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Palaeozoic Foraminifera: Systematics, palaeoecology and responses to global changes
Abstract
Because the Foraminifera are very sensitive to various environmental parameters (e.g., water temperature, salinity, light, etc.), there are important proxies used for palaeoenvironmental and palaeogeographic reconstructions. The evolution of the structure, shape and size of the mineralized tests of Foraminifera can directly reflect the variation of these parameters through geological time. Furthermore, their biostratigraphic value has been widely demonstrated. In this context, the systematics, evolution and ecological behaviour of the first mineralized Palaeozoic Foraminifera are important to discuss in order to have a clearer picture of former shallow marine environments, and finally understand their distribution through space and time. The systematics of the fossil group of Foraminifera that first developed a mineralized test remains under discussion. These early foraminifers are considered as Textulariata (as generally admitted), recrystallized Fusulinata or an independent group, sometimes called Astrorhizata. In this paper, we argue to assign the early foraminifers to the Fusulinata, and to subdivide this class into six orders: Parathuramminida, Archaediscida and Earlandiida (forming together the subclass Afusulinana n. subcl.), and Tournayellida, Endothyrida and Fusulinida (subclass Fusulinana nom. translat.). These subdivisions are discussed and linked to the first occurrences of the later classes: Miliolata, Nodosariata and Textulariata. The environmental living conditions of the first fossilized foraminifers remain enigmatic during the Early Palaeozoic (Cambrian-Silurian). During the Late Silurian, the unilocular Parathuramminida started to colonize the inner parts of ramps and platforms. The first plurilocular microgranular foraminifers (Semitextulariidae, Nanicellidae, and Eonodosariidae) developed in back-reefal systems and in deeper-water environments (“griottes”-type nodular limestone) from the late Early Devonian to the early Late Devonian. The Moravamminida, another group of possible Protista, are typical markers of Devonian inner ramp systems. The Semitextulariidae, Nanicellidae, and Eonodosariidae did not survive the Frasnian/Famennian crisis. From the Tournaisian to the Serpukhovian (Mississippian subsystem or Early Carboniferous), numerous new genera and species of Archaediscida, Tournayellida and Endothyrida flourished but remained confined to inner ramp environments. In deeper water depositional systems (i.e. coral thrombolite microbialites and/or nodular limestones), a few opportunistic Foraminifera were living up to the disphotic zone. During the Pennsylvanian (Bashkirian to Gzhelian), the habitats extended to more confined, shallower areas of the inner ramp (with Staffelloidea). During the Late Carboniferous and Permian, the larger Fusulinida (Schwagerinoidea) reached the outer platform as they have been commonly reworked in calciturbidites. During the Late Permian, some taxa were even able to live in hypersaline environments such as sabkhas and hypersaline lagoons. Two major biotic crises occurred during the Permian (post-Middle and post-Late Permian crisis), but the number of survivors after the PTE (Permian/Triassic Extinction) is probably higher than previously admitted. From the Cambrian to the Serpukhovian, the Foraminifera were probably all infaunal or living at the sediment/seawater interface. The TROX and TROX-2 models are consequently applicable. Anoxia, often suggested as triggering environmental crises, was likely not systematically lethal for many infaunal foraminifers. The late Tournaisian-Changhsingian Tetrataxis genus was probably the first epiphyte foraminifer, because of its conical, limpet-like test. The Tetrataxidae (e.g., Tetrataxis, Pseudotaxis and Abadehella) constituted the unique trochospirally coiled plurilocular foraminiferal family of the Palaeozoic. The Bradyinoidea, Ozawainelloidea, Staffelloidea, and the Pseudoschwagerinidae (Schwagerinoidea) are other examples of Pennsylvanian-Permian epiphytes but cannot be considered as planktonic taxa. All the other Schwagerinoidea are related to high-energy environments and coarse-grained substrates. Their history, as well as that of the Neoschwagerinoidea, was likely subject to the vicissitudes of their endosymbiotic algae.
... To delve into the automatic identification of fossils, we take fusulinids, a large group of fossil foraminifera dating back to c. 300 Ma, as the subject of our study. Fusulinids are the earliest larger benthic foraminifera that appeared in the shallow water of the Carboniferous and survived until the Late Permian (Pawlowski et al., 2003;Vachard et al., 2010). Their rapid evolution, as seen in morphological changes, makes them prominent index fossils for the Late Palaeozoic biostratigraphy, that is, dating the bearing rocks (BouDagher-Fadel, 2008;Ross & Ross, 1991). ...
... This procedure compresses the three-dimensional morphological features into two dimensions, which is also common in the studies of other fossils such as corals, brachiopods, archaeocyathids, plants and even vertebrate bones. To meet different research needs, multiple sections of fusulinid fossils, including axial, sagittal and tangential sections, could be produced, and axial sections are preferred for identification as they contain the most useful features (Sheng et al., 1988;Vachard et al., 2010). This slice-based identification of fusulinids is very beneficial for applying automatic identification models, as deep learning models based on two-dimensional images have already been well developed. ...
... the fossils and thus serves as a feature extraction (Saha et al., 2016;Weeks et al., 2023). For shell-forming organisms like fusulinids, the topology of their shell, such as the number and size of chambers and the manner of spinning and coiling, is sufficient to provide a great deal of information for their identification and classification (Ross & Ross, 1991;Sheng et al., 1988;Vachard et al., 2010). Skeletonization can be seen as a feature extractor based on this prior knowledge to help the model learn the morphological features of the fossil. ...
Identification of fossil species is crucial to evolutionary studies. Recent advances from deep learning have shown promising prospects in fossil image identification. However, the quantity and quality of labelled fossil images are often limited due to fossil preservation, conditioned sampling and expensive and inconsistent label annotation by domain experts, which pose great challenges to training deep learning‐based image classification models.
To address these challenges, we follow the idea of the wisdom of crowds and propose a multiview ensemble framework, which collects Original (O), Grey (G) and Skeleton (S) views of each fossil image reflecting its different characteristics to train multiple base models, and then makes the final decision via soft voting.
Experiments on the largest fusulinid dataset with 2400 images show that the proposed OGS consistently outperforms baselines (using a single model for each view), and obtains superior or comparable performance compared to OOO (using three base models for three the same Original views). Besides, as the training data decreases, the proposed framework achieves more gains. While considering the identification consistency estimation with respect to human experts, OGS receives the highest agreement with the original labels of dataset and with the re‐identifications of two human experts. The validation performance provides a quantitative estimation of consistency across different experts and genera.
We conclude that the proposed framework can present state‐of‐the‐art performance in the fusulinid fossil identification case study. This framework is designed for general fossil identification and it is expected to see applications to other fossil datasets in future work. Notably, the result, which shows more performance gains as train set size decreases or over a smaller imbalance fossil dataset, suggests the potential application to identify rare fossil images. The proposed framework also demonstrates its potential for assessing and resolving inconsistencies in fossil identification.
... They have an extremely long evolutionary history, possibly from Neoproterozoic, according to molecular evidence (Pawlowski et al., 2003;Tappan & Loeblich, 1988), to the modern days. Throughout their history, they exhibit high diversity and serve as an important component of the marine ecosystem (Gupta, 1999;Vachard et al., 2010). Fusulinids, herein refer to Order Fusulinida (Wedekind, 1937) under Class Fusulinata (Dubicka et al., 2021;Vachard et al., 2010) are Palaeozoic larger benthic foraminifera that developed calcareous, planispiral, mostly spindle-shaped tests with dozens to over 100 segmented chambers ( Figure 1a). ...
... Throughout their history, they exhibit high diversity and serve as an important component of the marine ecosystem (Gupta, 1999;Vachard et al., 2010). Fusulinids, herein refer to Order Fusulinida (Wedekind, 1937) under Class Fusulinata (Dubicka et al., 2021;Vachard et al., 2010) are Palaeozoic larger benthic foraminifera that developed calcareous, planispiral, mostly spindle-shaped tests with dozens to over 100 segmented chambers ( Figure 1a). They appeared in the shallow sea of the Carboniferous and then thrived until the Late Permian (Pawlowski et al., 2003;Vachard et al., 2010). ...
... Fusulinids, herein refer to Order Fusulinida (Wedekind, 1937) under Class Fusulinata (Dubicka et al., 2021;Vachard et al., 2010) are Palaeozoic larger benthic foraminifera that developed calcareous, planispiral, mostly spindle-shaped tests with dozens to over 100 segmented chambers ( Figure 1a). They appeared in the shallow sea of the Carboniferous and then thrived until the Late Permian (Pawlowski et al., 2003;Vachard et al., 2010). They evolved quickly with rapid morphological changes in the tests and therefore have been accepted as an eminent index fossil for the Late Palaeozoic biostratigraphy (BouDagher-Fadel, 2008;Ross & Ross, 1991). ...
Fusulinid foraminifera are among the most common microfossils of the Late Palaeozoic and act as key fossils for stratigraphic correlation, paleogeographic and paleoenvironmental indication, and evolutionary studies of marine life. Accurate and efficient identification forms the basis of such research involving fusulinids but is limited by the lack of digitized image datasets. This article presents the first large image dataset of fusulinids containing 2,400 images of individual samples subjected to 16 genera of all six fusulinid families and labelled to species level. These images were collected from the literature and our unpublished samples through an automatic segmentation procedure implementing BlendMask, a deep learning model. The dataset shows promise for the efficient accumulation of fossil images through automated procedures and will facilitate taxonomists in future morphologic and systematic studies.
... The taxonomic classification here used is mainly in accordance with that of Tappan (1987, 1992); Gaillot and Vachard (2007); Vachard et al. (2010;2015); Vachard (2018); Vachard and Le Coze (2022); and Kobayashi and Vachard (2022). Eighty five species of thirty foraminiferal genera were identified in the Syuranian-Askynbashian sequence in this research. ...
... Class Fusulinata Gaillot and Vachard, 2007. As stated by Vachard et al. (2010) and Vachard and Le Coze (2022), in spite of the inadequate discussion of Fusulinata by Maslakova et al. (1995), the name of Fusulinata, introduced by Maslakova (1990) as a foraminiferal subclass, has noticeable precedence over Fusulinana Vachard et al. (2010), even if the spelling of Fusulinana is more correct than the original Fusulinata (compared to the endings ana and ata used in the classifications of, e.g., V. Mikhalevich and G. Nestell). ...
... Class Fusulinata Gaillot and Vachard, 2007. As stated by Vachard et al. (2010) and Vachard and Le Coze (2022), in spite of the inadequate discussion of Fusulinata by Maslakova et al. (1995), the name of Fusulinata, introduced by Maslakova (1990) as a foraminiferal subclass, has noticeable precedence over Fusulinana Vachard et al. (2010), even if the spelling of Fusulinana is more correct than the original Fusulinata (compared to the endings ana and ata used in the classifications of, e.g., V. Mikhalevich and G. Nestell). ...
... The taxonomic classification here used is mainly in accordance with that of Tappan (1987, 1992); Gaillot and Vachard (2007); Vachard et al. (2010;2015); Vachard (2018); Vachard and Le Coze (2022); and Kobayashi and Vachard (2022). Eighty five species of thirty foraminiferal genera were identified in the Syuranian-Askynbashian sequence in this research. ...
... Class Fusulinata Gaillot and Vachard, 2007. As stated by Vachard et al. (2010) and Vachard and Le Coze (2022), in spite of the inadequate discussion of Fusulinata by Maslakova et al. (1995), the name of Fusulinata, introduced by Maslakova (1990) as a foraminiferal subclass, has noticeable precedence over Fusulinana Vachard et al. (2010), even if the spelling of Fusulinana is more correct than the original Fusulinata (compared to the endings ana and ata used in the classifications of, e.g., V. Mikhalevich and G. Nestell). ...
... Class Fusulinata Gaillot and Vachard, 2007. As stated by Vachard et al. (2010) and Vachard and Le Coze (2022), in spite of the inadequate discussion of Fusulinata by Maslakova et al. (1995), the name of Fusulinata, introduced by Maslakova (1990) as a foraminiferal subclass, has noticeable precedence over Fusulinana Vachard et al. (2010), even if the spelling of Fusulinana is more correct than the original Fusulinata (compared to the endings ana and ata used in the classifications of, e.g., V. Mikhalevich and G. Nestell). ...
... To delve into the automatic identification of fossils, we take fusulinids, a large group of fossil foraminifera dating back to c. 300 Ma, as the subject of our study. Fusulinids are the earliest larger benthic foraminifera that appeared in the shallow water of the Carboniferous and survived until the Late Permian (Pawlowski et al., 2003;Vachard et al., 2010). Their rapid evolution, as seen in morphological changes, makes them prominent index fossils for the Late Palaeozoic biostratigraphy, that is, dating the bearing rocks (BouDagher-Fadel, 2008;Ross & Ross, 1991). ...
... This procedure compresses the three-dimensional morphological features into two dimensions, which is also common in the studies of other fossils such as corals, brachiopods, archaeocyathids, plants and even vertebrate bones. To meet different research needs, multiple sections of fusulinid fossils, including axial, sagittal and tangential sections, could be produced, and axial sections are preferred for identification as they contain the most useful features (Sheng et al., 1988;Vachard et al., 2010). This slice-based identification of fusulinids is very beneficial for applying automatic identification models, as deep learning models based on two-dimensional images have already been well developed. ...
... the fossils and thus serves as a feature extraction (Saha et al., 2016;Weeks et al., 2023). For shell-forming organisms like fusulinids, the topology of their shell, such as the number and size of chambers and the manner of spinning and coiling, is sufficient to provide a great deal of information for their identification and classification (Ross & Ross, 1991;Sheng et al., 1988;Vachard et al., 2010). Skeletonization can be seen as a feature extractor based on this prior knowledge to help the model learn the morphological features of the fossil. ...
