Journal of Systematic Palaeontology最新文献_第9页

The fossil record of sabre-tooth characins (Teleostei: Characiformes: Cynodontinae), their phylogenetic relationships and palaeobiogeographical implications 剑齿特征的化石记录(直骨目:特征:犬齿科)、系统发育关系及其古地理意义

IF 2.6 2区地球科学

Journal of Systematic Palaeontology Pub Date : 2021-12-17 DOI: 10.1080/14772019.2022.2070717

G. A. Ballen, J. Moreno-Bernal, C. Jaramillo

{"title":"The fossil record of sabre-tooth characins (Teleostei: Characiformes: Cynodontinae), their phylogenetic relationships and palaeobiogeographical implications","authors":"G. A. Ballen, J. Moreno-Bernal, C. Jaramillo","doi":"10.1080/14772019.2022.2070717","DOIUrl":"https://doi.org/10.1080/14772019.2022.2070717","url":null,"abstract":"The family Cynodontidae is composed of freshwater fishes inhabiting drainages east of the Andes in South America. Its fossil record is mostly represented by isolated teeth that are difficult to identify. Here we describe fossil cranial remains of the extant species Hydrolycus scomberoides as well as isolated teeth that were identified as Hydrolycus and cf. Rhaphiodon in sediments of the late Pliocene Ware Formation in the Guajira Peninsula, west of the Andes. Novel, phylogenetically informative characters were found including the number of symphysial teeth, the plane of insertion of the leading teeth onto the dentary, the presence of accessory posterior dentigerous patches, and depressions and outline of the dentary. We performed a phylogenetic analysis combining morphological and molecular characters including both extant and extinct specimens, producing a well-resolved topology that recovers a novel sister-group relationship between the genera Hydrolycus and Cynodon, while the genus Rhaphiodon falls to the base of this clade. This contradicts earlier studies recovering Hydrolycus and Rhaphiodon as sister taxa. The phylogenetic position of Hydrolycus wallacei was found to be unstable. The occurrence of H. scomberoides in the late Pliocene of Guajira is a puzzle that could be explained by different mechanisms, including a persistent drainage connection across the Andes during the late Pliocene, and/or the result of severe drying and subsequent extinction.","PeriodicalId":50028,"journal":{"name":"Journal of Systematic Palaeontology","volume":"19 1","pages":"1679 - 1692"},"PeriodicalIF":2.6,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43144922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Redescription, taxonomy and phylogenetic relationships of Boavus Marsh, 1871 (Serpentes: Booidea) from the early–middle Eocene of the USA 美国始新世早期-中期Boavus Marsh的重新描述、分类和系统发育关系(蛇类:Booidea)

IF 2.6 2区地球科学

Journal of Systematic Palaeontology Pub Date : 2021-12-02 DOI: 10.1080/14772019.2022.2068386

Silvio Onary, A. S. Hsiou, Michael S. Y. Lee, A. Palci

{"title":"Redescription, taxonomy and phylogenetic relationships of Boavus Marsh, 1871 (Serpentes: Booidea) from the early–middle Eocene of the USA","authors":"Silvio Onary, A. S. Hsiou, Michael S. Y. Lee, A. Palci","doi":"10.1080/14772019.2022.2068386","DOIUrl":"https://doi.org/10.1080/14772019.2022.2068386","url":null,"abstract":"The extinct fossil snake Boavus occurs in early–middle Eocene localities in the United States. Four species are currently recognized, but until now, no formal phylogenetic analyses have been conducted to test its relationships within snakes. Here, we provide an osteological redescription and systematic revision of the genus, accompanied by phylogenetic analyses using multiple methods. Based on new morphological information obtained through first-hand observation and published descriptions, differences between Boavus occidentalis, B. agilis and B. affinis can be ascribed to normal intracolumnar vertebral variation, making the latter two junior synonyms of the first species. Our phylogenetic analyses retrieved Boavus within crown-Booidea as an early booid but outside of Boidae. A morphological and molecular analysis of booids, with dense taxon sampling including fossil and living forms, results in a new booid phylogeny. Boavus, along with other fossil booids from Europe (Eoconstrictor, Messelophis, Rieppelophis, Rageryx), suggests that crown-Booidea likely diverged earlier than estimated by some molecular studies (∼45.4 Ma).","PeriodicalId":50028,"journal":{"name":"Journal of Systematic Palaeontology","volume":"19 1","pages":"1601 - 1622"},"PeriodicalIF":2.6,"publicationDate":"2021-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46853913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

