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 0 毫秒
1.
Antiarchi (Pisces, Placodermi) from the Devonian of central and southern European Russia (Central Devonian Field) are studied. Antiarchs belong to three families, the Asterolepididae, Remigolepididae (suborder Asterolepidoidei), and Bothriolepididae (suborder Bothriolepidoidei). The diagnoses of the order, two suborders, three families, and five genera (two of which are new) are given. Sixteen species, including one new, are described; ten taxa are determined in open nomenclature. Morphological structures of representatives of these families are considered in detail. Classifications of antiarchs and their position in the system of the lower vertebrates are discussed. Devonian vertebrate localities of central and southern European Russia that have yielded antiarchs are listed. Each locality is characterized by its ichthyoassemblage.  相似文献   

2.
The bothriolepidid placoderms Bothriolepis markovskii sp. nov. from the southern Ural Mountains and Bothriolepididae gen. et sp. indet. from the Kuznetsk Coal Basin are described. The new species from the southern Ural Mountains has a high dorsal crest, resembling in this character Scottish B. cristata Traquair, Australian B. gippslandiensis Hills and B. cullodenensis Long, and B. heckeri Lukševičs from the Novgorod Region. The bothriolepidid from the Kuznetsk Coal Basin is similar to Bothriolepis from central Poland and Livnolepis from European Russia. The new finds expand the diversity and distribution of crested bothriolepidid antiarchs. Apparently, the high bone dorsal crest developed in parallel in the exoskeleton of different both-riolepidid groups.  相似文献   

3.
4.
Antiarch placoderms (Pisces, Placodermi, Antiarchi) from the Middle-Upper Devonian of Central and northern Asia (Asian part of the former Soviet Union) are described. Available antiarch specimens belong to 28 species (eight of which are described in open nomenclature), of 9 genera, 5 subfamilies, 6 families, 2 orders. The main localities of Middle-Late Devonian antiarchs are listed and provided with the data on stratigraphic distribution. The morphological structure of antiarchs and history of their study in Central and northern Asia are briefly considered. The principles of systematics and phylogeny of antiarchs, feature of their historical development in the Middle and Late Devonian of this area, and their paleozoogeographic relationships are discussed.  相似文献   

5.
6.
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   

7.
The osteostracans Reticulaspis menneri gen. et sp. nov. and Nucleaspis unica gen. et sp. nov. from the Lower Devonian Severnaya Zemlya Formation of October Revolution Island of the Severnaya Zemlya Archipelago are described. The perfect preservation of the exoskeleton structure of Reticulaspis menneri allows the design and growth mode of the exoskeleton, with a continuous reticular dental surface of the cephalothoracic shield to be characterized. Nucleaspis unica is represented by a juvenile stage, which is extremely scarce in this vertebrate group. The preoccupied generic name Ungulaspis Afanassieva et Karatajūt?-Talimaa, 1998 is replaced by Paraungulaspis.  相似文献   

8.
Eight new species of Ostreioceratidae are described from the Lower and Upper Devonian of Novaya Zemlya, Lower Devonian of the Pechora River basin, North Ural Mountains, and the Zeravshan Range: Ostreioceras admotum, O. simile, O. abruptum, O. sobolevi, Plagiostomoceras kuzmini, P. adumbratum, P.? acerbum, and P. vinogradovi. A new family Bogoslovskyidae is established in the order Palliocerida.  相似文献   

9.
Middle Devonian conodonts from the Si Phai section in NE Vietnam are described. The section ranges from the Middle Devonian ensensis to timorensis conodont zones to the Late Devonian rhomboidea conodont Zone. A rich overall assemblage is described, including 27 taxa of species or subspecies rank and 11 taxa described in an open nomenclature. Among the dominant Polygnathus forms, four new taxa are described: Polygnathus linguiformis saharicus subsp. nov., Polygnathus linguiformis vietnamicus subsp. nov., Polygnathus rhenanus siphai subsp. nov., and Polygnathus xylus bacbo subsp. nov. Conodont assemblages are attributed to polygnathid, polygnathid-klapperinid, and klapperinid conodont biofacies representing hemipelagic to pelagic environments. The klapperinid biofacies, unreported in the previous literature, are here attributed to offshore areas of the external shelf. The taxonomic compositions of the studied conodont assemblages, as well as their CAI characteristics (CAI 4–5), suggest a palaeogeographic affinity of the studied strata to the Chinese Devonian Guangxi Basin, and the South China Terrane in general. Furthermore, the conodont biofacies and the palaeogeographic distribution of the fauna are discussed.  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.
New genus and species of punctate rhynchonellids Sharovaella mirabilis are described from the Famennian (Upper Devonian) of Transcaucasia.  相似文献   

