scholarly journals Taphonomy and palaeoecology of the White Hunter Local Fauna

2017 ◽  
Author(s):  
Troy Myers
Keyword(s):  
Dry Forest ◽  
Early Miocene ◽  
Mammalian Fauna ◽  
Local Fauna ◽  
Open Forest ◽  
Modern Analogue ◽  
Wide Range ◽  
Closed Forest ◽  
Body Sizes ◽  
World Heritage Area

The White Hunter (WH) Local Fauna (LF) is one of the oldest assemblages from the Riversleigh World Heritage Area, belonging to Faunal Zone A and tentatively dated at approximately 24 Ma. The mammalian fauna has many plesiomorphic taxa and a wide range of body sizes are represented, although it is depauperate in medium to large arboreal mammals and over-represented by small to medium-sized macropodoids, vombatomorphians and carnivores. The non-mammalian vertebrate fauna also covers a wide body size range. The palaeoenvironmental conditions at the time of deposition have been contentious, ranging from hypotheses of cold and dry woodland to warm, wet rainforest, and many climatic and vegetation combinations in between. The autecologies of various species provide only equivocal support for palaeoenvironmental conclusions. Taphonomic and palaeoecologic data were tested herein to further illuminate palaeoenvironmental understanding. Mammalian post-cranial elements were examined for degree of weathering, abrasion, fragmentation, taxonomic bias and susceptibility to transport. No obvious bias against small vertebrates was observed. The fauna does not appear to represent a mixed-assemblage. Animals most likely died within close proximity to the site of deposition, although the absence of scavenger/carnivore damage militates against predation as the main source of accumulation. Trampling of elements may have been significant. Results suggest that WH may have been a moderately large ephemeral water body, subject to periodic drying and fed by a slow-moving creek. The climate was cooler than the early Miocene, with a distinct wet and dry season. Surrounding vegetation may have been a type without modern analogue combining structural, but not floristic, equivalents of open dry forest and closed rainforest. There is no evidence for gradational wet open forest types, but this may represent a rapid move to closed forest. These results are reinforced by palaeocommunity analysis of Riversleigh LFs which unite WH LF with a suite of early Miocene Lfs as a similar palaeocommunity type, perhaps antecedent to them.

scholarly journals Taphonomy and palaeoecology of the White Hunter Local Fauna

2017 ◽  
Author(s):  
Troy Myers
Keyword(s):  
Dry Forest ◽  
Early Miocene ◽  
Mammalian Fauna ◽  
Local Fauna ◽  
Open Forest ◽  
Modern Analogue ◽  
Wide Range ◽  
Closed Forest ◽  
Body Sizes ◽  
World Heritage Area

The White Hunter (WH) Local Fauna (LF) is one of the oldest assemblages from the Riversleigh World Heritage Area, belonging to Faunal Zone A and tentatively dated at approximately 24 Ma. The mammalian fauna has many plesiomorphic taxa and a wide range of body sizes are represented, although it is depauperate in medium to large arboreal mammals and over-represented by small to medium-sized macropodoids, vombatomorphians and carnivores. The non-mammalian vertebrate fauna also covers a wide body size range. The palaeoenvironmental conditions at the time of deposition have been contentious, ranging from hypotheses of cold and dry woodland to warm, wet rainforest, and many climatic and vegetation combinations in between. The autecologies of various species provide only equivocal support for palaeoenvironmental conclusions. Taphonomic and palaeoecologic data were tested herein to further illuminate palaeoenvironmental understanding. Mammalian post-cranial elements were examined for degree of weathering, abrasion, fragmentation, taxonomic bias and susceptibility to transport. No obvious bias against small vertebrates was observed. The fauna does not appear to represent a mixed-assemblage. Animals most likely died within close proximity to the site of deposition, although the absence of scavenger/carnivore damage militates against predation as the main source of accumulation. Trampling of elements may have been significant. Results suggest that WH may have been a moderately large ephemeral water body, subject to periodic drying and fed by a slow-moving creek. The climate was cooler than the early Miocene, with a distinct wet and dry season. Surrounding vegetation may have been a type without modern analogue combining structural, but not floristic, equivalents of open dry forest and closed rainforest. There is no evidence for gradational wet open forest types, but this may represent a rapid move to closed forest. These results are reinforced by palaeocommunity analysis of Riversleigh LFs which unite WH LF with a suite of early Miocene Lfs as a similar palaeocommunity type, perhaps antecedent to them.