Identification of fossil species is crucial to evolutionary studies. Recent advances from deep learning have shown promising prospects in fossil image identification. However, the quantity and quality of labeled fossil images are often limited due to fossil preservation, conditioned sampling, and expensive and inconsistent label annotation by domain experts, which pose great challenges to the training of deep learning based image classification models. To address these challenges, we follow the idea of the wisdom of crowds and propose a novel multiview ensemble framework, which collects multiple views of each fossil specimen image reflecting its different characteristics to train multiple base deep learning models and then makes final decisions via soft voting. We further develop OGS method that integrates original, gray, and skeleton views under this framework to demonstrate the effectiveness. Experimental results on the fusulinid fossil dataset over five deep learning based milestone models show that OGS using three base models consistently outperforms the baseline using a single base model, and the ablation study verifies the usefulness of each selected view. Besides, OGS obtains the superior or comparable performance compared to the method under well-known bagging framework. Moreover, as the available training data decreases, the proposed framework achieves more performance gains compared to the baseline. Furthermore, a consistency test with two human experts shows that OGS obtains the highest agreement with both the labels of dataset and the two experts. Notably, this methodology is designed for general fossil identification and it is expected to see applications on other fossil datasets. The results suggest the potential application when the quantity and quality of labeled data are particularly restricted, e.g., to identify rare fossil images.
... Such a morphologically simple foraminiferal community occurred up to the Middle Devonian, until the emergence of calcareous multilocular forms with true chambers, such as the bilocular flat and fan-shaped Semitextulariidae or planispiral and trochospiral Nanicellidae (Vachard et al., 1994;Vachard, 2016;Dubicka, 2017) during the so-called "Givetian Revolution" (Vachard et al., 2010). This radiation is claimed to be one of the most significant events in the entire history of the group and was most probably linked with the evolutionary development of the main modern foraminiferal clades (Pawlowski et al., 2003(Pawlowski et al., , 2013Dubicka and Gorzelak, 2017) and of some groups of foraminifera that died out completely (Dubicka et al., 2021a). ...
... This Devonian radiation might have been related to the emergence of foraminiferal symbiosis (kleptoplasty) with microalgae, which enabled foraminifera to remain photosynthetically active and largely benefit from the photosynthetic process (Dubicka et al., 2021b). Devonian multichambered foraminifera settled carbonate platforms that developed in shallow, warm, environments with high calcium carbonate production, including unique stromatoporoid-coral buildups (Racki and Soboń-Podgórska, 1993;Vachard et al., 2010). The strong connection between Foraminifera and their environment is confirmed by their joint disappearance during the Frasnian/Famennian biotic crisis (Ross and Ross, 1991;Vachard et al., 2010;Dubicka, 2017). ...
... Devonian multichambered foraminifera settled carbonate platforms that developed in shallow, warm, environments with high calcium carbonate production, including unique stromatoporoid-coral buildups (Racki and Soboń-Podgórska, 1993;Vachard et al., 2010). The strong connection between Foraminifera and their environment is confirmed by their joint disappearance during the Frasnian/Famennian biotic crisis (Ross and Ross, 1991;Vachard et al., 2010;Dubicka, 2017). Despite the fact that Eifelian-Givetian time was one of the most crucial periods for foraminiferal evolution (Pawlowski et al., 2003;Vachard et al., 2010), with the development of the first complex multichambered calcareous forms, Middle Devonian foraminiferal communities are still poorly known. ...
... 2009), the radiation of the calcareous foraminifers (Givetian revolution sensu Vachard et al., 2010), and the expansion and demise of gigantic stringocephalid brachiopods (Struve, 1992;Baranov et al., 2021). Of no less importance were significant extinction events in the mid-Givetian (Taghanic Crisis; House, 1996;Aboussalam, 2003;Aboussalam and Becker, 2011;Ernst, 2013) and at the Givetian/Frasnian boundary (Frasnes Event;House, 1985;Racki, 1993;Walliser, 1996;Becker et al., 2016Becker et al., , 2020. ...
... The microfossil record of the M0 and M1 sections is unique, insofar as it yielded an exceptionally well-preserved mid-Devonian foraminiferal community, rarely described from elsewhere, which provides a valuable insight into a significant evolutionary event, termed the foraminiferal "Givetian Revolution" (Vachard et al., 2010;Vachard, 2016). The mid-Devonian is regarded as one of the most important phases of the evolutionary history of foraminifers. ...
... The Mid-Devonian multichambered foraminifera settled in carbonate platforms that developed in shallow, warm, and high calcium carbonate precipitation environments, namely in stromatoporoid-coral build-ups, that constituted a unique ecosystem in geological history (Racki and Soboń-Podgórska, 1993;Vachard et al., 2010). The strong connection between the foraminifera and the environment they inhabited is confirmed by their joint disappearance during the Frasnian-Famennian biotic crisis (Ross and Ross, 1991;Vachard et al., 2010;Dubicka, 2017). ...
The middle and upper parts of the Skały Fm, Early to Middle Givetian in age, were investigated in four sections at Miłoszów Wood in the Łysogóry Region (northern region of the Holy Cross Mountains, central Poland). The dating is based on conodonts (Polygnathus timorensis Zone to the later part of the Polygnathus varcus/Polygnathus rhenanus Zone; early Polygnathus ansatus Zone cannot be excluded) and spores (Ex1–2 subzones) and, coupled with cartographic analysis and geophysical investigation, allows correlation within the strongly faulted succession. Significant lateral facies variations within the carbonate ramp depositional system in comparison with the better studied Grzegorzowice–Skały section, about 3 km distant, are documented, thanks to conodont-based correlation of both successions. Foraminifers, fungi, sponges, rugose and tabulate corals, medusozoans, microconchids and cornulitids, polychaetes (scolecodonts), molluscs (bivalves, rostroconchs, and gastropods), arthropods (trilobites and ostracods), bryozoans, hederelloids, ascodictyids, brachiopods, echinoderms (mostly crinoids, rare echinoids, holuthurians, and ophiocistoids), conodonts, fish, plants (prasinophytes, chlorophycophytes, and land plant spores), and acritarchs are present. Brachiopods are the most diverse phylum present (68 species), other richly represented groups are bryozoans and echinoderms; in contrast, cephalopods and trilobites are low in diversity and abundance. The muddy, middle to outer ramp biota (200 marine taxa, including 170 species of marine animals, 22 photoautotrophs, 6 forams) represents a mixture of allochthonous shallower-water communities (upper BA3), including storm- and possibly tsunami-affected coral mounds, and autochthonous deep-water soft-bottom brachiopod (e.g., Bifida–Echinocoelia) communities (BA 4–5). The richness and diversity of the Miłoszów biota is relatively high, comparable with other approximately coeval pre-Taghanic ecosystems during the Devonian climatic deterioration (cooling). Preliminary data indicate that in the Holy Cross Mountains,
no large-scale replacement of brachiopod (and probably many other benthic ones,
like crinoids) communities took place between the Early–Middle Givetian and the Early Frasnian, in contrast to the demise of the Hamilton/Upper Tully fauna in the Appalachian Basin. Such a similarity of pre- and post-Taghanic faunas does not exclude the occurrence of environmental perturbations and transient community turnovers, caused by immigrations during the Taghanic Biocrisis, but evidences the successful recovery of the indigenous biota.
... herein;Carixia Macfadyen, 1941;Warnan tellla Conil & Lys in Conil et al., 1977;Tolypam mina Rhumbler, 1895;?Palaeonubecularia Reitlinger, 1950;?Rectoglomus Malakhova, 1980;?Tansillites Nestell & Nestell, 2006. Range and distribution: Late Mississippian (Early Serpukhovian; Cózar et al. 2009;Vachard et al. 2010;Cózar et al. 2017;Vachard et al. 2018). Latest Permian, cosmopolitan. ...
... The genera of this lineage were successively considered as textulariates, with agglutinating walls, and consequently named Ammodiscus Reuss, 1862 and Glomospira; then, they were interpreted as miliolates with porcelaneous walls: Cornuspira and Hemigord iellina Vachard et al. 2010); then, they were regarded as dark microgranular-walled with Pseudoammodiscus and Pseudoglomo spira. Finally, nothing proves that these taxa have initially an agglutinated, microgranular or porcelaneous wall, because they are generally recrystallized. ...
... No other Palaeotextulariina are present in the studied area, while Tetrataxis and Climacammina remain numerous in Iran up to the end of the Permian (Gaillot & Vachard 2007;Vachard et al. 2010;Vachard & Le Coze 2021). ...
... Class FUSULINATA Gaillot and Vachard, 2007 The Fusulinata is the exclusive group of foraminifers, which is only composed of Palaeozoic representatives, and is completely absent in the Recent (Sen Gupta, 1999). This class is subdivided into two subclasses: Afusulinana Vachard et al., 2010, and Fusulinana Maslakova, 1990nom. correct. ...
... Earlandia Plummer, 1930 is one of the simplest Palaeozoic foraminifers. The First Appearance Datum (FAD) of this genus is Late Silurian (Vachard et al., 2010). Earlandia, as well as Polarisella Pinard, 1992, andEndoteba Vachard andRazgallah, 1988 are amongst the unique survivors from the PTB (Permian-Triassic Boundary) and continued to be present up to the Early Cretaceous (Gaillot and Vachard, 2007;Vachard et al., 2010;Vachard, 2018). ...
... The First Appearance Datum (FAD) of this genus is Late Silurian (Vachard et al., 2010). Earlandia, as well as Polarisella Pinard, 1992, andEndoteba Vachard andRazgallah, 1988 are amongst the unique survivors from the PTB (Permian-Triassic Boundary) and continued to be present up to the Early Cretaceous (Gaillot and Vachard, 2007;Vachard et al., 2010;Vachard, 2018). Chitralina? sp. is another representative of this family, in our material. ...
The taxonomic diversity of smaller foraminiferal faunas of the uppermost Carboniferous–lowermost Permian (upper Gzhelian–lower Asselian interval) has been accurately investigated in the Sanandaj-Sirjan Zone, Iran. They predominantly contain three foraminiferal classes: Fusulinata, Miliolata and Nodosariata, and six orders: Tuberitinida, Earlandiida, Archaediscida, Endothyrida, Cornuspirida, and Nodosariida. The presence of some remarkable taxa in palaeobiogeography such as Hemidiscus carnicus, that is reported for the first time in Iran, along with Rectogordius is noticeable. Furthermore, these smaller foraminifers are associated with significant fusulinid genera including Praepseudofusulina, “Nonpseudofusulina”, Pseudoschwagerina, and “Schellwienia?”, which indicated that during the latest Gzhelian–Asselian, the Sanandaj-Sirjan Zone was in the northern margin of the Palaeotethys, in a relatively low latitudinal position (ca. 30 ͦ S), with warm and humid conditions. This claim can also be evidenced by the presence of sandstones with high degree of chemical weathering, together with the limonite accompanied with a palaeosol in the Upper Carboniferous strata. The presence of a red earthy laterite with lenses of pisolitic bauxite along with a piece of fossil wood in the lowermost Permian beds, confirms the Peri-Tethyan position of the Sanandaj-Sirjan Zone during this period. This study also shows that the first appearance of Frondicularia in the Iranian material, that is the latest Gzhelian–early Asselian, is probably older than what is argued in materials from north-central Siberia (Late Permian and Triassic) and Germany (Sakmarian to Anisian, up to the Jurassic).
... The Spirillinida have a distinct 'monocrystalline' calcite (Dubicka, 2019) and the Carterinida make their shell by precipitating elliptical spicules increasing in size with every chamber added (Deutsch and Lipps, 1976). The consistency of these microstructural features as well as the overall morphology within orders throughout the fossil record (Vachard et al., 2010) suggests that the biomineralization mechanisms remained very similar after they first appeared. ...
... 3. A simplified foraminiferal evolutionary tree with emphasis on calcifying orders. The first fossil occurrences of calcifying members of these six orders are represented by circles (Loeblich and Tappan, 1964;Rettori et al., 1994;Gräfe, 2005;Vachard et al., 2010). The exact timing of the divergence is uncertain for most orders, and thus the dates are indicated tentatively here (Tappan and Loeblich, 1988;Holzmann and Pawlowski, 2017;Groussin et al., 2011;Rigaud et al., 2015). ...
Ongoing ocean acidification affects marine calcification, although the scope and magnitude of this impact is essentially unknown. Here, we investigate the evolutionary origin of shell building in foraminifera to understand the long-term interplay between ocean carbon chemistry and calcification. Our analysis of shell chemical composition reveals multiple, independent origins for foraminiferal calcification throughout the Phanerozoic. Differences between orders reflect the different physiological controls employed by foraminifera to take up Ca2+ and inorganic carbon from seawater for CaCO3 precipitation. With the long timespan involved, variability in seawater chemistry provided contrasting environments for calcification to arise, resulting in the diverse calcification strategies that exist today. This, in turn, explains the opposite responses of shell building to carbon perturbations. Our results call for adopting an evolutionary perspective when predicting the impact of perturbations on marine calcification and thereby, on the global carbon cycle.
... They showed that the facies of the Lower Permian succession at Dovžanova Soteska differs from that of the Carnic Alps (particularly equivalents of the Grenzland Formation). They divided the sedimentary succession between the underlying Schulterkofel Fm. and overlying Tarvis Breccia into the Dovžanova Soteska Formation, Born Formation and Rigelj Beds, which approximately correlate to the Grenzland Formation of the Carnic Alps (see summaries in Skaberne, 2009, andNovak et al., 2019). ...
