The new foraminiferal species Buzasina antarctica n.sp. is described from the Upper Cretaceous (Turonian) from IODP Site U1512 drilled in the Great Australian Bight. Compared with the type species, the new species is characterized by its larger dimensions, greater number of chambers, and less embracing final chamber. It is the only representative of the genus Buzasina found thus far in the Cretaceous of the high austral latitudes.
{"title":"Buzasina antarctica n. sp., a new lituolid foraminifer from the Upper Cretaceous at IODP Site 1512, Great Australian Bight","authors":"M. Kaminski, E. Wolfgring, A. Waśkowska","doi":"10.47894/mpal.66.2.04","DOIUrl":"https://doi.org/10.47894/mpal.66.2.04","url":null,"abstract":"The new foraminiferal species Buzasina antarctica n.sp. is described from the Upper Cretaceous (Turonian) from IODP Site U1512 drilled in the Great Australian Bight. Compared with the type species, the new species is characterized by its larger dimensions, greater number of chambers, and less embracing final chamber. It is the only representative of the genus Buzasina found thus far in the Cretaceous of the high austral latitudes.","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":"70443733","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}
C. T. Bergue, Maria da Saudade Araujo Santos Maranhao, Christiano Ng
Twenty-five species of Podocopida are reported in seven localities in the Sao Paulo State, Brazil, corresponding to the Serra Alta and Teresina formations (Middle to Upper Permian). The specimens are mostly preserved as steinkerns (internal molds), except some carbonitids and cytherocopines which are predominantly recrystallized. The results indicate marginal marine environments influenced by influxes of nonmarine waters, as suggested by the occurrence of Velatomorpha, Gutschickia, Carbonita and Darwinuloidea. Velatomorpha rochacamposi sp. nov. is described, and evidences of predation are reported for the first time in Paleozoic ostracods. This study contributes to the understanding of the ecology and evolution of nonmarine ostracods during the Late Paleozoic.
{"title":"The Permian podocopids (Crustacea: Ostracoda) from the Serra Alta and Teresina formations, Parana Basin, Brazil","authors":"C. T. Bergue, Maria da Saudade Araujo Santos Maranhao, Christiano Ng","doi":"10.47894/mpal.66.4.03","DOIUrl":"https://doi.org/10.47894/mpal.66.4.03","url":null,"abstract":"Twenty-five species of Podocopida are reported in seven localities in the Sao Paulo State, Brazil, corresponding to the Serra Alta and Teresina formations (Middle to Upper Permian). The specimens are mostly preserved as steinkerns (internal molds), except some carbonitids and cytherocopines which are predominantly recrystallized. The results indicate marginal marine environments influenced by influxes of nonmarine waters, as suggested by the occurrence of Velatomorpha, Gutschickia, Carbonita and Darwinuloidea. Velatomorpha rochacamposi sp. nov. is described, and evidences of predation are reported for the first time in Paleozoic ostracods. This study contributes to the understanding of the ecology and evolution of nonmarine ostracods during the Late Paleozoic.","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":"70444196","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 new Larger Benthic Foraminifera Pseudochoffatella minima n. sp. is described from the uppermost Barremian? to early upperAptian of the Taft Formation of theYazd Block, Central Iran. It differs from the upperAptian-lowermostAlbian type-species P. cuvillieri Deloffre by its reduced dimensions (test size, chamber height, diameter of proloculus), and can be considered as its direct ancestor. P. minima n. sp. occurs in wackestone in often monotypic assemblages. Differences to Balkhania balkhanica Mamontova (syn. Pseudochoffatella giganteaKaever), an allied taxon recorded from the lower Aptian of the Tirgan and Taft formations are constrained. P. minima n. sp. represents the third species of the genus besides the type-species P. cuvillieri Deloffre and the Cenomanian P. algeriana Peybernès, Calvez and Ciszak.
