The taxonomy of ostracods from one deep-water, one shallow shelf and three paralic sections spanning the end-Permian extinction in South China (Guizhou and Yunnan) is summarized and discussed.We report on the occurrence of nine species, including mass occurrences of Hollinella panxiensis Wang, on the surface of these clastic Permian-Triassic transitional beds. The preservation of the material allows for the description of the central muscle scar field of Langdaia suboblonga Wang, which is the first observation of this character for the genus. These firstly described assemblages differ from those from post-extinction microbial deposits in being dominated by Palaeocopida. They illustrate survival without recovery after the end-Permian crisis, as none of the reported taxa participated in the subsequent Triassic diversification. We relate this phenomenon to clastic input and show that the patchy survival of benthic faunas following the crisis is an interplay between environments and adaptive potential. The persistence of Palaeocopida as a function of their depth distribution is discussed with the illustration of short-term survival of Hollinellidae in shallow areas, as opposed to the survival of Kirkbyidae in deep-marine waters until, at least, the Late Triassic.
{"title":"Ostracods after the end-Permian extinction in South China: insights into non-microbial survival","authors":"M. Forel, A. Bercovici, Jianxin Yu","doi":"10.47894/mpal.66.5.02","DOIUrl":"https://doi.org/10.47894/mpal.66.5.02","url":null,"abstract":"The taxonomy of ostracods from one deep-water, one shallow shelf and three paralic sections spanning the end-Permian extinction in South China (Guizhou and Yunnan) is summarized and discussed.We report on the occurrence of nine species, including mass occurrences of Hollinella panxiensis Wang, on the surface of these clastic Permian-Triassic transitional beds. The preservation of the material allows for the description of the central muscle scar field of Langdaia suboblonga Wang, which is the first observation of this character for the genus. These firstly described assemblages differ from those from post-extinction microbial deposits in being dominated by Palaeocopida. They illustrate survival without recovery after the end-Permian crisis, as none of the reported taxa participated in the subsequent Triassic diversification. We relate this phenomenon to clastic input and show that the patchy survival of benthic faunas following the crisis is an interplay between environments and adaptive potential. The persistence of Palaeocopida as a function of their depth distribution is discussed with the illustration of short-term survival of Hollinellidae in shallow areas, as opposed to the survival of Kirkbyidae in deep-marine waters until, at least, the Late Triassic.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45126266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Behnam Sakhavati, Mostaa Yousefirad, M. Majidifard, A. Solgi, Z. Maleki
The Gachsaran Formation from the Fars Group has a vast extent in Saudi Arabia, United Arab Emirates and Qatar (Dam Formation). It extends from the Zagros Folded Belt Zone in the south of Iran to the north of Iraq, and even to northeast Syria (Fatha Formation). In order to eliminate the ambiguities of the proposed age and cover the regional information misplacements in cases where biostratigraphy studies can be effective, surface outcrops of these deposits were investigated in three stratigraphic sections near the border of Iran and Iraq, in the area behind the mountains of the Lurestan region (Posht-e-Kuh arc). According to similar results obtained in two other sections, the age of the Gachsaran Formation in the studied region is considered to be Early Miocene (Late Burdigalian). Comparison of the results of this study with biostratigraphic studies from other parts of the Middle East, which includes 16 study areas, shows that the Gachsaran Formation in Iran and its equivalent formations (Fatha and Dam) in neighboring countries have an age range of early Miocene (Aquitanian–Burdigalian) and even Burdigalian. This age has been determined by comparing the biological contents of the Gachsaran Formation with valid official biozones, as well as the presence of the index fossil Borelis melo curdica, to cover the information gap in the area. Isotopic studies of these sections in the region show that the maximum age of these sediments is early Miocene (Burdigalian), and this confirms the results of biostratigraphic studies.