A new species of Maomingosuchus from the Eocene of the Na Duong Basin (northern Vietnam) sheds new light on the phylogenetic relationship of tomistomine crocodylians and their dispersal from Europe to Asia 越南北部那阳盆地始新世的一新种Maomingosuchus为研究鳄鱼类的系统发育关系及其从欧洲到亚洲的传播提供了新的线索

IF 2.6 2区地球科学

Journal of Systematic Palaeontology Pub Date : 2021-11-17 DOI: 10.1080/14772019.2022.2054372

Tobias Massonne, Felix J. Augustin, Andreas T. Matzke, E. Weber, M. Böhme

{"title":"A new species of Maomingosuchus from the Eocene of the Na Duong Basin (northern Vietnam) sheds new light on the phylogenetic relationship of tomistomine crocodylians and their dispersal from Europe to Asia","authors":"Tobias Massonne, Felix J. Augustin, Andreas T. Matzke, E. Weber, M. Böhme","doi":"10.1080/14772019.2022.2054372","DOIUrl":"https://doi.org/10.1080/14772019.2022.2054372","url":null,"abstract":"Maomingosuchus acutirostris sp. nov. is a new tomistomine crocodile from the middle–upper Eocene deposits (late Bartonian–Priabonian age, 39–35 Ma) of the Na Duong Basin in northern Vietnam. M. acutirostris can be differentiated from the type species Maomingosuchus petrolicus by having an acute anterior tip of the premaxilla. Both species differ from another Maomingosuchus from Krabi (Thailand) by differences in the surangular–dentary suture and maxillary alveoli. According to our phylogenetic results, M. acutirostris seems to be the sister species to the group M. petrolicus + Krabi-Maomingosuchus. The close relationship between those three tomistomines is supported in the present phylogenetic analysis by three synapomorphies. In our phylogenetic analysis, Maomingosuchus was retrieved in a basal position forming the sister group to Paratomistoma + Gavialosuchus + Melitosaurus + Tomistoma, including the extant Tomistoma schlegelii. This phylogeny indicates three different dispersal events of Tomistominae from Europe towards eastern Asia: 1) for the stem lineage of Maomingosuchus, no later than the late Eocene; 2) for the stem lineage of Penghusuchus pani + Toyotamaphimeia machikanensis, no later than the early–middle Miocene; and (3) for the stem lineage of T. schlegelii, during the Neogene. http://zoobank.org/urn:lsid:zoobank.org:pub:19B27C1E-0A3F-4425-AA8C-F904277DF327","PeriodicalId":50028,"journal":{"name":"Journal of Systematic Palaeontology","volume":"19 1","pages":"1551 - 1585"},"PeriodicalIF":2.6,"publicationDate":"2021-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43827936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Systematic significance of wing morphology in extinct Prophalangopsidae (Insecta, Ensifera) revealed by geometric morphometrics and description of two new species 从几何形态计量学和两个新种的描述揭示了已灭绝的前翅目昆虫翅膀形态的系统意义

IF 2.6 2区地球科学

Journal of Systematic Palaeontology Pub Date : 2021-11-17 DOI: 10.1080/14772019.2022.2067491

Jun-Jie Gu, Ziqiang Xu, Rong Huang, Haijian Wang, Yanli Yue, D. Ren

{"title":"Systematic significance of wing morphology in extinct Prophalangopsidae (Insecta, Ensifera) revealed by geometric morphometrics and description of two new species","authors":"Jun-Jie Gu, Ziqiang Xu, Rong Huang, Haijian Wang, Yanli Yue, D. Ren","doi":"10.1080/14772019.2022.2067491","DOIUrl":"https://doi.org/10.1080/14772019.2022.2067491","url":null,"abstract":"Prophalangopsidae was a diverse family during the Late Mesozoic, but the variation and sexual dimorphism in their forewing morphologies are rarely discussed. Based on 43 specimens – of both sexes – from eight species, an investigation into wing venation variation among/within species of Prophalangopsidae was performed using geometric morphometrics and morphological comparisons. The results indicate that wing characters are reliable for taxonomy in fossil Prophalangopsidae and that variation in wing shape and venation is common within species. The structures of the forewings are analogous between sexes within species, and it is possible to pair males and females for a fossil species. Due to the potential existence of synonyms arising from the lack of knowledge on wing venation variation within species and sexes, the species richness of fossil prophalangopsids is probably over-estimated. The role of wing venation characters in systematics and phylogenetic analysis needs to be further analysed. In addition, two new species of Prophalangopsidae from the Middle Jurassic are described. http://zoobank.org/urn:lsid:zoobank.org:pub:BD2D00D6-9E55-46F9-AEB3-122FBBF99A06","PeriodicalId":50028,"journal":{"name":"Journal of Systematic Palaeontology","volume":"19 1","pages":"1587 - 1599"},"PeriodicalIF":2.6,"publicationDate":"2021-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45528000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

