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 46 毫秒
1.
Abstract: A new genus and species of Devonian tetrapod has been identified from material collected in 1947 from the southern slope of Mt. Celsius, Ymer Ø, North‐East Greenland. The specimen preserves both lower jaws, partial palate, premaxillae and maxillae, with a natural mould of parts of the shoulder girdle. The new taxon, Ymeria denticulata, shows differences in dentition, skull ornament and lateral line expression from both Acanthostega and Ichthyostega, but it shows a closer resemblance to the latter. A cladistic analysis not only suggests that Ymeria lies adjacent to Ichthyostega on the tetrapod stem, but also reveals substantial topological instability. As the third genus and the fifth species of tetrapod identified from North‐East Greenland, it demonstrates the high diversity of Devonian tetrapods in that region.  相似文献   

2.
The placoderm fauna of the late Famennian tetrapod‐bearing locality of Strud, Belgium, is studied on the basis of historical and newly collected material. It includes the previously described antiarch Grossilepis rikiki, the groenlandaspidid Turrisaspis strudensis sp. nov. and the actinolepidoideid Phyllolepis undulata. P. undulata is thoroughly described and joins the list of the valid Phyllolepis species confidently diagnosed. A morphometrical analysis performed on the centronuchal and anterior ventrolateral plates of the Phyllolepis material demonstrates that there is only one species of Phyllolepis in Belgium (thus, Phyllolepis konincki becomes a junior synonym of P. undulata), that P. rossimontina (Pennsylvania) is a synonym of P. undulata and that the unity of the genus Phyllolepis is strongly supported, although the characterization of several species within this genus is blurred. The strong resemblance between the faunal compositions in Strud and Red Hill (Pennsylvania, USA) suggests important faunal exchanges between these regions of the Euramerica landmass.  相似文献   

3.
A new notostracan crustacean, Strudops goldenbergi gen. et sp. nov., is described from the well‐preserved terrestrial arthropod fauna of the Upper Devonian of Strud, Belgium. The fossil notostracan bears a close resemblance to modern notostracans in possessing a large, simple head shield covering almost half of the whole body, a set of phyllopodous thoracic appendages and a legless posterior abdomen with a telson bearing a caudal furca. The differentiation and relative size of mouthparts and limbs suggest that these specimens are all adults. The notostracans described herein are the earliest clear members of the total group Notostraca.  相似文献   

4.
Abstract Archaeopteris macilenta is one of the most widespread plants in the Late Devonian. Based on fossils from the Frasnian Huangjiadeng Formation, Yichang District of Hubei Province, for the first time we study in detail the anatomy of this progymnosperm plant in South China. Ultimate axes are protostelic with three xylem sympodia and lack secondary tissue. Penultimate axes are eustelic, bearing eight sympodia and a thin band of secondary xylem. Radially symmetrical sympodia of mesarch primary xylem produce traces of appendages in a spiral arrangement. Archaeopteris macilenta and A. halliana (A. roemeriana) are dominant in the Frasnian and Famennian, respectively. Comparisons with these two species from other tectonic plates indicate consistent stelar architectures. Global spread, continuous occurrence, and identical anatomy during the Late Devonian indicate that Archaeopteris survived the Frasnian–Famennian extinction event. In this time, endemic genera and cosmopolitan taxa, including Archaeopteris, suggest the palaeogeographic isolation of South China and certain associations with other plates.  相似文献   

5.
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   

6.
Abstract: Microconchid tubeworms (Tentaculita) encrusting brachiopod shells have been investigated from the upper Frasnian – lower Famennian (Upper Devonian) deposits of the Central Devonian Field, Russia. The condition of microconchids and associated encrusting taxa is reported for the first time from the early Famennian recovery interval (crepida Chron) following the Frasnian–Famennian mass extinction. Two species, one new (Palaeoconchus variabilis sp. nov.) and the second one in open nomenclature (Palaeoconchus sp.), are described. Compared to lower Famennian specimens, they seem to be preferentially grouped on the anterior parts of the brachiopod host shells, which are interpreted as the most suitable sites away from the sea‐bottom and sediment. During the late Frasnian (Late rhenana Chron), microconchids, outnumbered by cornulitids and as abundant as foraminifers, were also associated with trepostome bryozoans, tabulates, rugose corals and various problematic encrusters. During the early Famennian recovery interval encompassing the crepida Chron, microconchids greatly outnumbered all associated encrusters, including the previously dominant cornulitids, while foraminifers, tabulates and rugose corals vanished. Early Famennian microconchids, represented by the single, albeit very abundant, species Palaeoconchus variabilis sp. nov., were opportunists that rapidly colonised the environment during the ongoing transgression following the regression‐driven biotic crisis in the area of the Central Devonian Field. In comparison to their late Frasnian predecessors and even other Middle Devonian specimens, no size reduction (the so‐called Lilliput effect) of early Famennian microconchid tubes was observed. It is probable that microconchids either rapidly attained their ‘normal’ sizes or they did not suffer any dwarfism following the Frasnian–Famennian event.  相似文献   