... The accompanying genus Dutkevitchia, e.g., D. complicata (Schellwien), abundantly occurring in the Born Fm. is also the most common genus in the middle Asselian rocks in the Urals (Forke, 1995(Forke, , 2002. Species of the genus Sphaeroschwagerina and the Rugosofusulina latispiralis group are present in many sections in the southern to northern Urals and occur even in the arctic realm (Vachard et al., 2010). Typical faunistic elements for both regions are also Rugosochusenella paragregaria ascedens (Rauzer-Chernousova) and Pseudochusenella pseudopointeli (Rauzer-Chernousova) (Forke, 2002). ...
The Rigelj Formation is a new lithostratigraphic unit of the Lower Permian Rattendorf Group in the Karavanke Mountains.
The Formation is up to 105 m thick and mainly composed of siliciclastic and fossiliferous carbonate sediments that are
entirely of shallow-marine setting. Conglomerates are interpreted as shoreface deposits, sandstones as deposits of
the upper to lower shoreface, and fossiliferous siltstones as offshore deposits. Fossiliferous limestones were deposited
in a shallow, open-marine shelf environment of moderate to low energy (wackestone, floatstone) and strong water
turbulence (packstone, rudstone). The siliciclastic and carbonate lithotypes form some well-developed backstepping
cycles starting with conglomerates, overlain by sandstones, siltstones and fossiliferous limestones that formed in an open
shelf environment without siliciclastic influx. Similar sedimentary cycles are developed in the Grenzland Formation of the
Carnic Alps.
The fusulinid fauna indicates that the Rigelj Formation ranges in age from the late Asselian to the middle Sakmarian.
In the western Karavanke Mountains and near Trögern, the Lower Permian lithostratigraphic succession is very similar
to the succession in the Carnic Alps with Tarvis Breccia resting on the Trogkofel Limestone and the Goggau Limestone.
Unlike this, in the central part of the Karavanke Mountains (Dovžanova Soteska–Mt. Pleschiwetz/Plešivec area) the Rigelj
Formation is erosively overlain by the Tarvis Breccia. The stronger diversification of the sedimentary environments within
the Karavanke-Carnic Alps in the Lower Permian after the uniform sedimentation in the Upper Carboniferous can be
attributed to block-faulting.
... In the literature, the species S. binkhorsti has been alternately regarded as a rotaliid (e.g., Reuss, 1862;Hofker, 1927;Brown and Brönnimann, 1957;Reiss, 1958Reiss, , 1963McGowran, 1966), a robertinid (e.g., Loeblich and Tappan, 1964), a discorbid (Loeblich and Tappan, 1987), or as a fusulinid (e.g., Hofker, 1963), entailing doubts about its high-rank classification. Foraminifers with a composite agglutinated/microgranular and hyaline radial or fibrous calcitic wall were traditionally classified within Fusulinana or Nodosariata (Loeblich and Tappan, 1987;Vachard et al., 2010). However, following the Permo-Triassic mass extinction, foraminifers displaying such composite walls are extremely rare and systematic classifications are more ambiguous. ...
... Several Robertinids display an umbilical notch (= diaphragm in Höglund, 1947, see, e.g., modern Ceratocancris or Robertina) that is related to an internal wall infolding that fully or partially subdivides chambers. Folia-like structures, usually named umbilical flaps, lobes, or tips (see diagnoses in Loeblich and Tappan, 1987) and structurally comparable foraminifers (e.g., Tetrataxis, Mohlerina, Altamirella) are also commonly found in attached position (Cossey and Mundy, 1990;Vachard et al., 2010;Schlagintweit, 2012;Schlagintweit et al., 2015). Observed attached specimens of S. binkhorsti are mostly juveniles (nepionts). ...
The benthic foraminifer Rosalina binkhorsti Reuss, 1862 is cosmopolitan in Late Cretaceous to early Paleogene shallow-water seas. It possesses a distinctive composite wall made of a continuous, agglutinated layer discontinuously covered by secondary hyaline outer deposits. Its taxonomic position, phylogeny, morphology, wall structure and composition have been debated for a long time. Based on an abundant, well-preserved material from the Danian of the Kambühel Formation in the Northern Calcareous Alps, Austria, we identify elements in the here emended species Stomatorbina binkhorsti, which support a strong affinity to the order Textulariida, within the genus Stomatorbina Dorreen, 1948. Usually regarded as free (non-fixing), S. binkhorsti is here illustrated attached to small bioclasts in high-energy carbonatic settings. The attached specimens are juvenile forms with a wall covered by massive hyaline deposits. This observation suggests that secondary lamellar parts added to the wall may have served for stabilization or fixation to the substrate.
... Эти фораминиферы предпочитали умеренные гидродинамические условия и обилие питательных веществ в бассейне. Т. К. Замилацкая [1972] предполагала нахождение их в более пресной воде, морфология раковин позволяла приподниматься над дном и перемещаться по водорослям, криноидеям и мшанкам [Королюк, Раузер-Черноусова, 1977;Pille, 2008;Vachard et al., 2010]. Представители Lasiodiscidae имеют широкое фациальное распространение, обладают легкой плоской камерой с выростами на верхней и нижней поверхностях. ...
Изучены ассоциации фораминифер из нижнепермских отложений рифовых массивов Торатау, Куштау и Юрактау. Определен их таксономический состав с учетом данных, ранее опубликованных предшествующими исследователями. Уникальной особенностью сообществ фораминифер (фузулинид и мелких фораминифер) Башкирских шиханов является неповторимый смешанный состав комплексов. В сообществах фораминифер присутствуют таксоны как широко латерально распространенные, так и эндемики; как виды северных акваторий, так и виды области Палеотетис. Таксономический состав фораминифер включает свыше 50 родов и более 180 видов. Приведена краткая характеристика стратиграфической приуроченности определенных родов и видов фораминифер в ассельско-артинских отложениях, слагающих рифовые массивы, а также основные сведения об условиях и образе жизни фораминифер. The foraminiferal assemblages from the Lower Permian deposits of the Toratau, Kushtau, and Yuraktau reef massifs were studied. Their taxonomic composition was determined taking into account the data published by previous researchers. A main feature of the foraminifera’s assemblages (fusulinids and small foraminifers) of Bashkir shikhans is the unique mixed composition of associations. Foraminiferal assemblages contain taxa both widely laterally distributed and endemic, both species of northern water areas and species of the Paleotethys area. The taxonomic composition of foraminifera is rich and varied, including more than 50 genera and more than 180 species. A brief description of the stratigraphic confinement of certain genera and species of foraminifers in the Asselian-Artinskian deposits that make up reef massifs is given, as well as basic information about the conditions and lifestyle of foraminifers.
... The higher rank classification is adopted from Vachard et al. (2010Vachard et al. ( , 2013. ...
The benthic foraminifera Murgeina apula (Luperto Sinni), originally described as Nummofallotia apula from the Upper Cretaceous of southern Italy, represents a common taxon in the middle-upper Cenomanian Sarvak Formation of southwestern Iran as well as the Campanian-early Maastrichtian of Croatia. The specific identity of the Iranian and Italian as well as Croatian specimens is confirmed by equivalent biometric data and identical test struc-ture. The agglutinated wall (inner part) of M. apula excludes its assignment to the porcelaneous Nummofallotia Barri-er & Neumann. Nummofallotia is currently placed in the family Meandropsinidae Henson, while for Murgeina with its bilamellar wall inclusion in the Ventrolaminidae Weynschenk is favoured. Nummofallotia cenomana Luperto Sinnni, described from the Cenomanian of southern Italy and lacking any hard facts for species discrimination (e.g., dimensions, inner structure) is herein considered tentatively a junior synonym of Murgeina apula requiring re-examination of the type-material. M. apula represents another survivor of the Cenomanian–Turonian boundary ex-tinction event and, with a long stratigraphic range from the middle Cenomanian to the (early) Maastrichtian, is similar to another Methusalem taxon such as Moncharmontia apenninica (De Castro) with a comparable range.
... Cavalier-Smith, 2003 Class Fusulinata Vachard, 2007 emend. Vachard, 2016 Subclass Afusulinana Vachard, Pille and Gaillot, 2010Order Parathuramminida Mikhalevich, 1980emend. Vachard, 2016 Superfamily Parathuramminoidea Fursenko in Rauzer-Chernousova and Fursenko, 1959 emend. ...
... In terms of paleobiogeography, there have been many recent developments and improved applications of LBF. As detailed in Papazzoni et al. (2017), these include advances in paleoenvironmental analyses, greater understanding of depositional systems, enhanced resolution of shallow-water biostratigraphy, and responses to climate change (e. g., Vachard, 2016;Vachard et al., 2010). In particular, the study of the 'nummulite banks' from the Jurassic-Paleogene greenhouse interval has brought about detailed knowledge about syndepositional cementation, as well as bank geometry and various stabilization processes (Guido et al., 2011). ...
... Remarks: The composition of this family is relatively 75 stable in the literature (compare Loeblich and Tappan, 1987;Vdovenko et al., 1993;Krainer et al., 2019). As proposed by Vachard et al. (2010) and confirmed by Cózar et al. (2010Cózar et al. ( , 2016 and Vachard et al. (2018), this family appears in the early Serpukhovian. Occurrence: Late Mississippian (early Serpukhovian)latest Permian, cosmopolitan. ...
Pennsylvanian stratigraphy, sedimentology, micropaleontology in southern New Mexico USA
... Remarks: The composition of this family is relatively 75 stable in the literature (compare Loeblich and Tappan, 1987;Vdovenko et al., 1993;Krainer et al., 2019). As proposed by Vachard et al. (2010) and confirmed by Cózar et al. (2010Cózar et al. ( , 2016 and Vachard et al. (2018), this family appears in the early Serpukhovian. Occurrence: Late Mississippian (early Serpukhovian)latest Permian, cosmopolitan. ...
The Pennsylvanian section at Bishop Cap in Doña Ana County, New Mexico, is 256 m thick, and we assign it to the La Tuna and Berino members of the Horquilla Formation. This limestone-dominated section consists mostly of wackestone, lesser amounts of packstone and minor amounts of grainstone and floatstone. The Horquilla Formation strata at Bishop Cap were deposited in a shallow but subtidal, warm-temperate, open marine shelf paleoenvironment of normal salinity. Foraminiferal (principally fusulinid) and conodont biostratigraphy indicates that the Bishop Cap Pennsylvanian strata are of Morrowan-late Desmoinesian (Bashkirian-Moscovian) age. We assign Pennsylvanian strata across much of southernmost New Mexico and into part of West Texas to the Horquilla Formation, a 300-1000 m thick succession of limestone and calcareous shale that generally lacks coarse-grained siliciclastic strata and weathers to an apparently cyclical step-and-ledge topography. We review briefly Horquilla Formation stratigraphic sections in southern New Mexico (Central Peloncillo Mountains, Animas Mountains, Little Hatchet Mountains, Big Hatchet Mountains, Klondike Hills, Tres Hermanas Mountains, Cooke’s Range, Silver City area and Robledo Mountains) and in West Texas (Franklin and Hueco mountains). These strata and other Horquilla strata in southeastern Arizona and northern Mexico (Sonora-Chihuahua), as well as Hueco Group strata in southern New Mexico-West Texas, are the deposits of platform and shelf carbonates that were relatively isolated from local tectonism and siliciclastic influx. They identify a long, currently west-east-oriented seaway we term the Horquilla seaway that extended from the Pedregosa basin of southeastern Arizona to the western part of the Delaware basin of West Texas. The Horquilla seaway was a Pennsylvanian-early Permian epicontinental seaway along the western periphery of tropical Pangea.
... Most foraminifera and microproblematica are described and discussed below (see Figures 8-9). The classification of foraminifers is based on Nejad et al. (2015), Pawlowski et al. (2013), Vachard et al. (2010), Gaillot & Vachard (2007), Hance et al. (2011) and Tappan and Loeblich (1988). The following are the abbreviations: N = Nammal section; Z = Zaluch section; n = Number of specimens; A = Amb Formation; W = Wargal Limestone; C = Chhidru Formation; M = Mianwali Formation. ...
A newly obtained foraminiferal assemblage from the Guadalupian−Lopingian, and Induan of the Western Salt Range (Pakistan) comprises 47 species (including 7 species of fusulinoideans) of 24 genera and 71 species (including 9 species of fusulinoideans) of 41 genera, in Nammal and Zaluch sections, respectively. Our results show that only 4 species went extinct during the Guadalupian−Lopingian mass extinction (GLME), suggesting the GLME was minor for smaller foraminifers in the Salt Range. Most species went extinct during the Permian-Triassic mass extinction (PTME), except the two survivor genera, Nodosinelloides and Planiinvoluta. During the end-Permian mass extinction, majorities of the species became extinct in lower part of Chhidru Formation, beacuse they are not tolerant to the terigenious-clastic input in the upper part of Chhidru Formation. The extinction process of foraminifers in the Nammal and Zaluch sections has been documented for the first time. Five foraminiferal assemblages are established in the shallow marine shelf deposits of Western Salt Range, i.e., Wordian Geinitzina araxensis assemblage in tide-influenced subaqueous delta to middle shelf environment, Capitanian Baisalina pulchra assemblage and Wuchiapingian Codonofusiella schubertellinoides assemblage in inner-outer shelf carbonate deposits, Changhsingian Colaniella pseudolepida assemblage and Induan Nodosinelloides-Planiinvoluta assemblage in mixed siliciclastic–carbonate shelf setting. The Baisalina pulchra and Codonofusiella schubertellinoides assemblages have wide geographic distribution and have been found in Transcaucasus, China, Turkey, Crimea and Oman. The other three assemblages (i.e., Geinitzina araxensis, Colaniella pseudolepida, and Nodosinelloides-Planiinvoluta assemblages) found in this study are likely local/regional assemblages. The foraminifers were observed with the standard microscopic system Leica-DM500. A total of 681 specimens of foraminifers are reported in the Zaluch Group and Mianwali Formation of Nammal and Zaluch sections. Five hundred ninety-nine smaller foraminifers specimens were recovered. Among the smaller foraminifera, Nodosinelloides, Pachyphloia, Geinitzina, Colaniella, Hemigordius, Tuberitina, and Langella are the most dominant genera. Larger foraminifera genera include Nankinella, Codonofusiella, Reichelina, Necdetina and Pisolina, represented by 82 specimens. A total of 3 classes (e.g., Nodosariata, Fusulinata, and Tubothalamea) and seven orders (i.e., Miliolida, Spirillinida, Lagenida, Parathuramminida, Endothyrida, Fusulinida, and Earlandiida) are identified in the current study. Among them, Lagenida becomes the most dominant by diversity and abundance. Shannon diversity and other indices rise progressively from Wordian to Changhsingian in the shallow marine sediments before dropping to zero in the Early Triassic mixed siliciclastic–carbonate shelf deposits.
