The Shahbazan Formation was deposited in the foreland basin in southwestern Iran( Lorestan Basin). In this research,microbiostratigraphy and depositional environmental implications related to the Shahbazan Formation a...The Shahbazan Formation was deposited in the foreland basin in southwestern Iran( Lorestan Basin). In this research,microbiostratigraphy and depositional environmental implications related to the Shahbazan Formation at the northern flank of Chenaerh anticline are discussed. Carbonate sequences of the Shahbazan Formation consist mainly of large benthic foraminifera along with other skeletal and non-skeletal components.Two biozones have been recognized by distribution of large foraminifera in the studied area that indicate middle Eocene age( Lutetian). Based on analysis of large benthic foraminiferal assemblages and microfacies features,7 different microfacies have been recognized,which can be grouped into three depositional environments: inner,middle and outer ramps.展开更多
The fossil trunks and rhizomes of Osmundaceae provide important information about its evolutionary history.Due to limited records of the Mesozoic trunks and rhizomes in the Eurasia of the Northern Hemisphere,our under...The fossil trunks and rhizomes of Osmundaceae provide important information about its evolutionary history.Due to limited records of the Mesozoic trunks and rhizomes in the Eurasia of the Northern Hemisphere,our understanding on the fossil diversity of the Osmundaceae is hindered.Two new species of the Osmundaceae trunks,Osmundacaulis asiatica sp.nov.and Osmundacaulis sinica sp.nov.representing the first discovery of the Mesozoic tree fern genus Osmundacaulis in Eurasia,are described from Wudalianchi and Qiqihar,Heilongjiang Province,Northeast China,which enriches the plant diversity of the Osmundaceae in the Eurasia,and provides vital evidence for studying the distribution,radiation and evolution of the genus during the Cretaceous.The fossil records suggest that Osmundacaulis species may have evolved from a common ancestor,which first appeared in the Australian portion of Pangaea,and then spread to ancient northern North America and ancient East Asia.Since then,they developed into different species through their own evolutionary lines.The Chinese species have a special local feature that the outer cortex is thicker than the inner cortex,in contrast with reported Osmundacaulis species having thinner outer cortex and thicker inner cortex.Long-term geographic isolation may have led to the radiation of diverse Osmundacaulis species and the appearance of region-specific features,such as the thick outer cortex and the thin inner cortex of the Chinese species.Among all reported Osmundacaulis species,the two new species found in China,O.nerii from the Jurassic of Australia and the O.lemonii from the Jurassic of the USA,have special groups of mucilage-sacs inside sclerenchyma ring of petiole base.Mucilage sacs probably originated independently among taxonomic groups,representing convergent adaptations to similar habitats,rather than indicating genetic inheritance from a common ancestor.展开更多
Well-preserved Cretaceous trunk fragments of Cycadeoidea(Cycadeoidaceae)were recently found in Keshan County,Heilongjiang Province,Northeast China.These fossils represent important evidence of the distribution of this...Well-preserved Cretaceous trunk fragments of Cycadeoidea(Cycadeoidaceae)were recently found in Keshan County,Heilongjiang Province,Northeast China.These fossils represent important evidence of the distribution of this group of plants in East Asia.In these trunk fragments,the stem cortices and leaf bases with cones are preserved.The leaf bases are rhombic with cones infrequently distributed among leaf bases.The cortex is broad and consists of fundamental parenchyma cells,numerous secretory ducts and C-shaped leaf traces with adaxial secondary xylem and abaxial secondary phloem.The genus Cycadeoidea,which is widely distributed in the Cretaceous deposits of East Asia,North America and Western Europe,was an important component of Cretaceous floras.Bennettitalean trunk fossils with well-preserved anatomical structures are rarely known from China.These fossils are important for studies of the evolution of genus Cycadeoidea and for stratigraphic correlation.展开更多
Charcoals collected from the middle-late Pliocene sediments of the Taigu Basin,Shanxi Province,China,have been identified as Ulmus sp.(Ulmaceae),Prunus sp.,Maloidoxylon sp.(Rosaceae),and Maclura sp.(Moraceae).These ta...Charcoals collected from the middle-late Pliocene sediments of the Taigu Basin,Shanxi Province,China,have been identified as Ulmus sp.(Ulmaceae),Prunus sp.,Maloidoxylon sp.(Rosaceae),and Maclura sp.(Moraceae).These taxa,along with the previously known fossils,indicate the occurrence of temperate climate and local wildfire at that time.Charcoals of trees and/or shrubs and the morphological changes of these charcoals demonstrate that crown fires and surface fires occurred in the Taigu Basin during the middle-late Pliocene.展开更多
