The larger benthic foraminifera and stratigraphy of the Upper Jurassic/Lower Cretaceous of Central Lebanon

Gheiasvand et al. (2020) use the two larger benthic foraminifera species Simplorbitolina manasi Ciry & Rat and Mesorbitolina parva (Douglass) (Orbitolinidae) as upper Aptian “potential index fossils” for parts of the Taft Formation in Central Iran. This age assignment is accompanied by changes to well-established orbitolinid biozona-tions (e.g. occurrence of Praeorbitolina in the late Aptian) with far-reaching implications. These data were also used in a later “multidisciplinary study” (Gheiasvand et al., 2021) for isotopic correlations (e.g., location of OAE`s), delimitation of palaeobiogeographic faunal provinces and related migration patterns. It is shown herein that the taxa identified as S. manasi and M. parva belong to Iraqia simplex Henson and Palorbitolina lenticularis (Blumenbach) respectively documenting a lower and not an upper Aptian age. This revised age and the different taxononomic inventory do not question all results obtained by Gheiasvand et al. (2020, 2021), but provide a revised basis interpretation.

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THE OCCURRENCE OF TWIN EMBRYOS, ABNORMAL MORPHOLOGIES AND TEST REPAIR IN LOWER CRETACEOUS ORBITOLINIDAE (LARGER BENTHIC FORAMINIFERA): EXAMPLES FROM FRANCE, SOMALIA, IRAN, TIBET, AND TEXAS

Acta Palaeontologica Romaniae ◽

10.35463/j.apr.2020.01.05 ◽

2020 ◽

pp. 43-50

Author(s):

FELIX SCHLAGINTWEIT

Keyword(s):

Benthic Foraminifera ◽

Lower Cretaceous ◽

Mechanical Fracture ◽

Larger Benthic Foraminifera ◽

Lower Aptian

Specimens displaying unusual ( " abnormal " or aberrant) test morphologies, for example, the presence of twin embryos, or test repair after damage, are reported from Lower Cretaceous Orbitolinidae. Twin embryos (which have not always been recognized as such in the literature) are described from the upper Barremian of Tibet and France (Palorbitolina lenticularis), the upper Albian of Somalia (Orbitolina gr. sefini), and the upper Aptian-early Albian of Texas (e.g., Mesorbitolina texana). Twin embryos have so far only been reported from the Orbitolininae (with complex embryo), and not from the Dictyoconinae (with simple embryo). Repaired partially damaged tests (the damage possibly caused by predation or mechanical fracture) are observed in lower Aptian orbitolinids from Iran. Regeneration after damage (bioadjustment) leads to malformed tests.

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A new upper Oligocene marine record from northern Sinai (Egypt) and its paleogeographic context

GeoArabia ◽

10.2113/geoarabia130159 ◽

2008 ◽

Vol 13 (1) ◽

pp. 59-84 ◽

Cited By ~ 1

Author(s):

Jochen Kuss ◽

Mohamed A. Boukhary

Keyword(s):

Benthic Foraminifera ◽

Lower Cretaceous ◽

Depositional Environments ◽

Larger Foraminifera ◽

Larger Benthic Foraminifera ◽

Sequence Stratigraphic ◽

Upper Oligocene ◽

Maximum Flooding Surface ◽

Warm Temperate

ABSTRACT The upper Oligocene Wadi Arish Formation is composed of a carbonate-dominated succession at Gebel Risan Aneiza (Sinai). The 77-m-thick unit disconformably overlies Jurassic to lower Cretaceous carbonates and is subdivided into three members, comprising six lithofacies units. The lower Wadi Arish member contains three units, a gypsiferous sandstone unit (Oa), overlain by two limestone units (Ob and Oc). The middle Wadi Arish member is represented by a conspicuous marl unit (Od) that is overlain by two upper limestone units (Oe and Of) of the upper Wadi Arish member. We discuss the euphotic subtidal depositional environments in conjunction with macro- and microfacies characteristics. Six microfacies types are defined, dominated by grain associations of rhodoliths, larger benthic foraminifera (rotaliids), corallinaceans, bivalves, peloids, few corals, and bryozoans. They characterize rhodalgal associations, common in non-tropical warm-temperate settings. Biostratigraphy is based on larger foraminifera. The middle Wadi Arish member corresponds with SB 23 (Chattian) and may correlate with Pg50, a regional maximum flooding surface. Our sequence stratigraphic interpretations define a late lowstand to early transgressive systems tract (lower Wadi Arish member), a late transgressive systems tract (middle Wadi Arish member), while the upper Wadi Arish member reflects highstand conditions. The paleogeographic setting and sequence stratigraphic interpretation of this unique upper Oligocene outcrop is placed in context of the northeast African-Arabian region.

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ORBITOLINIDS AND OTHER LARGER BENTHIC FORAMINIFERA FROM THE APTIAN-ALBIAN OF TIBET: CRITICAL DISCUSSION OF SOME RECENTLY PUBLISHED DATA

Acta Palaeontologica Romaniae ◽

10.35463/j.apr.2022.01.03 ◽

2021 ◽

pp. 17-23

Author(s):

FELIX SCHLAGINTWEIT

Keyword(s):

Shallow Water ◽

Benthic Foraminifera ◽

Lower Cretaceous ◽

Critical Discussion ◽

Individual Species ◽

Published Data ◽

Larger Benthic Foraminifera ◽

Stratigraphic Ranges

Orbitolinidae together with other larger benthic foraminifera are particularly important in Lower Cretaceous shallow-water biostratigraphy provided that they are correctly identified. Especially in the case of the Orbitolininae (with complex embryo), their biostratigraphic range with overlapping ranges corresponds to different lineages displaying ancestor-descendant relationship (e.g., Praeorbitolina-Mesorbitolina). In the last fifty years well established and repeatedly confirmed taxon ranges have been largely extended thereby diluting or negating any biostratigraphic value to individual species. Some biostratigraphic data provided by BouDagher-Fadel et al. (2017) from the Aptian-Albian of Tibet that are contradicting previous results are reviewed herein. This publication mostly refers to the stratigraphic ranges of Praeorbitolina cormyi Schroeder and Pseudochoffatella cuvillieri Deloffre towards the top of the Albian, and that of Palorbitolina lenticularis (Blumenbach) into the late Aptian, as well as some misidentifications.

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