum of Natural History, 1966-67). Phylogenetic analysis of brachythoracid arthrodires clearly shows the monophyly of Camuropiscidae and the aspinothoracid arthrodires. Heintzichthys gouldii and Gorgonichthys clarki are removed from Dinichthyidae and placed within aspinothoracid arthrodires. The remaining members in the family Dinichthyidae are united solely by plesiomorphic characters. A number of putative synapomorphies for the eubrachythoracid arthrodires are questioned; however, the validity of this taxon is supported by three synapomorphies.  相似文献   

12.
Recent investigations of the Middle and Upper Devonian Campo Chico Formation, north-west Venezuela, led to the discovery of a new aneurophytalean progymnosperm, Tetraxylopteris reposana sp. nov. The fossils allow the most detailed morphological outline of a species of Tetraxylopteris Beck to date, and indicate there was more variation within the genus than yet recognized. Tetraxylopteris reposana was probably a bushy plant which formed dense interlocking thickets. Its morphology highlights the similarity between Tetraxylopteris and Proteokalon Scheckler & Banks, and the potential synonymy of these taxa is discussed . Furthermore, there is a morphological continuum between the fertile organs of Tetraxylopteris and Rellimia Leclercq & Bonamo. As the first definitive documentation of Tetraxylopteris in Gondwana, this study indicates aneurophytalean progymnosperms were more widespread than formerly understood. The diversity of the Campo Chico Formation floras and similarity of their composition to northern palaeocontinent assemblages (e.g. the Catskills Clastic Wedge) support the concept of a largely uniform worldwide vegetation.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 275–303.  相似文献   

13.
Material of Hispanomys (Rodentia, Cricetodontinae) is described from various localities at Batallones (MN10) (Madrid, Spain). All of it belongs to a single species, which differs from the other known species of the genus and a new taxon, Hispanomys moralesi sp. nov. , is created for it. The samples from the various localities show differences interpreted as being the result of slight age disparities amongst the different sites. Although they were previously thought to be coeval, Batallones 10 is probably older than Batallones 1, which is possibly older than Batallones 3. Hispanomys moralesi sp. nov. is characterized by several morphological features such as the lack of cingula and mesolophs, the presence of well‐developed ectolophs, four‐ or five‐rooted M1, short or absent mesolophids, and reduced and simplified M3. Hispanomys moralesi sp. nov. is a relatively derived species, the evolutionary stage of which is comparable to those of other members of the genus from the Upper Vallesian. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 160 , 725–747.  相似文献   

14.
Hybodontoid and nonhybodontoid sharks are described from the Lower Triassic Vega‐Phroso Siltstone Member of Sulphur Mountain Formation on the basis of newly discovered material. The age of the classic fossil site ‘Wapiti Lake’ in the Canadian Rocky Mountains is discussed on the basis of new field data and one conodont found in association. Preliminary results suggest that these elasmobranch remains are between early Smithian and Spathian in age. Apart from the enigmatic genus Listracanthus and previously reported edestoids, the shark fauna consists of at least one hybodont, at least two questionable hybodontoid genera and an elasmobranch of enigmatic affinities, represented by peculiar denticles only and described as ‘genus A’incertae sedis. The presence of the only previously reported hybodont genus, cf. Palaeobates, is erroneous. The largest specimen represents the most complete Early Mesozoic shark known. The heterodonty of its dentition, fin spine morphology and the short, robust body shape imply it represents a member of a new family of shark, Wapitiodidae fam. nov. , and is described here as Wapitiodus aplopagus gen. et sp. nov. The unique dental morphology shows affinities to Polyacrodus but clearly differs in the complete lack of side cusps. Wapitiodus gen. nov. possesses a primitive fin spine structure. The tooth crowns are entirely blunt in the distal (posterior) tooth files, and are acuminate‐unicuspid in several anterior files. Tooth morphology, the shape of the basal cartilages, the proximal insertion of the fin spines and the pectoral fin structure are interpreted as diagnostic characters for this new genus, and possibly for the Wapitiodidae fam. nov. The majority of observed characters appear to be primitive and are reminiscent of Palaeozoic sharks, however, and these features include dorsal fin spine morphology and gross skull anatomy. A second species, provisionally placed in the same genus, is described as Wapitiodus homalorhizo sp. nov. Wapitiodus homalorhizo sp. nov. can be distinguished from W. aplopagus gen. et sp. nov. by the proportions of the fin spines, tooth morphology and possibly the body shape. Several isolated teeth and other fragmentary material are referred to either Wapitiodus gen. nov. sp. indet. or to ?Polyacrodus sp. (Polyacrodontidae gen. et sp. indet.). A third genus of elasmobranch (incertae sedis) is described as ‘Genus A’ and is recognized by its peculiar scales. © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 149 , 309–337.  相似文献   

15.
Three new species of mayfly nymphs, Clavineta excavata sp. nov., Clavineta brevinodia sp. nov., and Siberiogenites branchicillus sp. nov., from the Yixian Formation (Late Jurassic-Early Cretaceous) in western Liaoning Province, China, are described. These mature nymphs are small-sized, with the body less than 16.0 mm long. The systematic position of the genera Clavineta and Siberiogenites, which are recorded for the first time in the Yixian Formation, is briefly discussed.  相似文献   

