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1.
A previous study on the ammonitellas of Agoniatites vanuxemi (Hall, 1879) from the Middle Devonian Cherry Valley Limestone of New York State, USA, showed remarkable preservation of the internal morphology. In this paper, the ammonitellas of another ammonoid, a member of the Tornoceratidae, from the Cherry Valley Limestone are studied. The tornoceratids come from a weathered friable shale layer. The ammonitellas examined are from juvenile specimens, many of which appear to be loose in the matrix. Specimens were studied in median cross section using a Scanning Electron Microscope. Shell walls and septa appear as more heavily etched grooves surrounded by large blocks of calcite. Membrane-like structures are associated with several embryonic septa in one specimen. In one specimen, a primary varix marks the end of the ammonitella. The first two septa join the shell wall of the initial chamber at its dorsalmost point. The first septum (= proseptum) is asymmetrically concave adapically and attaches to the dorsal wall of the initial chamber, which extends into the first chamber. The second septum attaches at the end of this extension. The third septum attaches to the dorsal wall of the ammonitella coil. This arrangement differs from that in Agoniatites, where all three septa join the dorsal wall of the ammonitella at a single point. This difference cannot be easily explained by the tighter coiling of the ammonitella of the tornorceratids because they are not closely related to the agoniatites. In addition, although the tornoceratid ammonitella is similar to that of the agoniatids in many ways, it is half the size. 相似文献
2.
CHARLES W. THAYER 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1974,7(2):121-155
In the clastic Genesee Group of the Catskill delta, lateral changes of the fauna are believed to reflect onshore-offshore physicochemical gradients. A shoreward increase of infauna is interpreted as adaptation to increased environmental stress. Free immobile taxa were concentrated offshore, while vagile forms, presumably able to cope with shifting substrata, are dominant nearshore. A shorewards replacement of brachiopods by bivalves reflects the eurytopy and infaunal habits of the bivalves.
In Gencsee time, progradation was first rapid, then slow. The sequence is reversed in the superjacent Sonyea Group and the accompanying reversal of faunal patterns is strong evidence of faunal control by the rate of progradation. This indicates the hazardous nature of attempts to trace 'community evolutioneditor' using only a few studies from each period. 相似文献
In Gencsee time, progradation was first rapid, then slow. The sequence is reversed in the superjacent Sonyea Group and the accompanying reversal of faunal patterns is strong evidence of faunal control by the rate of progradation. This indicates the hazardous nature of attempts to trace 'community evolutioneditor' using only a few studies from each period. 相似文献
3.
Marine benthic communities in the Upper Devonian of New York 总被引:1,自引:0,他引:1
ZEDDIE P. BOWEN DONALD C. RHOADS A. LEE McALESTER 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1974,7(2):93-120
Four distinctive benthic communities occur in the mid-shelf deltaic deposits of the Upper Devonian Sonyea Group: the Bellerophon Community, dominated by herbivorous gastropods and deposit-feeding bivalves; the Prodrtctella Community, dominated by brachiopods with adaptations for life on muddy substrata; the Cypricardella Community, dominated by bivalves and brachiopods with a variety of adaptations; and the Rhipidomella Community, dominated by brachiopods adapted for life on sandy substrata. The geographic and stratigraphic occurrence of the communities suggest that their distribution was controlled by two principal sets of environmental variables: (1) onshore to offshore gradients in salinity, dissolved oxygen concentrations, and sedimentary substrata, and (2) rate of delta progradation. A change in the rate of delta build-out during mid-Sonyea time led to a dramatic change in onshore to offshore community patterns. The change suggests that great care must be used in constructing generalized community models for longer intervals of Paleozoic time. 相似文献
4.
HOWARD R. FELDMAN 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1980,13(1):27-46
Depositional environments of the Onondaga Limestone from central to southeastern New York are found to be normal, subtidal marine, due to the absence of characteristic supratidal or intertidal sedimentary features and the presence of a typical, diverse, marine level-bottom community framework. Post-mortem transport has not been extensive, as evidenced by low articulation ratios, lack of abraded valves, and complete ontogenetic gradations within species, which precludes large scale winnowing. Sedimentation rates appear to have been greatest in eastern New York where the Onondaga Limestone reaches a thickness almost three times that of the strata in central New York. Shaly beds in the central area represent periods of cessation of carbonate deposition rather than an influx of clastic material. Deposition terminated with the onset of deeper water characterized by a westerly advance of terrigenous sedimentation (the Marceilus Shale of the Hamilton Group). Nine brachiopod communities can be recognized in the Onondaga Limestone. There is a strong correlation between sediment-substrate and community type, reflecting the sedimentologic control of brachiopod community distribution. Sandy facies, cherty limestones and coral biostromes and bioherms are associated with inner-neritic deposition in Edgecliff time; argillaceous lime muds and lime sands are characteristic of mid-neritic deposition in Nedrow to Moorehouse time; and highly argillaceous lime muds are associated with outer-nerittc deposition in Seneca time. 相似文献
5.
