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We report the occurrence of the oldest known multi-chambered trochospiral, planispiral and planispiral/uniserial foraminifera from the Lower to Middle Cambrian deposits in Nova Scotia (Canada). Morphologically, these forms closely resemble modern marsh foraminifera. If these are in fact similar or the same as present marsh foraminifera, their apparent lack of morphological evolution, and the agglutinated and complex multichambered nature of these foraminifera suggest that: 1) these organisms must have some unique characteristics favoring the development of a successful assemblage that appears to have survived to the present, 2) complex chamber arrangements started to develop before 500 Ma, and 3) either these forms are the ancestors to all multi-chambered foraminifera–including the calcareous foraminifera which are the dominant foraminiferal group today – or there was parallel evolution where these went undetected for 200 m.y. when the next occurrence of these chamber arrangements is reported.
Similar foraminifera have been found in Carboniferous and younger deposits where it is clear these were associated with ancient marshes. These fill some of the time gap between the Cambrian forms and modern marsh species.
Devonian radiolarians from four new sections at Shaijingpo, Lila, Bazhai, and Shiti Reservoir in southern China are described. Faunas from these localities are assigned to eight families, 15 genera and 30 species, with the introduction of one new species Trilonche parapalimbola n. sp. Wang. The stratigraphic significance of the Middle Devonian Eoalbaillella lilaensis fauna, morphotypic variation within the genus Helenifore and the abundance and diversity of the Upper Devonian Holoeciscus foremanae fauna are discussed.
The holotype of Neoeponides duwi (Nakkady 1950), originally described as a variety of Discorbis pseudoscopos Nakkady, is re-described and re-figured. This species appears to have no phylogenetic relationship with D. pseudoscopos. Neoeponides duwi is recorded in Paleocene shelf sediments in the Middle East and, assigned to Eponides pseudoelevatus, in West Africa. In Egypt, N. duwi typically occurs in inner to middle shelf deposits, but it has also been found dominant (up to 60% of the benthic assemblage) in transgressive deposits in deeper parts of the basin. Its distribution pattern, the association with highly variable and occasionally extremely high plankton/benthos ratios (>99.5% plankton) and with TOC-enriched laminated dark sediments, suggests an opportunistic response to limited and/or variable oxygenation at the seafloor.
Swadelina n. gen. is erected to comprise a short-ranging clade of late Desmoinesian (middle Pennsylvanian) idiognathodontid conodonts characterized by Pa elements with a deep medial trough, extensive anterior ornamentation, and an extremely short carina. The Pb elements have a small, relatively indistinct cusp, and dissimilar development of the anterior and posterior processes. Swadelina (Sw.) probably evolved through paedomorphosis from an untroughed Idiognathodus ancestor well before the appearance of similarly troughed Streptognathodus Pa elements in the Missourian (late Pennsylvanian). We currently recognize Sw. nodocarinata (Jones 1941) and Sw. neoshoensis n. sp. as component species. Swadelina occurs in both North America and Eurasia with a limited range, in strata that are otherwise characterized by pronounced provincialism. With further study of international occurrences, a species of Swadelina may provide for the definition and correlation of an appropriate GSSP stage/series boundary between the middle and upper parts of the Pennsylvanian Subsystem.
Pleurosigma strigosum W. Smith is not a variety of P. angulatum (Quekett) W. Smith but a different species, as confirmed in SEM. This conclusion agrees with that of Hendey (1964), who typified the species. P. finmarchicumCleve in Cleve and Möller 1882 does not show specific differences from P. strigosum. This paper gives descriptions and criteria for differentiation for P. strigosum, P. acutum Norman ex Ralfs in Pritchard, P. latum Cleve in Cleve et Grunow and P. sabangi Meister, a species that is not restricted to tropical seas - hitherto its only record. The second record of P. sterrenburgii Stidolph, from a truly antipodal locality, also raises questions regarding its distribution.
Nummulites lyelliD'Archiac and Haime 1853, is described for the first time from photographs of both generations, using material from the species type locality at El-Mishgigah, in the El-Gharaq Formation exposed in the Fayum Depression. Nummulites praelyelli n.sp., described from the Mokattam Formation below the Citadel of Salah El Din, in the eastern part of Cairo, is interpreted to be the ancestor of Nummulites lyelli Archiac and Haime. The main ontogenetic trend in this newly identified lineage is a gradual change from tight to lax coiling during growth, whereas the opposite onotgenetic trend is found in the lineage of Nummulites gizehensis (Forskål) In this work, the group of Nummulites gizehensis and allied species is separated from the group of Nummulites lyelli, partly on this basis but definitively on the basis of granulation and septal morphology. We suggest that at the beginning of the Bartonian, Nummulites lyelli ecologically displaced the Late Lutetian Nummulites gizehensis in both space and time, rather than evolving from it.
The calcareous nannofossil species Neobiscutum romeinii, N. parvulum, and Cruciplacolithus primus, are considered in modern zonation schemes as index species for the lowermost Paleocene. Our studies, however, reveal that they are consistently present in upper Maastrichtian calcareous nannofossil zone CC26. The two Neobiscutum species were found several meters below the Cretaceous-Paleogene (K-P) boundary in cores from Brazos River (Texas) and Antioch Church (Alabama), and in outcrops at Geulhemmerberg (the Netherlands), El Kef (Tunisia), and Jebel Qurtasiyyat (Jordan). Except for the Jordanian record, the same applies to the occurrence of C. primus. These coccoliths are extremely small, ranging from 0.8 to 2.5µm for Neobiscutum and 1.5 to 3.5µm for C. primus, and they constitute less than 1% of the calcareous nannofossil association. This may explain why they were not consistently detected below the K-P boundary in earlier investigations. Since these species are not exclusively Paleocene indicators only their prominent acmes or, alternatively, the index species Biantholithus sparsus should be used to unambiguously identify the lowermost Paleocene. The geographic coverage in our study indicates that the late Maastrichtian appearances of N. romeinii, N. parvulum and C. primus are typical for marginal seas of the Northern Hemisphere.
The skeletal structure of Prunopyle antarctica Dreyer is examined and redescribed on the basis of new observations from sediment samples from the Antarctic Ocean. Various forms of the species are illustrated.
Cocoarota orali, a new foraminifer species, is described from the Upper Maastrichtian and Upper Danian levels of Niksar (Tokat); from the Upper Danian levels of Gölköy (Ordu) and Tecer (Sivas); from the Thanetian level in the Gürlevik Mountain (Sivas), Elazýð and Safranbolu (Karabük); from the Cuisian-Lower Lutetian levels of Andýrýn (Kahramanmaraþ) regions, all in Turkey. The new species is characterized by its test shape, two layered wall and hexagonal ornamentation. It is provisionally assigned within Cocoarota genus because of its test shape, coiling and other structural features, but differs from other species in Cocoarota by its two layered wall.