The global stratotype sections and points for the bases of the Selandian(Middle Paleocene)and Thanetian(Upper Paleocene)stages have been defined in the coastal cliff along the Itzurun Beach at the town of Zumaia in th...The global stratotype sections and points for the bases of the Selandian(Middle Paleocene)and Thanetian(Upper Paleocene)stages have been defined in the coastal cliff along the Itzurun Beach at the town of Zumaia in the Basque Country,northern Spain.In the hemipelagic section exposed at Zumaia the base of the Selandian Stage has been placed at the base of the Itzurun Formation,ca.49 m above the Cretaceous/Paleogene boundary.At the base of the Selandian,marls replace the succession of Danian red limestone and limestone-marl couplets.The best marine,global correlation criterion for the basal Selandian is the second radiation of the important calcareous nannofossil group.展开更多
Rock samples'TOC content is the best indicator of the organic matter in source rocks.The origin rock samples’analysis is used to calculate it manually by specialists.This method requires time and resources becaus...Rock samples'TOC content is the best indicator of the organic matter in source rocks.The origin rock samples’analysis is used to calculate it manually by specialists.This method requires time and resources because it relies on samples from many well intervals in source rocks.Therefore,research has been done to aid this effort.Machine learning algorithms can estimate total organic carbon instead of well logs and stratigraphic studies.In light of these efforts,the current work present a study on automating the total organic carbon estimation using machine learning approaches improved by an evolutionary methodology to give the model flexibility and precision.Genetic algorithms,differential evolution,particle swarm optimization,grey wolf optimization,artificial bee colony,and evolution strategies were used to improve machine learning models to predict TOC.The six metaheuristics were integrated into four machine learning methods:extreme learning machine,elastic net linear model,linear support vector regression,and multivariate adaptive regression splines.Core samples from the YuDong-Nan shale gas field,located in the Sichuan basin,were used to evaluate the hybrid strategy.The findings show that combining machine learning models with an evolutionary algorithms in a hybrid fashion produce flexible models that accurately predict TOC.The results show that,independent of the metaheuristic used to guide the model selection,optimized extreme learning machines attained the best performance scores according to six metrics.Such hybrid models can be used in exploratory geological research,particularly for unconventional oil and gas resources.展开更多
The extant Cabrera’s vole,Microtus cabrerae,differs in morphology and evolutionary history from the other species of Microtus.This arvicoline has unique derived features in the cranium,mandible and dentition.Probably...The extant Cabrera’s vole,Microtus cabrerae,differs in morphology and evolutionary history from the other species of Microtus.This arvicoline has unique derived features in the cranium,mandible and dentition.Probably its most conspicuous features are its large size,the high skull in lateral view,the long and distally broad nasals,and the triangle shape of the anteroconid complex,with a marked labio-lingual asymmetry of the occlusal surface of the first lower molars.In this study,we propose a phylogenetic lineage that includes Cabrera’s vole in what until now has been the Microtus subgenus Iberomys.Paleontological information and several life history traits support the elevation of Iberomys to the rank of genus.Genus Iberomys comprises species that have appeared in succession during the Quaternary:in the Early Pleistocene,the extinct I.huescarensis in the Middle Pleistocene,the extinct I.mediterraneus and in the Late Pleistocene,the extant I.cabrerae.Interestingly,the extant species shows several biological singularities,such as multiple polymorphic copies of the SRY male-specific gene in both males and females,and the lowest basal metabolic rate in relation to weight among arvicoline species.Likewise,its habitat requirement is unique among the Iberian arvicolines.Accordingly,the biological and paleontological data that we present in this work support the elevation of its taxonomic rank to that of genus.This study also suggests a modification of nomenclature:Microtus(Iberomys)brecciensis is replaced with I.mediterraneus and the common name of the extant M.(I.)cabrerae changed from‘topillo’to‘iberon’to improve conservation and protection actions.展开更多
