Wall structures in selected Paleozoic lagenide foraminifera

Groves, JR
Rettori, R
Altıner, Demir
Paleozoic lagenide foraminifera are strikingly similar morphologically to Mesozoic and Cenozoic Lagenida, but because benthic foraminifers suffered a catastrophic reduction in diversity during the end-Permian mass extinction, it is unclear whether the similarities of Paleozoic lagenides and younger unquestioned Lagenida link them evolutionarily or are the product of convergence. Seven species representing five families of Paleozoic lagenide foraminifers were examined and found to possess mostly monolamellar hyaline-radial walls, as in extant nodosariid Lagenida. Exceptions are Protonodosaria rauserae Gerke, 1959, whose wall is not optically radial, and Syzrania amazonica Altiner and Savini, 1997, whose hyaline-radial wall may or may not be accompanied by a secreted inner microgranular layer. The inner microgranular layer is an element that is thought to have been inherited from the ancestral Fusulinida. Its absence in all but the earliest and morphologically simplest Paleozoic lagenides indicates more advanced wall structure than generally has been ascribed to this group. The wall in Pachyphloia spp. is secondarily thickened, suggesting plesio- or ortho-monolamellar construction, whereas other examined species exhibit atelo-monolamellar wall structure. These types of lamellarity are common among modern nodosariids. Thus, on the basis of not only morphologic similarity but also similar wall structure, we strongly suspect evolutionary continuity of lagenides across the Permian-Triassic boundary. The question is not completely resolved, however, because lagenides have not yet been recovered from lowest Triassic rocks.


Survival and recovery of calcareous foraminifera pursuant to the end-Permian mass extinction
Groves, JR; Altıner, Demir (Elsevier BV, 2005-09-01)
Ninety-one percent of calcareous foraminiferal genera became extinct during the end-Permian mass extinction. The Early Triassic Epoch was a survival phase characterized by a short-lived proliferation of disaster forms and then I prolonged interval of low diversity. The orders Miliolida and Lagenida experienced limited taxonomic re-diversification in Early and Late Anisian time, respectively. All fusulinoidean fusulinides became extinct in Late Permian time, and only two non-fusulinoidean genera persisted in...
Timing of depositional regime changes during the Late Cretaceous evolution of the Southern Pontides (Ankara, Central Anatolia, Turkey)
Sariaslan, Nisan; Altıner, Sevinç; Altıner, Demir (Elsevier BV, 2020-08-01)
During the Cretaceous, vast amounts of marine sediments were deposited along the south-facing active margin of the Eurasia. A stratigraphic section of 91 m was analyzed for planktonic foraminifera (75 samples), with the aim of establishing a refined biostratigraphy of Cenomanian-Campanian deposits in Central Anatolia. A biostratigraphic framework comprising nine biozones was established. In ascending order, the Rotalipora cushmani, Whiteinella archaeocretacea and Helvetoglobotruncana helvetica zones were de...
The Cretaceous Mardin Group carbonates in southeast Turkey: Lithostratigraphy, foraminiferal biostratigraphy, microfacies and sequence stratigraphic evolution
Ozkan, Recep; Altıner, Demir (Elsevier BV, 2019-06-01)
The Mardin Group strata, as a product of the Cretaceous carbonate platform developed in the northern margin of the Arabian Platform, consists of a thick sedimentary sequence composed mostly of carbonates with subordinate clastic sediments. In this study, three stratigraphic sections Turkoglu, Derik and Inisdere addressing this sequence have been investigated in terms of lithostratigraphy and biostratigraphy combined with microfacies analysis and sequence stratigraphic interpretation. A comprehensive examina...
The genus Lepidorbitoides evolution and its stratigraphic significance in some Anatolian basins Turkey
ÖZCAN, ERCAN; Altıner, Sevinç (Elsevier BV, 1999-01-01)
Evolution of Lepidorbitoides in some flysch basins of Anatolia has been investigated considering the early ontogenesis in horizontal sections. Different developmental states of L. pembergeri, L. campaniensis, L. bisambergensis, L. minor and L. socialis have been described and illustrated with their morphometric features based on the earliest chamber arrangement. A correlation scheme of phylogenetic developmental states of Lepidorbitoides to the planktonic foraminiferal zones is also proposed. Populations wi...
Origin and early evolutionary radiation of the Order Lagenida (Foraminifera)
Groves, JR; Altıner, Demir; Rettori, R (Cambridge University Press (CUP), 2003-09-01)
The Order Lagenida is a monophyletic group of calcareous foraminifers that originated in Middle Pennsylvanian time via acquisition of hyaline-radial wall structure and loss of microgranular wall structure, the latter being characteristic of the close sister group and likely ancestor, the Fusulinida. Early lagenides are delineated into subgroups on the basis of presence or absence of partitioning within their tests. and among partitioned forms, on continuous versus discontinuous growth styles. Partitioned, d...
Citation Formats
J. Groves, R. Rettori, and D. Altıner, “Wall structures in selected Paleozoic lagenide foraminifera,” JOURNAL OF PALEONTOLOGY, pp. 245–256, 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47980.