THOMAS H. WOLOSZ 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1992,25(3):283-290
Wolosz. T. H. 1992 07 15: Turbulence-controlled succession in Middle Devonian reefs of eastern New York State.
The Edgecliff Member ol the Middle Devonian Onondaga Formation contains numerous reefs comprised of two distinct facies. The Phaceloid Colonial Rugosan Facies consists of thickets and mounds, while the Favositid/Crinoidal Sand facies occurs as flank beds surrounding rugosan mounds and as low shield-shaped banks interbedded with thickets of the colonial rugosan facics. Three of these reefs - the North Coxsackie. Albrights and Roberts Hill reefs - have been studied in order to determine the factors that controlled their development and their preserved paleocommunity succession. Both the Roberts Hill and Albrights reefs display well-developed rugosan mounds with an internal succession of rugosan genera. The North Coxsackie reef is a crinoidal sand bank with rugosan thickets and a back-reef satellite mound. Based on the lithology of the underlying limestone in which the reefs are rooted, the North Coxsackie reef is considered to have grown in a shallow-water environment, landwards of the two other reefs. Successional sequences or partial sequences are common to the three reefs, and are found to be reversible - a response attributed to changes in sea-level. As a result, the successions preserved in these reefs are interpreted as having been controlled by degree ol water turbulence. 相似文献
The Edgecliff Member ol the Middle Devonian Onondaga Formation contains numerous reefs comprised of two distinct facies. The Phaceloid Colonial Rugosan Facies consists of thickets and mounds, while the Favositid/Crinoidal Sand facies occurs as flank beds surrounding rugosan mounds and as low shield-shaped banks interbedded with thickets of the colonial rugosan facics. Three of these reefs - the North Coxsackie. Albrights and Roberts Hill reefs - have been studied in order to determine the factors that controlled their development and their preserved paleocommunity succession. Both the Roberts Hill and Albrights reefs display well-developed rugosan mounds with an internal succession of rugosan genera. The North Coxsackie reef is a crinoidal sand bank with rugosan thickets and a back-reef satellite mound. Based on the lithology of the underlying limestone in which the reefs are rooted, the North Coxsackie reef is considered to have grown in a shallow-water environment, landwards of the two other reefs. Successional sequences or partial sequences are common to the three reefs, and are found to be reversible - a response attributed to changes in sea-level. As a result, the successions preserved in these reefs are interpreted as having been controlled by degree ol water turbulence. 相似文献
6.
GEORGE R. McGHEE Jr. ROBERT G. SUTTON 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1981,14(1):27-43
Ecological and statistical analyses of the Late Frasnian (Late Devonian) fauna of the Java Group of New York reveals the presence of three benthic marine communities. Using sedimentological and stratigraphic criteria, the Java Group may be divided into five physical-environmental zones: nearshore marine, platform, prodelta, open shelf, and slope and basin. The Ambocoelia- Cariniferella, Tylothyris-Schizophoria . and C yrtospirifer-Douvillina Communities inhabited open shelf, outer platform - prodelta, and inner platform - nearshore habitats. respectively. Java species gradient curves overlap each other continuously, and species optima replace each other in a regular fashion along the onshore-offshore environmental gradient. No evidence for competitive exclusion between species or sharp habitat discontinuities (ecotones) is seen for Java ecosystems. The same three-fold division of communities, in equivalent habitats, can be seen in central Appalachian marine environments located approximately 500 km away along the ancient shoreline. The distribution of communities in this region appears to be directly related to the position and relative size of fluviodeltaic systems along the 500 km of ancient coastline. Palacoecology. communities, Braschiopoda. palaegeography. Devonian. Frasnian, Appalachians, New. York . 相似文献
7.