... On the other hand, the presence of widespread and abundant foraminifers can be indicative of tropical and subtropical palaeolatitudinal belts (Arefifard, 2017;Davydov, 2014;Vachard, Pille, & Gaillot, 2010). ...
The Mississippian successions of the Alborz tectonostratigraphic zone have been studied in several sections (Dozdehban, Naserabad, Shahmirzad, and Mighan) extending from north to southeast. The sedimentological data indicate three main facies associations (FA): (FA1) a basin to distal outer ramp of low-energy, low-oxygen environment with low bioturbation and less developed in situ fossils; (FA2) a middle ramp facies accompanied by storm-induced sediments (tempestites), echinoderm-dominated mud mounds, and high fragmentation of skeletal components; and (FA3) an inner ramp facies, represented by sand shoal, and lagoonal/back-barrier, mainly characterized by the dominance of oolitic, bioclast, and intraclast grainstones. The sedimentary features imply the formation of the succession on a broad flat-topped, high-to-moderate-energy shelfal carbonate ramp which had been open to the N/NE, the downslope direction, as revealed by local palaeoenvironmental reconstructions. Analysis of several proxies indicates a subtropical palaeoclimate evidenced by (a) widespread tempestite facies and occurrence of storm-depositional processes, (b) diverse and abundant pellet-forming thalassinoideans and burrowing echinoids trace fossil assemblages, (c) geochemical proxy indicating a palaeotemperature of 23°–25°, and (d) a rich subtropical heterozoan fossil association. The data provided here imply the palaeolatitudinal position of the Alborz Mississippian ramp is 30–40°S along the southern margin of the Palaeotethys.
... Semitextulariids were globally distributed on Devonian inner shelves, in shallow marine, well-illuminated habitats such as tropical reefs and lagoons (see Table S1). They, as well as other well-known Devonian groups such as Nanicellidae and Eonodosariidae, died out following the Kellwasser event of the Frasnian-Famennian crisis (Vachard et al., 2010) that triggered the rapid collapse of the prolific stromatoporoid coral reef ecosystems. In principle, the origin of Semitextularia occurred at the beginning of the Middle Devonian foraminiferal radiation, which is the so-called "Givetian revolution" (Vachard et al., 2014) and is considered the most important Paleozoic evolutionary event for these protists. ...
Photosynthetically active foraminifera are prolific carbonate producers in warm, sunlit, surface waters of the oceans. Foraminifera have repeatedly developed mixotrophic strategies (i.e., the ability of an organism or holobiont to both feed and photosynthesize) by facultative or obligate endosymbiosis with microalgae or by sequestering plastids (kleptoplasts) of ingested algae. Mixotrophy provides access to essential nutrients (e.g., N, P) through feeding while providing carbohydrates and lipids produced through photosynthesis, resulting in substantial energetic advantage in warm, sunlit environments where food and dissolved nutrients are scarce. Our morphological as well as stable carbon isotope data provide, as of now, the earliest (Mid-Devonian) evidence for photosynthetic activity in the first advanced, multichambered, calcareous foraminifera, Semitextularia, from the tropical shelf of the Laurussia paleocontinent. This adaptation likely influenced the evolutionary radiation of calcareous Foraminifera in the Devonian (“Givetian revolution”), one of the most important evolutionary events in foraminiferal history, that coincided with the worldwide development of diverse calcifying marine communities inhabiting shelf environments linked with Devonian stromatoporoid coral reefs.
... Among many taxonomic works in the history of fusuline study, Thompson (1948) provided the first comprehensive "textbook" to compile and describe fusuline genera established by that time, in which fusulines were allocated to a family rank and a total of 49 genera were collected. With regard to the higher taxonomy of fusulines, with the rising of the taxonomic rank of Foraminifera to the rank of phylum or subphylum, that of fusuline foraminifers has also been upgraded from a traditional superfamily category to an order or superorder rank (Rauzer-Chernousova and Fursenko, 1959;Thompson, 1964;Rozovskaya, 1975;Loeblich and Tappan, 1987;Sheng et al., 1988;Rauzer-Chernousova et al., 1996;Gaillot and Vachard, 2007;Vachard et al., 2010Vachard et al., , 2013Vachard, 2016;Vachard in Krainer et al., 2019). ...
This paper proposes a synthesis of the taxonomy, phylogeny, palaeogeographic distribution, regional biostratigraphy, and palaeobiogeographic faunal development of Carboniferous fusuline foraminifers. They appeared in the latest Tournaisian and comprised a small-sized, morphologically conservative taxonomic group during the Mississippian. Fusulines became larger and prevailed in Pennsylvanian foraminiferal assemblages. Carboniferous fusulines consist of Ozawainellidae, Staffellidae, Schubertellidae, Fusulinidae, and Schwagerinidae, in which 95 genera are considered as valid taxonomically. Upsizing their shells throughout the Pennsylvanian is likely related to symbiosis with photosynthetic microorganisms, which was accelerated by the acquisition of a keriothecal wall in Late Pennsylvanian schwagerinids. Regional fusuline succession data from 40 provinces provide a refined biostratigraphy, enabling zonation and correlation with substage- or higher-resolution precision in the Pennsylvanian. Their spatio-temporal faunal characteristics show that fusulines had a cosmopolitan palaeobiogeographic signature in Mississippian time, suggesting unrestricted faunal exchange through the palaeoequatorial Rheic Ocean. After the formation of Pangea, Pennsylvanian fusulines started to show provincialism, and their distributions defined the Ural-Arctic Region in the Boreal Realm, Palaeotethys, Panthalassa, and North American Craton regions in the Palaeoequatorial Realm, and Western Gondwana and Eastern Peri-Gondwana regions in the Gondwana Realm. The Western Palaeotethys and East European Platform Subregions maintained higher generic diversity throughout the Pennsylvanian.
... Moreover, Neothailandina has partitions of the chambers, which correspond to transverse septula (Fig. 2.13, 2.15, 2.18). The supposed original aragonitic test mineralogy in Thailandinidae suggests a close phylogenetic relationship to the existing fusuline family Staffellidae (Vachard et al., 2010), but the development of parachomata and transverse septula is disparate from that family. In view of the higher taxonomy of the fusulines, therefore, Thailandina and Neothailandina should be considered as forming a distinct family that constitutes a small collateral clade of Staffellidae in the superfamily Staffelloidea of the order Fusulinida. ...
The fusuline genera Thailandina Toriyama and Kanmera, 1968 and Neothailandina Toriyama and Kanmera, 1968 were established by Toriyama and Kanmera (1968) based on material from the Khao Phlong Phrab section of the Permian Rat Buri Limestone in central Thailand that is currently assigned to the Khao Khad Formation of the Saraburi Group (Ueno and Charoentitirat, 2011). These fusuline genera are peculiar in having parachomata and replaced tests by secondary mineralization. Moreover, Neothailandina was described to have a test with transverse septula, considered to be characteristic for Neoschwagerinidae. Based on these remarkable test features, Toriyama and Kanmera (1968) newly introduced the subfamily Thailandininae to accommodate these two new genera and assigned it to the Neoschwagerinidae, despite the lack of septula in Thailandina . Later, Kobayashi et al. (2010) argued that Thailandina and Neothailandina are just a mixed grouping of several known genera of schwagerinids, verbeekinids, and neoschwagerinids that are too altered by recrystallization to be recognizable, and rejected the taxonomic validity of these two genera as well as Thailandininae.
The Khao Phlong Phrab section represents one of the standard late Cisuralian−Guadalupian (late early−middle Permian) fusuline successions in the eastern Paleotethys (Zhang and Wang, 2018) and contains not only Thailandina and Neothailandina but also abundant schwagerinid, verbeekinid, and neoschwagerinid fusulines (Toriyama, 1975; Fig. 1). I investigated the original specimens described by Toriyama and Kanmera (1968) and Toriyama (1975) from the section that are housed in the Department of Earth and Planetary Sciences of Kyushu University, Japan. I found that most of the grounds for Kobayashi et al.'s (2010) arguments to regard the thailandinin genera as taxonomically invalid are not supported by observations on these specimens as explained in the account that follows. In this taxonomic note, I propose that Thailandina and Neothailandina , and their family Thailandinidae, should be retained as valid taxonomic groups.
... genus Earlandia, well known from the Carboniferous and characterized by rectilinear, bilocular tests with microgranular walls, is also present in the uppermost Permian (Changhsingian) deposits of the Southern Biofacies Belt in Turkey (Altıner et al., 2000), as well as in several localities of the Middle East (Gaillot and Vachard, 2007). It is a Permian-Triassic boundary survivor Groves et al., , 2007Vachard et al., 2010;Krainer and Vachard, 2011), also appearing in the lowermost Triassic deposits of the Great Bank of Guizhou. Recently, Nestell et al. (2015) opposed the use of Earlandia in the Early Triassic and suggested classifying all Earlandia-like forms within the agglutinated genus Hyperammina. ...
Foraminifera are important components of tropical marine benthic ecosystems and their recovery pattern from the end-Permian mass extinction can yield insights into the Mesozoic history of this group. Here we report the calcareous and agglutinated foraminifera recovered from five measured stratigraphic sections on the Great Bank of Guizhou, an uppermost Permian to Upper Triassic isolated carbonate platform in the Nanpanjiang Basin, south China. The material contains >100 Triassic species, including three that are newly described ( Arenovidalina weii n. sp., Meandrospira ? enosi n. sp., and Spinoendotebanella lehrmanni n. gen., n. sp.), ranging from Griesbachian (Induan) to Cordevolian (Carnian) age. The species belong to the classes Miliolata, Textulariata, Fusulinata, Nodosariata, and to an unknown class housing all aragonitic forms of the orders Involutinida and Robertinida. Based on previously established conodont zones and carbon isotope chemostratigraphy, the Griesbachian (early Induan) through Illyrian (late Anisian) interval has been subdivided into 12 foraminiferal zones and two unnamed intervals devoid of foraminifera. Following the extinction at the Permian-Triassic boundary, habitable ecological niches of Griesbachian age were invaded by disaster taxa that subsequently became extinct during the Dienerian (late Induan) and left no younger descendants. The disaster taxa were replaced by Lazarus taxa with Permian origins, which were then decimated by the Smithian-Spathian (mid-Olenekian) boundary crisis. The tempo of recovery appears to have been modulated by environmental changes during the Griesbachian through Smithian that involved both climate change and expansion of anoxic ocean bottom waters. Uninterrupted and lasting recovery of benthic foraminifera did not begin until the Spathian.
UUID: http://zoobank.org/2a6e9061-b163-402a-9098-8765a80576b3
... In O1, the occurrence of the stenohaline fauna, like brachiopods and echinoderms, corroborated the open marine environment. The normal salinity, prevalence of well-oxygenated waters and high supply of nutrients are among the favourable ecological conditions for these organisms (Pomar 2001;Vachard et al. 2010;Sardar Abadi et al. 2015). Moreover, the increase in the ratio of echinoderms and benthic foraminifera confirmed the fair circulation in the environment (Flügel 2010). ...
Zoophycos is widely distributed in the marine strata of the Middle Permian Ruteh For- mation in the Alborz Mountain, Iran. The investigation of the Zoophycos , along with environmental variables is a useful tool for interpretation of the palaeoenvironmental and sequence stratigraphy anal- ysis. The petrographic observations led to the identification of ten facies in four facies belts including tidal flat, lagoon, shoal, and open marine, deposited on a homoclinal ramp. Moreover, two third- order depositional sequences were recognized in response to the sea- level fluctuations within the Ruteh For - mation. Detailed studies of the sequence stratigraphy revealed a relationship between the occurrences of Zoophycos and changes in the hydrodynamic condition in the basin. It appears that Zoophycos has been influenced by the ecological and palaeoenvironmental parameters, such as sedimentation rate, nutrient supply, oxygen, wave base, and substrate in the shallow to deep environments. Based on the sedimentological and ichnological analysis, Zoophycos has been formed with various dimensions, morphology, fillings, and densities together with rising and falling in the sea-level. The trace- maker has followed an opportunistic strategy in the unstable conditions of shallow environments, whereas it has chosen a k-selected strategy in more stable deep environments. Additionally, variability in Zoophycos illustrates, how the trace- maker adopted itself with environmental sequences. This reason, owing to optimal conditions, has caused that the abundance of Zoophycos was high in the Transgres- sive System Tracts (TST). Evidence shows that the response of Zoophycos to the ecological properties of the environment usually has deposit- feeder and chemosymbiosis behaviours.
... Carboniferous subclasses. Afusulinana Vachard, Pille and Gaillot, 2010;Fusulinana Maslakova, 1990emend. Vachard, 2016 Remarks. ...