The vertebrate fossil record from the Balearic Islands(western Mediterranean)has improved considerably over the past decade,especially in Mallorca and Menorca.In Menorca,the Pliocene terrestrial fauna was updated by t...The vertebrate fossil record from the Balearic Islands(western Mediterranean)has improved considerably over the past decade,especially in Mallorca and Menorca.In Menorca,the Pliocene terrestrial fauna was updated by the discovery and description of the large-sized leporid Nuralagus,several reptiles and an amphibian.In Mal-lorca,paleontological exploration yielded 2 deposits with a Late Miocene/Early Pliocene chronology,Calóden Rafelino(CdR)and Na Burguesa-1(NB-1).So far,4 new mammalian taxa and 2 new reptiles have been iden-tified for the CdR deposit,whereas the faunal assemblage from the recently discovered deposit(Apr 2012)of NB-1 is currently composed of,at least,6 terrestrial mammals,8 reptiles and an amphibian.Its faunal composi-tion and some primitive characteristics of the obtained taxa suggest that the chronology of this deposit is slight-ly earlier than the CdR.The terrestrial vertebrates recorded in these 2 Mallorcan deposits are changing the view of the paleofaunal assemblage previously known for the Plio-Pleistocene of the island.Morphological charac-teristics displayed by some of the taxa suggest that these faunas would be at the beginning of an isolated evo-lution.In this paper we present a preliminary report on the fossils recovered from the NB-1 deposit,as well as some unpublished data from CdR,and we analyze the whole fauna from both Mallorcan deposits,focusing on taxonomical and paleobiogeographical aspects.展开更多
文摘The Shahbazan Formation was deposited in the foreland basin in southwestern Iran( Lorestan Basin). In this research,microbiostratigraphy and depositional environmental implications related to the Shahbazan Formation at the northern flank of Chenaerh anticline are discussed. Carbonate sequences of the Shahbazan Formation consist mainly of large benthic foraminifera along with other skeletal and non-skeletal components.Two biozones have been recognized by distribution of large foraminifera in the studied area that indicate middle Eocene age( Lutetian). Based on analysis of large benthic foraminiferal assemblages and microfacies features,7 different microfacies have been recognized,which can be grouped into three depositional environments: inner,middle and outer ramps.
基金supported by the National Natural Science Foundation of China(Grant No.31970234)the Ministry of Natural Resources,China(Grant No.12111300000018001)Key-Lab for Evolution of Past Life and Environment in Northeast Asia,Ministry of Education,China(Grant No.2018JDEPw001)。
文摘The fossil trunks and rhizomes of Osmundaceae provide important information about its evolutionary history.Due to limited records of the Mesozoic trunks and rhizomes in the Eurasia of the Northern Hemisphere,our understanding on the fossil diversity of the Osmundaceae is hindered.Two new species of the Osmundaceae trunks,Osmundacaulis asiatica sp.nov.and Osmundacaulis sinica sp.nov.representing the first discovery of the Mesozoic tree fern genus Osmundacaulis in Eurasia,are described from Wudalianchi and Qiqihar,Heilongjiang Province,Northeast China,which enriches the plant diversity of the Osmundaceae in the Eurasia,and provides vital evidence for studying the distribution,radiation and evolution of the genus during the Cretaceous.The fossil records suggest that Osmundacaulis species may have evolved from a common ancestor,which first appeared in the Australian portion of Pangaea,and then spread to ancient northern North America and ancient East Asia.Since then,they developed into different species through their own evolutionary lines.The Chinese species have a special local feature that the outer cortex is thicker than the inner cortex,in contrast with reported Osmundacaulis species having thinner outer cortex and thicker inner cortex.Long-term geographic isolation may have led to the radiation of diverse Osmundacaulis species and the appearance of region-specific features,such as the thick outer cortex and the thin inner cortex of the Chinese species.Among all reported Osmundacaulis species,the two new species found in China,O.nerii from the Jurassic of Australia and the O.lemonii from the Jurassic of the USA,have special groups of mucilage-sacs inside sclerenchyma ring of petiole base.Mucilage sacs probably originated independently among taxonomic groups,representing convergent adaptations to similar habitats,rather than indicating genetic inheritance from a common ancestor.