{"title":"Age of the Gachsaran Formation and equivalent formations in the Middle East based on Foraminifera","authors":"Behnam Sakhavati, Mostaa Yousefirad, M. Majidifard, A. Solgi, Z. Maleki","doi":"10.47894/mpal.66.5.06","DOIUrl":"https://doi.org/10.47894/mpal.66.5.06","url":null,"abstract":"The Gachsaran Formation from the Fars Group has a vast extent in Saudi Arabia, United Arab Emirates and Qatar (Dam Formation). It extends from the Zagros Folded Belt Zone in the south of Iran to the north of Iraq, and even to northeast Syria (Fatha Formation). In order to eliminate the ambiguities of the proposed age and cover the regional information misplacements in cases where biostratigraphy studies can be effective, surface outcrops of these deposits were investigated in three stratigraphic sections near the border of Iran and Iraq, in the area behind the mountains of the Lurestan region (Posht-e-Kuh arc). According to similar results obtained in two other sections, the age of the Gachsaran Formation in the studied region is considered to be Early Miocene (Late Burdigalian). Comparison of the results of this study with biostratigraphic studies from other parts of the Middle East, which includes 16 study areas, shows that the Gachsaran Formation in Iran and its equivalent formations (Fatha and Dam) in neighboring countries have an age range of early Miocene (Aquitanian–Burdigalian) and even Burdigalian. This age has been determined by comparing the biological contents of the Gachsaran Formation with valid official biozones, as well as the presence of the index fossil Borelis melo curdica, to cover the information gap in the area. Isotopic studies of these sections in the region show that the maximum age of these sediments is early Miocene (Burdigalian), and this confirms the results of biostratigraphic studies.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47181641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Upper Cretaceous successions of the Arabian Platform in Batman and surroundings (SE Turkey) comprise the Garzan and Lower Germav formations. Shallow water limestones of the Garzan Formation contain rich benthic foraminiferal assemblages. The conformably overlying LowerGermav Formation consists mostly of marls and includes planktonic foraminifera, which suggest a relatively deeper marine environment. Benthic and planktonic foraminiferal assemblages fromboth formations were studied in 28 samples collected from a 155-m-thickmeasured section. Diverse benthic foraminiferal assemblages are mainly dominated by Orbitoides megaloformis Papp and Küpper, O. media (d’Archiac), Omphalocyclus anatoliensis Ozcan, Dicyclina schlumbergeri Munier-Chalmas, Trochospira avnimelechi Hamaoui, Nezzazata simplex Omara, Nezzazatinella picardi (Henson), Antalyna korayi Farinacci and Koyluoglu, Fleuryana adriatica (DeCastro), Biconcava bentori Hamaoui, Cuneolina pavonia d’Orbigny,C. ketini Inan, Moncharmontia apenninica (DeCastro), M. compressa (De Castro), Fissoelphidium operculiferum Smout and Vandenbroekia munieri Marie. Themajority of Late Cretaceous taxa are long-ranging. Orbitoides media and O. megaloformis within this assemblage have been documented both in the upper Campanian and Maastrichtian strata from the Tethyan Province. The age of the Garzan Formation is determined to be Maastrichtian based on the presence of Antalyna korayi, C. ketini and Fleuryana adriaticia. The abundance of opportunist planktonic foraminifera (i.e., biserial heterohelicids and rugoglobigerinids) throughout the Lower Germav Formation shows that the environmentwas not very deep during the deposition of the unit. Maastrichtian taxa such as Globotruncanita conica (White) and Globotruncanella minuta Caron and Gonzales Donoso appear in the middle part of the Lower Germav Formation, but these are absent from the lower part of the formation.