12.
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   

13.
14.
15.
On the basis of standard trawl survey made at the shores of the Republic of Korea in the Sea of Japan, species composition, ratio of species in catches, and size composition of eelpouts (fam. Zoarcidae) at depths 123–330 m is analyzed. Five species of eelpouts are found in the investigated region: Bothocara hollandi, Lycodes nakamurae, L. sadoensis, L. tanakae, and Petroschmidtia toyamensis. For the first time for the south-western part of the Sea of Japan, quantitative characteristics of distribution, size composition, and bottom temperature of capture are reported for each eelpout species. L. sadoensis is a common species in this region.  相似文献   

16.
17.
Three osteostracan genera, Tannuaspis, Tuvaspis and Ilemoraspis, from the Silurian and Devonian of the Autonomous Republic of Tuva and the Autonomous Region of Khakassia (USSR), are revised on the basis of the type material briefly described by Obruchev (1956, 1961, 1964). Tannuaspis bears some resemblances with the Tremataspididae. Tuvaspis may be closely related to Tannuaspis. Finally, there is no evidence of paired fins and cornual processes in Ilemoraspis (neither is there any evidence of their absence). Tannuaspis and Ilemoraspis share some characters which are not found in any other osteostracan: widely separated orbits, very small and oval lateral fields, situated at the same level as the median dorsal field. These resemblances may suggest that these two genera (to which Tuvaspis may be added) form a monophyletic group of osteostracans, which may be endemic to this part of Central Asia.  相似文献   

18.
A new genus and species of pachyosteomorph arthrodire, Omalosteus krutoensis gen. et sp. nov. from shallow-water marine deposits of the Evlanovo Regional Stage (Upper Frasnian, Upper Devonian) of the Central Devonian Field is described. It is tentatively referred to the family Trematosteidae Gross, 1932, which was earlier believed to be endemic to central Europe. The new genus is characterized by a rounded, dorsoventrally compressed cross section of the pectoral region and smooth head shield and postcranial membrane bones. The centrale is elongated, forming a narrow lateral lobe. The praeorbitale, postorbitale, and centrale come in contact in the center of the orbital region. The mediodorsale is wide, its carinal process projects considerably posteriorly. The anterior margin of the anterior ventrolaterale lacks articular facets for the interlaterale.  相似文献   

19.
A new species of notothenioid fish, Pogonophryne bellingshausenensis n. sp., is described from the Bellingshausen Sea, Antarctica. The new species belongs to the dorsally-spotted “mentella” group of the genus and is characterized by having a short (about 13% SL) mental barbel with a short (about 16% of barbel length), narrow (barely wider than the stalk), and relatively inconspicuous terminal expansion composed of short, irregular, fingerlike processes. Compared to most other dorsally-spotted species of Pogonophryne (“barsukovi”, “marmorata”, and “mentella” groups), P. bellingshausenensis has a relatively wide (about 7% SL) interorbital region. An unspotted patch on the median dorsal surface of the head, posterior to the posttemporal ridges and anterior to the first dorsal fin, has not been observed previously in any dorsally-spotted species. The holotype was collected at 1,947 m, one of the deepest records for any species of Pogonophryne. A revised key to the ten species of the “mentella” group of Pogonophryne is also provided.  相似文献   

20.
Several articulated, but incomplete, acanthodians from the Bunga Beds (late Givetian/early Frasnian) of the southern coast of New South Wales are tentatively identified as ischnacanthids. Heads are missing from all three prepared specimens. They exhibit the following characters: two dorsal fin spines; long, slender scapulocoracoids; slender, relatively deeply inserted, unpaired fin spines; minute scales with a fairly smooth, flat, crown; and an increase in size of normal body scales towards the tip of the tail. The fish are preserved in black, finely laminated shales, which were probably deposited as deep water, lacustrine sediments. The rarity, burial conditions, and headless state of the Bunga Beds acanthodians indicate that they might have died in shallow water, sunk to the bottom, refloated by gas‐induced buoyancy, with the heads lost while drifting out to deeper waters, where the bodies finally sank to a scavenger‐free, anaerobic substrate.  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