Naslov
Lutetian Orthophragminae from the Istrian Peninsula (Adriatic Sea, Croatia and Slovenia)

Autori
Ćosović, Vlasta ; Drobne, Katica

Vrsta, podvrsta i kategorija rada
Poglavlja u knjigama, znanstveni

Knjiga
Paleogene Shallow Benthos of The Tethys

Urednik/ci
Hottinger, Lukas ; Drobne, Katica

Izdavač
Slovenska akademija znanosti in umetnosti (SAZU)

Grad
Ljubljana

Godina
1998

Raspon stranica
173-181

ISBN
961-6242-13-X

Ključne riječi
Orthophragminae, Discocyclina, Orbitoclypeus, Lutetian, Istria

Sažetak
Four foraminiferal assemblages rich inorthophragminids from Istria (Osp, Ragancini-Lišani, Šterna and Pićan) were dated as of Early and Middle Lutetian age, respectively, based on the Alveolina and Nummulites assemblages. Orthophragminids inhabited the sea-bottom (within the photic zone) of the Adriatic carbonate latform during the demise of the platform. Their abundance and diversification confirmed that nutrient cline rose over the light limit. Moreover, studies of their outer morphologies, in spite of different stratigraphic levels; showed a clear trend towards the increasing flatness of the tests wih increasing dephs; as well as the domination in frequency distribution of discocyclinids over asterocyclinids specimens. The test's shape changes, described and named as Orthophragmina morphogroups, coincide with the stages ofseveral evolutionary lineages (Less, 1987), implying that environmental changes during the Early and Middle Lutetian, possibly, occurred in various parts within the western Tethyan provinces.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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