A new hadrosauriform dinosaur from the Wessex Formation, Wealden Group (Early Cretaceous), of the Isle of Wight, southern England 来自英格兰南部怀特岛威尔登群(早白垩纪)韦塞克斯组的一种新鸭嘴龙

IF 2.6 2区地球科学

Journal of Systematic Palaeontology Pub Date : 2021-11-10 DOI: 10.1080/14772019.2021.1978005

J. Lockwood, D. Martill, S. Maidment

{"title":"A new hadrosauriform dinosaur from the Wessex Formation, Wealden Group (Early Cretaceous), of the Isle of Wight, southern England","authors":"J. Lockwood, D. Martill, S. Maidment","doi":"10.1080/14772019.2021.1978005","DOIUrl":"https://doi.org/10.1080/14772019.2021.1978005","url":null,"abstract":"A new genus and species of non-hadrosaurid hadrosauriform dinosaur, Brighstoneus simmondsi gen. et sp. nov., is described from the Lower Cretaceous Wessex Formation of the Isle of Wight. The new taxon has two autapomorphies, a nasal having a modest nasal bulla with convex sides, and primary and accessory ridges on the lingual aspect of the maxillary crown. The dentary has at least 28 alveolar positions, which is the highest number recorded in an ornithopod with non-parallel sided alveoli, creating a character combination that is unique within Iguanodontia. The hadrosauriform fauna of the Barremian–Aptian Wealden Group on both the Isle of Wight and mainland England has been represented for almost a century by just two taxa, the robust Iguanodon bernissartensis and the more gracile Mantellisaurus atherfieldensis, with referred material often being fragmentary or based on unassociated elements. This discovery increases the known hadrosauriform diversity in England and, together with recent discoveries in Spain, suggests that their diversity in the upper Wealden of Europe was considerably wider than initially realized. This find also has important implications for the validity of the Mantellisaurus atherfieldensis hypodigm, and a reassessment of existing material is suggested. http://zoobank.org/urn:lsid:zoobank.org:pub:31F0D48F-C1DA-406E-A811-1F5937ED19F4","PeriodicalId":50028,"journal":{"name":"Journal of Systematic Palaeontology","volume":"19 1","pages":"847 - 888"},"PeriodicalIF":2.6,"publicationDate":"2021-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46584734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 14

Ontogenetic changes in the postcranial skeleton of Mussaurus patagonicus (Dinosauria, Sauropodomorpha) and their impact on the phylogenetic relationships of early sauropodomorphs 巴塔哥尼亚Mussaurus patagonicus（恐龙，蜥脚形目）颅后骨骼的个体发生变化及其对早期蜥脚形动物系统发育关系的影响

IF 2.6 2区地球科学

Journal of Systematic Palaeontology Pub Date : 2021-11-02 DOI: 10.1080/14772019.2022.2039311