新发现的大底栖有孔虫Pseudochoffatella minima n. sp.来自巴雷米亚最上层?伊朗中部西azd地块塔夫脱组早上天纪。它与上aptian -下mostalbian模式种P. cuvillieri Deloffre在尺寸(试验尺寸、室高、前叶直径)上有所不同，可以认为是其直系祖先。小孢子虫通常在单型组合中出现在尾岩中。与Tirgan和Taft组下Aptian记录的同类分类群Balkhania balkhanica Mamontova(同:Pseudochoffatella giganteaKaever)的差异受到限制。除模式种P. cuvillieri Deloffre和Cenomanian P. algeriana Peybernès、Calvez和Ciszak外，P. minima n. sp.是该属的第三种。
{"title":"Pseudochoffatella minima n. sp., a new Larger Benthic Foraminifera from the Lower Cretaceous of Central Iran","authors":"F. Schlagintweit, K. Rashidi, Reza Hanifzadeh","doi":"10.47894/mpal.66.2.08","DOIUrl":"https://doi.org/10.47894/mpal.66.2.08","url":null,"abstract":"The new Larger Benthic Foraminifera Pseudochoffatella minima n. sp. is described from the uppermost Barremian? to early upperAptian of the Taft Formation of theYazd Block, Central Iran. It differs from the upperAptian-lowermostAlbian type-species P. cuvillieri Deloffre by its reduced dimensions (test size, chamber height, diameter of proloculus), and can be considered as its direct ancestor. P. minima n. sp. occurs in wackestone in often monotypic assemblages. Differences to Balkhania balkhanica Mamontova (syn. Pseudochoffatella giganteaKaever), an allied taxon recorded from the lower Aptian of the Tirgan and Taft formations are constrained. P. minima n. sp. represents the third species of the genus besides the type-species P. cuvillieri Deloffre and the Cenomanian P. algeriana Peybernès, Calvez and Ciszak.","PeriodicalId":49816,"journal":{"name":"Micropaleontology","volume":"92 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70444436","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}
M. H. Malik, L. Babalola, K. Al-Ramadan, M. Kaminski
The Middle Jurassic Dhruma Formation of Saudi Arabia is of economic importance because it contains three hydrocarbon reservoirs. We report the first record of physically extracted benthic foraminiferal assemblages from the Middle Jurassic D5 and D6 member outcrops near Riyadh, Central Saudi Arabia, using the acetic acid method. This study of Middle Jurassic limestone units is intended to improve our understanding about the depositional environments of the area and related bio-events. Microfossils such as foraminifera are important in this aspect in that they can be recovered from core samples where entiremacrofossils such as ammonites are rare. This study focuses on the taxonomy and biostratigraphy of the foraminifera and examines their contribution to the previously established Jurassic biozonation.Atotal of 35 species belonging to 19 genera are identified. Ten sedimentological facies showing depositional energy variations from deep marine muds to shallow high-energy oolitic grainstones are identified. The extracted foraminifera are tied to the stratigraphic and sedimentological columns of the D5–D6 member outcrop. The depositional environment model of this portion of the formation is interpreted to be an open marine ramp setting.
{"title":"Integrated micropaleontology, sedimentology and sequence stratigraphy of the Middle Jurassic D5-D6 Members of the Dhruma Formation, Central Saudi Arabia","authors":"M. H. Malik, L. Babalola, K. Al-Ramadan, M. Kaminski","doi":"10.47894/mpal.66.6.05","DOIUrl":"https://doi.org/10.47894/mpal.66.6.05","url":null,"abstract":"The Middle Jurassic Dhruma Formation of Saudi Arabia is of economic importance because it contains three hydrocarbon reservoirs. We report the first record of physically extracted benthic foraminiferal assemblages from the Middle Jurassic D5 and D6 member outcrops near Riyadh, Central Saudi Arabia, using the acetic acid method. This study of Middle Jurassic limestone units is intended to improve our understanding about the depositional environments of the area and related bio-events. Microfossils such as foraminifera are important in this aspect in that they can be recovered from core samples where entiremacrofossils such as ammonites are rare. This study focuses on the taxonomy and biostratigraphy of the foraminifera and examines their contribution to the previously established Jurassic biozonation.Atotal of 35 species belonging to 19 genera are identified. Ten sedimentological facies showing depositional energy variations from deep marine muds to shallow high-energy oolitic grainstones are identified. The extracted foraminifera are tied to the stratigraphic and sedimentological columns of the D5–D6 member outcrop. The depositional environment model of this portion of the formation is interpreted to be an open marine ramp setting.","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":"70444903","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}
M. Hadi, N. Ozgen-Erdem, Derya Sinanoğlu, S. Sarkar, Azam Zareh
Benthic foraminiferal assemblages dominated by Alveolina species from the Ypresian (Ilerdian-Cuisian) are studied herein from numerous localities of Iran and Turkey. From these successions, highly diversified assemblage of 58 alveolinid species are identified along with their detailed biostratigraphical application, which resulted in the recognition of eight shallow benthic zones (SBZ5-SBZ12). Our findings are based upon the distribution ranges of Alveolina from the Ilerdian-Cuisian sediments in Iran (Central Tethys) that are considered to have a strong affinity with their coeval fauna in Turkey (Western Tethys). In this study, the wide expansion ranges of Alveolina permit us to achieve a high-resolution biostratigraphy and apply the shallow benthic zones of the peri-Mediterranean region (Western Tethys) to the Ilerdian-Cuisian successions in Iran (Central Tethys). Nevertheless, the distribution of some Alveolina species, even the zonalmarkers consisting of Glomalveolina lepidula, Alveolina ellipsoidalis, A. pisiformis, A. laxa, A. subpyrenaica, A. varians, A. fornasinii and A. canavarii are found occurring at younger stratigraphic levels in Iran and/or Turkey than in the western European shallow marine deposits.