7.
Foraminifers from typical Kulm environments are described from 4 localities at the eastern and northern border of the Rhenish Massif: aQuasiendothyra fauna of uppermost Devonian age (Famennian); a Chernyshinellinae fauna of the lower Dinantian Cf1 Zone (middle Tournaisian); upper Dinantian foraminifers from the Cf4δ to Cf6γ Zones (Middle and Upper Viséan). The foraminifer assemblages of the Cf6 Zone (V3b + c), in theGoniatites crenistria schmidtianus toNeoglyphioceras spirale Subzones, seem to be variegated in Germany and Belgium, but they are definitively poorer than contemporaneous faunes in the British Isles and the Russian Platform.  相似文献   

8.
9.
10.
Recent fieldwork has uncovered three new localities from the Lower Devonian of Mezquita de Loscos (Teruel Province, Spain) with further plant mega-fossils and the first record of micro-fossils. Such plant remains have been interpreted as belonging to a basal euphyllophyte, Taeniocrada-like stems, Hostinella genus and paired sporangia. Fourteen spore taxa were recovered, including Ambitisporites, Aneurospora, Brochotriletes, Chelinospora, Emphanisporites, Gneudnaspora and Retusotriletres, among others. New evidence confirms a Lochkovian age for this outcrop and suggests that the plant diversity was more complex than originally documented.  相似文献   

11.
晚泥盆世弗拉期末F-F的生物灭绝事件,导致珊瑚以及许多浅海底栖生物灭绝,几乎整个法门期珊瑚群都处于残存阶段,华南地区目前只在湖南的个别地方发现少量的Smithiphyllum。直到法门期末珊瑚和其它一些造礁底栖生物开始复苏,出现了不少与典型泥盆纪珊瑚存在很大差别的新分子。华南泥盆纪最晚期(Strunian)的珊瑚可划分成上、下两个组合:上部Cystophrentis组合;下部Eocaninophyllum组合。泥盆—石炭纪之交的另一次生物灭绝事件,使新生的泥盆纪最晚期的珊瑚又遭灭绝。  相似文献   

12.
The genus Entactinosphaera Foreman, 1963 is revised; it is shown to combine seven different genera, which are distinguished by morphological characters and belong to three orders of two radiolarian classes: the class Sphaerellaria, order Entactiniata (Bientactinosphaera, Entactinosphaera, Helioentactinia, Radiobisphaera), and class Spumellaria, orders Cancelliata (Retientactinosphaera, Magnisphaera) and Spongiata (Spongentactinia). New radiolarian taxa from the Middle Frasnian-Lower Famennian of the Timan-Pechora Basin and from the Lower Famennian of the Polar Ural Mountains, Russia, are described: Retientactinosphaera gen. nov., R. magnifica sp. nov., and R. clavata sp. nov.  相似文献   

13.
Anew genus, Zezinia gen. nov., and two new species, Zezinia multicostata sp. nov. and Zaigunrostrum nakhichevanense sp. nov., are described from the Upper Devonian of Transcaucasia. The first genus is one of the last Frasnian representatives of the family Uncinulidae. The Famennian Z. nakhichevanense sp. nov. belongs to punctate rhynchonellids of the family Trigonirhynchiidae.  相似文献   

