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1.
Fossilised traces of swimming amphibians, assigned to Batrachichnus delicatulus and Serpentichnus robledoensis igen. et isp. nov., are described from the Lower Permian of the Robledo Mountains, southern New Mexico. The B. delicatulus specimen is interpreted as a trackway of a small 'amphibian' (temnospondyl, nectridean, microsaur or juvenile embolomere) swimming straight ahead. S. robledoensis consists of repeated pes imprints separated by discontinuous, L-shaped imprints (body traces). It is interpreted as a trackway of an 'amphibian' swimming in a similar manner to the motion of a side-winding snake. The producer of S. robledoensis is more distinctive than in B. delicatulus , and is suggestive of the lysorophian Brachydectes . This is the first locomotory trace to be assigned to this 'amphibian' group.  相似文献   

2.
Neil John McMillan 《Ichnos》2013,20(3):203-212
A new genus and species of alga called Sinoglypha nassichuki is identified and described from Guadalupian rocks of the Delaware Basin, New Mexico. It occurs in tilted to almost upright position in laminites generally accepted as being deposited in deep, anoxic water. The fossils are noncalcareous, having a wavy nature. They are not classed as trace fossils of animals. They are leafy, 2–5 cm long and may be preserved in original position.

If Sinoglypha is an alga it leads to the tentative, but not new, conclusion that perhaps the water was not deep but shallow enough for light penetration—30 meters for the upper part of the Bell Canyon Formation.  相似文献   

3.
We describe an arthropod body impression associated with arthropod trackways of the ichnogenus Stiaria from the Lower Permian (upper Wolfcampian) Robledo Mountains Formation (Hueco Group) in the Prehistoric Trackways National Monument of southern New Mexico. The probable producer of these traces was a scorpion, and we name the likely scorpionid resting trace Alacranichnus braddyi, new ichnogenus and ichnospecies. There are no prior reports of scorpionid body impressions from terrestrial settings in the fossil record.  相似文献   

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6.
New taxa of detached seeds are described from the Kungurian (Lower Permian) of the Middle Cis-Urals: Laevigatospermum compressum gen. et sp. nov., Hirsutospermum paniculatum gen. et sp. nov., Rugosospermum callosum gen. et sp. nov., and Craspedosperma filiferum sp. nov. The systematic position of the new taxa is discussed.  相似文献   

7.
New Catillocrinidae Allocatillocrinus rarus sp. nov., with a previously unknown tegmenal structure, Paracatillocrinus shamovi sp. nov., and P. shakhtauensis sp. nov., with an unusual relative position of the crown and stem are described from the Artinskian Stage (Lower Permian) of the western slope of the Middle and Southern Ural Mountains (Boets, Krasnoufimsk, and Shakh-Tau localities). The genus Allocatillocrinus has not previously been recorded from the Permian, while Paracatillocrinus has only previously been reported from the Upper Permian of Timor Island.  相似文献   

8.
Distribution of members of the thermophilic genus Pteronites in the Upper Paleozoic beds of northeastern Asia is briefly considered. A new species, Pteronites magnus sp. nov., from the Lower Permian of the Omolon Massif is described.  相似文献   

9.
Summary Isolated sponge bioherms are documented from the Lower Ordovician Makkol Formation of the Taebaek Group in the Taebaeksan Basin, mideast Korea. They are formed by an association of a lithistid spongeArchaeoscyphia, a receptaculidCalathium and stromatolitic algae, and share many features with the Lower Ordovician buildups known elsewhere. These bioherms were established in an incised bottom and reached up to about 1 m in height. As the bioherms grew upward, they were more severely affected by intense wave action and frequent storms, which eventually perished the bioherms. The occurrence ofArchaeoscyphia-Calathium association suggests a close biogeographic link between Korea and North China, supporting the paleogeographic model that the Taebaeksan Basin was connected through contiguous shallow waters to North China in the early Paleozoic.  相似文献   

10.
Two new genera and five new species of Lower Permian radiolarians, Arcoclathrata alekseevi gen. et sp. nov., Entactinia pinrasensis sp. nov., Microporosa rozhnovi gen. et sp. nov., M. aktastensis sp. nov., and Somphoentactinia saecularis sp. nov., from the Southern Urals and Northern Mugodzhary are described. The new spherical radiolarian taxa belong to three orders: Entactiniata, Cancelliata, and Spongiata of two classes, Sphaerellaria and Spumellaria.  相似文献   

11.
New nymphs of the gryllones insects (Insecta; Gryllones) Iblatta attrepida gen. et sp. nov. (Eoblattida incertae sedis) and Tshekardushka artenatis gen. et sp. nov. (Reculida incertae sedis) from the Lower Permian Chekarda locality (Kungurian Stage of Russia) are described. The nymph of Czekardia blattoides Martynov, 1940 (Eoblattida incertae sedis) from Chekarda is redescribed.  相似文献   