The Carboniferous foraminifera are composed of representatives of three classes: Fusulinata, Miliolata and Nodosariata. Despite ample literature on Paleozoic Allogromiata and Textulariata, the real presence of these classes remains questionable during the Carboniferous and are thus excluded herein. The main biostratigraphical markers belong to the superfamilies Archaediscoidea, Lasiodiscoidea and Bradyinoidea; even if many genera among the archaediscoids have still a controversial nomenclature, as well as some lasiodiscids and bradyinoids. Secondary biostratigraphical markers belong to Lituotubelloidea (= “Tournayelloidea” of the authors), Endothyroidea and Loeblichioidea (these latter giving rise to the primitive Fusulinida). The Miliolata appear at the Visean/Serpukhovian boundary interval. The typical Carboniferous miliolates are primitive nubeculariins and cornuspirinins. Tubiphytids might be miliolate and cyanobacterium consortia, derived from the nubeculariin Palaeonubecularia . The most primitive nodosariates (syzraniids) appear in the Moscovian; and gave rise, in the latest Carboniferous, to Protonodosaria , Nodosinelloides , and possibly Polarisella , Paravervilleina and oldest Geinitzinoidea. Palaeobiological data are mainly provided by the genera Bradyina, Tetrataxis and Climacammina . Palaeobiogeographical distributions of Pojarkovella , Janischewskina, Eosigmoilina , Brenckleina , Spireitlina , Hemigordius and Syzrania testify to the successive foraminiferal migrations between Palaeotethys, Ural and Panthalassan oceans. Two taxa are created: Eoparastaffellidae and Banffellinae.
... In shallow-waters, during the Kasimovian-Gzhelian, the persistence of stenohaline organisms such as bryozoans, brachiopods and foraminifera, tends to reflect normal salinity conditions (Oertli 1964;Flügel 2010). However, during the Kasimovian, the abundance of staffellids (Fig. 13), commonly considered to have wider environmental tolerance (Vachard et al. 2010), associated to sporadic schwagerinids documents possibly a time interval with slightly higher salinity, related to a restricted environment and/or semi-restricted conditions, likely controlled by sea-level fluctuations. Conversely, the Late Kasimovian-Gzhelian deep-water rocks are composed of microbioclastic peloidal packstone and grainstone, in situ fine-grained burrowed wackestone and packstone deposited in a low energy depositional environment, marls and thin allochthonous bioclastic packstone, grainstone, floatstone and rudstone layers (calciturbidites). ...
The Pennsylvanian is characterized by intense paleoenvironmental changes related to glacio-eustatic sea-level fluctuations and major tectonic events, which affected the evolution of biocommunities. Most known Pennsylvanian tropical reefs and mounds are predominantly composed of calcareous algae (e.g. phylloid algae, Archaeolithophyllum), calcareous sponges, fenestrate bryozoans, Tubiphytes, and microbialites. However, in Houchang (southern China), the Late Pennsylvanian carbonate platform records a large coral reef lacking any analogs in age (Gzhelian), size (80-100 m thick) and composition (high biodiversity). The large coral reef developed at the border of the Luodian intraplatform basin. The intraplatform basin is characterized by the deposition of green algal grainstone, coated grain grainstone and bioclastic packstone, grainstone, floatstone and rudstone in shallow-waters. In the deep-water shelf, lithofacies are composed of burrowed bioclastic wackestone, microbioclastic peloidal packstone, grainstone, and fine-grained burrowed wackestone and packstone. In this context, the coral reef developed on a deep-shelf margin, in a moderate to low energy depositional environment, below the FWWB.
The scarcity of Pennsylvanian coral reefs suggests global unfavorable conditions, which can be attributed to a complex pattern of several environmental factors, including seawater chemistry (aragonite seas), paleoclimatic cooling related to continental glaciation, and the biological competition with the more opportunistic and adaptive phylloid algal community that occupied similar platform margin paleoenvironments. The existence of the large Bianping coral reef in southern China, as well as a few additional examples of Pennsylvanian coralliferous bioconstructions, provides evidence that coral communities were able to endure the Late Paleozoic fluctuating paleoenvironmental conditions in specific settings. One of such settings appears to have been the deep shelf margin, where low light levels decreased competition with the phylloid algal community.
... For example, Amphistegina has tiny cups on the interior surface of its test that contain the symbionts (Lee 2006). The first foraminifera that likely had photosymbionts were the mid-Paleozoic fusulinids (Fig. 3.9); they dominated carbonate banks and platforms until the end of that era (Vachard et al. 2010). Evidence for photosymbiosis in these foraminifera includes their relatively large size (for foraminifera), complex internal morphology, ecologic and geographic distributions in tropical environments on reefs and carbonate banks, and overall similarity to modern symbiont-bearing alveolinellids (Lipps and Severin 1986;Severin and Lipps 1989;Lee 2006;Groves et al. 2012). ...
Photosymbiosis has been an important process in the evolution of ancient reef systems and in reef success today. Modern reefs and many of those in the geologic past inhabited nutrient-depleted settings. The complete collapse of some ancient reef ecosystems may be attributed to the breakdown of the ecologic and physiologic relationships between symbiont and host. Many algal groups developed symbioses with calcifying metazoans and protists and live with them, but the most common of these today are dinoflagellates in the genus Symbiodinium , sometimes called zooxanthellae. This photosymbiotic relationship conferred important metabolic advantages to both partners, allowing exploitation of tropical, shallow-water oligotrophic settings. In addition to improved metabolism, a by-product was rapid calcification which increased the growth of reefs and provided advantages to the hosts through larger and stronger skeletal support. Strong evolutionary pressures exerted by the symbiont-host relationship created bonds and favored longevity and adaptive novelty. Photosynthesis accounts for the remarkable reef growth and carbonate sedimentation in the tropics. Photosymbiosis gave reef organisms an adaptive edge to develop new life strategies that could not be developed by organisms which did not foster this relationship. Many living calcified organisms harbor many different photosymbionts and likely a variety of ancient calcified organisms did too (foraminifera, calcified sponges, corals, brachiopods and bivalve mollusks). Symbiodinium now a dominant symbiont apparently appeared in the Eocene and so was probably not utilized by earlier reef organisms, although the fossil record of dinoflagellates most closely related to Symbiodinium extends back to the Triassic. Today Symbiodinium inhabits a wide variety of unrelated host organisms from protists to mollusks. While the identity of more ancient photosymbionts is unclear, indirect evidence suggests photosymbiotic ecosystems existed as far back as the Proterozoic and possibly even earlier.
Assessment of photosymbiosis in ancient reef ecosystems requires recognition of specific characteristics possessed by the calcifying reef organisms. Since the symbionts do not fossilize, the presence of photosymbiosis in fossils is a working hypothesis based on modern symbioses and best confirmed by a set of specific morphologic adaptations and isotopic analyses. Important among these is the thin tissue syndrome—the modification to achieve the “solar panel” effect. Large size and unusual or complex morphology also may indicate photosymbiosis. In the case of colonial organisms such as corals, high levels of corallite integration, where corallites are modified for increasing cooperation, may assist because most colonial photosymbiotic organisms today, such as corals, are exclusively photosymbiotic.
Analysis of organisms and reefs through geologic time permits assessment of the strength of photosymbiosis as a driving force. Reef ecosystems revealing the strongest assessment for photosymbiosis are those of the mid-Paleozoic (Late Ordovician to Devonian), late Paleozoic, early Mesozoic and Neogene. The Early Cambrian archaeocyathan (sponge) reefs indicate photosymbiosis but perhaps with different ancient symbionts such as cyanobacteria, also contained in some modern sponges. Reef ecosystems of the late Paleozoic and early part of the Jurassic indicate the presence of some photosymbiosis. The extinction of many photosymbiotic reef ecosystems during critical intervals of mass extinctions may have been driven by the failure of the symbiosis or demise of the symbionts. Reef gaps in the geologic record reflect the absence of photosymbiosis. The present-day reef crisis involves disturbance of photosymbiosis, and study of future reef declines will benefit by application of data from the fossil record.
... With increasing water depth, the percentage of these taxa falls, whilst the small lagenids become dominant. This pattern is also reported from other regions such as Iran, as well as other sections in South China (Insalaco et al., 2006;Gu et al., 2007;Vachard et al., 2010;Zhang and Gu, 2015). The lagenids are dominated by those with a bloomed in slope settings, and this genus persists into the Triassic. ...
The Permian-Triassic mass extinction, the greatest biotic crisis in Earth history, triggered the complete replacement of ecosystems with the 5–10% surviving species giving rise to the Mesozoic fauna. Despite a long history of systematic studies on Permian-Triassic foraminifera, there have been few investigations into spatial and temporal patterns of survivorship and evolution during this critical interval. We interrogate a high-resolution data set comprising newly obtained and previously published foraminiferal data (including 13,422 specimens in 173 species in 62 genera) from seven well-studied Permian-Triassic successions that record a transect of platform to basin facies in South China. Shallow-water settings seen at the Cili and Dajiang sections suffered a single-pulse, sudden extinction with high extinction rates at the end of the Palaeofusulina sinensis Zone; deeper-water and slope environments seen at Liangfengya and Meishan experienced a two-pulse extinction in the Clarkina yini and Isarcicella staeschei zones; basinal settings, seen at Shangsi, Gujiao and Sidazhai, record a single, less devastating extinction pulse in and slightly above the C. yini Zone. In the Late Permian, foraminiferal diversity was greatest on the shallow platforms, where 76.4% of species recorded in our study lived. The two pulses of the Permian-Triassic extinction prompted this foraminiferal diversity hotspot to move to deeper slope settings (comprising 75.6% of contemporary species) and finally basinal settings (comprising 88.8% of species). We propose that foraminifera migrated to deeper water to avoid overheating and toxicity in shallow waters that were driven by the emplacement of the Siberian Traps and coeval volcanic activities around the Paleotethys Ocean. This study provides a methodological framework for investigating survival mechanisms for foraminifers and other taxonomic groups during mass extinction events.
... All of the species of the fusulinacean families Neoschwagerinidae and Verbeekinidae became extinct, removing all of the large and morphologically complex species that were specialised for photosymbiosis in warm, shallow marine waters (Kasuy et al. 2012;Kobayashi 2012;Zhang and Payne 2012;Groves and Wang 2013). Only the smaller and morphologically simpler species of foraminifera survived (Vachard et al. 2010). ...
The modern loss of species diversity has been labelled the ‘sixth extinction’ subsequent to the five major mass extinctions widely recognised in the Phanerozoic geologic record – the end-Ordovician (443.8 Ma), the Late Devonian (372.2 Ma), end-Permian (251.9 Ma), end-Triassic (201.4 Ma) and end-Cretaceous (66 Ma) events. Rankings in terms of numbers of genera suffering extinction, and especially in terms of ecological impact, however, put the end-Guadalupian (end-Capitanian) (259.8 Ma) extinction event in the same category with the other major mass extinctions. Thus, there were apparently six major Phanerozoic mass extinctions, and the current loss of species should perhaps be called the ‘seventh extinction’.
... Several authors (e.g., Groves, Altiner, and Nestell) consider these forms as belonging to Pseudoammodiscus. In contrast, Gaillot & Vachard (2007), Vachard et al. (2010), and Vachard (2016a, b) consider that the microgranular Pseudoammodiscus disappear in the Serpukhovian, where they are replaced by porcelaneous forms called Cornuspira by Vachard but Turrispiroides by other authors (see the work of Groves or Cózar, for instance). ...
Carboniferous and Permian strata crop out in Central Iran. The Asad-Abad section has yielded Gzhelian and Asselian fusulinid levels. Here we describe the smaller foraminifers of this section for the first time and introduce four biozones based on these taxa. Biozone I with Monotaxinoides? melanogaster n. sp. is interpreted to be early?-middle? Gzhelian in age (with possible reworkings affecting up to Moscovian/Kasimovian? levels) based upon the principle of superposition and of previous datings of the underlying series, but in the absence of direct datings by fusulinids of this lowermost part of the section.
Further, Monotaxinoides? are generally known in the Bashkirian-Moscovian. Biozone II includes Raphconilia spp., Protonodosaria spp., and Rectogordius? minimus n. sp. and is
interpreted as middle?-late Gzhelian in age. Biozone III includes
Turrispiroides spp., Calcivertella anguinea, Calcitornella
heathi, and Vervilleina crescenticamerata n. sp., and
we base its early Asselian age on associated fusulinids. Finally,
Biozone IV includes Cribrogenerina? sp. and Nodosinelloides
longissima; its middle to late Asselian age, based on
fusulinids, is confirmed by associated smaller foraminifers.
The foraminiferal assemblages display marked differences
in composition and stratigraphic distribution compared with
those of Alborz and Tabas Block. Principally, they have unexpected
similarities with several North American assemblages,
especially the three new species: Monotaxinoides?
melanogaster n. sp., Rectogordius? minimus n. sp., and
Vervilleina crescenticamerata n. sp.
Lower Devonian (Pragian – Emsian) reefal deposits of Sierra Morena (SW Spain) contain locally abundant calcified cyanobacteria, calcareous alga, and various microfossils including foraminifers. Calcified cyanobacteria are represented by Girvanella spp. A–C, which form crusts and clumps of various shape. Supposed green alga (?Dasycladales) is represented by a new genus with one new species, Bediaella hispanica gen. nov. sp. nov. Algospongia include Vasicekia margaritula (Saltovskaya, 1986) n. comb. Microproblematica is represented by Rothpletzella sp. The studied assemblages indicate photic and warm conditions in a shallow and well-agitated environment with normal salinity, and probably mirror episodes of shallowing due to eustatic sea level fluctuations.
This study reports the new discovery of relatively abundant foraminiferal faunas from the upper Serpukhovian–lowermost Bashkirian? of the Ghaleh Formation in the Shahreza region of the Sanandaj–Sirjan Zone, Iran. Four successive assemblages spanning the upper Serpukhovian–lowermost Bashkirian? are proposed: (1) Assemblage with Biseriella minima and Eostaffellina paraprotvae; (2) Assemblage with Bradyina cribrostomata; (3) Assemblage with Parastaffella utkaensa and Plectostaffella spp., (4) Assemblage with Plectostaffella ex gr. varvariensis. The newly discovered foraminiferal assemblages of the Sanandaj–Sirjan Zone have some species in common with assemblages of the Russian Platform, Donets Basin, Urals, and Western Europe. Ikensieformis aff. mirifica, and Eostaffella igoi, and a new species Ikensieformis persiaensis sp. nov. are described. The microfacies analysis of the Ghaleh Formation limestones suggests a moderate to high-energy shallow marine warm environment, more likely of the inner ramp.