A new genus of lycopods from the Devonian of New York State 总被引:2,自引:0,他引:2
JAMES D. GRIERSON HARLAN P. BANKS 《Botanical journal of the Linnean Society. Linnean Society of London》1983,86(1-2):81-101
Drepanophycus colophyllus Grierson & Banks is transferred to llaskinsia Grierson & Banks on the basis of the morphology of its leaves and its anatomical structure. Slender, dichotomizing axes bear helically arranged leaves that are falcate, petiolate, simple, lanceolate and entire. A solid cylinder of metaxylem is surrounded by ridges of protoxylem. Pitting on tracheid walls is annular, helical, reticulate, scalariform to circular-bordered. This lycopod extends from early Givetian into early Frasnian time in the Catskill strata of eastern New York State. The effect of cleavage of fossiliferous rock on patterns observed on the exposed fossils and the bearing of recent research on the fossil history of lycopods are discussed. 相似文献
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10.
《动物学报(英文版)》2012,58(4)
1 IntroductionMimicry occurs when one species (the mimic)evolves to resemble a second species (the model) because of the selective benefits associated with confusing a third species (the receiver).For example,natural selection can favor phenotypic convergence between completely unrelated species when an edible species receives the benefit of reduced predation by resembling an inedible species that predators avoid. 相似文献
11.
New York has 22 documented species of tiger beetles (Coleoptera: Cicindelidae). Over half of these species are considered rare, at risk, or potentially extirpated from the state. These rare species specialize on three sandy habitat types under threat from human disturbance: beaches, pine barrens, and riparian cobble bars. In 2005, we began a status assessment of eight of New York’s rarest tiger beetles, examining museum records, searching the literature, and conducting over 130 field surveys of historical and new locations. Significant findings included (1) no detections of four of the eight taxa; (2) no vehicle-free beach habitat suitable for reintroducing Cicindela dorsalis dorsalis; (3) C. hirticollis at only 4 of 26 historical locations; (4) C. patruela patruela at only one site statewide; and (5) C. ancocisconensis at only 3 of 28 de novo survey sites. Additional species that might be declining deserve our attention, as do some threats to tiger beetle habitats, like lack of beach wilderness, fire suppression in pine barrens, and river damming. Rarity in tiger beetles is a result of varying ecologies, which suggest different conservation strategies. Future inventory and documentation of tiger beetle occurrences need to take into account the metapopulation structure and imperfect detectability of these rare insects. 相似文献
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13.
Hedgerows as habitat corridors for forest herbs in central New York, USA 总被引:12,自引:1,他引:12
1 Samples from 32 hedgerows ( c. 6 m wide, with full-grown trees) in central New York included 39 forest herb taxa, comprising nearly 70% of the forest herb taxa found in adjacent forest samples.
2 We sampled three types of hedgerow. Two types were attached to forest: remnant hedgerows ( n = 14), and regenerated hedgerows ( n = 11 ) that had grown up spontaneously between open fields in the last 50 years. There were no significant differences between remnant and regenerated hedgerows in the richness or abundance of forest herbs, presumably indicating colonization of regenerated hedgerows. Such colonization implies that hedgerows serve a corridor function.
3 The species composition of forest herbs in hedgerows attached to forest stands showed a strong affinity with that of the adjacent stand, both for remnant and regenerated hedgerows.
4 There was a distance effect within hedgerows. Richness of forest herbs and similarity of composition to forest declined with distance along the hedgerow from forest, implying colonization from the adjacent attached stand.
5 The third type of hedgerow sampled, isolated remnants ( n = 7), was not lower in richness or abundance of forest herbs than hedgerows attached to forest. 相似文献
2 We sampled three types of hedgerow. Two types were attached to forest: remnant hedgerows ( n = 14), and regenerated hedgerows ( n = 11 ) that had grown up spontaneously between open fields in the last 50 years. There were no significant differences between remnant and regenerated hedgerows in the richness or abundance of forest herbs, presumably indicating colonization of regenerated hedgerows. Such colonization implies that hedgerows serve a corridor function.
3 The species composition of forest herbs in hedgerows attached to forest stands showed a strong affinity with that of the adjacent stand, both for remnant and regenerated hedgerows.
4 There was a distance effect within hedgerows. Richness of forest herbs and similarity of composition to forest declined with distance along the hedgerow from forest, implying colonization from the adjacent attached stand.
5 The third type of hedgerow sampled, isolated remnants ( n = 7), was not lower in richness or abundance of forest herbs than hedgerows attached to forest. 相似文献
14.