12.
The seasonal succession of the phytoplankton of a small reservoir(Guelph Lake, Ontario) in the spring-summer of 1982 was comparedto that in 1981. Mixing of the deeper waters occurred severaltimes throughout the summer in 1982 but not in 1981. The waterat 10 m became anoxic for only 2 weeks in late July in 1982.In contrast, in 1981, the water at 10 m became anoxic at thebeginning of July and remained so until mid-September. The phytoplanktondynamics observed in 1982 did not follow the typical progressionfrom spring diatoms to summer species adapted to survive understratified conditions, as in 1981. Diatoms were present throughoutthe summer in higher amounts in 1982 than in 1981. The mostobvious difference in the two summers was the much greater abundanceof Aphanizomenon flow-aquae in 1982. Other blue-green algaeincluding Microcystis aeruginosa, Gomphosphasria lacustris,and Lyngbya birgei appeared earlier on in 1982, but did notimmediately increase in abundance as in 1981. In 1982, ratesof phytoplankton community change were low in May and June andincreases were observed in mid-July, early August, late Augustand late September. In contrast, in 1981, the rate of communitychange increased in late May, mid-June, early July and lateJuly and remained low throughout August and September. 1Present address: Department of Zoology, University of Alberta,Edmonton, Alberta T6G 2E1, Canada. 2Present address: CSIRO Division of Fisheries Research, G.P.O.Box 1538, Hobart, Tasmania 7001, Australia  相似文献   

13.
Seasonal succession of algae in a eutrophic stream in Southern England   总被引:1,自引:7,他引:1  
J. W. Moore 《Hydrobiologia》1977,53(2):181-192
The epipelic and epilithic algal communities in a small eutrophic stream situated in southern England expanded rapidly during March of both 1973 and 1974 primarily in response to changing light conditions. Although numbers varied greatly during the summer, these fluctuations were probably not due to nutrient, temperature or light conditions. High rates of disappearance of algae from the substrate were correlated with flooding, a deterioration of attachment characteristics and high metabolic rates. The episammic algal community consisted of only a few species, all of which showed maximum development during the summer. Although the well developed attachment mechanism and small size of the species undoubtedly aid in their ability to colonize sand grains, each species must be able to withstand frequent burial in the bottom deposits. Although temperature was probably an important factor controlling the number of epiphytes associated with Cladophora glomerata, light seemed to be of relatively less importance. Large numbers of isopods, amphipods and copepods occurred in the stream but their grazing seemed to have had little effect of the standing crop of the algae.  相似文献   

14.
New grylloblattid insects are described from the Upper Permian and Lower Triassic of European Russia and Kazakhstan: Kuplya minutissima gen. et sp. nov. (Tshekardominidae) from the Severodvinian locality Novo-Aleksandrovka (Orenburg Region); Parachauliodites orthopteroides gen. et sp. nov. (Chaulioditidae), Permofossilis commasticatus gen. et sp. nov. (Permotermopsidae), Megakhosarodes tensilis sp. nov. (Megakhosaridae), and Baharellinus dilaceratus sp. nov. (Blattogryllidae) from the Severodvinian locality Isady (Vologda Region); Dvinopedes salariovensis gen. et sp. nov. (Chaulioditidae) from the Vyatkian locality Aristovo (Vologda Region); Klyazmia karasevi gen. et sp. nov. (Chaulioditidae) from the Vyatkian locality Sokovka (Vladimir Region); Megakhosarodes borealis sp. nov. (Megakhosaridae) from the Vyatkian locality Balymotikha (Vladimir Region); Sigmophlebia rugulosa sp. nov. (Tshekardominidae) from the Upper Permian locality Karaungir (East Kazakhstan Province); and Chauliodites kitshmengensis sp. nov. and C. nedubrovensis sp. nov. (Chaulioditidae) from the Induan locality Nedubrovo (Vologda Region).  相似文献   

15.
J. W. Moore 《Hydrobiologia》1977,53(3):213-219
The standing crop of phytoplankton in a canal in southern England remained low during 1973 and 1974, seldom exceeding 5 × 104 cells/1. Since phosphorus, nitrogen and silicon occurred abundantly in the water, competition with higher plants for some other substance must have limited development. Although the standing crop of epiphytic algae associated withNasturtium officinale andGroenlandia densa seemed to be limited by the number of attachment sites, this factor was of little importance in the case of algae attached toCladophora glomerata. Achnanthes minutissima v.cryptocephala was always predominant in the epiphytic assemblages, representing 50–8o% by numbers of the flora. The limited pool of predominant epiphytic taxa may have restricted the communities' ability to adapt to fluctuations in environmental conditions. The grazing of isopods, amphipods and molluscs probably never limited algal densities.  相似文献   