A. Otero, D. Pol

{"title":"Ontogenetic changes in the postcranial skeleton of Mussaurus patagonicus (Dinosauria, Sauropodomorpha) and their impact on the phylogenetic relationships of early sauropodomorphs","authors":"A. Otero, D. Pol","doi":"10.1080/14772019.2022.2039311","DOIUrl":"https://doi.org/10.1080/14772019.2022.2039311","url":null,"abstract":"Early sauropodomorphs were diverse in Gondwana, being particularly well represented in South America. Mussaurus patagonicus is one of the best-known non-sauropod sauropodomorphs that inhabited the Southern Hemisphere. Its importance relies on its phylogenetic position close to Sauropoda and also because it is known from a well-represented ontogenetic series, including embryos, neonate and late immature skeletons, which are particularly scarce among sauropodomorphs. In this regard, Mussaurus represents an excellent opportunity to explore anatomical and palaeobiological constraints during the ontogeny of early stages of the evolution of the group. We present the osteology of the postcranial skeleton of immature specimens of Mussaurus, highlighting the main anatomical changes that occurred during its ontogeny. The phylogenetic position of this taxon based on mature specimens is evaluated through a parsimony analysis, corroborating its position as closer to Sauropoda than most other early sauropodomorphs. Immature stages of this taxon were also evaluated phylogenetically, showing an overall phylogenetic signal that positioned them closer to the root of Sauropodomorpha than the mature specimens. However, the cranial and some postcranial anatomical partitions of neonates and late immature specimens have different phylogenetic signals, showing derived traits present in Sauropoda and related taxa (and supporting the hypothesis of paedomorphic evolution in certain regions of the skeleton). Our analysis shows that most of the appendicular apomorphies in Mussaurus appear late in ontogeny, whereas axial characters (in particular for OS 1), including those of the skull and the presacral vertebrae, show derived character states early in ontogeny that are congruent with the phylogenetic position of mature specimens. Ontogenetic series of other sauropodomorph species, however, are required to test if this pattern applies to the entire group.","PeriodicalId":50028,"journal":{"name":"Journal of Systematic Palaeontology","volume":"19 1","pages":"1467 - 1516"},"PeriodicalIF":2.6,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48364432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

A new †Pachycormiformes (Actinopterygii) from the Upper Jurassic of Gondwana sheds light on the evolutionary history of the group 冈瓦纳大陆上侏罗纪的一个新的†Pachycormiformes（Actinopterygii）揭示了该类群的进化史

IF 2.6 2区地球科学

Journal of Systematic Palaeontology Pub Date : 2021-11-02 DOI: 10.1080/14772019.2022.2049382

Soledad Gouiric-Cavalli, G. Arratia

{"title":"A new †Pachycormiformes (Actinopterygii) from the Upper Jurassic of Gondwana sheds light on the evolutionary history of the group","authors":"Soledad Gouiric-Cavalli, G. Arratia","doi":"10.1080/14772019.2022.2049382","DOIUrl":"https://doi.org/10.1080/14772019.2022.2049382","url":null,"abstract":"As part of the transition from Holostei to Teleostei, †Pachycormiformes represent a key group of fishes. However, the anatomy and phylogenetic relationships of the group in the context of the neopterygians are far from being understood. In this contribution we describe a new pachycormiform, †Kaykay lafken gen. et sp. nov., from the Upper Jurassic of Argentina. We made an exhaustive review of morphological characters of holostean and teleostean fishes and explore through a cladistic analysis the phylogenetic relationships of the new species. †Kaykay gen. nov. is retrieved among †Pachycormiformes as being the sister taxon of the macrocarnivorous clade composed of †Orthocormus and †Hypsocormus. Among †Pachycormiformes the pattern of relationships mostly agrees with previous hypotheses, although our study highlights the still poor knowledge of the anatomy of this group. According to our results †Saurostomus is the sister taxon of other toothed pachycormids. †Orthocormus species are recovered as a monophyletic group. The unsolved position of †Pachycormus and †Sauropsis might be a consequence of poor preservation, revealing a lack of understanding of their anatomy. Our phylogenetic analysis also confirms the rapid radiation of holosteans and teleosteomorphs in the Early Triassic and the radiation of pholidophoriforms in the Middle Triassic. †Aspidorhynchoidei radiate in the Early Jurassic. The large ghost ranges (e.g. between †Aspidorhynchoidei and Teleosteomorpha) evidence biases in the fossil record. http://zoobank.org/urn:lsid:zoobank.org:pubE78932B3-8F3C-4181-A91F-FC34358C5508","PeriodicalId":50028,"journal":{"name":"Journal of Systematic Palaeontology","volume":"19 1","pages":"1517 - 1550"},"PeriodicalIF":2.6,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46222100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Taxonomy and phylogeny of the ‘football stars’ (Asteroidea, Sphaerasteridae) “足球明星”的分类和系统发育（小行星目，鞘翅目）

IF 2.6 2区地球科学

Journal of Systematic Palaeontology Pub Date : 2021-10-21 DOI: 10.1080/14772019.2021.1960911

A. Gale

引用次数: 1

The earliest chimaeriform fish from the Carboniferous of Central Russia 俄罗斯中部石炭纪最早的嵌合体鱼

IF 2.6 2区地球科学

Journal of Systematic Palaeontology Pub Date : 2021-10-21 DOI: 10.1080/14772019.2021.1977732

