A Tournaisian (earliest Carboniferous) conglomerate-preserved non-marine faunal assemblage and its environmental and sedimentological context

10.7287/peerj.preprints.27102v1 ◽

2018 ◽

Author(s):

Jennifer A Clack ◽

Carys E Bennett ◽

Sarah J Davies ◽

Andrew C Scott ◽

Janet Sherwin ◽

...

Keyword(s):

Size Range ◽

Atmospheric Oxygen ◽

Aerial Exposure ◽

Faunal Assemblage ◽

Marine Fauna ◽

Extinction Event ◽

Marine Fossils ◽

Devonian Extinction ◽

Microfossil Assemblage ◽

Insight Into

A conglomerate bed from the Tournaisian Ballagan Formation of Scotland preserves a rich array of vertebrate and other non-marine fossils providing an insight into the wider ecosystem and palaeoenvironment that existed during this pivotal stage of Earth history. It challenges hypotheses of a long-lasting post-extinction trough following the end-Devonian extinction event. The fauna recovered includes a wide size range of tetrapods, rhizodonts and dipnoans, from tiny juveniles or small-bodied taxa up to large adults, and more than one taxon of each group is likely. Some fauna, such as actinopterygians and chondrichthyans, are rare as macrofauna but are better represented in the microfossil assemblage. The fauna provides evidence of the largest Carboniferous lungfish ever found. The specimens are preserved in a localised, poorly-sorted conglomerate which was deposited in the deepest part of a river channel, the youngest of a group of channels. In addition to the fossils (micro- and macro-), the conglomerate includes locally-derived clasts of palaeosols and other distinctive elements of the surrounding floodplains. Charcoal fragments represent stem and possible trunk tissue from arborescent pteridosperms. Preservation of the fossils indicates some aerial exposure prior to transport, with abrasion from rolling. The findings presented here contrast with other published trends in vertebrate size that are used to interpret a reduction in maximum sizes during the Tournaisian. The richness of the fauna runs counter to the assumption of a depauperate non-marine fauna following the end-Devonian Hangenberg event, and charcoal content highlights the occurrence of fire, with the requisite levels of atmospheric oxygen during that stage.

A Tournaisian (earliest Carboniferous) conglomerate-preserved non-marine faunal assemblage and its environmental and sedimentological context

10.7287/peerj.preprints.27102 ◽

2018 ◽

Author(s):

Jennifer A Clack ◽

Carys E Bennett ◽

Sarah J Davies ◽

Andrew C Scott ◽

Janet Sherwin ◽

...

Keyword(s):

Size Range ◽

Atmospheric Oxygen ◽

Aerial Exposure ◽

Faunal Assemblage ◽

Marine Fauna ◽

Extinction Event ◽

Marine Fossils ◽

Devonian Extinction ◽

Microfossil Assemblage ◽

Insight Into

A conglomerate bed from the Tournaisian Ballagan Formation of Scotland preserves a rich array of vertebrate and other non-marine fossils providing an insight into the wider ecosystem and palaeoenvironment that existed during this pivotal stage of Earth history. It challenges hypotheses of a long-lasting post-extinction trough following the end-Devonian extinction event. The fauna recovered includes a wide size range of tetrapods, rhizodonts and dipnoans, from tiny juveniles or small-bodied taxa up to large adults, and more than one taxon of each group is likely. Some fauna, such as actinopterygians and chondrichthyans, are rare as macrofauna but are better represented in the microfossil assemblage. The fauna provides evidence of the largest Carboniferous lungfish ever found. The specimens are preserved in a localised, poorly-sorted conglomerate which was deposited in the deepest part of a river channel, the youngest of a group of channels. In addition to the fossils (micro- and macro-), the conglomerate includes locally-derived clasts of palaeosols and other distinctive elements of the surrounding floodplains. Charcoal fragments represent stem and possible trunk tissue from arborescent pteridosperms. Preservation of the fossils indicates some aerial exposure prior to transport, with abrasion from rolling. The findings presented here contrast with other published trends in vertebrate size that are used to interpret a reduction in maximum sizes during the Tournaisian. The richness of the fauna runs counter to the assumption of a depauperate non-marine fauna following the end-Devonian Hangenberg event, and charcoal content highlights the occurrence of fire, with the requisite levels of atmospheric oxygen during that stage.