{"title":"Distribution of Alveolina assemblages in the Ypresian (Ilerdian-Cuisian) successions from Iran and Turkey (central and western Tethys): biostratigraphic implications for regional correlation","authors":"M. Hadi, N. Ozgen-Erdem, Derya Sinanoğlu, S. Sarkar, Azam Zareh","doi":"10.47894/mpal.66.1.02","DOIUrl":"https://doi.org/10.47894/mpal.66.1.02","url":null,"abstract":"Benthic foraminiferal assemblages dominated by Alveolina species from the Ypresian (Ilerdian-Cuisian) are studied herein from numerous localities of Iran and Turkey. From these successions, highly diversified assemblage of 58 alveolinid species are identified along with their detailed biostratigraphical application, which resulted in the recognition of eight shallow benthic zones (SBZ5-SBZ12). Our findings are based upon the distribution ranges of Alveolina from the Ilerdian-Cuisian sediments in Iran (Central Tethys) that are considered to have a strong affinity with their coeval fauna in Turkey (Western Tethys). In this study, the wide expansion ranges of Alveolina permit us to achieve a high-resolution biostratigraphy and apply the shallow benthic zones of the peri-Mediterranean region (Western Tethys) to the Ilerdian-Cuisian successions in Iran (Central Tethys). Nevertheless, the distribution of some Alveolina species, even the zonalmarkers consisting of Glomalveolina lepidula, Alveolina ellipsoidalis, A. pisiformis, A. laxa, A. subpyrenaica, A. varians, A. fornasinii and A. canavarii are found occurring at younger stratigraphic levels in Iran and/or Turkey than in the western European shallow marine deposits.","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":"70444039","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}
Cribellopsis Arnaud-Vanneau (upper Berriasian-Albian) represents a rather simple structured orbitolinid species that are classically differentiated above all by dimensional and morphological criteria. Previously reported from the upper Hauterivian to Albian interval, a new species is described as Cribellopsis delicatula n. sp. from the upper Berriasian-lower Valanginian of France, Switzerland ("Jura Mountains"; Vions, Chambotte, and Vuache formations), and Iran (Fahliyan Formation). Known since the sixties from southwestern Europe, it has been figured several times since then in open nomenclature. C. delicatula n. sp. is characterized by its high-conical test and delicate structural elements, combined with a reduced chamber height. Most Valanginian occurrences of the Orbitolinidae (including Cribellopsis) are from the former northern Neotethyan margin (Spain, France, Sardinia/Italy, Switzerland, Romania, Bulgaria, Serbia). Cribellopsis delicatula n. sp. represents the oldest known species of the genus and is here reported from both margins of the former Neotethyan ocean.