Encrusting foraminifers locally can play an essential reef-forming role such as in the Carnian fossiliferous Hallstatt Limestones of Austria where a dense succession of hardgrounds occurs with numerous small buildups (up to 2 cm high) composed of sessile foraminifers. Similar foraminiferal micro-buildups occur in a 10-cm-thick bed in the basinal facies in the basal Zechstein (Upper Permian) strata in the Radlin 60 borehole, in western Poland. Foraminiferal micro-buildups of presumably columnar habit account for up to a half of the volume. The growth of columns was interrupted by hiatal surfaces, although usually the growth of columns was restored afterwards. In the upper part of the bed with foraminiferal micro-buildups, the foraminiferal en-crustations become visibly less abundant, and in most cases, they have a shape of less regular masses. The bed with foraminiferal micro-buildups abounds in closely spaced discontinuity (hiatal) surfaces, occasionally encrusted by foraminifers. Tubular foraminifers in the bed with foraminiferal micro-buildups are accompanied by various encrusting organisms, possibly microbes; they are grouped under the name Palaeonubecularia. In the intercolumnar spaces, common Midiella sp. occur. During deposition, the conditions were mostly suboxic, and various types of ferruginous morphs, common in the lower part of the bed, suggest that dysoxiceanoxic interfaces produced various microaerophilic environments for iron-bacteria. The environmental conditions during the deposition of the upper part of the bed were very similar to those characterizing the starved basin environment in which the bioclastic-peloidal and oncoidal sediments in the Zechstein Limestone have been formed. In turn, the lower part of the bed registers the transition from normal (= not starved) marine conditions , with a clear chemocline, to the starved basin conditions. The deposition of the bed was coeval with the Kupferschiefer deposition based on the correlation of d 13 C curves, which implies that the previous stratigraphical concept of basal Zechstein strata has to be re-evaluated.
Benthic foraminifera are significant indicators of habitat changes and are useful for paleoenvironmental reconstruction. During the Permian period, the variation in species, individual sizes, and morphological characteristics of the different assemblages, such as the fusulinids, is a clue to paleoecological and paleoenvironmental interpretations. The eastern part of the Sichuan Basin, located near the equator in the middle Permian, Guadalupian period, was precipitated by thick beds of marine carbonate rocks with numerous benthic foraminifera. In this study, we record the species and calculate the frequency of benthic foraminifera from 445 thin sections of Guadalupian (Maokou Formation) marine carbonate rocks. Seven types of benthic foraminiferal biofacies are recognized and associated with five sedimentary microfacies in the Erya and Huilongchang sections, eastern Sichuan area. During the early Guadalupian period, small uniserial nodosariids and Endothyrida dominated the benthic foraminiferal assemblages; in the middle Guadalupian period, species of Miliolida, Ammodiscidae, and uniserial nodosariids were common; however, the species of Fusulinida, such as Schwagerina sp. and Verbeekina sp., were abundant in the late Guadalupian period. The associated sedimentary microfacies indicates a shallow open platform to marginal platform. In our study area, the early Guadalupian was deposited in an open platform to grain shoals. This was followed by gradual shallowing as the sedimentary environment shifted to marginal shallow shoals from the middle to late Guadalupian period until the paleoweathering abruptly terminated the deposition at the end of the Guadalupian period.
The Carboniferous sedimentary sequence at the Mighan section with 450 m thickness are studied with respect to the microfossils specially foraminifers and biozones. Based on the stratigraphic distribution of the index species, the age of the Mobarak Formation in the studied section is identified as the Late Tounaisian (Ivorian)- middle Visean (Moliniacian). With studying and identification of the foraminifers, Tounaisian- Visean stages boundary and their evolution trend until the end of the Lower Carboniferous sedimentation are studied. Five foraminifer biozones, GZ1-GZ5, are introduced for the Mobarak Fm. in the studied locality, which can be compared to the Belgium and the north France biozones, respectively. The most important ecologic and environmental factors that directly affect the distribution, abundance and lifestyle and the mode of preservation of biota and trace fossils are consist of oxygen level, light, salinity and nutrients during the deposition of the carbonate sediments of the Mobarak Formation. Achieved results in this research provide valuable information of the distribution of the bio/ facies associations, lifestyle and manner of the prevailing organisms (benthic, feeding and suspension feeding) and their reaction to the dominated sedimentary processes and changes in the sedimentary environment conditions in the various parts of the carbonate systems and their controlling factors.
Significance
Most calcareous Paleozoic foraminifera have been traditionally assigned to one high-level taxonomic rank, Fusulinata, based on one common feature, a microgranular test texture. Unfortunately, this inorganic trait has not been sufficiently documented. These results show that Paleozoic foraminifera are taxonomically diverse as observed in recent foraminifera with varied test characteristics, suggesting that different biomineralization mechanisms occurred in Paleozoic foraminifera.
In this study, middle to late Mississippian microfossil assemblages from the Maritimes Basin of eastern Canada (Nova Scotia, SW Newfoundland, and New Brunswick) are closely compared to those from Western Paleotethys basins. The comparison is focused mainly on foraminifers and calcareous algae. Most foraminifers and algae described from the Maritimes Basin are considered cosmopolitan, and the occurrence in western Europe and northern Africa of taxa previously considered endemic to the North America Realm suggests a close paleobiogeographic relationship. This European/African correlation is further supported by other foraminiferal/algal taxa, the importance of which were previously overlooked, including: Plectogyranopsis ex gr. P. hirosei (Okimura, 1965), Mikhailovella Ganelina, 1956, Koktjubina windsorensis (Mamet, 1970), Polysphaerinella bulla Mamet, 1973, Mstinia Dain in Dain and Grozdilova, 1953, Haplophragmina Reitlinger, 1950, Omphalotis Shlykova, 1969, Pseudolituotuba Vdovenko, 1971, Pseudoendothyra Mikhailov, 1939, Saccamminopsis (Sollas, 1921) Vachard and Cózar, 2003, Kamaenella Mamet and Roux, 1974, and Anthracoporellopsis Maslov, 1956. Some species recorded in the Maritimes Basin have been typically recorded in Britain and Ireland in the southern platform of Laurussia. This implies a connection via the Rhenohercynian Ocean, whereas statistical analyses suggest that Maritimes Basin assemblages are closer to those of the Gondwana platform, which could have been established via the Paleotethys Ocean, and also with terranes northwest of the Variscan Front, in which its most logical connection should be with a still-open Rheic Ocean during the Visean and early Serpukhovian. Those taxa demonstrate a more-or-less continuous faunal and microfloral interchange between the Maritimes Basin and the Western Paleotethys paleobiogeographic realm. Furthermore, the width of the Paleotethys and Rheic oceans separating these regions is not considered excessive, particularly during the late Visean and early Serpukhovian.
It is a consensus that marine carbonate archives the isotopic composition of seawater dissolved inorganic carbon (DIC, δ13Csw), the largest active C reservoir in the hydrosphere. Carbonate carbon isotope (δ13Ccarb) excursions have been used to reflect perturbations of the global carbon cycle and related environmental change. However, the deep time δ13Ccarb records indicate faster and more pronounced perturbations of the carbon cycle compared to the present day. Here, we report δ13Ccarb and elemental compositions of Late Paleozoic carbonate sections from South China, showing negative correlations between δ13Ccarb and Fe2+ content of carbonate (Fecarb). We suggest that, because Late Paleozoic carbonate was mainly produced by benthic carbonate-secreting organisms, δ13Ccarb recorded the isotopic composition near the seafloor, where benthic flux derived from anaerobic organic matter degradation delivers both Fe2+ and 13C-depleted DIC from porewater. The binary mixing between seawater and benthic flux would result in the deviation of δ13Ccarb from δ13Csw. The negative correlation implies that δ13Ccarb is influenced by benthic flux and is affected by the seafloor redox and sedimentation rate. The deep time spatially heterogeneous and temporally oscillatory δ13Ccarb records in the basin-scale could be alternatively attributed to the variations of local environmental factors rather than a δ13Csw depth-gradient. Thus, the seafloor carbonate precipitation is continuously affected by diagenetic reactions in sediments, suggesting that δ13Ccarb recording the seawater DIC composition is conditional. Our study urges that the interpretation of δ13Ccarb should also consider the sedimentary process and depositional environment of marine carbonate.
The name Paynita is proposed for a new dagmaritin genus from the upper Changhsingian (Permian) carbonates of the Southern Biofacies Belt in Turkey. Paynita permotaurica differs from its ancestor Paradagmarita monodi by a hook-shaped fold in the apertural flap terminating systematically against the inner surface of the septal wall to protect the opening from one chamber to the other. It is associated with several species of dagmaritins, belonging to Paradagmarita, Paradagmacrusta, Louisettita, Dagmarita, Danielita, and Bidagmarita. The overall analysis of dagmaritins reveals that the stratigraphic range of the group is from Wordian to Changhsingian. The revised chronostratigraphy in the type area of the genus Sengoerina indicates that this oldest dagmaritin was derived from Globivalvulina cyprica in the Wordian. The first occurrences of genera Dagmarita and Danielita postdate the first occurrence of Sengoerina in the Wordian. Paynita is the last evolutionary step of the Sengoerina-Dagmarita-Crescentia-Paradagmarita lineage characterized by a planar apertural flap whose structure practically remained unchanged during the process of evolution. Paynita is the first genus in this lineage displaying fold in the apertural flap similar to the evolution of Louisettita from Dagmarita.
Detailed studies of upper Cisuralian (i.e., upper lower Permian) fusulinids make it possible to decipher the paleobiogeographic relations of central Iran, as part of the Cimmerian terranes, with other Paleotethyan regions. Two sections, Bagh-e Vang and Shesh Angosht, located in east-central Iran, are revised. Four local fusulinid biozones are distinguished: upper Yakhtashian Pamirina darvasica and Sakmarella spp. Zone, lower Bolorian Misellina ( Brevaxina ) dyrhenfurthi Zone, mid-Bolorian Cuniculinella Zone, and upper Bolorian Misellina ( Misellina ) cf. M . ( M .) termieri Zone (probably equivalent to the traditional Misellina ( Brevaxina ) parvicostata Zone). Taxonomically, the main results are as follows: (1) a clarification is provided of the fusulinid genus or subgenus “ Cuniculina ,” the name of which is pre-occupied, and its synonymy with Cuniculinella ; and (2) a lectotype is designated for Darvasites ( Alpites ) sinensis (Chen, 1934). The mid-Bolorian Cuniculinella Zone is recognized for the first time in Iran. Among the Bolorian fusulinids, Cuniculinella is reported in SE Pamir, Karakoram, central Afghanistan, SW Japan, central Japan, and California, confirming the faunal affinity of the study area in east-central Iran with both Paleotethyan and Panthalassan bioprovinces. Such a distribution is considered to have resulted from combined effects of global warming during the upper Cisuralian, warm oceanic currents along the Paleotethys Ocean, and the northward drift of the Iran block toward lower paleolatitudes.
A 3 m thick carbonate sequence from northern Chios Island is assigned here to the latest Capitanian/earliest Wuchiapingian transitional interval. It is characterized by abundant gymnocodiacean algae, associated with some miliolate, nankinellin and nodosariate foraminifers. These strata display bioaccumulated perireefal microfacies with richthofeniid brachiopods and inozoa calcisponges. They are biostratigraphically characterized by a foraminifera assemblage composed of Reichelina cf. simplex, Dunbarula? sp., Altineria alpinotaurica together with the genera Labioglobivalvulina, Frondina and Robuloides. Other perireefal microfacies show abundant fragments of a new tubiphytid species, Tubiphytella guevenci Vachard nov. gen. nov. sp. Based on this study, the paleogeographical distribution of Altineria alpinotaurica now includes Chios, in addition to the Taurus and the NW and central Iran, whereas primitive forms of the genus are also known in Tunisia and Armenia. This paleobiogeographic distribution would suggest that all these regions still belonged to the Perigondwana margin in the early Wuchiapingian times. Consequently, it is likely that the opening of the Neotethys ocean did not begin prior to the late Wuchiapingian-early Changshingian transitional interval.
A compilation of key literature on larger benthic foraminifera in the geological record made during the course of research for a chapter on Larger Benthic Foraminifera for the new Geological Time Scale 2020 book. Suggestions of important omissions welcome
Among Permian smaller foraminifers, the genus Dagmarita is one of the most studied due to its worldwide distribution. The detailed study of the Zal (NW Iran) and Abadeh (Central Iran) stratigraphic sections led to redescription of the genus Dagmarita and its taxonomic composition. In Dagmarita , a peculiar generic morphological character, represented by a secondary valvular projection, has been detected for the first time among globivalvulinid foraminifers. The phylogeny of Dagmarita , and in particular its ancestor Sengoerina , is discussed and the new species, D . ghorbanii n. sp. and D . zalensis n. sp., are introduced. Analogies and differences among all the species belonging to Dagmarita are highlighted and morphological features of the new taxa are shown in 3D reconstructions, useful for understanding differently oriented sections of the specimens in thin section.