{"title":"Foraminifera from the Maastrichtian Garzan and Lower Germav formations of the Arabian Platform (Batman, SE Turkey)","authors":"Derya Sinanoğlu, N. Ozgen-Erdem, Bilal Sarı","doi":"10.47894/mpal.66.5.05","DOIUrl":"https://doi.org/10.47894/mpal.66.5.05","url":null,"abstract":"The Upper Cretaceous successions of the Arabian Platform in Batman and surroundings (SE Turkey) comprise the Garzan and Lower Germav formations. Shallow water limestones of the Garzan Formation contain rich benthic foraminiferal assemblages. The conformably overlying LowerGermav Formation consists mostly of marls and includes planktonic foraminifera, which suggest a relatively deeper marine environment. Benthic and planktonic foraminiferal assemblages fromboth formations were studied in 28 samples collected from a 155-m-thickmeasured section. Diverse benthic foraminiferal assemblages are mainly dominated by Orbitoides megaloformis Papp and Küpper, O. media (d’Archiac), Omphalocyclus anatoliensis Ozcan, Dicyclina schlumbergeri Munier-Chalmas, Trochospira avnimelechi Hamaoui, Nezzazata simplex Omara, Nezzazatinella picardi (Henson), Antalyna korayi Farinacci and Koyluoglu, Fleuryana adriatica (DeCastro), Biconcava bentori Hamaoui, Cuneolina pavonia d’Orbigny,C. ketini Inan, Moncharmontia apenninica (DeCastro), M. compressa (De Castro), Fissoelphidium operculiferum Smout and Vandenbroekia munieri Marie. Themajority of Late Cretaceous taxa are long-ranging. Orbitoides media and O. megaloformis within this assemblage have been documented both in the upper Campanian and Maastrichtian strata from the Tethyan Province. The age of the Garzan Formation is determined to be Maastrichtian based on the presence of Antalyna korayi, C. ketini and Fleuryana adriaticia. The abundance of opportunist planktonic foraminifera (i.e., biserial heterohelicids and rugoglobigerinids) throughout the Lower Germav Formation shows that the environmentwas not very deep during the deposition of the unit. Maastrichtian taxa such as Globotruncanita conica (White) and Globotruncanella minuta Caron and Gonzales Donoso appear in the middle part of the Lower Germav Formation, but these are absent from the lower part of the formation.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47604771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Here we present a detailed taxonomic study of Alveolina assemblages from the Hormak section, northern Zahedan, Iran. The Alveolina specimens have been recovered from a 16 meters thick shallow-water Eocene succession cropping out in an area of limited extent. Sixteen species have been identified including Alveolina cf. oblonga, A. ruetimeyeri, A. minuta, A. cf. cosigena, A. sp. cf. A. schwageri, A. sp. aff. A. azzarolii, A. haymanaensis, A. canavarii, A. canavarii karsakensis, A. coudurensis, A. histrica histrica, A. bayburtensis, A. cf. azzarolii, A. stercusmuris, A. kieli and A. elliptica nuttalli. The record of Alveolina species spans from SBZ10 (early Cuisian) to SBZ13 (early Lutetian). The systematic study provides new insight on the paleobiogeographic dispersal among the Sistan Ocean zone (central Tethys region) and may permit to make projections for future studies on neighboring Tethyan regions.
{"title":"Upper Ypresian to Lower Lutetian (SBZ 10 to 13) Alveolina stratigraphic horizons from the Hormak section, Zahedan District, Sistan Suture Zone, Eastern Iran","authors":"مهدی هادی, لورنزو کونسورتی, M. Vahidinia","doi":"10.47894/mpal.66.4.04","DOIUrl":"https://doi.org/10.47894/mpal.66.4.04","url":null,"abstract":"Here we present a detailed taxonomic study of Alveolina assemblages from the Hormak section, northern Zahedan, Iran. The Alveolina specimens have been recovered from a 16 meters thick shallow-water Eocene succession cropping out in an area of limited extent. Sixteen species have been identified including Alveolina cf. oblonga, A. ruetimeyeri, A. minuta, A. cf. cosigena, A. sp. cf. A. schwageri, A. sp. aff. A. azzarolii, A. haymanaensis, A. canavarii, A. canavarii karsakensis, A. coudurensis, A. histrica histrica, A. bayburtensis, A. cf. azzarolii, A. stercusmuris, A. kieli and A. elliptica nuttalli. The record of Alveolina species spans from SBZ10 (early Cuisian) to SBZ13 (early Lutetian). The systematic study provides new insight on the paleobiogeographic dispersal among the Sistan Ocean zone (central Tethys region) and may permit to make projections for future studies on neighboring Tethyan regions.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42558123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Atusa Honarmand, M. Vahidinia, M. H. M. Gharaie, میثم شفیعی اردستانی
