Results 11 to 20 of about 3,769 (223)
The dorsal shell wall structure of Mesozoic ammonoids [PDF]
Acta Palaeontologica Polonica, 2017 The study of pristine preserved shells of Mesozoic Ammonoidea shows different types of construction and formation of the dorsal shell wall. We observe three major types: (i) The vast majority of Ammonoidea, usually planispirally coiled, has a prismatic ...
Gregor Radtke, Helmut Keupp
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Conellae, enigmatic structures on cephalopod shells—shapes, distribution, and formation [PDF]
Acta Palaeontologica Polonica, 2019 Conellae, enigmatic cone-shaped structures which can be found on the surface of internal moulds of cephalopod shells (predominantly of ammonoids), are regarded herein as the product of remote (biologically induced) biomineralization formed in closed-off ...
René Hoffmann +2 more
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Reproductive biology and anatomy of ammonites [PDF]
Scientific ReportsAmmonoid anatomy is still poorly known and every new record of a specimen with soft tissue-preservation yields valuable information. In view of the impressive morphological disparity of ammonoids, we can also expect some disparity in soft tissue anatomy.
Christian Klug +6 more
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Postmortem transport in fossil and modern shelled cephalopods [PDF]
PeerJ, 2018 The chambered shells of cephalopod mollusks, such as modern Nautilus and fossil ammonoids, have the potential to float after death, which could result in significant postmortem transport of shells away from living habitats. Such transport would call into
Margaret M. Yacobucci
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About the stratigraphic position of the Lower Aptian Roloboceras hambrovi (Ammonoidea) level
Carnets de Géologie, 2008 In the stratotype of the Lower Aptian substage the position of the assemblage that includes Roloboceras spp. and Megatyloceras spp. has been clearly established as being in the middle part of the upper Bedoulian. Some authors have erected this horizon as
Conte Gabriel +3 more
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3D-Analysis of a non-planispiral ammonoid from the Hunsrück Slate: natural or pathological variation? [PDF]
PeerJ, 2017 We herein examine the only known non-planispirally coiled early Devonian ammonoid, the holotype specimen of Ivoites opitzi, to investigate if the host was encrusted in vivo and if these sclerobionts were responsible for the trochospiral coiling observed ...
Julia Stilkerich +2 more
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Extreme abundance of ammonoids in mass accumulations from the Late Devonian of the Moroccan Anti-Atlas [PDF]
Acta Palaeontologica Polonica, 2022 The eastern Anti-Atlas is renowned for its highly fossiliferous outcrops of Devonian rocks. Ammonoids occur in rock-forming numbers at many localities in the Tafilalt and Maïder.
MERLE GREIF +2 more
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, 2006 International audienceOne of the significant results of the multidisciplinary investigations carried out during recent years in the Lower Aptian historical stratotype of the Cassis-La Bédoule region (South-Eastern France) was a proposal to update the ...
P. Ropolo +4 more
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Dimorphism in tetragonitid ammonoid Tetragonites minimus from the Upper Cretaceous in Hokkaido, Northern Japan [PDF]
Acta Palaeontologica Polonica, 2022 Mature modifications, ontogeny, and dimorphism of the small-sized tetragonitid ammonoid Tetragonites minimus were investigated in 43 specimens from the Santonian, Upper Cretaceous of the northwestern area of Hokkaido, Japan.
DAISUKE AIBA
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Terr@ Plural, 2021 Although the fossil record from Antarctica is increasing continuously, there is still a great lack of knowledge regarding the past biodiversity of this continent. Here we present the first occurrences of the ammonoid Pseudophyllites? cf.
Roberto Videira-Santos +2 more
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