Zobrazeno 1 - 10
of 110
pro vyhledávání: '"Helmut Keupp"'
Publikováno v:
Zitteliana, Vol 96, Iss , Pp 179-221 (2022)
Forty gastropod species of the subclass Heterobranchia are described from the Upper Jurassic (Upper Kimmeridgian) reefal limestones of South Germany, including ten species in open nomenclature and further ten species of uncertain identity. Six specie
Externí odkaz:
https://doaj.org/article/9d4aabe8216f4f9ba22096cf933000b8
Publikováno v:
Zitteliana, Vol 96, Iss , Pp 135-143 (2022)
Our paper shows several clusters of circular fossil egg capsules from the Franconian Amaltheenton Facies (Lower Jurassic, Upper Pliensbachian), mostly found in the clay pit south of Buttenheim. The egg capsules are scatteredly and irregularly arrange
Externí odkaz:
https://doaj.org/article/b37f39cdf93b4e298eae7a850e6d5028
Early teleost otolith morphogenesis observed in the Jurassic of Franconia, Bavaria, southern Germany
Autor:
Werner Schwarzhans, Helmut Keupp
Publikováno v:
Zitteliana, Vol 96, Iss , Pp 51-67 (2022)
The otoliths described in this study are from the late Pliensbachian of the Buttenheim clay pit near Bamberg, Franconia, northern Bavaria, and represent one of the earliest teleost otolith assemblages known so far. A total of 351 otoliths have been r
Externí odkaz:
https://doaj.org/article/5cf111e165164183b89c876299301f56
Publikováno v:
Acta Palaeontologica Polonica, Vol 64, Iss 4, Pp 815-830 (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-
Externí odkaz:
https://doaj.org/article/cc5f7b5226944c699e58930a49af12c8
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
Publikováno v:
PLoS ONE, Vol 8, Iss 1, p e54038 (2013)
Biomineralization in calcareous dinophytes (Thoracosphaeracaea, Peridiniales) takes place in coccoid cells and is presently poorly understood. Vacuolar crystal-like particles as well as collection sites within the prospective calcareous shell may pla
Externí odkaz:
https://doaj.org/article/ca1b7446b4b544a5844697ce016e082b
Autor:
Helmut Keupp
Publikováno v:
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 306:29-35
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9ec4183f208c14e55e88b44d93f13ead
https://doi.org/10.1127/njgpa/2022/1095
https://doi.org/10.1127/njgpa/2022/1095
Autor:
Helmut Keupp, Dirk Fuchs
Publikováno v:
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 298:55-66
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1abc74049266a2bca74bad3f04798278
https://doi.org/10.1127/njgpa/2020/0933
https://doi.org/10.1127/njgpa/2020/0933
Publikováno v:
Acta Palaeontologica Polonica, Vol 64, Iss 4, Pp 815-830 (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-
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d48d4691bd49ceb0952144c93cc0b865
http://www.app.pan.pl/archive/published/app64/app006402019.pdf
http://www.app.pan.pl/archive/published/app64/app006402019.pdf