The Upper Cretaceous Abtalkh Formation of the Kopet-Dagh Basin (northeastern Iran) was studied in four stratigraphic sections (Bahadorkhan, Hammam Galeh, Type section and Shorab). All sections display limestones, shales and calcareous shales. The Bahadorkhan section is approximately 480 m thick. We identified 32 planktonic foraminifera species belonging to 13 genera in 6 biozones: 1. Dicarinella asymetrica Total Range Zone, 2. Globotruncanita elevata Partial Range Zone, 3. Contusotruncana plummerae Interval Zone, 4. Radotruncana calcarata Total Range Zone, 5. Globotruncanella havanensis Partial Range Zone and Globotruncana aegyptiaca Interval Zone. Based on foraminiferal biostratigraphy, the Bahadorkhan section was dated to the latest Santonian to late Campanian. This study identifies 11 genera and 25 species of planktonic foraminifera in the 1500m thick Hammam Galeh section, spanning 7 biozones: 1. Dicarinella asymetrica Total Range Zone, 2. Globotruncanita elevata Partial Range Zone, 3. Contusotruncana plummerae Interval Zone, 4. Radotruncana calcarata Total Range Zone, 5. Globotruncanella havanensis Partial Range Zone, 6. Globotruncana aegyptiaca Interval Zone, 7. Gansserina gansseri Interval Zone. Latest Santonian to late Campanian ages have been established for the Abtalkh Formation. The type locality of the Abtalkh Formation is 750mthick and contains 31 planktonic foraminiferal species belonging to 12 genera. Based on this fossil content, we identified 6 biozones. The age of the formation is estimated to be the latest Santonian to late Campanian, as for the Bahadorkhan type section. The Shorab section of the Abtalkh Formation is 990m thick. In this section, 19 species belonging to 10 genera were identified, as were 5 biozones: 1. Globotruncanita elevata Partial Range Zone, 2. Contusotruncana plummerae Interval Zone, 3. Radotruncana calcarata Total Range Zone, 4. Globotruncanella havanensis Partial Range Zone, 5. Globotruncana aegyptiaca Interval Zone. Based on this fossil assemblage, the Shorab section dates to the early to late Campanian.
{"title":"Biostratigraphy of Upper Cretaceous planktonic foraminifera of the Abtalkh Formation in an east-west transect, Kopet-Dagh Basin, northeastern Iran","authors":"Atusa Honarmand, M. Vahidinia, M. H. M. Gharaie, میثم شفیعی اردستانی","doi":"10.47894/mpal.66.4.02","DOIUrl":"https://doi.org/10.47894/mpal.66.4.02","url":null,"abstract":"The Upper Cretaceous Abtalkh Formation of the Kopet-Dagh Basin (northeastern Iran) was studied in four stratigraphic sections (Bahadorkhan, Hammam Galeh, Type section and Shorab). All sections display limestones, shales and calcareous shales. The Bahadorkhan section is approximately 480 m thick. We identified 32 planktonic foraminifera species belonging to 13 genera in 6 biozones: 1. Dicarinella asymetrica Total Range Zone, 2. Globotruncanita elevata Partial Range Zone, 3. Contusotruncana plummerae Interval Zone, 4. Radotruncana calcarata Total Range Zone, 5. Globotruncanella havanensis Partial Range Zone and Globotruncana aegyptiaca Interval Zone. Based on foraminiferal biostratigraphy, the Bahadorkhan section was dated to the latest Santonian to late Campanian. This study identifies 11 genera and 25 species of planktonic foraminifera in the 1500m thick Hammam Galeh section, spanning 7 biozones: 1. Dicarinella asymetrica Total Range Zone, 2. Globotruncanita elevata Partial Range Zone, 3. Contusotruncana plummerae Interval Zone, 4. Radotruncana calcarata Total Range Zone, 5. Globotruncanella havanensis Partial Range Zone, 6. Globotruncana aegyptiaca Interval Zone, 7. Gansserina gansseri Interval Zone. Latest Santonian to late Campanian ages have been established for the Abtalkh Formation. The type locality of the Abtalkh Formation is 750mthick and contains 31 planktonic foraminiferal species belonging to 12 genera. Based on this fossil content, we identified 6 biozones. The age of the formation is estimated to be the latest Santonian to late Campanian, as for the Bahadorkhan type section. The Shorab section of the Abtalkh Formation is 990m thick. In this section, 19 species belonging to 10 genera were identified, as were 5 biozones: 1. Globotruncanita elevata Partial Range Zone, 2. Contusotruncana plummerae Interval Zone, 3. Radotruncana calcarata Total Range Zone, 4. Globotruncanella havanensis Partial Range Zone, 5. Globotruncana aegyptiaca Interval Zone. Based on this fossil assemblage, the Shorab section dates to the early to late Campanian.