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During the early Eocene, Rajasthan was positioned near the equator and had a warm and humid tropical climate dominated by tropical rainforests like the present-day equatorial forests of South India. Many of the plants retrieved as fossils from Rajasthan are growing there as refugee. This study further strengthens this view as it reports a new species of Uvaria L. from the early Eocene sediments of Bikaner (Rajasthan) showing its best resemblance with the extant U. zeylanica Deless. ex DC., which is presently growing in the evergreen forests of South India and Sri Lanka. The genus is thought to have originated in Africa, and the present finding gives an idea about its geologic distribution in Asia and Australasia via India relying on ‘stepping stone’ hypothesis during the Early Eocene Climatic Optimum (EECO) when climatic conditions were favourable for the luxuriant growth of tropical vegetation. A general cooling trend after EECO and change in the configuration of land and sea affected the climate on the regional scale causing total devastation of tropical evergreen forests that existed in western India during the depositional time; this change is ultimately responsible for creating dry and desertic conditions prevailing in the area at present. 相似文献
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Jianhua Jin Jue Qiu You’an Zhu Tatyana M. Kodrul 《Plant Systematics and Evolution》2010,285(3-4):159-163
The first fossil record of the genus Nageia Gaertner from the Tertiary of southern China is reported. Nageia hainanensis sp. nov. is described from the Eocene Changchang Formation of Hainan Island. The extant species of Nageia are widely distributed in southeastern Asia, from northeastern India to southeastern China and southern Japan, and southward through Indochina to the Malay Archipelago and New Guinea. The fossil evidence of Nageia has been discovered from the Lower Cretaceous of the Far East of Russia and Japan. The distribution of both modern and fossil species of Nageia indicates that this genus could have originated in the northeastern part of Asia in the Early Cretaceous and spread to south China at least in the Eocene. Discovery of Nageia fossil record in south China provides important evidence for the geological and phytogeographic history of the genus. 相似文献
4.
Yuriy S. Mamontov Nadezhda A. Konstantinova Evgeny E. Perkovsky Michael S. Ignatov 《Journal of bryology》2017,39(4):336-341
A fossil species of the extant liverwort genus Frullania Raddi is described and illustrated, based on a single inclusion in a piece of Rovno amber (Ukraine) that shares its age with Late Eocene Baltic amber, its northern contemporary. Frullania rovnoi is characterised by leaves with a rounded dorsal lobe and the absence of ocelli. The ventral lobe is inflated and forms a saclike lobule, which is bell-shaped and somewhat constricted above the mouth. The bifid underleaves have several blunt teeth or angulations along the shoulder. The Rovno fossil differs sufficiently from morphologically similar species preserved in Baltic and Bitterfeld amber as to be described as new to science. The shape of the lobules and underleaves, as well as the absence of ocelli, indicate an affiliation to F. sect. Australes, hitherto represented in Eocene amber inclusions solely by F. schumannii (Casp.) Grolle. The Rovno fossil is distinguished from extant species of F. subg. Australes and from F. schumannii by having roughly and irregularly dentate-angulate underleaf margins. 相似文献
5.