The Oligocene Berwick Quarry Flora — Rainforest in a Drying Environment

1993 ◽  
Vol 6 (5) ◽  
pp. 399 ◽  
Author(s):  
MS Pole ◽  
RS Hill ◽  
N Green ◽  
MK Macphail
Keyword(s):  
Recent Work ◽  
Early Miocene ◽  
Late Oligocene ◽  
Fossil Species ◽  
Open Forest ◽  
Closed Forest

The Late Oligocene to possibly earliest Early Miocene Benvick Quany macrofossil flora was first described very early in this century by Henry Deane, but has since been largely ignored. Recent work at the quarry has led to major new collections and a reinvestigation of the flora. Seventeen taxa of macrofossils have been recovered, including Agathis, Dacrycarpus, four species of Lauraceae, Gymnostoma, Nothofagus, Eucalyptus, an indeterminate Myrtaceae and Proteaceae, three possible Cunoniaceae, and six unidentified taxa. Fagus maideni Deane is formally transferred to Nothofagus Blume. Nothofagus johnstoni Hill, Fagus luemanni Deane, and Atherosperma berwickense Deane, are considered to be junior synonyms of the species N. maideni (Deane) comb. nov. Only one of the seven fossil species of Eucalyptus established by Deane can be recognised in our material: E kitsoni Deane. His Lomatia species are probably Cunoniaceae. The Berwick Quarry flora contains species which are consistent with rainforest in the region, however, the flora is also notable for the presence of leaves of Eucalyptus, leaving little doubt that the flora at Berwick Quarry represents a mixture of rainforest and open forest taxa. The vegetation was probably a mosaic of open and closed forest, representing some of the earliest evidence for seasonality in Australia during the development of the modem flora. Palynological samples are dominated by Nothofagus subgenus Brassospora and Fuscospora.

Assessing the Ergonomic Benefits of a New Adjustable Forklift Backrest

2020 ◽  
Vol 64 (1) ◽  
pp. 976-980
Author(s):  
Pranav Madhav Kuber ◽  
Ehsan Rashedi
Keyword(s):  
Comparative Study ◽  
Motion Capture ◽  
Center Of Pressure ◽  
Body Movement ◽  
Pressure Change ◽  
Motion Capture System ◽  
Design Features ◽  
Wide Range ◽  
Body Sizes ◽  
The Mean

A new forklift backrest has been developed by incorporating adjustability concepts into the design to facilitate comfort to a wide range of users. We have conducted a comparative study between the new and original backrests to assess the effectiveness of design features. Using the phenomenon of restlessness, discomfort of the user was associated with the amount of body movement, where we have used a motion- capture system and a force platform to quantify the individuals’ movement for a wide range of body sizes. Meanwhile, subjective comfort and design feedback were collected using a questionnaire. Our results showed a reduction in the mean torso movement and the maximum center of pressure change of location by 300 and 6 mm, respectively, for the new design. Taking advantage of adjustability feature, the new backrest design exhibited enhanced comfort for longer durations and reduced magnitude of discomfort for a wide range of participants’ body sizes.

scholarly journals REPTILES DEL BOSQUE SECO ESTACIONAL EN EL CARIBE COLOMBIANO: DISTRIBUCIÓN DE LOS HÁBITATS Y DEL RECURSO ALIMENTARIO

2016 ◽  
Vol 21 (2) ◽  
pp. 365-377
Author(s):  
Luis Eduardo Rojas Murcia ◽  
Juan E. Carvajal Cogollo ◽  
Javier Alejandro Cabrejo Bello
Keyword(s):  
Food Resource ◽  
Horizontal Distribution ◽  
Dry Forest ◽  
Caribbean Region ◽  
Homogeneous Distribution ◽  
Similar Species ◽  
Use Of Resources ◽  
Climatic Period ◽  
Wide Range ◽  
The Caribbean