Cribellopsis Arnaud-Vanneau(上贝里亚-阿尔bian)是一种结构相当简单的眶鸟属物种，主要通过尺寸和形态标准进行区分。先前在上Hauterivian至Albian区间报道的一新种Cribellopsis delicatula n. sp.来自瑞士法国的上berriasia -下Valanginian(“Jura Mountains”;Vions, Chambotte和Vuache阵型)和Iran (Fahliyan阵型)。自60年代以来，它在欧洲西南部被人们所知，此后在公开命名法中被多次提及。其特点是其高锥形试验和精致的结构元素，结合降低室高。大多数在瓦兰吉尼亚出现的Orbitolinidae(包括Cribellopsis)来自前新特提斯北部边缘(西班牙、法国、撒丁岛/意大利、瑞士、罗马尼亚、保加利亚、塞尔维亚)。克里贝lopsis delicatula n. sp代表了该属已知的最古老的物种，在这里报道了来自前新特提斯海洋的两个边缘。
{"title":"Cribellopsis delicatula n. sp., an early Orbitolinidae from the upper Berriasian to lower Valanginian of SE France, Switzerland and Iran","authors":"F. Schlagintweit, M. Yazdi-Moghadam","doi":"10.47894/mpal.66.4.05","DOIUrl":"https://doi.org/10.47894/mpal.66.4.05","url":null,"abstract":"Cribellopsis Arnaud-Vanneau (upper Berriasian-Albian) represents a rather simple structured orbitolinid species that are classically differentiated above all by dimensional and morphological criteria. Previously reported from the upper Hauterivian to Albian interval, a new species is described as Cribellopsis delicatula n. sp. from the upper Berriasian-lower Valanginian of France, Switzerland (\"Jura Mountains\"; Vions, Chambotte, and Vuache formations), and Iran (Fahliyan Formation). Known since the sixties from southwestern Europe, it has been figured several times since then in open nomenclature. C. delicatula n. sp. is characterized by its high-conical test and delicate structural elements, combined with a reduced chamber height. Most Valanginian occurrences of the Orbitolinidae (including Cribellopsis) are from the former northern Neotethyan margin (Spain, France, Sardinia/Italy, Switzerland, Romania, Bulgaria, Serbia). Cribellopsis delicatula n. sp. represents the oldest known species of the genus and is here reported from both margins of the former Neotethyan ocean.","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":"70444352","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}
Three Guadalupian allochthonous debris flow beds in a slope-to-basin facies succession in northern Gilleland Canyon of the northwest Glass Mountains were sampled for fusulinid biostratigraphic age-dating. The deeper water allochthonous debris flow beds underlie the shelf-margin packstone-grainstone facies of the Willis Ranch Member of the Word Formation (3rd Word Limestone Bed of King 1931) (middle Guadalupian, early Wordian), which forms a distinct bench all along the west wall of Gilleland Canyon (114–169m above base of measured section). The uppermost GV-RC1 sample, from 104 m in the measured section, contained the fusulinids Parafusulina sellardsi, P. antimonioensis, P. deliciasensis, P. rothi, P. trumpyi, and P. boesei. SampleGV-CM1, from 83min the section, contained P. sellardsi, P. deliciasensis, P. rothi, P. boesei, and P. lineata. The lowest sample GV-CM20, from 76 m in the section, contained only P. deliciasensis and P. wildei. According to previous studies, most of these species appear in Roadian-aged strata and range upward into early Wordian-aged strata, but the common occurrence of P. sellardsi in the upper two samples, and the occurrence of P. antimonioensis in the uppermost sample confirm an early Wordian age.
