A Taxus leafy branch with attached ovules from the Lower Cretaceous of Inner Mongolia, North China

Xu, Xiaohui; Sun, Bainian; Yan, Daojiang; Jin, Wang; Dong, Chunxia

doi:10.1016/j.cretres.2014.12.014

Cited by 17 publications

(6 citation statements)

References 37 publications

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“…The most recent common ancestor of Cephalotaxaceae and Taxaceae was set to a minimum age of 163.5 Mya ( Florin, 1963 ). The stem age of Taxus was set to a minimum age of 100 Mya ( Xu et al , 2015 ). We used the uncorrelated log-normal relaxed molecular clock approach, which allows uncertainty in the age of calibrations to be represented as prior distributions rather than as strict calibration/fixed points.…”

Section: Methodsmentioning

confidence: 99%

Plastome phylogenomics ofCephalotaxus(Cephalotaxaceae) and allied genera

Liu

Landis

et al. 2020

Annals of Botany

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Background and Aims Cephalotaxus is a paleo-endemic genus in East Asia that consists of ~7–9 conifer species. Despite its great economic and ecological importance, the relationships between Cephalotaxus and related genera, as well as the interspecific relationships within Cephalotaxus, have long been controversial, resulting in contrasting taxonomic proposals in delimitation of Cephalotaxaceae and Taxaceae. Based on plastome data, this study aims to reconstruct a robust phylogeny to infer the systematic placement and the evolutionary history of Cephalotaxus. Methods A total of eleven plastomes, representing all species currently recognized in Cephalotaxus and two Torreya species, were sequenced and assembled. Combining these with previously published plastomes, we reconstructed a phylogeny of Cephalotaxaceae and Taxaceae with nearly full taxonomic sampling. Under a phylogenetic framework and molecular dating, the diversification history of Cephalotaxus and allied genera was explored. Key Results Phylogenetic analyses of 81 plastid protein-coding genes recovered robust relationships between Cephalotaxus and related genera, as well as providing a well-supported resolution of interspecific relationships within Cephalotaxus, Taxus, Torreya and Amentotaxus. Divergence time estimation indicated that most extant species of these genera are relatively young, although fossil and other molecular evidence consistently show these genera are ancient plant lineages. Conclusions Our results justify the taxonomic proposal that recognizes Cephalotaxaceae as a monotypic family, and contribute to a clear-cut delineation between Cephalotaxaceae and Taxaceae. Given that extant species of Cephalotaxus are derived from recent divergence events associated with the establishment of monsoonal climates in East Asia and Pleistocene climatic fluctuations, they are not evolutionary relics.

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Section: Methodsmentioning

confidence: 99%

Plastome phylogenomics ofCephalotaxus(Cephalotaxaceae) and allied genera

Liu

Landis

et al. 2020

Annals of Botany

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“…A starting tree with branch lengths satisfying all fossil prior constraints was created manually according to the RaxML inferred tree. The node uniting Taxaceae and Cupressaceae was calibrated with a minimum age of 197 Ma (Florin, , ); the age of Taxus was set to a minimum age of 100 Ma (Xu et al, ). We modeled all calibrations as an exponential distribution (Ho & Philips, ) with a mean of 1 and an offset (hard bound constraint) that equaled the minimum age of the calibration.…”

Section: Methodsmentioning

confidence: 99%

Plastome phylogenomic analysis of Torreya (Taxaceae)

Zhang

Landis

et al. 2019

J of Sytematics Evolution

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Torreya Arn., a small genus of Taxaceae, consists of six species occurring in North America and eastern Asia. Several phylogenetic studies have previously been undertaken to reveal relationships within this genus, although only a few DNA segments or species were used. In the present study, we sequenced five Torreya plastomes and combined these with two existing plastomes from the genus to investigate plastome evolution and phylogenetic relationships within Torreya. All sequenced Torreya plastomes shared the same complement of 82 protein‐coding genes, 4 ribosomal RNA genes, and 31 transfer RNA genes. Phylogenetic inference using a maximum likelihood framework consisted of an 82‐gene, 17‐taxon dataset, including all species of Torreya, resolved Torreya as a monophyletic clade. Strongly supported relationships within the genus include the position of the early diverging T. jackii Chun, the two sister pairs T. fargesii Franch.–T. nucifera (L.) Siebold & Zucc. and T. grandis Fortune ex Lindl.–T. californica Torr., and the monophyly of the clade including T. fargesii var. yunnanensis, T. fargesii, and T. nucifera. In addition to the inference of species relationships, divergence time estimation and biogeographical analysis were carried out. The diversification of Torreya was estimated to be approximately 8.9 Ma. Ancestral state reconstruction of the geographical area suggested China/eastern North America as the most likely ancestral region for the six extant Torreya species.