基金supported by the National Natural Science Foundation of China(Grant No.31970234)the Ministry of Natural Resources,China(Grant No.12111300000018001)the Key Laboratory for the Evolution of Past Life and Environment in Northeast Asia,Ministry of Education,China(Grant No.2018JDEPw001)。
文摘Well-preserved Cretaceous trunk fragments of Cycadeoidea(Cycadeoidaceae)were recently found in Keshan County,Heilongjiang Province,Northeast China.These fossils represent important evidence of the distribution of this group of plants in East Asia.In these trunk fragments,the stem cortices and leaf bases with cones are preserved.The leaf bases are rhombic with cones infrequently distributed among leaf bases.The cortex is broad and consists of fundamental parenchyma cells,numerous secretory ducts and C-shaped leaf traces with adaxial secondary xylem and abaxial secondary phloem.The genus Cycadeoidea,which is widely distributed in the Cretaceous deposits of East Asia,North America and Western Europe,was an important component of Cretaceous floras.Bennettitalean trunk fossils with well-preserved anatomical structures are rarely known from China.These fossils are important for studies of the evolution of genus Cycadeoidea and for stratigraphic correlation.
基金supported by National Natural Science Foundation of China(Grant Nos.30770148,30990241,30530050,39770046 and 41072022)
文摘Charcoals collected from the middle-late Pliocene sediments of the Taigu Basin,Shanxi Province,China,have been identified as Ulmus sp.(Ulmaceae),Prunus sp.,Maloidoxylon sp.(Rosaceae),and Maclura sp.(Moraceae).These taxa,along with the previously known fossils,indicate the occurrence of temperate climate and local wildfire at that time.Charcoals of trees and/or shrubs and the morphological changes of these charcoals demonstrate that crown fires and surface fires occurred in the Taigu Basin during the middle-late Pliocene.
文摘The global stratotype sections and points for the bases of the Selandian(Middle Paleocene)and Thanetian(Upper Paleocene)stages have been defined in the coastal cliff along the Itzurun Beach at the town of Zumaia in the Basque Country,northern Spain.In the hemipelagic section exposed at Zumaia the base of the Selandian Stage has been placed at the base of the Itzurun Formation,ca.49 m above the Cretaceous/Paleogene boundary.At the base of the Selandian,marls replace the succession of Danian red limestone and limestone-marl couplets.The best marine,global correlation criterion for the basal Selandian is the second radiation of the important calcareous nannofossil group.
基金supported by the Federal University of Juiz de Fora (UFJF).C.S.thanks CAPES (Finance Code 001)L.G.thanks CNPq (401796/2021-3,307688/2022-4,and 409433/2022-5)for their financial support.
文摘Rock samples'TOC content is the best indicator of the organic matter in source rocks.The origin rock samples’analysis is used to calculate it manually by specialists.This method requires time and resources because it relies on samples from many well intervals in source rocks.Therefore,research has been done to aid this effort.Machine learning algorithms can estimate total organic carbon instead of well logs and stratigraphic studies.In light of these efforts,the current work present a study on automating the total organic carbon estimation using machine learning approaches improved by an evolutionary methodology to give the model flexibility and precision.Genetic algorithms,differential evolution,particle swarm optimization,grey wolf optimization,artificial bee colony,and evolution strategies were used to improve machine learning models to predict TOC.The six metaheuristics were integrated into four machine learning methods:extreme learning machine,elastic net linear model,linear support vector regression,and multivariate adaptive regression splines.Core samples from the YuDong-Nan shale gas field,located in the Sichuan basin,were used to evaluate the hybrid strategy.The findings show that combining machine learning models with an evolutionary algorithms in a hybrid fashion produce flexible models that accurately predict TOC.The results show that,independent of the metaheuristic used to guide the model selection,optimized extreme learning machines attained the best performance scores according to six metrics.Such hybrid models can be used in exploratory geological research,particularly for unconventional oil and gas resources.
