Show/Hide Menu
Hide/Show Apps
anonymousUser
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Frequently Asked Questions
Frequently Asked Questions
Browse
Browse
By Issue Date
By Issue Date
Authors
Authors
Titles
Titles
Subjects
Subjects
Communities & Collections
Communities & Collections
The genera Lepidorbitoides and Orbitcoides: evolution and stratigraphic significance in some Anatolian basins
Date
1999-07-01
Author
ÖZCAN, ERCAN
Altıner, Sevinç
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
2
views
0
downloads
Early ontogenetic morphologic features previously recognized as evolutionary parameters in Lepidorbitoides and Orbitoides have been tested in several flysch successions of Anatolia. Increase in embryo size (Li + ii), number of epi-embryonic chambers (E) and organization of embryonal chamber arrangement from 'quadrilocular' to 'bilocular' and multilocular in Orbitoides, increase in deuteroconch size (D), in deuteroconch-protoconch ratio (D/P) and in number of adauxiliary chambers (Ad) in Lepidorbitoides have been recognized as the main evolutionary trends, thus allowing the correlation of these features with time. The different developmental stages in Lepidorbitoides, i.e. L. pembergeri, L. campaniensis, L. bisambergensis, L. minor, L. socialis, and in Orbitoides, i.e. O. media, O. megaloformis, O. gruenbachensis, O. apiculata and O. gensacicus, have been described and illustrated based on the biometry of the populations. The values observed in some horizons, however, may not reflect the true phylogenetic stage of the orbitoidal taxa, especially in the species of Orbitoides, which usually show a wide variation of evolutionary parameters in the same population. A correlation scheme of phylogenetic development in Lepidorbitoides and Orbitoides with the planktonic foraminiferal zones is proposed. Lepidorbitoides populations with highly asymmetric 'quadriserial' nepionts occurring stratigraphically below the symmetric ones in Early Maastrichtian are thought to deserve a particular taxonomic status. In Orbitoides, a new embryonal chamber morphology previously undescribed from horizontal sections has been discovered. Copyright (C) 1999 John Wiley & Sons, Ltd.
Subject Keywords
Lepidorbitoides
,
Orbitoides
,
Early ontogeny
,
Biometry
,
Biostratigraphy
,
Plankton-benthos correlation
,
Late Cretaceous
,
Anatolia
,
Turkey
URI
https://hdl.handle.net/11511/53899
Journal
GEOLOGICAL JOURNAL
Collections
Department of Geological Engineering, Article