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43222924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ecostratigraphy of offshore North Coast of Trinidad and near Tobago is poorly resolved, although biogenic gas production for which it would be useful is widespread. Recent work has shown that a wake and eddy in the Guiana Current and Orinoco Plume to the lee of NWTobago influence benthic foraminiferal assemblages. This ecostratigraphical study of planktonic foraminiferal assemblages examines three piston cores taken on the lee of NW Tobago. Core 1 (upper bathyal) was most distal to the nutrient-rich Orinoco Plume and Core 3 (outer neritic) the most proximal. The assemblage turnover index (ATI) and analysis of variance (ANOVA) determined that the relative community stability at each site did not differ, showing similar community stabilities within the wake and plume. However, an abnormally high abundance of the deep-dwelling, nutrient-loving Globorotalia truncatulinoidesdextral in Core 2 indicated an oceanographic boundary between Cores 1 and 2 along which the Orinoco Plume abuts the oligotrophic ocean. This is reflected in the distributions of other planktonic foraminiferal morphotypes such as G. bulloides, Gn. obesa and G. ruberpink. SHE analysis detected two biozones in Cores 2 and 3, possibly marking a change in nutrient influx. Principal component analysis reinforced the nutrient influx as amajor factor acting at Cores 2 and 3 in thewake andOrinoco Plume, Core 2 being seasonally impactedwhile Core 3 lies permanently within the Orinoco Plume. We conclude that oceanographic complexity off NW Tobago affects the distributions of planktonic foraminiferal morphotypes at the kilometer scale. Our results will prove to be a powerful tool in deciphering the geological history of the Orinoco Plume.
{"title":"Effects of flow disturbances on Holocene planktonic foraminiferal ecostratigraphy","authors":"Lai Shan Sum, B. Wilson, Chantelle Ragoonath","doi":"10.47894/mpal.66.2.03","DOIUrl":"https://doi.org/10.47894/mpal.66.2.03","url":null,"abstract":"The ecostratigraphy of offshore North Coast of Trinidad and near Tobago is poorly resolved, although biogenic gas production for which it would be useful is widespread. Recent work has shown that a wake and eddy in the Guiana Current and Orinoco Plume to the lee of NWTobago influence benthic foraminiferal assemblages. This ecostratigraphical study of planktonic foraminiferal assemblages examines three piston cores taken on the lee of NW Tobago. Core 1 (upper bathyal) was most distal to the nutrient-rich Orinoco Plume and Core 3 (outer neritic) the most proximal. The assemblage turnover index (ATI) and analysis of variance (ANOVA) determined that the relative community stability at each site did not differ, showing similar community stabilities within the wake and plume. However, an abnormally high abundance of the deep-dwelling, nutrient-loving Globorotalia truncatulinoidesdextral in Core 2 indicated an oceanographic boundary between Cores 1 and 2 along which the Orinoco Plume abuts the oligotrophic ocean. This is reflected in the distributions of other planktonic foraminiferal morphotypes such as G. bulloides, Gn. obesa and G. ruberpink. SHE analysis detected two biozones in Cores 2 and 3, possibly marking a change in nutrient influx. Principal component analysis reinforced the nutrient influx as amajor factor acting at Cores 2 and 3 in thewake andOrinoco Plume, Core 2 being seasonally impactedwhile Core 3 lies permanently within the Orinoco Plume. We conclude that oceanographic complexity off NW Tobago affects the distributions of planktonic foraminiferal morphotypes at the kilometer scale. Our results will prove to be a powerful tool in deciphering the geological history of the Orinoco Plume.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70444121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pseudorhapydionina moulladei Pêcheux 1995 from the Paleocene of Mexico is taxonomically revised herein. Due to the presence of a bi- or tri-serial growth instead of planispiral juvenile stage, the species cannot be included in Pseudorhapydionina De Castro. Instead, it is assigned to Serrakielina Schlagintweit and Rashidi becoming S. moulladei (Pecheux 1995) comb. nov. The differences to the type-species S. chahtorshiana (Paleocene of Iran) bear on the thickness of septula, general dimensions, number of branches in the stellate foramina, which result in S. moulladei as being smaller than S. chahtorshiana, but having thicker setptula especially in the adult chambers. Based on our observations and studying the records available from the literature, it is concluded that Serrakielina moulladei (Pecheux 1995) comb. nov. and S. chahtorshiana characterize the Paleocene Caribbean and Central Tethys bioprovinces, respectively. Further records of Serrakielina sp. from the literature have been found in the Paleocene of Spain and Guatemala.