<p>Con el fin de caracterizar la distribución horizontal (repartición de los hábitats) y la utilización del recurso alimentario (tipo y tamaño de las presas) del ensamblaje de reptiles del bosque seco estacional al norte de la región Caribe de Colombia, en el departamento del Cesar, se realizaron cinco salidas de campo con una duración de doce días cada una. Los muestreos se realizaron en jornadas diurnas y nocturnas, en un diseño de transectos replicados a lo largo de diferentes hábitats que incluyeron: pastizales, bordes e interiores de bosque. Se realizaron análisis descriptivos de uso de hábitat en un perfil de vegetación por cada época climática y análisis de amplitud y sobreposición de nicho. Se registraron 38 especies de 14 familias del orden Squamata. Las especies se distribuyeron de manera homogénea entre zonas abiertas y boscosas. Se encontraron registros de 31 categorías de presa en 109 estómagos de seis especies de serpientes (61 estómagos) y siete de lagartos (48 estómagos) con un porcentaje de estómagos vacíos de 38 %. Las presas de mayor importancia para los lagartos fueron Coleoptera y Araneae, y para las serpientes fueron los anfibios. La mayoría de las especies presentaron un amplio espectro de dieta y entre especies similares, como entre Anolis auratus y A. gaigei, se presentó uso de recursos similares. En síntesis, el ensamblaje de reptiles presentó una distribución homogénea en los hábitats evaluados (áreas abiertas y boscosas) y el recurso alimentario fue variado entre las diferentes especies; la estacionalidad de la zona presenta un papel fundamental en la estructura del ensamblaje de reptiles, presentándose menos abundancia durante la época seca, tanto en las áreas abiertas como en las boscosas.</p><p><strong>Reptiles from the Seasonal Dry Forest the Caribbean Region: Distribution of Habitat and use of Food Resource</strong></p><p><strong>ABSTRACT</strong></p><p>We assessed the horizontal distribution and use of the food resource of the reptile’s assemblage of the seasonal tropical dry forest in the North of the Caribbean region of Colombia, department of Cesar. Five fieldtrips of 12 days each were performed, sampling was diurnal and nocturnal, following a transect design replicated along different habitats including grasslands, edge and interior of forest. We performed descriptive analyzes of habitat use, using a profile of vegetation by each climatic period; we also did an analysis of amplitude and niche overlap. We recorded 38 species of 14 families of the Squamata order. Species distributed evenly between open and forested areas. Record of 31 categories of prey in 109 stomachs of six species snakes (61 stomachs) and seven of lizards (48 stomachs) with a percentage of empty stomachs of 38 % was found. The preys of greater importance for the lizards were Coleoptera and Araneae and for snakes, amphibians. Most of the species presented a wide range of diet and between similar species, such as Anolis auratus and A. gaigei, found a similar use of resources. In summary, the assembly of reptiles presented a homogeneous distribution in the habitats evaluated (forested and open areas) and the food resource varied among the different species; the seasonality of the area plays a fundamental role on the structure of this reptile assembly with less abundance during the dry season in both, open and forested habitats.</p>

scholarly journals Relative skull size as one of the factors limiting skull shape variation in passerines

2021 ◽  
Author(s):  
Oksana Shatkovska ◽  
Maria Ghazali
Keyword(s):  
Body Mass ◽  
Shape Variation ◽  
Absolute Size ◽  
Terrestrial Locomotion ◽  
Skull Shape ◽  
Skull Size ◽  
Dietary Preferences ◽  
Wide Range ◽  
Body Sizes ◽  
Biomechanical Constraints

Despite a considerable interest of researchers to the issue of variation in skull shapes of birds and factors influencing it, some drivers associated with the design features of an entire bird body, which are important for both successful terrestrial locomotion and flight, are overlooked. One of such factors, in our opinion, is relative skull size (skull length in relation to body mass), which can affect the position of the body's center of gravity. We tested effects of relative skull size, allometry (i.e. absolute skull size), and diet on variation in skull shape. The study was conducted on 50 songbird species with a wide range of body mass (8.3g to 570g) and dietary preferences (granivores, insectivores/granivores, insectivores, omnivores). Skull shape was analyzed using 2D geometric morphometrics. We revealed that similar patterns of skull shape occur among passerines with different body sizes and diets. The relative skull size predicted skull shape to a similar extent and with a similar pattern as the absolute size. In our opinion, the effect of the relative skull size on skull shape variation is likely due to biomechanical constraints related to flight.

scholarly journals The body-size dependence of mutual interference

2014 ◽  
Vol 10 (6) ◽  
pp. 20140261 ◽  
Author(s):  
John P. DeLong
Keyword(s):  
Population Dynamics ◽  
Body Size ◽  
Size Dependence ◽  
Empirical Support ◽  
Mutual Interference ◽  
The Body ◽  
Wide Range ◽  
Stabilizing Effect ◽  
Body Sizes ◽  
Size Scales

The parameters that drive population dynamics typically show a relationship with body size. By contrast, there is no theoretical or empirical support for a body-size dependence of mutual interference, which links foraging rates to consumer density. Here, I develop a model to predict that interference may be positively or negatively related to body size depending on how resource body size scales with consumer body size. Over a wide range of body sizes, however, the model predicts that interference will be body-size independent. This prediction was supported by a new dataset on interference and consumer body size. The stabilizing effect of intermediate interference therefore appears to be roughly constant across size, while the effect of body size on population dynamics is mediated through other parameters.