Johnson D. L. J. Hager A. Hunt D. A. Griffith S. Blount S. Ellsworth J. Hintz R. Lucci A. Mittiga D. Prokhorova L. Tidd M. M. Millones M. Vincent 《中国科学C辑(英文版)》2005,48(1):92
A program of house dust sample collection and analysis has begun in Syracuse, New York, USA, in order to determine the feasibility of a geography-based exposure assessment for urban metals. The sampling program, and the protocols it employs, is described for two different types of wipe media, Ghost Wipes and Whatman Filters. Preliminary results show that strong spatial patterns of floor dust loading (mg dust per square foot) can be observed for data aggregated at a spatial scale of about 1600 m (~2.5 km2). Floor dust metal concentrations were similar to those found in other urban environments, with some regional variation. The median floor dust Pb concentration was ~108 mg · kg?1 for this initial data set of ~264 sampled residential locations, and varied from 50 to 1100 mg Pb · kg?1. 相似文献
15.
D. L. Johnson J. Hager A. Hunt D. A. Griffith S. Blount S. Ellsworth J. Hintz R. Lucci A. Mittiga D. Prokhorova L. Tidd M. M. Millones M. Vincent 《中国科学:生命科学英文版》2005,48(Z1)
A program of house dust sample collection and analysis has begun in Syracuse, New York, USA, in order to determine the feasibility of a geography-based exposure assessment for urban metals. The sampling program, and the protocols it employs, is described for two different types of wipe media, Ghost Wipes and Whatman Filters. Preliminary results show that strong spatial patterns of floor dust loading (mg dust per square foot) can be observed for data aggregated at a spatial scale of about 1600 m (-2.5 km2). Floor dust metal concentrations were similar to those found in other urban environments, with some regional variation. The median floor dust Pb concentration was -108 mg ·kg-1 for this initial data set of -264 sampled residential locations, and varied from 50 to 1100 mg Pb ·kg-1. 相似文献
16.
D. L. Johnson J. Hager A. Hunt D. A. Griffith S. Blount S. Ellsworth J. Hintz R. Lucci A. Mittiga D. Prokhorova L. Tidd M. M. Millones M. Vincent 《中国科学C辑(英文版)》2005,48(Z1)
A program of house dust sample collection and analysis has begun in Syracuse,New York, USA, in order to determine the feasibility of a geography-based exposure assessment for urban metals. The sampling program, and the protocols it employs, is described for two different types of wipe media, Ghost Wipes and Whatman Filters. Preliminary results show that strong spatial patterns of floor dust loading (mg dust per square foot) can be observed for data aggregated at a spatial scale of about 1600 m (~2.5 kin2). Floor dust metal concentrations were similar to those found in other urban environments, with some regional variation. The median floor dust Pb concentration was ~108 mg· kg-1 for this initial data set of ~264 sampled residential locations, and varied from 50 to 1100 mg Pb · kg-1. 相似文献
17.
An increased understanding of lake sturgeon (Acipenser fulvescens) population dynamics is a key requirement for successful management efforts. Little is known regarding the Grasse River population of lake sturgeon except that it is one of a few populations in New York State where spawning has been documented. Thus our purpose was to assess the current status of lake sturgeon in the Grasse River system, including age, growth, mortality, and abundance. Age was determined for 196 of 211 lake sturgeon by examination of sectioned pectoral fin rays. Ages ranged from 0 to 32 years and the annual mortality rate for fish between ages 7 and 14 was 16.8%. The weight (W, g) to total length (TL, mm) relationship was W = 1.281 × 10?6TL3.202. The von Bertalanffy growth equation was TL = 1913(1?e?0.0294(t+9.5691)). While the range of observed ages was similar to that of nearby St. Lawrence River populations, mean weight at age for an individual at 1000 mm TL was lower than that observed for lake sturgeon within Lake St. Francis of the St. Lawrence River. Predicted growth based on von Bertalanffy parameters was similar to that observed for the nearby Lake St. Francis. An open population estimator using the POPAN sub‐module in the Program MARK produced an abundance estimate of 793 lake sturgeon (95% CI = 337–1249). 相似文献
18.