基金This work was supported by MICINN Projects CGL2009-12703-C03-03,CGL2012-38434-C03-01,Fundacion Ancestros,Fundación Atapuerca,Fundación Biodiversidad(Project‘Bases para la conservación del Iberón,M.cabrerae,en España’),Grupos consolidados del Gobierno de Aragon y Fondo Social Europeo(European Social Fund).Hugues-Alexandre Blain(IPHES)scanned part of the work of Cuvier of 1812 from the original personal exemplar.We are grateful to the people from different institutions who provided materials for the present study:Pablo Martínez Rica(IPE)and Josefina Barreiro(Dpto.Aves y Mamíferos,Museo Nacional de Ciencias Naturales de Madrid).Andy Currant(NHM)provided material from Westbury-sub-Mendip and Lutz Maul(Senckenberg,Weimar)provided material from Untermassfeld.Comments made by Ignacio Martínez(Universidad de Alcaláde Henares/Instituto de Salud Carlos III),Alvaro Morcillo(Madrid),María Melero(Logroño),JoséA.Garrido-García(Estación Biológica de Doñana),Rafael Diaz de la Guardia(Universidad de Jaen),Boris Krystufek(University of Primorska)and Juan Jiménez(Conselleria de Valencia)improved the drafts of this article.JoséM.López-García is a beneficiary of a Beatriu de Pinós postdoctoral fellowship(2011BP-A00272)from the Generalitat de Catalunya,a grant co-funded by the European Union through the Marie Curie Actions of the 7th Framework Program for R+D.M.A.Galindo-Pellicena is a beneficiary of grants BES-2007-15368,and Fundacion Atapuerca.
文摘The extant Cabrera’s vole,Microtus cabrerae,differs in morphology and evolutionary history from the other species of Microtus.This arvicoline has unique derived features in the cranium,mandible and dentition.Probably its most conspicuous features are its large size,the high skull in lateral view,the long and distally broad nasals,and the triangle shape of the anteroconid complex,with a marked labio-lingual asymmetry of the occlusal surface of the first lower molars.In this study,we propose a phylogenetic lineage that includes Cabrera’s vole in what until now has been the Microtus subgenus Iberomys.Paleontological information and several life history traits support the elevation of Iberomys to the rank of genus.Genus Iberomys comprises species that have appeared in succession during the Quaternary:in the Early Pleistocene,the extinct I.huescarensis in the Middle Pleistocene,the extinct I.mediterraneus and in the Late Pleistocene,the extant I.cabrerae.Interestingly,the extant species shows several biological singularities,such as multiple polymorphic copies of the SRY male-specific gene in both males and females,and the lowest basal metabolic rate in relation to weight among arvicoline species.Likewise,its habitat requirement is unique among the Iberian arvicolines.Accordingly,the biological and paleontological data that we present in this work support the elevation of its taxonomic rank to that of genus.This study also suggests a modification of nomenclature:Microtus(Iberomys)brecciensis is replaced with I.mediterraneus and the common name of the extant M.(I.)cabrerae changed from‘topillo’to‘iberon’to improve conservation and protection actions.
基金This paper is included in the projects CGL2012-38087,CGL2009-12703-C03-03,EHU 10/32(Universidad del País Vasco UPV/EHU)and CGL2012-38358.
文摘The vertebrate fossil record from the Balearic Islands(western Mediterranean)has improved considerably over the past decade,especially in Mallorca and Menorca.In Menorca,the Pliocene terrestrial fauna was updated by the discovery and description of the large-sized leporid Nuralagus,several reptiles and an amphibian.In Mal-lorca,paleontological exploration yielded 2 deposits with a Late Miocene/Early Pliocene chronology,Calóden Rafelino(CdR)and Na Burguesa-1(NB-1).So far,4 new mammalian taxa and 2 new reptiles have been iden-tified for the CdR deposit,whereas the faunal assemblage from the recently discovered deposit(Apr 2012)of NB-1 is currently composed of,at least,6 terrestrial mammals,8 reptiles and an amphibian.Its faunal composi-tion and some primitive characteristics of the obtained taxa suggest that the chronology of this deposit is slight-ly earlier than the CdR.The terrestrial vertebrates recorded in these 2 Mallorcan deposits are changing the view of the paleofaunal assemblage previously known for the Plio-Pleistocene of the island.Morphological charac-teristics displayed by some of the taxa suggest that these faunas would be at the beginning of an isolated evo-lution.In this paper we present a preliminary report on the fossils recovered from the NB-1 deposit,as well as some unpublished data from CdR,and we analyze the whole fauna from both Mallorcan deposits,focusing on taxonomical and paleobiogeographical aspects.