{"title":"Serrakielina moulladei (Pecheux 1995) comb. nov., a further inhabitant of the Caribbean foraminiferal bioprovince during the Paleocene","authors":"F. Schlagintweit, L. Consorti","doi":"10.47894/mpal.66.6.03","DOIUrl":"https://doi.org/10.47894/mpal.66.6.03","url":null,"abstract":"Pseudorhapydionina moulladei Pêcheux 1995 from the Paleocene of Mexico is taxonomically revised herein. Due to the presence of a bi- or tri-serial growth instead of planispiral juvenile stage, the species cannot be included in Pseudorhapydionina De Castro. Instead, it is assigned to Serrakielina Schlagintweit and Rashidi becoming S. moulladei (Pecheux 1995) comb. nov. The differences to the type-species S. chahtorshiana (Paleocene of Iran) bear on the thickness of septula, general dimensions, number of branches in the stellate foramina, which result in S. moulladei as being smaller than S. chahtorshiana, but having thicker setptula especially in the adult chambers. Based on our observations and studying the records available from the literature, it is concluded that Serrakielina moulladei (Pecheux 1995) comb. nov. and S. chahtorshiana characterize the Paleocene Caribbean and Central Tethys bioprovinces, respectively. Further records of Serrakielina sp. from the literature have been found in the Paleocene of Spain and Guatemala.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70444764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In 1983 one of us (JGV) in collaboration with J. Van Hinte described the new foraminiferal species Hyperammina rugosa from the Oligocene of DSDP Hole 345 in the Norwegian Sea. It was also reported from the Eocene at Site 346, Lower Miocene at Site 348, and the Oligocene-Miocene at Site 348 (Verdenius and Van Hinte 1983). The species Hyperammina rugosa was subsequently reported throughout the North Sea, Norwegian Sea, and Barents Sea region (Kaminski and Gradstein 2005). The species has been reported more recently from the Miocene of the Fram Strait region and the Central Arctic Ocean by Kaminski et al. (2005, 2009), from the Upper Cretaceous (Santonian–Campanian) of the southern Norwegian Sea by Setoyama and Kaminski (2015), and from the Upper Cretaceous to Paleogene of the Outer Carpathian region by Bindiu et al. (2019) and by Bubik (2019).
1983年，我们中的一个人(JGV)与J. Van Hinte合作，描述了挪威海DSDP 345孔渐新世的有孔虫新物种Hyperammina rugosa。在346号遗址始新世、348号遗址中新世下和348号遗址渐新世-中新世也有报道(Verdenius and Van Hinte 1983)。随后，在北海、挪威海和巴伦支海地区陆续发现了该物种Hyperammina rugosa (Kaminski and Gradstein 2005)。最近，卡明斯基等人(2005年，2009年)在弗拉姆海峡地区中新世和北冰洋中部报道了该物种，Setoyama和卡明斯基(2015年)在挪威海南部的上白垩纪(圣安东尼奥- -坎帕尼亚)报道了该物种，Bindiu等人(2019年)和Bubik(2019年)在喀尔巴阡山脉外地区的上白垩纪至古近纪报道了该物种。
{"title":"Hyperammina grosserugosa, nom. nov., a replacement name for Hyperammina rugosa Verdenius and Van Hinte 1983","authors":"J. Verdenius, M. Kaminski","doi":"10.47894/mpal.66.6.07","DOIUrl":"https://doi.org/10.47894/mpal.66.6.07","url":null,"abstract":"In 1983 one of us (JGV) in collaboration with J. Van Hinte described the new foraminiferal species Hyperammina rugosa from the Oligocene of DSDP Hole 345 in the Norwegian Sea. It was also reported from the Eocene at Site 346, Lower Miocene at Site 348, and the Oligocene-Miocene at Site 348 (Verdenius and Van Hinte 1983). The species Hyperammina rugosa was subsequently reported throughout the North Sea, Norwegian Sea, and Barents Sea region (Kaminski and Gradstein 2005). The species has been reported more recently from the Miocene of the Fram Strait region and the Central Arctic Ocean by Kaminski et al. (2005, 2009), from the Upper Cretaceous (Santonian–Campanian) of the southern Norwegian Sea by Setoyama and Kaminski (2015), and from the Upper Cretaceous to Paleogene of the Outer Carpathian region by Bindiu et al. (2019) and by Bubik (2019).","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70445060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Based on the distinctly higher number of species of Orbitolinidae in the Cretaceous compared to the Paleogene, the former have witnessed much more taxonomic analyses. Although, there has been a "lively" debate among specialists working on Cretaceous taxa, it is rather broad consensus that the presence/absence of horizontal partitions (= rafters; part of exoskeleton) in the marginal zone is a criterion of specific rank. Recently, however, another taxonomic concept has been used for Paleogene Orbitolinidae by giving this trait generic rank (Fallotella vs. Pseudofallotella). If applied to