16.
香溪河库湾浮游藻类种类演替及水华发生趋势分析   总被引:19,自引:1,他引:19  
三峡水库一期工程蓄水前半年(2003年1月—2003年6月)和蓄水后(2003年7月—2004年12月)期间,香溪河库湾浮游藻类的种类演替和数量变化的调查结果。与蓄水前的数据相比,蓄水仅半年绿藻的种类数就明显增加,约相当于蓄水前的3倍;硅藻的种类数略有减少;其余各门藻类的种类数亦有轻度变化。整个调查期间,藻类细胞密度和生物量的最高峰值均出现在S6采样点,细胞密度达6.93×107cells/L(2004年6月),生物量达87.24mg/L(2004年3月),其余采样点基本显示由北向南依次递减的趋势。本文参考早期资料并比较不同类型水域中藻类的种类演替和垂直分布情况,对三峡湖北库区水域水华的发生趋势进行了分析,初步认为三峡干流江段形成藻类水华的几率较小;流动的支流水域,在阳光充足、水温逐渐升高的春季容易发生藻类水华;在较封闭的静水区则随时都有发生藻类水华的可能性。  相似文献   

17.
Exceptionally well-preserved specimens of Mizzia yabei (Karpinsky) were discovered in bituminous packstone intercalations of the early Upper Permian Maokou Formation of Anxian County (Sichuan, China). Staining techniques and x-ray diffraction reveal that the organic encrustation around the central stem and the lateral branches consists of aragonite. Average aragonite contents range between 27% and 40%. The bulk of the remaining 60–73% calcite represents cement. The total Sr-content is 3, 400 ppm, indicating 8,000–10,000 ppm for the aragonite fraction. The organically precipitated aragonite was deposited as closely packed fibres, 10–20 μm long and 0.5–1 μm wide. The fibres are arranged in clinogonal (water-jet) fascicles, which diverge towards the central (spar-filled) stem. This microstructure shows that the mineralization of the mucilage started at the periphery of the extracellular encrustation and progressed toward its interior. Diagenetic alterations of the original aragonite include various stages of breakdown of the fibres into 0.5–1 μm large granules (micritization), minor syntaxial growth of the fibres and local transformation of acicular aragonite into neomorphic calcite. The dasycladaleans from the Permian of Sichuan appear to be by far the oldest representatives of this order with preserved aragonitic mineralogy and microstructure. Comparably well-preserved examples are only known from Eocene and younger deposits.  相似文献   

18.
The insect fauna of the Lower Permian Tyulkino locality in the Perm Region of Russia is considered. New members of the orders Trichoptera and Eoblattida are described. Members of the primitive family Microptysmatidae (suborder Protomeropina) are typical of the Lower and Middle Permian deposits of Eurasia and are represented by the two genera: Microptysmella Kukalová-Peck et Willmann, 1990 and Kamopanorpa Martynov, 1928. Kamopanorpa tyulkiana sp. nov. and K. tamarae sp. nov. (Trichoptera, Microptysmatidae) and Parakhosara kamica sp. nov. (Eoblattida, Megakhosaridae) are described.  相似文献   

19.
Meteorological effects on variation of airborne algae in Mexico   总被引:2,自引:0,他引:2  
Sixteen species of algae were collected from 73.8 m3 of air. Eleven were obtained in Minatitlán and eleven in México City. The data show that similar diversity occurred between the two localities, in spite of the difference in altitude. This suggests that cosmopolitan airborne microorganisms might have been released from different sources. Three major algal divisions (Chlorophyta, Cyanophyta and Chrysophyta) formed the airborne algal group. Also, a large concentration of 2220 algae m–3 was found near sea-level, while lower amounts were recorded at the high altitude of México City. The generaScenedesmus, Chlorella andChlorococcum dominated. Striking relationships were noted between the concentration of airborne green and blue-green algae, and meteorological conditions such as rain, vapour pressure, temperature and winds for different altitudes. In Minatitlán a linear relationship was established between concentration of algae and both vapour pressure (mbar) and temperature (° C), while in México City the wind (m s–1) was associated with variations in the algal count.  相似文献   

20.
The bioeroding foraminifer Troglotella incrustans Wernli and Fookes (Bolletino della Societa Paleontologica Italiana 31, 1992, 95), is widely reported from Bajocian?, and Oxfordian to Lower Cenomanian (with a Late Jurassic acme) shallow‐water limestones of the Tethyan realm. A single specimen of a boring foraminifer, assigned to T. incrustans, has now been observed from the Lower Permian (Sakmarian) Community Pit Formation of the Doña Ana Mountains, New Mexico, USA. Surviving the end‐Permian mass extinction, T. incrustans might be a Lazarus taxon that persisted in refuges. This finding represents the oldest record of a foraminifer exhibiting an euendolithic way of life. Boring foraminifera have not been previously recorded from strata older than the Jurassic. Boring traces of potentially foraminiferan origin, however, have been already reported from the Lower Carboniferous (?Ordovician).  相似文献   

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