The genus Osmunda L. contains approximately 10 extant species widely distributed in tropical and temperate regions, with the greatest concentration of species in East and Southeast Asia. Osmunda is characterized by dimorphic or commonly hemidimorphic fronds with dimorphic pinnae. Its geological history has been traced back to the Triassic. Most records of the genus are based on rhizomes and rarely on pinnae bearing sporangia and spores. Here, we describe fossil pinnae, sporangia, and spores of Osmunda lignitum (Giebel) Stur recovered from the middle Eocene of the Changchang Formation in the Changchang Basin, Hainan Island and the Youganwo Formation in the Maoming Basin, Guangdong, South China. The fossils closely resemble the extant Osmunda banksiifolia (C. Presl) Kuhn of the subgenus Plenasium on the basis of their morphological and anatomical structures. The present occurrence of O. lignitum indicates subg. Plenasium flourished and extended from the high latitude regions such as Northeast China to the low latitude areas of South China during the middle Eocene. Large numbers of specimens described here also indicate that Osmunda was the dominant understory fern element beneath mixed evergreen broad-leaf angiosperm and gymnosperm forests living in a warm and humid environment. 相似文献
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? Premise of the Study: Calocedrus is among the genera with a typical eastern Asian-western North American disjunct distribution today. The origin of its modern distribution pattern can be better understood by examining its fossil record. ? Methods: The present article reports for the first time a new fossil species of this genus based on compressed material from the Oligocene Ningming Formation of Guangxi, South China, in its present major distribution area in eastern Asia. ? Key Results: Calocedrus huashanensis sp. nov. is most similar to the two extant eastern Asian species, C. macrolepis and C. formosana, in gross morphology of foliage shoots and bears a close resemblance to the latter in cuticle structure. It shows a general similarity to the North American fossil representatives of the genus in alternately branched foliage shoots but is clearly different from the European Paleogene species characterized by oppositely branched leafy shoots. ? Conclusions: This discovery provides new evidence for the floristic exchange of this genus between eastern Asia and North America before the Oligocene (most likely in the Eocene), presumably via the Bering land bridge. The flattened leafy shoots and dimorphic leaves with thin cuticle, open stomatal pits, and shallowly sunken guard cells of the present fossils suggest a rather humid climate during the Oligocene in the Ningming area, South China. 相似文献
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In this paper, we describe a new species Magnolia nanningensis sp. nov., based on exceptionally well‐preserved mummified fossil woods from the late Oligocene of the Nanning Basin, Guangxi, South China. The features of these woods indicate a close affinity to the section Michelia of the subgenus Yulania belonging to the genus Magnolia sensu lato (Magnoliaceae). Magnolia nanningensis is the first fossil record of the section Michelia from China, the modern diversity center of this group. These mummified woods provide fossil evidence supporting molecular dating that estimated an Oligocene age for divergence of the tropical evergreen section Michelia and the temperate deciduous section Yulania. Helical thickenings on vessel walls and a high degree of vessel grouping found in these fossil woods could be adaptive to temporary, possibly seasonal, droughts and, as suggested by other woods from the Nanning Basin, could be indicative of a monsoon‐influenced tropical climate in Guangxi during the late Oligocene. Helical thickenings have not been reported in magnoliaceous fossil woods prior to the Oligocene. The appearance of this trait was presumably a response to abrupt climate cooling near the Eocene–Oligocene boundary, followed by increase in climate seasonality. The associated increase of latitudinal zonation might be a possible trigger for divergence between the tropical evergreen sect. Michelia and the temperate deciduous sect. Yulania. 相似文献
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Many of the oldest definitive members of the Rosaceae are present in the Eocene upland floras of the Okanogan Highlands of
northeastern Washington State and British Columbia, Canada. Over a dozen rosaceous taxa representing extant and extinct genera
of all four traditionally recognized subfamilies are known from flowers, fruits, wood, pollen, and especially leaves. The
complexity seen in Eocene Rosaceae suggests that hybridization and polyploidy may have played a pivotal role in the early
evolution of the family. Increased species diversity and the first appearance of additional modern taxa occur during the Late
Paleogene in North America and Europe. The Rosaceae become increasingly important components of fossil floras during the Neogene,
with taxa adapted to many habitats. 相似文献
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Fossil flowers with affinities to Malpighiaceae have been discovered in the Middle Eocene Claiborne formation of northwestern Tennessee. The new taxon Eoglandulosa warmanensis gen. et sp. nov. Taylor and Crepet, has paired glands on the five sepals, clawed petals and tricolporate pollen with reticulate ornamentation and an unusual infratectal wall structure of anastomosing elements. The fossil is similar in wall structure to some extant species of Malpighiaceae. Glandular floral morphology in extant species is associated with specific anthophorid bee pollinators and the fossil evidence suggests that such specific plant-pollinator relationships existed during the Eocene. This fossil species also suggests that by the Eocene, South American floral elements had migrated to North America via island pathways, and that the Mississippi embayment was nearly frost-free. 相似文献
10.
