Results 11 to 20 of about 125 (99)
The relationships of antiarchs (Devonian placoderm fishes)—evidence supporting placoderm monophyly
Journal of Vertebrate Paleontology, 2008 A recent analysis of the vascularization of the pectoral fin in antiarchs indicated that they resembled jawless osteostracans rather than other jawed vertebrates, thereby challenging the monophyly of the class Placodermi. Examination of the evidence proposed to support this new hypothesis shows misinterpretation of well-established morphology in a ...
Gavin C Young
exaly +2 more sources
Mathematical Problems in Engineering, Volume 2018, Issue 1, 2018., 2018 A composite structure, including concrete antiarches and bolts, was designed to control the floor heave. This semiclosed structure may reinforce the floor and the two bottom corners of the roadway. Then, based on some relative assumptions, we established a model for this structure.
Wenxiang Zheng +3 more
wiley +2 more sources
Geobios, 1995 Abstract Variability in representatives of Bothriolepidae (Placodermi, Antiarchi) from the Main Devonian Field, north-western part of the Eest European Platform (Latvia and NW Russia) is studied using the method recently proposed by Cherepanov (1986) .
exaly +4 more sources
Copulation in antiarch placoderms and the origin of gnathostome internal fertilization [PDF]
Nature, 2014 Reproduction in jawed vertebrates (gnathostomes) involves either external or internal fertilization. It is commonly argued that internal fertilization can evolve from external, but not the reverse. Male copulatory claspers are present in certain placoderms, fossil jawed vertebrates retrieved as a paraphyletic segment of the gnathostome stem group in ...
Long, J. +11 more
openaire +4 more sources
Taphonomy of the vertebrate bone beds from the Klūnas fossil site, Upper Devonian Tērvete Formation of Latvia [PDF]
Estonian Journal of Earth Sciences, 2012 Combined sedimentological and taphonomical study of the siliciclastic sequence of the Tērvete Formation in the stratotypical area was aimed at revealing the formation of the three oryctocoenoses discovered and related structural and textural features of ...
Jeļena Vasiļkova +3 more
doaj +1 more source
Mathematical Problems in Engineering, Volume 2020, Issue 1, 2020., 2020 To improve the efficient and precise seeding of potatoes, a novel combination vacuum and spoon belt metering device was designed. The overall structure and working principle of vacuum and spoon belt metering devices were illustrated and analyzed.
Zhang Wanzhi +6 more
wiley +1 more source
Devonian antiarch placoderms from Belgium revisited [PDF]
Acta Palaeontologica Polonica, 2013 ANR Program n° 2010 BLAN-607 “TERRES: Global perspectives on the terrestrialisation process”
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Postfire Safety Investigation on Prestressed RPC Beams after Exposure to Elevated Temperatures
Advances in Materials Science and Engineering, Volume 2020, Issue 1, 2020., 2020 Since the postfire safety of prestressed RPC beams after exposure to elevated temperatures needs to be studied and proved, this paper prepares eight smart prestressed RPC beams with intelligent sensors built in to monitor the internal temperature, force, and strain. The residual bearing tests after fire are carried out. The failure process of the beams
Yan Kai +5 more
wiley +1 more source
Stability Mechanism and Repair Method of U‐Shaped Steel Reverse Arch Support in Soft Floor Roadway
Advances in Civil Engineering, Volume 2020, Issue 1, 2020., 2020 This paper is aimed at the inverted arch support instability of track roadway with mining level +1100 m in Liuyuanzi Coal Mine. By means of field investigation, theoretical analysis, numerical calculation, and engineering practice, the instability reasons of inverted arch structure are expounded, the mechanical mechanism of instability of inverted arch
Chao Wang +4 more
wiley +1 more source
Известия высших учебных заведений: Геология и разведка, 2016 The stratigraphie distribution and systematic composition of the Middle-Upper Devonian remains of antiarchs from the sediments of Central Kazakhstan are analyzed. Central Kazakhstan ichthyofauna contains mainly endemic taxons of antiarchs.
S. V. Moloshnikov
doaj +1 more source