UUID: http://zoobank.org/3d8eb14c-7757-4cbd-877c-4bacd2d156da
Seven foraminiferal zones [Parathurammina dagmarae–Saltovskajina scitula–Neoarchaesphaera, Septaglomospiranella primaeva, Quasiendothyra (Eoquasiendothyra) bella, Q. (Eoendothyra) communis, Q. (E.) regularis, Q. (Q.) kobeitusana–Endoglomospiranella imminuta, and Q. (Q.) konensis–End. Nigra] have been identified from Famennian Stage carbonate sections in Tajikistan and compared to foraminiferal sequences from the Franco-Belgian Basin, the Russian part of the Eastern European Platform, the Ural Mountains (Russia), and Kyrgyzstan. The lower Famennian boundary is marked by the rapid extinction of all Frasnian Stage multicameral forms, which are replaced by a complex of single-chambered foraminifers of the P. dagmarae–S. scitula–Neoarchaesphaera Zone. This boundary practically coincides with the base of the middle Palmatolepis triangularis conodont zone. The upper Famennian boundary is recognized by the sharp change from endothyroid foraminifers of the Quasiendothyra konensis–Endoglomospiranella nigra Zone to a complex of simple mono- and bilocular forms of the Carboniferous Bisphaera malevkensis–Earlandia minima Zone. This boundary in the most intensely studied section at Shishkat is located 16 cm below the boundary of the Siphonodella praesulcata and S. sulcata conodont zones.
The stratigraphic correlation of Sphaeroschwagerina in lowermost Permian strata around the world is discussed. In the Canadian Arctic species of the taxon are confined to a narrow late Asselian time interval. This contradicts Henderson in Beauchamp et al. (1989) who suggested a late Sakmarian age for strata containing Spaheroschwagerina on the basis of condonts.
The diversity curve of Permian fusulinid genera shows two peaks corresponding to the Asselian-Sakmarian and Midian times. The minimal generic diversity is recorded in the late Bolorian. The most significant extinction events occurred at the end of the Midian (71% of all genera), Bolorian (48%), Asselian (27%) and Sakmarian (23%) ages. The fusulinid assemblage was most notably changed by the appearance of new genera (52% of the total number) in the Kubergandian age. These data identify two main stages (Asselian-Bolorian and Kubergandian-Dorashamian) and four second-order stages (Asselian-Sakmarian, Yakhtashian-Bolorian, Kubergandian-Midian, and Dzhulfian-Dorashamian) in the Permian history of fusulinids. The main stages correspond to two Permian series of the East European scale, which can be considered as subsystems named Cisuralian and Tethysian, respectively. The latter are subdivided into the Uralian, Darvasian, Yanghsingian and Lopingian series which correspond to the second-order stages. The scale suggested does not contradict the traditional two-member subdivision and has an advantage over the accepted global three-member chronostratigraphic scale because the series suggested are more proportional to each other in scope and reflect natural evolutionary processes of the marine biota. In addition, the application of the global scale to the Tethyan sequences is hampered by a limited number of criteria used in the drawing of series and stage boundaries, as evidenced by the existing different views on the position of the lower Guadalupian boundary in the Tethyan sections.
The diversity curve of the Permian fusulinid genera shows two peaks corresponding to the Asselian-Sakmarian and the Midian times. The minimal generic diversity is recorded in the late Bolorian time. The most significant extinction events occurred at the end of the Midian (71% of the total amount of all genera), Bolorian (48%), Asselian (27%) and Sakmarian (23%) ages. The fusulinid assemblage was most notably changed by the appearance of new genera (52% of the total number) in the Kubergandian age. These data allow recognition of two main stages (Asselian-Bolorian and Kubergandian-Dorashamian) and four second-order stages (Asselian-Sakmarian, Yakhtashian-Bolorian, Kubergandian-Midian, and Dzhulfian-Dorashamian) in the Permian history of fusulinids. The main stages correspond to two Permian series of the East European scale, which can be considered as subsystems named Cisuralian and Tethysian, respectively. The latter are subdivided into the Uralian, Darvasian, Yangsingian and Lopingian series which corresponding to the second-order stages. The scale suggested does not contradict the traditional two-member subdivision and has an advantage over the accepted global three-member chronostratigraphic scale because the series suggested are more proportional to each other in scopes and reflect natural evolutionary processes of the marine biota. In addition, the application of the global scale to the Tethyan sequences is hampered by a limited number of criteria used in the drawing of series and stage boundaries, as evidenced by the existing different views on the position of the lower Guadalupian boundary in the Tethyan sections.
This reference is for an abstract only. A full paper was not submitted for this conference.
The carbonates and evaporites of the Late Permian Khuff Formation form widespread reservoirs across the Arabian plate and concentrate the biggest gas resources in the world. The material studied includes 1500 samples from outcrops in Iran (Zagros), Turkey, Saudi Arabia and South China. The objectives of the study were (1) to build a robust biotratigraphic framework based on a detailed description of algal-foraminiferal biotic content, (2) to characterize the depositional environments and their temporal successions during the Late Permian and Early Triassic. By comparison of fossils distribution, the Middle/Late Permian Khuff deposits are divided into 8 units limited at their tops by turnovers levels, corresponding to significant reshapings of biotic assemblages. During the Late Permian, the Zagros (Iran), Taurus (Turkey), South China and even Japan share similar foraminiferal assemblages and represent intermittently connected palaeobiogeographic provinces. Palaeoecological results show that the structurally controlled palaeohighs are successively drowned and that the system evolves progressively from a rimmed platform towards an almost uniformly fl at ramp. The major oolitic units (reservoirs) developed within high-subsiding areas by sediment volume funneling, mainly during the late Wuchiapingian (upper K4 reservoir equivalent) and early triassic (K2 reservoir equivalent). The thermal subsidence during the Neotethyan spreading is likely the main factor that drove the Khuff deposition on the Arabian platform and can be related to the demise of the regional permian fauna. The new framework is expected to provide an important tool for further subsurface studies and correlations.
Middle and Late Permian reefs flourished for about 20 million years in the Tethys, the Panthalassan ocean, the Delaware Basin, the Zechstein Basin, and the Northwest Pangean cratonic basin Eight reef types, which were differentiated on the basis of their taxonomic composition, belong to four significantly different reef environmental settings: (1) The Tethyan carbonate factory has the highest taxonomic diversity of macro-reefbuilders, yields massive, probably zooxanthellate rugose corals, and is mud-rich. Reef domains occur along the southwestern shelf margin and on Cimmerian as well as Cathyasian terranes. Typical representatives are sponge reefs found in Tunisia or Oman and coral reefs described from China. (2) Epeiric reefs are dominated by micro-framework (e.g., microbial precipitates and low-growing metazoans), large amounts of synsedimentary, marine-phreatic cements, and few macro-reefbuilders. Classic localities are known from the Delaware and the Zechstein basins. (3) Reefs of some Panthalassan oceanic buildups (e.g., Mino terrane, Japan) are composed of calcimicrobes, low-growing metazoans, and large amounts of sediment, but macro-reefbuilders (large coralline sponges and massive rugose corals) are absent. (4) Cool-water reefs differ significantly from their tropical counterparts by depositional geometries and taphonomic history. The ethinoderm- and bryozoan-rich associations, which lack cosmopolitan Archaeolithoporella hidensis, accumulated in biostromes on slightly dipping ramps and did not develop structures with significant relief. The faunas are reworked due to moderate synsedimentary cementation and high turbulence and are well known from the Northwest Pangean cratonic basin.
Important Permian reefbuilders are microbes, Archacolithoporella, Shamovella (formerly Tubiphytes), coralline sponges, rugose corals, calcareous algae, bryozoans, and brachiopods Algal–cement reefs with various percentages of microbial precipitates area common reef type, lacking only in the high latitudes, and have a cosmopolitan character; Shamovella, Archaeolithoporella, and sponges are common and widespread reefbuilders.
Permian reef evolution is discontinuous and characterized by pulses of growth as well as the final demise of late Paleozoic communities followed by the severe gap without true metazoan reefs during the Scythian. The end-Permian mass extinction is twofold, comprising a pre-Lopingian and a Changhsingian event. The latest Permian reefs are restricted to the equator and are characterized by high diversities Intercalated sediments enriched in calcareous algae indicate global warming.
Middle and Late Permian reefs bear an underestimated hydrocarbon reservoir potential, especially in (1) epeiric basins with occasional upwelling of hypersaline waters, (2) karstified and dolomitized Tethyan reefs, (3) carbonates related to upwelling at continental margins, and (4) cool-water carbonates with reefbuilders. Productive reservoirs are known from Tethyan reefs, including China, Thailand, and Tunisia.
The Late Pennsylvanian Yucca Mound complex is a carbonate buildup on the western side of the Sacramento shelf facing the Oro Grande basin, in south-central New Mexico. This complex is an accumulation of algal and foraminiferal boundstones and phylloid-algal packstones and wackestones which have been subjected to several periods of subaerial exposure. The growth history of this organic complex is related closely to late Paleozoic cyclic sedimentation in a tectonically active area, and is thought to be the result of progressive offlapping growth stages down the western flank of the active La Luz anticline. The oldest beds exposed in the complex (plumose masses of algal and foraminiferal boundstone) formed within wave base on the crest of an earlier organic buildup. The crest of the older buildup was subaerially exposed while a thick accumulation of carbonate mud replete with the phylloid algae, Ivanovia, started forming against its western (seaward) flank. As sea level rose and submerged the earlier mound, the phylloid-algal accumulation kept pace with sea-level rise and onlapped the older mound, despite a few brief interruptions. When the phylloid algae built up into wave base, and attained its climax stage of evolution, a typical shallow-water facies developed. This distinctive rock type on the preserved, rounded mound top contains abundant forams, both encrusting and mobile chambered forms, together with fish remains and conodonts. A bedded detrital flank facies, composed of broken phylloid-algal material, and concentrated remains of forams, fish, and conodonts that inhabited the upper mound, is present on the shelfward (lee) side of the complex. Abundant, algally coated skeletal grains characterize the flank facies, which is easily recognizable elsewhere within the area, mainly in mound-flanking beds. When sea level dropped, Yucca Mound growth ceased, and smaller boundstone accumulations were formed down the offshore flank of the main mound complex. The varied growth history of this particular organic buildup demonstrates just how much opportunity existed for subaerial and littoral diagenetic processes to act on and to modify the varied rock facies common in late Paleozoic phylloid-algal buildups.
Data on numbers of marine families within 91 metazoan classes known from the Phanerozoic fossil record are analyzed. The distribution of the 2800 fossil families among the classes is very uneven, with most belonging to a small minority of classes. Similarly, the stratigraphic distribution of the classes is very uneven, with most first appearing early in the Paleozoic and with many of the smaller classes becoming extinct before the end of that era. However, despite this unevenness, a Q -mode factor analysis indicates that the structure of these data is rather simple. Only three factors are needed to account for more than 90% of the data. These factors are interpreted as reflecting the three great “evolutionary faunas” of the Phanerozoic marine record: a trilobite-dominated Cambrian fauna, a brachiopod-dominated later Paleozoic fauna, and a mollusc-dominated Mesozoic-Cenozoic, or “modern,” fauna. Lesser factors relate to slow taxonomic turnover within the major faunas through time and to unique aspects of particular taxa and times. Each of the three major faunas seems to have its own characteristic diversity so that its expansion or contraction appears as being intimately associated with a particular phase in the history of total marine diversity. The Cambrian fauna expands rapidly during the Early Cambrian radiations and maintains dominance during the Middle to Late Cambrian “equilibrium.” The Paleozoic fauna then ascends to dominance during the Ordovician radiations, which increase diversity dramatically; this new fauna then maintains dominance throughout the long interval of apparent equilibrium that lasts until the end of the Paleozoic Era. The modern fauna, which slowly increases in importance during the Paleozoic Era, quickly rises to dominance with the Late Permian extinctions and maintains that status during the general rise in diversity to the apparent maximum in the Neogene. The increase in diversity associated with the expansion of each new fauna appears to coincide with an approximately exponential decline of the previously dominant fauna, suggesting possible displacement of each evolutionary fauna by its successor.
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, discontinuously growing forms may be further delineated on the basis of test symmetry and on modifications to chamber shape and apertural complexity. Early lagenides underwent rapid taxonomic differentiation during late Moscovian and early Kasimovian time. Taxonomic differentiation was accompanied by rapid dispersal from the presumed center of origin in the midcontinent-Andean area to tropical and subtropical shelves worldwide. By Early Permian time certain lagenides were adapted to cool water paleoenvironments, as evidenced by their occurrences in high paleolatitudes and even in glaciomarine basins. Early Permian lagenides do not exhibit marked provincialism, but there is evidence for paleolatitudinal control on assemblages. The midcontinent-Andean and present Arctic areas contain similar, diverse faunas from low- to mid paleolatitudes along the western margin of Pangaea. These faunas share many elements in common with faunas from the tropical and subtropical eastern margin of Pangaea (Paleotethys). In contrast, the Europe-Urals, Siberian and Australian areas are characterized by a slightly different faunal association from mid- to high paleolatitudes in both hemispheres. Panthalssan faunas are less well known, but seemingly contain only cosmopolitan taxa.
The marine Carboniferous succession of the Tindouf Basin is poorly known. This preliminary note concentrates on the Tournaisian-Serpukhovian interval. It primarily deals with the sedimentation and the microfossils of the southern part of the basin. Moreover, sedimentological and micropaleontological data are also provided for the northern and central part. Sedimentological study enables recognition of 12 microfacies ranging from open marine below storm wave action to supratidal with continental influx. The proposed model is that of a homoclinal ramp marl-sandstone-limestone interrupted by numerous tempestites. Sedimentary cycles in the Late Visean are particularly numerous. Calcareous algae are mostly Stacheiinae and benthic foraminifers, Archaediscidae and Endothyridae. The prolific Late Visean assemblages become scarce in the Serpukhovian and peter out in the Bashkirian. This reflects the progression from a marine ramp to a paralic basin. We propose a regional biostratigraphic scale based on the biozones of MAMET (1974) and of LYS (1986) which are correlated with those of Conil in CONIL et al (1990).