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“…According to the abovementioned palynological analysis, we name the palynological assemblages of this study area Psophosphaera-Perinopollenites-Cycadopites. (Jin, Wang, & Du, 2013;Xu et al, 2015). Other paleontologists also found a large number of macrofossils in the Guyang Formation (Table 1).…”

Section: Resultsmentioning

confidence: 90%

“…The palynomorph assemblages of the Guyang Basin are dominated by gymnosperm pollen and filicopsida spores. Most of the gymnosperm pollen are conifers pollen represented by Perinopollenites , Classopollis , Piceaepollenites , Taxodites and Araucariacites , contain a large amount of Ginkgoales and Cycad pollen grains, plant macrofossils discovered in the study area, and include Coniopteris simplex , Podozamites lanceolatus , Sequoia gracilis , Ginkgo lepida , Sabinites gracilis , Elatides manchurensis , Elatides sp., Sabinites neimngonglica , Torreya grandis , Stenorachis lepida , Equisetites sp., and Taxus guyangensis (Jin, Wang, & Du, ; Xu et al, ). Other paleontologists also found a large number of macrofossils in the Guyang Formation (Table ).…”

Section: Discussionmentioning

confidence: 99%

“…The exact ages of the Guyang Formation remain ambiguous because neither reliable radiometric ages nor biostratigraphic index fossils have been reported from these formations. Xu, Sun, Yan, Wang, and Dong (2015) compared characteristics of the flora and the characters of the deposits and considered that the Guyang Formation correlates to the Shahai and Fuxin Formations in the Fuxin Basin of northeastern China (Deng et al, ; Tan & Zhu, ; Xu et al, ). Therefore, the age of the Guyang Formation is tentatively considered to be Aptian−Albian (Xu et al, ; Figure ).…”

Section: Geological Settingmentioning

confidence: 99%

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Pollen and spores from Lower Cretaceous in Guyang Basin of Inner Mongolia, China and their palaeoclimatic and paleoecological significance

et al. 2017

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Research on the climate and vegetation of the Cretaceous is fundamental to understanding the present environment. The present study focuses on the Lower Cretaceous Guyang Formation (Inner Mongolia), which yields unique macrofossils and diverse palynological assemblages that are used to understand the palaeoecology. In total, 56 genera are identified in the examined assemblage, which are dominated by spores and pollen of pteridophytes and gymnosperms. The gymnosperm pollen is dominated by Taxodiaceae, which belong to Coniferales, and a large proportion of pollen attributable to the Cycadophyta and Ginkgopsida. The pteridophyte spores are dominated by taxa attributable to the Lygodiaceae and Cyatheaceae. Quantitative analysis based on the geographical distribution of modern plant communities and the Sporomorph Ecogroup (SEG) model, the palynomorph associations are used to infer the presence of a closed coniferous forest dominated by Podozamitales, Picea and Podocarpus with understory vegetation comprising ferns prevailed. The fossil palyno flora indicates a warm and humid subtropical climate during Early Cretaceous of Inner Mongolia.

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A Taxus leafy branch with attached ovules from the Lower Cretaceous of Inner Mongolia, North China

Cited by 17 publications

References 37 publications

Plastome phylogenomics ofCephalotaxus(Cephalotaxaceae) and allied genera

Plastome phylogenomics ofCephalotaxus(Cephalotaxaceae) and allied genera

Plastome phylogenomic analysis of Torreya (Taxaceae)

Pollen and spores from Lower Cretaceous in Guyang Basin of Inner Mongolia, China and their palaeoclimatic and paleoecological significance

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