scholarly journals Changes in small mammal assemblage structure across a rain forest/open forest ecotone

1998 ◽  
Vol 14 (2) ◽  
pp. 187-198 ◽  
Author(s):  
STEPHEN E. WILLIAMS ◽  
HELENE MARSH
Keyword(s):  
Species Richness ◽  
Small Mammal ◽  
Rain Forest ◽  
Habitat Heterogeneity ◽  
Large Change ◽  
Open Forest ◽  
Live Trapping ◽  
Sclerophyll Forest ◽  
World Heritage Area ◽  
Forest Ecotone

The effect of the change in vegetation structure from closed rain forest to tall open forest on the small mammal assemblage was studied by live trapping at three sites where the ecotone was very narrow (> 20 m) near the southern end of the Wet Tropics World Heritage Area of Australia. Habitat heterogeneity was significantly higher in the mixed open forest/ecotone area than in the adjacent rain forest. There was a large change in the struture of the small mammal assemblage coincident with the vegetation discontinuity. Although the species richness of small mammals was relatively constant across the gradient, the evenness and diversity of the assemblage declined across the transition from open forest into rain forest and biomass increased, largely due to the high abundance of Rattus fuscipes in the rain forest. The results suggest that the species richness of the small mammal assemblage was not determined by the spatial heterogeneity of the vegetation struture. The species composition of the rain forest is probably related to the historical biogeography of the area whereas the species richness of the wet sclerophyll forest is probably due to a mass-area effect from the adjcant large areas of rain forest and dry sclerophyll forest. However, the evenness, and therefore the diversity of the assemblage, was strongly affected by habitat heterogeneity.

Foraging ecology of the horseshoe bat, Rhinolophus megaphyllus (Rhinolophidae), in eastern Australia

2004 ◽  
Vol 31 (4) ◽  
pp. 403 ◽  
Author(s):  
Chris R. Pavey ◽  
Chris J. Burwell
Keyword(s):  
Prey Capture ◽  
Foraging Ecology ◽  
Light Trap ◽  
Foraging Strategy ◽  
Flying Insects ◽  
Open Forest ◽  
Eastern Australia ◽  
Wide Range ◽  
Horseshoe Bat ◽  
Conservation Concern

The foraging ecology of the eastern horseshoe bat, Rhinolophus megaphyllus, was examined at five sites spread along 2100 km of its Australian distribution in coastal Queensland. Foraging strategy and prey-capture behaviour of light-tagged bats were similar across sites. Bats were observed foraging during continuous flight at all sites, whereas perch hunting was observed (rarely) at only one site. Bats captured insects by aerial hawking, with a single record of gleaning. In rainforest bats spent most time close to vegetation whereas openings were favoured in open forest/woodland. Only flying insects were captured and, although a wide range of taxa was taken, Lepidoptera (all sites) and Coleoptera (all sites except one) were the primary prey. Occurrence in faeces of Lepidoptera, Coleoptera, and other taxa combined, varied across sites and across seasons, but there was no three-way interaction between taxon, site and season. Comparison of insect taxa in faeces with those captured in a light-trap set at foraging grounds indicated that insects were selectively captured by R. megaphyllus. The foraging ecology of R. megaphyllus is similar to that of other horseshoe bats in its relative stability across a large geographic range. Although the species is currently not of conservation concern in Australia, aspects of its foraging ecology suggest that it may become regionally threatened in areas with high levels of vegetation clearance.

Distribution of Nocturnal Forest Birds and Mammals in North-Eastern New South Wales: Relationships With Environmental Variables and Management History.

1995 ◽  
Vol 22 (3) ◽  
pp. 359 ◽  
Author(s):  
RP Kavanagh ◽  
S Debus ◽  
T Tweedie ◽  
R Webster
Keyword(s):  
New South ◽  
New South Wales ◽  
Forest Birds ◽  
Dry Forest ◽  
Forest Types ◽  
Regional Survey ◽  
Similar Frequency ◽  
South Wales ◽  
Wide Range ◽  
North Eastern

A regional survey of the forests in north-eastern New South Wales recorded eight species of nocturnal forest birds and nine species of arboreal marsupials from 291 sites. Three major environmental gradients accounting for the distribution of these species in north-eastern New South Wales were identified: elevation, forest type (wet forest types having a dense mesic understorey or dry forest types having an open or sparse understorey), and logging intensity. Characteristic assemblages of species were associated with each end of these three gradients. A core group of species occurred across a wide range of environmental conditions, including logged and unlogged forest. Most species occurred with similar frequency in logged and unlogged forest. Implications for forest management are discussed.

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