A detailed micropalaeontological analysis (foraminifera and calcareous algae) has been made of the Brigantian Basal Stratotype section at Janny Wood in the Stainmore Trough, and sections in the Rookhope, Allenheads, Feizor and Back Scar boreholes on the Alston and Askrigg blocks of northern England. The sections contain a complete composite succession from the upper Asbian to the Pendleian. Using the first appearances, last appearances and the acmes of the foraminiferal and algal taxa, it is possible to recognize eight assemblages in the shallow-water platform facies of the Alston and Askrigg blocks. Several taxa occur earlier in the Janny Wood section (Stainmore Trough) than in the boreholes on the adjacent blocks and many common taxa in what is currently regarded as the highest Asbian part of the Janny Wood section are more typical of the Brigantian. All the palaeontological data suggest that the Birkdale Limestone and possibly the Robinson Limestone in the Janny Wood section could be Brigantian, although there is an absence of basal Brigantian foraminiferal markers (e.g. Loeblichia and Janischewskina). Nevertheless, the basal Brigantian stratotype boundary could be moved from its current position at the base of the Peghorn Limestone to a lower level, preferably at the base of the Birkdale Limestone.
In the Givetian of the Ain el Khira section (Western Morocco), 15 species of Parathuramminina and Moravamminida are described, two of which are new: Tubeporina (?) polydermoides n. sp. and Palachemonella maroccana n. sp. Precisions about the systematics of the Moravamminida (microproblematical Algae or Foraminifera) are given. -English summary
The Carboniferous from several boreholes and outcrops in western Libyan Basins is analyzed, and comparison is made with the Illizi Basin in Algeria. This study's results provide new data on microfacies, microfossils, biostratigraphy and sedimentology, which can be used to draw a rough outline of the paleogeographic development of these basins.
Among tropical foraminifers a number of families and genera reach large sizes, commonly ranging from 3 mm³ in volume to more than 300 mm³. Many of these are part of lineages that have extensive fossil records and formulation of an ecological framework for the extant representatives may have applicability to related foraminifers in carbonate deposits as old as Cretaceous and by analogy to the extinct late Paleozoic fusulinaceans. Most large, living foraminiferal genera are associated with a symbiotic photosynthetic partner. Some of these photosynthetic partners are zooxanthellae similar to those in tropical, shallow water, hermatypic corals. Most large foraminifers show one or more type of shell adaptation for the effective utilization of their symbionts. In general, large foraminifers are important constituents of coral reef ecological systems and are geographically limited in their distribution to surface water having temperatures greater than 20°C, to shallow shelf areas in the upper part of the photic zone, and to normal (35.5 ppt or higher) salinities. Only a few larger genera, such as the alveolinids, are common in the middle part of the photic zone.
Throughout most of northern Arizona the Redwall Limestone of Mississippian age is readily divisible into four lithologic units, designated in ascending order as the Whitmore Wash, Thunder Springs, Mooney Falls, and Horseshoe Mesa Members. The first and third members are thick-bedded to massive carbonate rock. The Horseshoe Mesa Member is relatively thin-bedded limestone, and the Thunder Springs Member is distinctive because it consists of chert beds alternating with thin beds of carbonate rock. Trends in thickness of the various members indicate that the sediment that formed the Redwall was deposited on an even, gently sloping shelf that extended westward from the Defiance positive element, a low landmass located near the present eastern border of northern Arizona. The Peach Springs and Payson ridges projected west and southwest, respectively, from the positive element. These ridges, which were partly submerged and partly above sea level during Mississippian time, are indicated by the patterns of isopach lines and, in part, by the distribution of faunas. The ridges divided the Arizona section of the shelf into three segments: the northernmost, which slopes northwest toward the Cordilleran geosyncline, and the other two, which slope toward the south and southwest. Two transgressions and two regressions of the western and southern seaways are believed to be represented by the Redwall. The first transgression, which is recorded by thick beds of clastic sediment of the Whitmore Wash Member, was less extensive than the second, which is recorded by massive beds of the Mooney Falls Member, for on the western margins of the Defiance positive element the Mooney Falls Member overlaps the two lower members. Furthermore, south of Grand Canyon the Whitmore Wash and Thunder Springs Members lap against the Payson ridge without covering it, whereas the Mooney Falls Member, although relatively thin, extends across it. Regression is believed to be represented by thin beds of the Thunder Springs and Horseshoe Mesa Members, which are interpreted to be the result of low base level caused by silting up with clastic material and consequent retreat of the sea. Cycles in sedimentation are well developed in some parts of the Redwall, especially in the upper two members in which differences in grain size represent five major cycles recognized throughout the extent of the Grand Canyon. These textural differences, ranging from aphanitic to coarse grained, are considered to be not measures of the amount of transportation, as with terrigenous sediments, but reflections of the degree of turbulence or the lack of turbulence during deposition. They are interpreted as indicators of cyclic fluctuations in environment, probably related to changes in wave base. Several clearly defined facies within the Redwall indicate environments of deposition. The clastic limestone that forms a major part of the formation, especially in the offshore areas to the west and south, is believed to represent normal marine conditions where circulation was good and turbulence moderate to strong. Uniform finely crystalline dolomite probably developed through early diagenetic processes on the sea floor. On the basis of its distribution pattern the dolomite seems to have formed under shoal conditions, especially where it borders the shore of the Defiance positive element and along Peach Springs ridge. Oolitic limestone at the top of both major transgressive units is interpreted as reflecting the oscillatory conditions of sea level that provided wave and current agitation at times of maximum sea advance in shoal areas bordering the ridges. Aphanitic limestone, representing accumulations of lime mud, seems to be developed best in the uppermost, or Horseshoe Mesa, member, where, as the seas regressed, nearshore waters may have been isolated and certainly were very calm. Original textures and some structures are preserved in most limestones of the Redwall, and they give much evidence concerning oceanographic factors of the time. Generalizations have been developed concerning the character of the bottom, degrees of energy represented, depth, salinity, and other factors for various parts of the formation. Although these factors differed greatly with time and space, the general conclusions reached are that (1) depths were very shallow to moderate, (2) the sea floor was composed nearly entirely of lime mud and lime sand, which contained no terrigeneous material but with great crinoidal accumulations locally, (3) turbulence ranged from considerable to none, and (4) the sea was clear and warm and nowhere contained saline concentrations sufficient to form evaporites. Chert forming thin irregular beds, locally lenticular and nodular, occurs at two prinicpal positions in the stratigraphic section, and in each it alternates with thin beds of carbonate rock. Chert is prominent throughout the Thunder Springs Member and forms thin but definite zones near the top of the Mooney Falls Member. This chert is believed to have formed on the sea floor during early diagenesis, as evidenced by petrography, paleogeography, and faunal relations. Regional differences in the abundance and type of associated fossils, recorded on a series of 4-foot-square sample plots made throughout the Grand Canyon, suggest a probable relation between fossil distribution and genesis of the chert. The fauna of the Redwall is abundant and varied, but preservation in many places is poor, and numerous specimens can be collected only locally. The most common fossils are brachiopods, corals, foraminifers, and crinoids, but blastoids, gastropods, cephalopods, and pelecypods are not rare. Bryozoans are abundant in the chert of the Thunder Springs Member but uncommon elsewhere. Other organisms locally distributed but not common are algae, trilobites, fish, holothurians, and ostracodes. These groups have been studied by specialists and are the subject of Chapters V through XII1. Certain of the faunal groups, notably the corals and foraminifers, show some degree of vertical zoning and so have furnished important data on age and correlation. Among the corals, the zones of Dorlodotia inconstans and Mk helinia expansa are especially significant because of their persistence from section to section across broad areas. The foraminiferal zones are broader and less sharply defined, but they represent a series of major changes in species from bottom to top of the formation. Age determination made on the basis of foraminifers and brachiopods indicate that the base of the Redwall is progressively younger as it passes from areas that were offshore eastward or northward toward the Defiance positive element; the top of the Redwall, in contrast, is shown to be progressively younger away from the positive element. Thus basal beds of Kinderhook age are recognized at Grand Wash, Quartermaster, and Meriwitica Canyons to the northwest, but the lowest strata are of Osage age at Bridge Canyon, Grandview, and other sections closer to the landmass. Likewise, units with fossils of middle Meramec age occur in western Grand Canyon, but, except in the one place discussed in the following paragraph, topmost beds farther east in Grand Canyon are of Osage age. South of Grand Canyon the youngest member of the Redwall (Horseshoe Mesa) has been removed by pre-Supai Formation erosion. Rocks still younger than the Horseshoe Mesa once may have covered the entire region, possibly representing a third sequence of transgression and regression. At Bright Angel trail in eastern Grand Canyon, for example, a unique unit at the top of the Redwall section contains fossils of Chester age and apparently represents a remnant of Late Mississippian rocks that survived as an inlier there.
A revised six-kingdom system of life is presented, down to the level of infraphylum. As in my 1983 system Bacteria are treated as a single kingdom, and eukaryotes are divided into only five kingdoms: Protozoa, Animalia, Fungi, Plantae and Chromista. Intermediate high level categories (superkingdom, subkingdom, branch, infrakingdom, superphylum, subphylum and infraphylum) are extensively used to avoid splitting organisms into an excessive number of kingdoms and phyla (60 only being recognized). The two 'zoological' kingdoms, Protozoa and Animalia, are subject to the International Code of Zoological Nomenclature, the kingdom Bacteria to the International Code of Bacteriological Nomenclature, and the three 'botanical' kingdoms (Plantae, Fungi, Chromista) to the International Code of Botanical Nomenclature. Circumscriptions of the kingdoms Bacteria and Plantae remain unchanged since Cavalier-Smith (1981). The kingdom Fungi is expanded by adding Microsporidia, because of protein sequence evidence that these amitochondrial intracellular parasites are related to conventional Fungi, not Protozoa. Fungi are subdivided into four phyla and 20 classes; fungal classification at the rank of subclass and above is comprehensively revised. The kingdoms Protozoa and Animalia are modified in the light of molecular phylogenetic evidence that Myxozoa are actually Animalia, not Protozoa, and that mesozoans are related to bilaterian animals. Animalia are divided into four subkingdoms: Radiata (phyla Porifera, Cnidaria, Placozoa, Ctenophora), Myxozoa, Mesozoa and Bilateria (bilateral animals: all other phyla). Several new higher level groupings are made in the animal kingdom including three new phyla: Acanthognatha (rotifers, acanthocephalans, gastrotrichs, gnathostomulids), Brachiozoa (brachiopods and phoronids) and Lobopoda (onychophorans and tardigrades), so only 23 animal phyla are recognized. Archezoa, here restricted to the phyla Metamonada and Trichozoa, are treated as a subkingdom within Protozoa, as in my 1983 six-kingdom system, not as a separate kingdom. The recently revised phylum Rhizopoda is modified further by adding more flagellates and removing some 'rhizopods' and is therefore renamed Cercozoa. The number of protozoan phyla is reduced by grouping Mycetozoa and Archamoebae (both now infraphyla) as a new subphylum Conosa within the phylum Amoebozoa alongside the subphylum Lobosa, which now includes both the traditional aerobic lobosean amoebae and Multicilia. Haplosporidia and the (formerly microsporidian) metchnikovellids are now both placed within the phylum Sporozoa. These changes make a total of only 13 currently recognized protozoan phyla, which are grouped into two subkingdoms: Archezoa and Neozoa; the latter is modified in circumscription by adding the Discicristata, a new infrakingdom comprising the phyla Percolozoa and Euglenozoa). These changes are discussed in relation to the principles of megasystematics, here defined as systematics that concentrates on the higher levels of classes, phyla, and kingdoms. These principles also make it desirable to rank Archaebacteria as an infrakingdom of the kingdom Bacteria, not as a separate kingdom. Archaebacteria are grouped with the infrakingdom Posibacteria to form a new subkingdom, Unibacteria, comprising all bacteria bounded by a single membrane. The bacterial subkingdom Negibacteria, with separate cytoplasmic and outer membranes, is subdivided into two infrakingdoms: Lipobacteria, which lack lipopolysaccharide and have only phospholipids in the outer membrane, and Glycobacteria, with lipopolysaccharides in the outer leaflet of the outer membrane and phospholipids in its inner leaflet. This primary grouping of the 10 bacterial phyla into subkingdoms is based on the number of cell-envelope membranes, whilst their subdivision into infrakingdoms emphasises their membrane chemistry; definition of the negibacterial phyla, five at least partly photosynthetic, relies chiefly on photosynthetic mechanism and cell-envelope structure and chemistry corroborated by ribosomal RNA phylogeny. The kingdoms Protozoa and Chromista are slightly changed in circumscription by transferring subphylum Opalinata (classes Opalinea, Proteromonadea, Blastocystea cl. nov.) from Protozoa into infrakingdom Heterokonta of the kingdom Chromista. Opalinata are grouped with the subphylum Pseudofungi and the zooflagellate Developayella elegans (in a new subphylum Bigyromonada) to form a new botanical phylum (Bigyra) of heterotrophs with a double ciliary transitional helix, making it necessary to abandon the phylum name Opalozoa, which formerly included Opalinata. The loss of ciliary retronemes in Opalinata is attributed to their evolution of gut commensalism. The nature of the ancestral chromist is discussed in the light of recent phylogenetic evidence.
The late Precambrian and L.Cambrian autochthonous sedimentary sequences in N. Norway and adjoining areas and their fossils are reconsidered, and the available specimens are re-described. One L. Cambrian foraminiferal fossil (Spirosolenites spiralis) and one Late Precambrian medusoid coelenterate (Kullingia concentrica) are named as new genera and species. The thickness changes and breaks in sedimentation in the platform cover compared with the 'miogeosynclinal' Digermul section are demonstrated. -Authors