历史概述 蝇子草属蔓生组(Sect.Cucubaloidcae)是Edgeworth M.P.在1874年建立的。他在《Fl.Brit.Ind.》(1874)一卷中记载了印度和锡金的3个种(Silene? stracheyiEdgew.,S.khasiana Rohrb.,S.vagans C.B.Clarke),对组的特征作了简略的英文记载,但无拉丁文记载,也未指明组的模式种。从19世纪后期到20世纪初有不少学者,如Rohrbach P.(1869),Franchet A.(1886),Williams F.N.(1909),SmithW.W.(1919),Limpricht W.(1922)等相继发表了本组许多新种。但多数未做系统研究。其中仅Williams F.N.(1896),Pax et Hoffman(1934)和Chowdhuri P.K.(1957)等,在各自建立的Silene(或Melandrium)系统中直接或间接涉及到本组植物。而这些分类系统多不能反映本组的系统关系。 相似文献
11.
The genus Swertia is one of the large genera in Gentianaceae, including 154
species, 16 series and 11 sections. It is disjunctly distributed in Europe, Asia, Africa and N.
America, but entirely absent from Oceania and S. America.
According to Takhtajan’s (1978) regionalization of the world flora, Swertia is found in
14 regions. Eastern Asiatic region with 86 species, of which 58 are local endemics, 13 series
and 9 sections, ranks the first among all the regions. The highest concentration of the taxa
and endemics in Eastern Asiatic region occurs in SW China-Himalayan area (Sikang-Yunnan
P. , W. Sichuan, W. Yunnan-Guichou Plateau of China and NE. Burma, N. Burmense P. ,
E. Himalayan P. and Khasi-Manipur P. ). In this area there are 74 species (48 endemics),
12 series, and 9 sections; thus about half species of the world total, three quarters of series
and 82% of sections occur in this small area. Besides, the taxa at different evolutionary
stages in Swertia also survive here. It is an indication that SW. China-Himalayan area is a
major distribution centre of the genus Swertia. In addition, Sudan-Zambezian Region in
Africa, with 22 species, 4 series and 2 sections, is a second distribution centre.
The primitive type of the genus Swertia is Sect. Rugosa which consists of 2 series and
23 species. It is highly centred in the mountains of SW. China (Yunnan, Sichuan, Guizhou
and SE. Xizang) where 2 series and 16 species occur. Among them 15 species of Ser. Rugosae were considered as the most primitive groups in this genus. From our study, the outgroup of Swertia is the genus Latouchea Frahch. , which is distributed in Yunnan, Sichuan,
Guizhou, Hunan, Guangdong, Guangxi and Fujian. The two groups overlap in distribution
in SW. China. According to the principle of common origin, the ancestor of two genera ap peared most probably in this overlapping area. It was inferred that SW. China Was the birth-place of the genus Swertia.
Four sections of Swertia have different disjunct distribution patterns: Sect. Ophelia is of
Tropic Asia, Africa and Madagascar disjunct distribution; sect. Swertia is of north temperate distribution; sect. Spinosisemina is in Tropical Asia (Trop. India to S. China and Philipines); sect. Platynema also is in Tropical Asia (Java, Sumatra, Himalayas to SW. China).
These disjunct patterns indicate that the Swertia floras between the continents or between
continent and islands have a connection with each other. From paleogeographical analysis,
Swertia plants dispersed to Madagascar before the Late Cretaceous, to SE. Asian Islands in
the Pleistocene, to North America in the Miocene. The distribution of Swertia in Madagascar might be later than that in Asia. Therefore the origin time of the genus Swertia was at
least not later than the Late Cretaceous, and might be back to the Mid-Cretaceous.