16.
A fauna of provannid and provannid‐like shells is described from Upper Cretaceous seep carbonates in Hokkaido, Japan. We describe two new provannid species, Provanna tappuensis sp. nov. and Desbruyeresia kanajirisawensis sp. nov. , with preserved protoconchs of unquestionable provannid type with decollate apex. This material confirms the occurrence of Provannidae as early as the Middle Cenomanian. We also describe Hokkaidoconcha gen. nov. and a new family Hokkaidoconchidae fam. nov. , with two named species, H. hikidai sp. nov. and H. tanabei sp. nov . Hokkaidoconchidae are possibly related to the Provannidae, judging from a similar, but not decollate larval shell, although the juvenile teleoconch whorls differ in being of a general cerithimorph appearance and the details of the aperture are unknown. Furthermore, we review the published fossil record of Provannidae and Abyssochrysidae, and we consider that in those older than the Eocene, there is no evidence preserved that unequivocally supports a position there. The Jurassic Acanthostrophia acanthica from Italy seems to be the oldest known record of Abyssochrysidae, and the most reliable occurrence of the family, older than from the Miocene. Other fossil, pre‐Miocene species that have been classified in the Abyssochryssidae are provisionally referred to Hokkaidoconchidae. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154 , 421–436.  相似文献   

17.
A bryozoan fauna containing seven species is described from the Upper Frasnian (Upper Devonian) rocks in the Khoshyeilagh Section, Alborz Mountains (northern Iran). The studied bryozoan assemblage includes one new trepostome species, Eridotrypella alborzensis sp. nov., an additional four species identified at species level: two trepostomes, Minussina akkayaensis Volkova, 1974 and Leptotrypella inaudita Morozova, 1961, and two rhabdomesine cryptostomes, Bigeyella mariae (Morozova, 1961) and Saffordotaxis multispinata (Morozova, 1955). Furthermore, two species are described in open nomenclature: the trepostome Schulgina sp. and the rhabdomesine cryptostome Nicklesopora sp. The studied fauna shows a close similarity at the species level between northern Iran and the Altai-Sayan Folded Belt (Russia), south China, and Transcaucasia.  相似文献   

18.
In this contribution a new representative of the taxon Meidiama Marcus, 1946, Meidiama uruguayensis sp. nov. , from Uruguay, is described, as are six more new species, for which three new genera are proposed: Dreuxiola philippi gen. nov. sp. nov. , from the French subantarctic archipelago Kerguelen; Yorknia aprostatica gen. nov. sp. nov. ; Serrula byronensis gen. nov. sp. nov. ; Serrula maxillaria sp. nov. ; Serrula concharum sp. nov. ; and Serrula acuta sp. nov. , from eastern Australia and Tasmania. Arguments are presented to propose a new taxon to contain these new species, rather than include them in the Archimonocelididae Meixner, 1938 (of which Meidiama has been considered a member so far), as well as to remove the Calviriinae Martens & Curini‐Galletti from the Archimonocelididae to become a separate taxon Calviriidae. Possible autapomorphies for the three families are discussed. It is also concluded that, with the present state of our knowledge, no sound indications can be given about close relationships. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 759–773.  相似文献   

19.
Cumaceans (Crustacea: Peracarida) belonging to the family Bodotriidae collected between 206 and 3680 m depth, during the French campaigns BIOCAL and BIOGEOCAL in waters of New Caledonia, KARUBAR in Indonesia and BORDAU 1 around Fiji were studied. The 93 specimens belonging to this family were assigned to 11 species, ten of them new to science, namely Cyclaspis variosculpta sp. nov., Cyclaspis richeri sp. nov., Cyclaspis dictyota sp. nov., Cyclaspis decora sp. nov., Cyclaspis magna sp. nov., Cyclaspoides erugatus sp. nov., Alticuma? ectyphum sp. nov., Apocuma pacificum sp. nov., Hypocuma fragosum sp. nov. and Bathycuma coremium sp. nov. The genera Cyclaspoides and Hypocuma are recorded for the first time from the Pacific Ocean. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 152 , 227–254.  相似文献   

20.
A new camuropiscid arthrodire, Latocamurus coulthardi gen. et sp. nov., is described from the Upper Devonian Gogo Formation, Western Australia. Latocamurus , known from two complete specimens, is recognized as a camuropiscid by its narrow, spindle-shaped armour, deep postnasal plates participating in the orbits, preorbital plates which meet mesially, cheek unit firmly sutured to skull roof, posterior check plates tightly interconnected and much reduced, and the robust durophagous dentition. It is characterized by its downturned snout, broad, flat rostral plate, and narrow, deep parasphenoid. It is placed phyletically as the plesiomorphic sister taxon to all other camuropiscids which are more derived in having, inter alia , an anterior lateral plate which anteriorly contacts the anterior ventrolateral plate and pointed rostral plates. The family Camuropiscidae Dennis & Miles 1979b is redefined to incorporate features of the new genus. Camuropiscids and Incisoscutum are closely related by features of the postnasal plate and cheek.  相似文献   

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