{"title":"Fusulinids from slope debris flow beds in the Word Formation (Guadalupian, Middle Permian), Gilleland Canyon, northwestern Glass Mountains, West Texas","authors":"G. Wahlman, George C. Vaughan, M. Nestell","doi":"10.47894/mpal.66.6.01","DOIUrl":"https://doi.org/10.47894/mpal.66.6.01","url":null,"abstract":"Three Guadalupian allochthonous debris flow beds in a slope-to-basin facies succession in northern Gilleland Canyon of the northwest Glass Mountains were sampled for fusulinid biostratigraphic age-dating. The deeper water allochthonous debris flow beds underlie the shelf-margin packstone-grainstone facies of the Willis Ranch Member of the Word Formation (3rd Word Limestone Bed of King 1931) (middle Guadalupian, early Wordian), which forms a distinct bench all along the west wall of Gilleland Canyon (114–169m above base of measured section). The uppermost GV-RC1 sample, from 104 m in the measured section, contained the fusulinids Parafusulina sellardsi, P. antimonioensis, P. deliciasensis, P. rothi, P. trumpyi, and P. boesei. SampleGV-CM1, from 83min the section, contained P. sellardsi, P. deliciasensis, P. rothi, P. boesei, and P. lineata. The lowest sample GV-CM20, from 76 m in the section, contained only P. deliciasensis and P. wildei. According to previous studies, most of these species appear in Roadian-aged strata and range upward into early Wordian-aged strata, but the common occurrence of P. sellardsi in the upper two samples, and the occurrence of P. antimonioensis in the uppermost sample confirm an early Wordian age.","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":"70444551","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}
Multilocular benthic foraminifera are divisible into serial (Se) and spiral (Sp) morphogroups. Beneath oxic bottom waters, the Se morphogroup lives infaunally. Spiral species are typically epifaunal. Thus, the Se infauna react to different environmental factors from most Sp epifauna. Previous investigations of the Se:Sp ratio found that the serial infauna migrate toward the sediment/water interface with decreasing sediment oxygen levels, increasing the Se:Sp ratio in suboxic environments. We examine assemblage turnover within the Se and Sp morphogroups at two Brasso Formation exposures (planktonic foraminiferal Zones M4b-M6, deep middle bathyal palaeodepth). Ten samples were taken from Mayo Pond Side (MPS), and four from the stratigraphically younger Mayo Quarry Southside (MQSS). Across all samples, the Se morphogroup species richness was almost the same as that for the Sp morphogroup. The mean Shannon Function H did not differ between the exposures. At MPS, approxiimately 20% of the total assemblage belonged to the Se morphogroup, compared with approximately 36% at MQSS, giving a higher Se:Sp ratio at MQSS than at MPS. A sample-wise assemblage turnover index (ATIs) was calculated across the exposures. A peak in total assemblage ATIs reflected the MPS and MQSS samples being taken from different biofacies (MQSS = Cibicidoides crebbsi dominant; MPS = Anomalinoides mecatapenensis dominant). Mean ATIs (total assemblage) differed significantly between the exposures. Across all samples, mean Se ATIs was significantly different from and greater than mean Sp ATIs. ANOVA was used to compare means of Se ATIs and Sp ATIs at MPS and MQSS (four means in total). It showed a significant difference between at least two means. At both exposures the Se morphogroup's ATIs was greater than the Sp ATIs. This greater Se ATIs is apparently related to changing dissolved oxygen concentrations in sediment pore water associated with increasing proximity to an oxygen minimum zone over time.
{"title":"Contrasting paleoecologies of spiral and serial benthic foraminifera in deep middle bathyal exposures, lower to middle Miocene Brasso Formation, Trinidad,West Indies","authors":"B. Wilson, L. Hayek","doi":"10.47894/mpal.66.4.01","DOIUrl":"https://doi.org/10.47894/mpal.66.4.01","url":null,"abstract":"Multilocular benthic foraminifera are divisible into serial (Se) and spiral (Sp) morphogroups. Beneath oxic bottom waters, the Se morphogroup lives infaunally. Spiral species are typically epifaunal. Thus, the Se infauna react to different environmental factors from most Sp epifauna. Previous investigations of the Se:Sp ratio found that the serial infauna migrate toward the sediment/water interface with decreasing sediment oxygen levels, increasing the Se:Sp ratio in suboxic environments. We examine assemblage turnover within the Se and Sp morphogroups at two Brasso Formation exposures (planktonic foraminiferal Zones M4b-M6, deep middle bathyal palaeodepth). Ten samples were taken from Mayo Pond Side (MPS), and four from the stratigraphically younger Mayo Quarry Southside (MQSS). Across all samples, the Se morphogroup species richness was almost the same as that for the Sp morphogroup. The mean Shannon Function H did not differ between the exposures. At MPS, approxiimately 20% of the total assemblage belonged to the Se morphogroup, compared with approximately 36% at MQSS, giving a higher Se:Sp ratio at MQSS than at MPS. A sample-wise assemblage turnover index (ATIs) was calculated across the exposures. A peak in total assemblage ATIs reflected the MPS and MQSS samples being taken from different biofacies (MQSS = Cibicidoides crebbsi dominant; MPS = Anomalinoides mecatapenensis dominant). Mean ATIs (total assemblage) differed significantly between the exposures. Across all samples, mean Se ATIs was significantly different from and greater than mean Sp ATIs. ANOVA was used to compare means of Se ATIs and Sp ATIs at MPS and MQSS (four means in total). It showed a significant difference between at least two means. At both exposures the Se morphogroup's ATIs was greater than the Sp ATIs. This greater Se ATIs is apparently related to changing dissolved oxygen concentrations in sediment pore water associated with increasing proximity to an oxygen minimum zone over time.","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":"70444651","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 benthic foraminifera Pseudolituonella reicheli Marie is widely reported from Cenomanian shallow-water carbonates of the Caribbean (Mexico) area and the Neotethyan realm. Its wall-structure is classified as imperforate, homogeneous microgranular. Specimens from the Cenomanian Sarvak Formation of southwestern Iran (Zagros Zone) yield the presence of a pseudo-keriothecal wall-structure an observation that has already been obtained from the Eocene P. robineti Gallardo Garcia and Serra-Kiel in Serra-Kiel et al. With the “reappearance†of an equivalent morphological trait and the double test size after twomainmass-extinctions (C/T andK/Pg), P. robineti might be an example of Cope`s rule. Further comments on the suprageneric classification, other species of Pseudolituonella and phylogeny are provided.
