Zobrazeno 1 - 4
of 4
pro vyhledávání: '"Gregor Radtke"'
Autor:
Gregor Radtke, Helmut Keupp
Publikováno v:
Acta Palaeontologica Polonica, Vol 62, Iss 1, Pp 59-96 (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 prismat
Externí odkaz:
https://doaj.org/article/9e0deb9f6b874d2cbd33322df5e67e42
Publikováno v:
Acta Palaeontologica Polonica, Vol 61, Iss 3, Pp 503-517 (2016)
The ultrastructure of pristine shells of Jurassic and Cretaceous lytoceratid and perisphinctid ammonoids indicates that flares and parabolae represent homologous structures. Both mark an interruption of shell growth. We dismiss earlier interpretation
Externí odkaz:
https://doaj.org/article/032dba71de0e43a29aa6732e86d4df6e
Autor:
Gregor Radtke, Helmut Keupp
Publikováno v:
Palaeontology. 59:409-421
Radial sculptural elements (e.g. ribs, lirae), formed by imbrication of two succeeding shell lamellae are found in members of both the Nautiloidea (Cymatoceras) and Ammonoidea (Phylloceratinae and Aspidoceratinae). Their formation involves periodic c
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5ed339a7cf445407c5c7b8c7b67441b4
https://doi.org/10.1111/pala.12233
https://doi.org/10.1111/pala.12233
Autor:
Helmut Keupp, Gregor Radtke
Publikováno v:
Swiss Journal of Palaeontology. 135:109-124
The structure of pristine preserved shells of Jurassic and Cretaceous ammonoids was examined to identify whether the character states of varices and constrictions are homologous or homoplasic traits. The internal structure of varices and constriction
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::dba63c591fa6cbdd4839009a766f74ae
https://doi.org/10.1007/s13358-015-0095-9
https://doi.org/10.1007/s13358-015-0095-9