O. A. Lebedev, E. Popov, Sergey V. Bagirov, Igor P. Bolshiyanov, R. Kadyrov, E. Statsenko

{"title":"The earliest chimaeriform fish from the Carboniferous of Central Russia","authors":"O. A. Lebedev, E. Popov, Sergey V. Bagirov, Igor P. Bolshiyanov, R. Kadyrov, E. Statsenko","doi":"10.1080/14772019.2021.1977732","DOIUrl":"https://doi.org/10.1080/14772019.2021.1977732","url":null,"abstract":"The ancestry of chimaeriform chondrichthyan fishes can be traced back to the Late Triassic (∼220 Ma). To date, only one chimaeriform suborder, the Echinochimaeroidei, has been recognized from the Palaeozoic. The origin and evolution of the chimaeriforms has been a matter of debate for more than a hundred years. This problem is aggravated by the scarcity of holomorphic fossils; the bulk of the material includes only hard parts of the jaw apparatus and other skeletal elements. Here we describe the oldest record of the Chimaeriformes, represented by tooth plates from the lower Carboniferous deposits (∼338–332 Ma) of Russia, as Protochimaera mirabilis gen. et sp. nov., and establish a new family and suborder based upon their particular morphological and histological features. The newly described tooth plates demonstrate a continuous layer of varitubate dentine over their oral surfaces; beak-shaped mandibular plates have been formed by fusion of a labial component of cutaneous origin to two others formed orally. Three separate vascular systems enabled the growth of these histological components. The beak and wear facets suggest a grasping-cutting feeding action and are the earliest example of this feeding mode in fishes after the placoderm extinction at the end of the Devonian. Phylogenetic analysis of the dental characters places these stem chimaeriforms as a sister group to the Chimaeroidei. http://zoobank.org/urn:lsid:zoobank.org:pub:urn:lsid:zoobank.org:pub:5593C7FE-B5B5-4922-8D32-BF0440D89192","PeriodicalId":50028,"journal":{"name":"Journal of Systematic Palaeontology","volume":"19 1","pages":"821 - 846"},"PeriodicalIF":2.6,"publicationDate":"2021-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47254376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Distinctive quadrangular seed-bearing structures of gnetalean affinity from the Late Jurassic Morrison Formation of Utah, USA 美国犹他州晚侏罗世Morrison组独特的具有片麻岩亲和性的四边形种子结构

IF 2.6 2区地球科学

Journal of Systematic Palaeontology Pub Date : 2021-10-21 DOI: 10.1080/14772019.2021.1968522

S. Manchester, Xiaoqing Zhang, C. Hotton, S. Wing, P. Crane

{"title":"Distinctive quadrangular seed-bearing structures of gnetalean affinity from the Late Jurassic Morrison Formation of Utah, USA","authors":"S. Manchester, Xiaoqing Zhang, C. Hotton, S. Wing, P. Crane","doi":"10.1080/14772019.2021.1968522","DOIUrl":"https://doi.org/10.1080/14772019.2021.1968522","url":null,"abstract":"A new kind of seed-bearing structure is described based on three-dimensional casts and partially permineralized small cones from the Upper Jurassic Brushy Basin Member of the Morrison Formation, in the Henry Mountains of Utah. Cones of Dayvaultia tetragona gen. et sp. nov. are obovate in lateral view, 10.0–11.0 mm long, square in cross-section and 5.1–8.0 mm wide, with a thick wall composed of four tightly adhering bracts that open apically to expose the tips of six or eight elongate, four-lobed seeds. Micro-CT scanning reveals that the seeds are borne on a cup-shaped receptacle in a regular opposite and decussate manner. This regular arrangement, as well as similarities of the seeds to several kinds of Early Cretaceous chlamydospermous seeds, including those of Lobospermum and Battenispermum, suggests a relationship to extant and Cretaceous members of Gnetales. The sedimentary context in which the cones occur, combined with their local abundance, suggests that Dayvaultia was common on intermittently inundated well-drained floodplains during Morrison times, enhancing insight into the vegetation that supported the diverse vertebrate faunas for which the Morrison Formation is well known. http://zoobank.org/urn:lsid:zoobank.org:pub:0ECD4B37-E6B6-4050-B45A-28D713321EB8","PeriodicalId":50028,"journal":{"name":"Journal of Systematic Palaeontology","volume":"19 1","pages":"743 - 760"},"PeriodicalIF":2.6,"publicationDate":"2021-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47513056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4