the Cretaceous, this approach would result in artificial groups and the creation of several new genera for currently used species that both include species with and without rafters (Coskinolinella, Heterocoskinolina, Montseciella, Paracoskinolina, Praedictyorbitolina, Simplorbitolina, Valserina). The present contribution is a plea for a uniform taxonomic approach, preferring the simpler, longer, wider and more natural usage of the "Cretaceous approach". Further difficulties on the taxonomical ranking of Orbitolinidae features are due to their fossil nature (extinct group), as no modern representatives are available for comparisons. This fact also speaks for the use of a pragmatic and uniform approach.
{"title":"Taxonomic use of the exoskeleton in the family Orbitolinidae (Foraminifera): Aplea for a uniform Cretaceous/Paleogene approach","authors":"F. Schlagintweit","doi":"10.47894/mpal.66.1.03","DOIUrl":"https://doi.org/10.47894/mpal.66.1.03","url":null,"abstract":"Based on the distinctly higher number of species of Orbitolinidae in the Cretaceous compared to the Paleogene, the former have witnessed much more taxonomic analyses. Although, there has been a \"lively\" debate among specialists working on Cretaceous taxa, it is rather broad consensus that the presence/absence of horizontal partitions (= rafters; part of exoskeleton) in the marginal zone is a criterion of specific rank. Recently, however, another taxonomic concept has been used for Paleogene Orbitolinidae by giving this trait generic rank (Fallotella vs. Pseudofallotella). If applied to the Cretaceous, this approach would result in artificial groups and the creation of several new genera for currently used species that both include species with and without rafters (Coskinolinella, Heterocoskinolina, Montseciella, Paracoskinolina, Praedictyorbitolina, Simplorbitolina, Valserina). The present contribution is a plea for a uniform taxonomic approach, preferring the simpler, longer, wider and more natural usage of the \"Cretaceous approach\". Further difficulties on the taxonomical ranking of Orbitolinidae features are due to their fossil nature (extinct group), as no modern representatives are available for comparisons. This fact also speaks for the use of a pragmatic and uniform approach.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"128 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70443695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patterns of diversity in the modern planktic foraminifera indicate a latitudinal diversity gradient (LDG), which peaks in the mid-latitude regions. Plankton distributional patterns are oftenmost strongly associated with temperature and are expected to change in response to expanded tropical water masses. Defining the underlying causes of climatic and oceanographic processes, however, requires detailed, local-scale diversity curves and evolutionary metrics, as well as solid taxonomic concepts of planktic foraminifera, to test the oceanographic processes driving evolution ofmarine plankton. Currently, diversity estimates for the planktic foraminifera are mainly based on global datasets skewed towards tropical to subtropical sites and conducted at coarse resolutions that hamper investigations of evolutionary processes, especially for short-lived climate perturbations. Here, we present 10-kyr resolution diversity curves and 25-kyr resolution local first appearance and extirpation rates of planktic foraminifera for four Ocean Drilling Program sites that extend from the temperate northern edge of the modern-day position of the Kuroshio Current Extension (KCE) to the tropics. We provide an updated taxonomic review of late Neogene planktic foraminiferal species from within the influence of the KCE. These data allow for investigations of the western Pacific LDG and patterns of evolution through the late Neogene in response to tectonic and climate events. Our results indicate that a mid-latitude diversity peak has been prominent in the western Pacific since at least 12.1Ma, with highest diversity generally on the northern edge of the KCE. These data contradict previous studies indicating highest diversity is located +/- 20 degrees, as our data reveal highest diversity for the planktic foraminifera at +/- 35 degrees N likely due to strong seasonality. Development of the modern North Pacific gyre system due to closure of the Central American Seaway and constriction of the Indonesian Throughflow increased the LDG between the tropics and the northernmost site, likely in response to KCE intensification. Diversity was only slightly affected during the mid-Piacenzian Warm Period (approx. 