Nitrogen deposition,distribution and cycling in a subalpine spruce-fir forest in the Adirondacks,New York,USA 总被引:5,自引:1,他引:5
Andrew J. Friedland Eric K. Miller John J. Battles James F. Thorne 《Biogeochemistry》1991,14(1):31-55
Nitrogen inputs, fluxes, internal generation and consumption, and outputs were monitored in a subalpine spruce-fir forest at approximately 1000-m elevation on Whiteface Mountain in the Adirondacks of New York, USA. Nitrogen in precipitation, cloudwater and dry deposition was collected on an event basis and quantified as an input. Throughfall, stemflow, litterfall and soil water were measured to determine fluxes within the forest. Nitrogen mineralization in the forest floor was estimated to determine internal sources of available N. Lower mineral horizon soil water was used to estimate output from the ecosystem. Vegetation and soil N pools were determined.During four years of continuous monitoring, an average of 16 kg N ha–1 yr–1 was delivered to the forest canopy as precipitation, cloudwater and dry deposition from the atmosphere. Approximately 30% of the input was retained by the canopy. Canopy retention is likely the result of both foliar uptake and immobilization by bark, foliage and microorganisms. Approximately 40 kg of N was made available within the forest floor from mineralization of organic matter. Virtually all the available ammonium (mineralized plus input from throughfall) is utilized in the forest floor, either by microorganisms or through uptake by vegetation. The most abundant N component of soil water solutions leaving the system was nitrate. Net ecosystem fluxes indicate accumulation of both ammonium and nitrate. There is a small net loss of organic N from the ecosystem. Some nitrate leaves the bottom of the B horizon throughout the year. Comparisons with other temperate coniferous sites and examination of the ecosystem N mass balance indicate that N use efficiency is less at our site, which suggests that the site is not severely limited by N. 相似文献
19.
Environmentally controlled phyletic evolution, blindness and extinction in Late Devonian tropidocoryphine trilobites 总被引:1,自引:0,他引:1
RAIMUND FEIST EUAN N. K. CLARKSON 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1989,22(4):359-373
The Middle and Upper Devonian carbonate succession of the Montagne Noire, Southern France has been precisely zoned by an unbroken sequence of conodont zones. Stratigraphic control is excellent, and has allowed evolutionary changes in tropidocoryphine trilobites, which occur throughout the succession, to be directly established. The tropidocoryphine had been a stable group for some 40 million years prior to the Middle Givetian. In their last few million years, however, they underwent rapid evolution and exhibit some striking transformations of the cephalon and the regression and virtual disappearance of the eye within a relatively short space of time. They also show a marked diminution in size, and lose their original relief so that the glabella becomes virtually flush with the surface. There are two separate lineages, both of which show eye-reduction and subsequent blindness. In the earlier lineage Tropidocoryphe (Longicoryphe)-Erbenicoryphe, the main features of the ancestral rootstock are conserved and the stable, strongly divergent anterior sutural pattern of the cephalon remains the same. The eye, however, became reduced to a slightly convex surface lacking lenses, only indistinctly defined. Erbenicorphe is confined to well-oxygenated facies, and probably lived as a shallow burrower within the sediment; it became extinct in the early Frasnian. The second lineage T. (Longicoryphe)-Pterocoryphe- Pteroparia shows a remarkable backward migration of the suture, which progressively swings posteriorly in successive species spanning four Frasnian conodont zones (about three million years duration). At the same time the eye progressively degenerates so that the last forms are blind. Sutural migration and eye reduction are not genetically linked, however; the unusual form of the cephalon and suture probably resulted from an adaptation to the euxinic environment in which Pterocoryphe originated. The loss of the eye resulted from the adoption of an endobenthic habit in Pteroparia which descended from the ancestral Pterocoryphe but which had migrated to an oxygenated facies. Eye-reduction is therefore parallel in the two lineages, but superimposed upon a different original cephalic configuration. The last Pteroparia became extinct when the late Frasnian fauna became overwhelmed by the first pulse of the ‘Kellwasser Event’ (probably an anoxic overturn). The evolving characters, through virtually all observed steps, show progressive unidirectional change without sudden breaks or saltations. Such unidirectional evolution is an adaptive response to constant long-lasting environmental influences. □Evolution, Devonian trilobites, France, gradualism, eye reduction. 相似文献
20.
Tessier JT 《American journal of botany》2004,91(9):1371-1377
Leaf habit correlates with multiple physiological traits. Understanding ecophysiology is therefore dependent on knowledge of leaf habit. A variety of leaf habits exists within forest understory plant communities. Oxalis acetosella is one such understory plant and has long been considered a wintergreen, meaning that it keeps a set of leaves for one full year, replacing them with a new set during spring. To assess the leaf habit of O. acetosella and place it into a classification scheme of leaf habits, leaves of four populations of O. acetosella were repeatedly censused for two years in a northern hardwood forest of the Catskill Mountains, New York, USA. New leaves developed and old leaves senesced throughout the year, yielding a continual replacement of leaves and a summer peak in leaf number. Leaves that developed in the fall and winter had longer maximum life spans than leaves that developed during the summer. The name "seasonalgreen" is suggested to describe the continual development, senescence, and presence of leaves and annual peak in leaf number within O. acetosella. The functional significance of this leaf habit in this species and the possibility of its presence in other species deserve further study. 相似文献