The Mechanism of active capture of animal food by the Sergestid Shrimp Acetes Sibogae Australis

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400041588 ◽

1998 ◽

Vol 78 (2) ◽

pp. 497-508 ◽

Cited By ~ 4

Author(s):

Lachlan Mcleay ◽

C.G. Alexander

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Prey Capture ◽

Size Range ◽

The Third ◽

Feeding Modes ◽

In Captivity ◽

Combined Actions ◽

Wide Size Range ◽

Scanning Electron

Combining the use of scanning electron microscopy and microcinematography with functional and behavioural observations has clarified many aspects underlying the feeding processes of the small planktonic sergestid shrimp Acetes sibogae australis. In captivity Acetes sibogae australis is an opportunistic feeder that uses four principal feeding modes to capture a wide size range of prey: Artemia nauplii (<0.33 mm), copepods (<1mm) and moribund Acetes (up to 25 mm). Prey capture is effected by combined actions of the first three pairs of pereiopods and the third maxillipeds before transfer to the more dorsal second maxillipeds. The second maxillipeds are the principal appendages used in securing, manipulating, sorting and rejecting prey before insertion into the vicinity of the inner mouthparts.

Frequent and intense fires in the final coals of the Paleozoic indicate elevated atmospheric oxygen levels at the onset of the End-Permian Mass Extinction Event

International Journal of Coal Geology ◽

10.1016/j.coal.2019.03.016 ◽

2019 ◽

Vol 207 ◽

pp. 75-83 ◽

Cited By ~ 8

Author(s):

Zhiming Yan ◽

Longyi Shao ◽

I.J. Glasspool ◽

Juan Wang ◽

Xuetian Wang ◽

...

Keyword(s):

Mass Extinction ◽

Atmospheric Oxygen ◽

Oxygen Levels ◽

Extinction Event ◽

Mass Extinction Event ◽

Permian Mass Extinction

Ontogeny of Drevermannia and the origin of blindness in Late Devonian proetoid trilobites

Geological Magazine ◽

10.1017/s0016756805001421 ◽

2006 ◽

Vol 143 (1) ◽

pp. 89-104 ◽

Cited By ~ 10

Author(s):

RUDY LEROSEY-AUBRIL

Keyword(s):

Ontogenetic Development ◽

Late Devonian ◽

Developmental Strategy ◽

Larval Size ◽

Growth Series ◽

Extinction Event ◽

Alternative Hypotheses ◽

Devonian Extinction

Numerous silicified and calcareous sclerites of various sizes, recovered from the latest Famennian of Thuringia (Germany), allow the description of the first complete growth series of a blind proetoid trilobite: Drevermannia richteri. In addition, the partial ontogenetic development of Drevermannia antecurvata sp. nov. and undetermined species, Drevermannia sp. 1, are described. The proetoid anaprotaspides, associated with D. richteri, illustrate that a marked increase in larval size occurred prior to the terminal Devonian extinction event. Considering the homogeneity of larval size in older Devonian proetoids, it is interpreted as evidence that the developmental strategy of these trilobites was significantly modified. Though largely speculative, two alternative hypotheses are proposed to explain this modification. Finally, all three ontogenetic sequences show that ocular structures never develop externally in Drevermannia, but also illustrate that the development of optical nerves is not completely lost in this group. This suggests that blindness in the Drevermannia lineage followed a centripetal mode of eye reduction.

Reducing particle loss in a critical orifice and an aerodynamic lens for focusing aerosol particles in a wide size range of 30 nm — 10 μm

Journal of Mechanical Science and Technology ◽

10.1007/s12206-014-1238-4 ◽

2015 ◽

Vol 29 (1) ◽

pp. 317-323 ◽

Cited By ~ 5

Author(s):

Tae-Hyun Hwang ◽

Seok-Hwan Kim ◽

Soo Hyung Kim ◽

Donggeun Lee

Keyword(s):

Size Range ◽

Aerosol Particles ◽

Particle Loss ◽

Wide Size Range

Faunal assemblages from the upper Horseshoe Canyon Formation, an early Maastrichtian cool-climate assemblage from Alberta, with special reference to the Albertosaurus sarcophagus bonebedThis article is one of a series of papers published in this Special Issue on the theme Albertosaurus.

Canadian Journal of Earth Sciences ◽

10.1139/e10-005 ◽

2010 ◽

Vol 47 (9) ◽

pp. 1159-1181 ◽

Cited By ~ 37

Author(s):

Derek W. Larson ◽

Donald B. Brinkman ◽

Phil R. Bell

Keyword(s):