{"title":"New data on Pseudolituonella Marie 1954, emended herein, benthic foraminifera from the Cenomanian of the Sarvak Formation of SWIran (Zagros Zone) - Phylogenetic considerations","authors":"F. Schlagintweit, M. Yazdi-Moghadam","doi":"10.47894/mpal.66.6.04","DOIUrl":"https://doi.org/10.47894/mpal.66.6.04","url":null,"abstract":"The benthic foraminifera Pseudolituonella reicheli Marie is widely reported from Cenomanian shallow-water carbonates of the Caribbean (Mexico) area and the Neotethyan realm. Its wall-structure is classified as imperforate, homogeneous microgranular. Specimens from the Cenomanian Sarvak Formation of southwestern Iran (Zagros Zone) yield the presence of a pseudo-keriothecal wall-structure an observation that has already been obtained from the Eocene P. robineti Gallardo Garcia and Serra-Kiel in Serra-Kiel et al. With the “reappearance†of an equivalent morphological trait and the double test size after twomainmass-extinctions (C/T andK/Pg), P. robineti might be an example of Cope`s rule. Further comments on the suprageneric classification, other species of Pseudolituonella and phylogeny are provided.","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":"70444785","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}
Pei Fang, Bo Xu, B. Huber, Shijia Liu, Youhua Zhu, Hui Luo
Well-preserved and abundant planktonic foraminifera have been recovered from limestones of the Cretaceous oceanic red beds (CORBs) from the Yongla section in Gyangze, southern Tibet. This foraminiferal assemblage is dominated by species of Contusotruncana, Globotruncana, and Globotruncanita. The assemblage contains 21 species belonging to 7 genera and suggests a late Campanian to early Maastrichtian age, which permits amore precise age constraint for CORBs in the Gyangze area. This planktonic assemblage provides an important biostratigraphic datum for the correlations of theCORBs in theHimalayan region of the northern Tethys. The interval yielding foraminifers in the Yongla section may be the youngest known CORB in the Gyangze area.
{"title":"Late Campanian to early Maastrichtian planktonic foraminiferal assemblages from Cretaceous oceanic red beds (CORBs) in the Yongla section, Gyangze, southern Tibet","authors":"Pei Fang, Bo Xu, B. Huber, Shijia Liu, Youhua Zhu, Hui Luo","doi":"10.47894/mpal.66.2.01","DOIUrl":"https://doi.org/10.47894/mpal.66.2.01","url":null,"abstract":"Well-preserved and abundant planktonic foraminifera have been recovered from limestones of the Cretaceous oceanic red beds (CORBs) from the Yongla section in Gyangze, southern Tibet. This foraminiferal assemblage is dominated by species of Contusotruncana, Globotruncana, and Globotruncanita. The assemblage contains 21 species belonging to 7 genera and suggests a late Campanian to early Maastrichtian age, which permits amore precise age constraint for CORBs in the Gyangze area. This planktonic assemblage provides an important biostratigraphic datum for the correlations of theCORBs in theHimalayan region of the northern Tethys. The interval yielding foraminifers in the Yongla section may be the youngest known CORB in the Gyangze area.","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":"70443837","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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