14.
Archaeopteris macilenta is one of the most widespread plants in the Late Devonian.Based on fossils from the Frasnian Huangjiadeng Formation,Yichang District of Hubei Province,for the first time we study in detail the anatomy of this progymnosperm plant in South China.Ultimate axes are protostelic with three xylem sympodia and lack secondary tissue.Penultimate axes are eustelic,bearing eight sympodia and a thin band of secondary xylem.Radially symmetrical sympodia of mesarch primary xylem produce traces of appendages in a spiral arrangement.Archaeopteris macilenta and A.halliana (A.roemeriana) are dominant in the Frasnian and Famennian,respectively.Comparisons with these two species from other tectonic plates indicate consistent stelar architectures.Global spread,continuous occurrence,and identical anatomy during the Late Devonian indicate that Archaeopteris survived the Frasnian-Famennian extinction event.In this time,endemic genera and cosmopolitan taxa,including Archaeopteris,suggest the palaeogeographic isolation of South China and certain associations with other plates.  相似文献   

15.
Remains of two large sarcopterygians are described from Famennian deposits in Belgium. One of them is referred to Eusthenodon wängsjöi Jarvik; it is the first occurrence of this genus in Belgium. The other, much larger one, appears to be a tristichopterid. It has a postspiracular; size and shape of the mandible similar to those of Platycephalichthys skuenicus and P. bischoffi ; snout and cheek patterns close to those of Eusthenodon ; unusual shape of the supratemporal resembling that of Hyneria , Mandageria and Platycephalichthys skuenicus ; and tooth histology quite similar to that of Eusthenodon and Platycephalichthys .  相似文献   

16.
New genus and species of punctate rhynchonellids Sharovaella mirabilis are described from the Famennian (Upper Devonian) of Transcaucasia.  相似文献   

17.
The crinoids and blastoids from the Pilton (Beds) Formation of the type Devonian of north Devonshire are revised. These fossils were monographed by the Rev. G. F. Whidborne in 1898, but have not been studied since that time. Recent studies on various groups of fossils from the Pilton and related rocks in North Devon confirm that the great majority of these fossils are Famennian, although three specimens from Fremington are probably Early Carboniferous (Tournaisian). We identify four blastoid taxa from a fauna that is sparse and poorly preserved; two spiraculates, one fissiculate, and one taxon unidentifiable at the ordinal level. Mesoblastus cf. M. crenulatus from the Gattendorfia Zone (Lower Carboniferous) near Fremington is the oldest known representative of this genus. The crinoid fauna is somewhat more diverse, but the preservation is equally poor. No changes are made in the flexible crinoids. Among camerate crinoids, one species is reassigned to Eumorphocrinus and one is retained in Actinocrinites. Specimens of some crinoids, such as Rhodocrinites and Megistocrinus, are so poorly preserved that certain identification was not possible. The hexacrinoid Adelocrinus, relegated to uncertainty for 150 years, is here shown to be a valid genus that is very similar to Arthroacantha, but not synonymous with it. Among the cladid crinoids, the dominant groups are those within the Superfamily Scytalocrinacea, which includes Bridgerocrinus, Sostronocrinus, and Scytalocrinus, all of which are placed in the new family Sostronocrinidae. One new species, Glossocrinus whidbornei, is named. Non‐pinnulate cladids, common in older Devonian rocks, do not occur. The fauna shows considerable similarity with faunas from eastern North America and Germany. It shows less resemblance to the extensive Famennian crinoid and blastoid fauna of north‐western China, despite some remarkable congruencies, especially the occurrence of very similar species of Actinocrinites in these widely separated areas.  相似文献   

18.
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   

19.
An anatomically preserved lycopsid, Lobodendron fanwanensegen. et sp. nov. Liu, Wang, Xue & Meng, is described from the Upper Devonian (Famennian) Wutong Formation of Changxing County, Zhejiang Province, China. The fossil plant bears slender, dichotomously branched axes. The vascular strand consists of solid terete primary xylem and lobed secondary xylem, which implies the result from the activity of possibly discontinuous cambium. The new plant has character combinations that do not conform to any branches in the canopy of the tree-lycopsids known previously, but resemble those of the basal part of some pseudoherbaceous lycopsids. This new plant may exemplify a Late Devonian lycopsid with a pseudoherbaceous growth habit.  相似文献   

20.
Paleontological Journal - A new dipnoan genus and species Anchidipterus dariae Krupina, gen. et sp. nov. (Dipteridae) is described based on a lower jaw specimen from the Famennian (Upper Devonian)...  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