3.2-2.9Ma),with diversity gradients between the equatorial site and southernmost mid-latitude sites becoming similar, perhaps indicating a weaker thermal gradient developing in the northwest Pacific as the KCE and warmer waters were displaced northwards.With intensification of Northern Hemisphere glaciation came a decrease in diversity at the northernmost site, hypothesized to be caused by subtropical gyre constriction and southward displacement of subpolar surface waters. The beginning of the mid-Pleistocene transition marks an increase in diversity gradients, especially between the northernmost and tropical sites. A detailed taxonomic evaluation of planktic foraminiferal species has led to synonymization of what we consider regional morphological variants, as well as revised ta
{"title":"Late Neogene and Quaternary diversity and taxonomy of subtropical to temperate planktic foraminifera across the Kuroshio Current Extension, northwest Pacific Ocean","authors":"A. Lam, R. Leckie","doi":"10.47894/mpal.66.3.01","DOIUrl":"https://doi.org/10.47894/mpal.66.3.01","url":null,"abstract":"Patterns of diversity in the modern planktic foraminifera indicate a latitudinal diversity gradient (LDG), which peaks in the mid-latitude regions. Plankton distributional patterns are oftenmost strongly associated with temperature and are expected to change in response to expanded tropical water masses. Defining the underlying causes of climatic and oceanographic processes, however, requires detailed, local-scale diversity curves and evolutionary metrics, as well as solid taxonomic concepts of planktic foraminifera, to test the oceanographic processes driving evolution ofmarine plankton. Currently, diversity estimates for the planktic foraminifera are mainly based on global datasets skewed towards tropical to subtropical sites and conducted at coarse resolutions that hamper investigations of evolutionary processes, especially for short-lived climate perturbations. Here, we present 10-kyr resolution diversity curves and 25-kyr resolution local first appearance and extirpation rates of planktic foraminifera for four Ocean Drilling Program sites that extend from the temperate northern edge of the modern-day position of the Kuroshio Current Extension (KCE) to the tropics. We provide an updated taxonomic review of late Neogene planktic foraminiferal species from within the influence of the KCE. These data allow for investigations of the western Pacific LDG and patterns of evolution through the late Neogene in response to tectonic and climate events. Our results indicate that a mid-latitude diversity peak has been prominent in the western Pacific since at least 12.1Ma, with highest diversity generally on the northern edge of the KCE. These data contradict previous studies indicating highest diversity is located +/- 20 degrees, as our data reveal highest diversity for the planktic foraminifera at +/- 35 degrees N likely due to strong seasonality. Development of the modern North Pacific gyre system due to closure of the Central American Seaway and constriction of the Indonesian Throughflow increased the LDG between the tropics and the northernmost site, likely in response to KCE intensification. Diversity was only slightly affected during the mid-Piacenzian Warm Period (approx. 3.2-2.9Ma),with diversity gradients between the equatorial site and southernmost mid-latitude sites becoming similar, perhaps indicating a weaker thermal gradient developing in the northwest Pacific as the KCE and warmer waters were displaced northwards.With intensification of Northern Hemisphere glaciation came a decrease in diversity at the northernmost site, hypothesized to be caused by subtropical gyre constriction and southward displacement of subpolar surface waters. The beginning of the mid-Pleistocene transition marks an increase in diversity gradients, especially between the northernmost and tropical sites. A detailed taxonomic evaluation of planktic foraminiferal species has led to synonymization of what we consider regional morphological variants, as well as revised ta","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"14 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70444524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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