Western North America ◽

Special Issue ◽

Warm Climate ◽

Faunal Assemblage ◽

Faunal Assemblages ◽

Relative Rarity ◽

Fish Remains ◽

Horseshoe Canyon Formation ◽

Insight Into ◽

Cool Climate

The faunal assemblage from the early Maastrichtian portion of the Horseshoe Canyon Formation is described on the basis of four new vertebrate microfossil localities and remains from the Albertosaurus bonebed. All of the localities sampled were deposited during a cool, dry climate at a palaeolatitude of ∼58°N. Thus, these assemblages provide insight into a northern cool-climate assemblage in the early Maastrichtian of western North America. This fauna is characterized by the presence of taxa with more northern affinities, such as Holostean A, champsosaurs, Troodon , and toothed birds. Warm-climate taxa, such as crocodylians, large and diverse turtles, and albanerpetontids are notable in their absence. The Albertosaurus bonebed locality at the top of unit 4 of the Horseshoe Canyon Formation was deposited during the initial stages of a trend to a warmer and wetter climate that is represented in unit 5. The bonebed shares many taxa with the underlying vertebrate microfossil localities. However, a notable difference is the presence of Atrociraptor marshalli from the Albertosaurus bonebed but not the other localities in the upper Horseshoe Canyon Formation. The presence of Atrociraptor may be attributable to this change in climate rather than local ecological conditions. Also, the assemblages are different in the paucity of fish remains in the bonebed, and the relative rarity of shed hadrosaur teeth. The low abundance of aquatic taxa and rarity of shed teeth of hadrosaurs indicate that the locality is largely autochthonous, with little material being transported into the site.

Hardgrounds in the Lower Leintwardine Beds (Silurian) of the Welsh Borderland

Geological Magazine ◽

10.1017/s0016756800032556 ◽

1980 ◽

Vol 117 (4) ◽

pp. 311-326 ◽

Cited By ~ 8

Author(s):

Lesley Cherns

Keyword(s):

Shallow Water ◽

Aerial Exposure ◽

Subsequent Removal ◽

Faunal Assemblage ◽

Inner Shelf ◽

Water Conditions ◽

History Of

SummaryThe base of the Lower Leintwardine Beds (Silurian-Ludlow Series) in the shelf sequences of the Welsh Borderland is marked by a widespread development of shelly conglomeratic limestone beds. Borings into some intraclasts indicate that they were hardgrounds. The early lithification, sometimes in situ, of both sand-grade and mud-grade carbonates is demonstrated by the conglomerates. Some compound intraclasts (‘hiatus concretions’) indicate a complex history of deposition, scouring and lithification. Boring of clasts which have not been further eroded is inferred to have taken place locally. The borings are of the narrow, single entrance form referable to Trypanites. The distribution of the conglomerates relates closely to Leintwardinian palaeogeography. Repeated hardground formation in sequences of inner shelf areas reflects episodic deposition alternating with periods of omission and erosion. There is evidence throughout the shelf of a break in sedimentation with hardground formation at the end of Bringewoodian times. The nature of the conglomerates suggests that they formed in shallow water conditions; there is no lithological indication of sub-aerial exposure. The absence of the Aymestry Limestone in the SE shelf is more probably due to its non-deposition or lateral lithological change to muddier beds with a different faunal assemblage than to its subsequent removal by erosion.

The effect of oleic acid on the synthesis of Fe3−xO4 nanoparticles over a wide size range

Physical Chemistry Chemical Physics ◽

10.1039/c5cp03395k ◽

2015 ◽

Vol 17 (41) ◽

pp. 27373-27379 ◽

Cited By ~ 25

Author(s):

Carlos Moya ◽

Xavier Batlle ◽

Amílcar Labarta

Keyword(s):

Thermal Decomposition ◽

Oleic Acid ◽

Structural Properties ◽

Acid Concentration ◽

Size Range ◽

Benzyl Ether ◽

Oleic Acid Concentration ◽

Wide Size Range

This work reports on the effect of the oleic acid concentration on the magnetic and structural properties of Fe3−xO4 nanoparticles synthesized by thermal decomposition of Fe(acac)3 in benzyl-ether.

Production, Characterization, and Deposition of Carbon Clusters

MRS Proceedings ◽

10.1557/proc-206-733 ◽

1990 ◽

Vol 206 ◽

Cited By ~ 2

Author(s):

Y. K. Bae ◽

D. C. Lorents ◽

R. Malhotra ◽

C. H. Becker ◽

D. Tse ◽

...

Keyword(s):

High Temperatures ◽

Thermal Desorption ◽

Size Range ◽

Ion Source ◽

Carbon Clusters ◽

Heating Process ◽

Cluster Ion Source ◽

Semiconductor Clusters ◽

Cluster Ion ◽

Wide Size Range

ABSTRACTWe have developed a new cluster ion source that can generate intense beams of metal and semiconductor clusters of a very wide-size range. With the source, we have observed intense beams of carbon clusters with mean cluster sizes of up to 4000 atoms/clusters. However, we have found that for generating small fullerenes, such as C60 and C70, the recently discovered technique by Kraetschmer et al. is much more efficient. By improving the technique, we have generated gram quantities of C60 and C70 and systematically investigated their thermal desorption properties. During the heating process, we have discovered that at high temperatures the bulk fullerenes, fullerite, transformed to another form of carbon, which still evaporates at temperatures above 700 C, but does not dissolve in benzene.