The genus Swertia first fully developed and differentiated, forming some taxa at different evolutionary stages (Rugosa, Swertia, Poephila, Ophelia and Platynema etc. ) in the original area, and these taxa quickly dispersed in certain directions during the Late Cretaceous-Middle Tertiary when the global climate was warm and no much change. There seem
to be three main dispersal routes from the origin area to different continents; (1) The westward route i. e. from SW. China, along the Himalayas area to Kashmir, Pakistan,
Afghanistan and Iran, and then southwestwards into Africa throuth Arabia. Four sections
(Poephila, Macranthos, Kingdon-Wardia and Ophelia) took this dispersal route. Most
species of sect. Ophelia dispersed along this route, but a few along southern route and north
ern route. Sect. Ophelia greatly differentiated in Africa and the African endemic sectionSect. Montana was derived from it. The two sections form there a second distribution center
of Swertia. (2) The southward route, i. e. towards S. India through the Himalayas, and
towards SE. Asian islands through C. and S. China, Indo-China. Along this dispersal route
sect. Platynema, Sect. Spinosisemina and a few species of Sect. Ophelia dispersed; (3) The
northward rout, i. e. northwards across N. China, C. Asia to a high latitude of Euasia,
and also through E. Asia into N. America. The following groups took this route: sect. Rugosa, sect. Swertia, sect. Frasera, sect. Heteranthos and sect. Ophelia ser. Dichotomae.
Therefore, it seems that the genus Swertia originated in SW. China and then dispersed
from there to N. and S. Asia, Africa, Europe and North America and formed the moderndistribution pattern of this genus. 相似文献
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ROLF SCHMIDT YVONNE BONE 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2003,36(4):345-356
The first extensive and stratigraphically detailed taxonomic study of the Middle to Late Eocene Bryozoa of the St Vincent Basin has identified more than 200 species of Cheilostomata and 50 species of Cyclostomata. There are three biogeographic groups: basin endemic, Australian and global. Two-thirds (116) of the cheilostome species and seven genera are currently considered endemic to this basin. Most species are endemic to Australia and similar to those found in the Oligo-Miocene of Victoria. The Cellariidae are a common component of most Australian Cainozoic deposits, but the species are highly dissimilar, with 13 of the 17 species here being new. The global component indicates that biogeographic links with regions outside Australia still existed in the Eocene. The cyclostome genus Reticrescis is only known from the Australian and Antarctic Eocene. Ten genera have their first occurrence in the Eocene St Vincent Basin. The Phidoloporidae and Smittinidae represent the most diverse and ubiquitous groups at a geological time close to their time of origination. Contemporaneous sediments in Antarctica, eastern Europe and North America also have a diverse fauna of this family, pointing to a strong Tethyan link. Rhamphosmittina lateralis (MacGillivray) is still extant in New Zealand, having an exceptionally long time range of 40 million years. Overall, the fauna has a distinct Late Cretaceous character. A new genus of Onychocellidae appears similar to genera that were common in Cretaceous Tethyan faunas but rare during the Cainozoic. This similarity ends in the Oligocene, after which the Australian bryozoan became endemic 相似文献
13.
《Palaeoworld》2022,31(3):443-454
Although liverworts are widely distributed around the world with a large number of extant species, reliable fossil records are relatively rare. Here, we report a new species, Ricciopsis baojishanensis Han and Yan, n. sp. (Ricciaceae) and an unnamed species, Hepaticites sp. from the Late Triassic Nanying’er Formation in Baojishan Basin, Baiyin City, Gansu Province, Northwest China. The generic designation is based on detailed comparison of the gross morphology with related fossil and extant species. The new species is characterized by its rosette-forming thallus, dichotomous branching, ribbon-like segments and entire margins. The current fossils represent the first record of liverwort from the Late Triassic in Baojishan Basin, Gansu Province. Based on the different fossil records of the Ricciaceae, we suggest that these taxa were widely distributed during Late Triassic to Oligocene worldwide, mainly in warm temperate and tropical environments, similar with their current distribution. The discovery of the present fossils indicates that the climate of Baojishan Basin in Late Triassic is warmer and more humid than that of today. 相似文献
14.
ZHOU Zhe-Kun 《植物分类学报:英文版》1999,37(4):369-385
The fossil history of the Fagaceae from China and its systematic and biogeographic
implications are discussed based on revisionary studies of the fossil records. No creditable
macrofossil record of the Fagaceae exists in the Cretaceous deposits and all the Cretaceous microfossil reports remain equivocal and require further study. The Paleocene fossils show the
appearance and diversification of the two groups corresponding to the subfamilies Fagoideae
and Castaneoideae sensu Nixon. By the Eocene, all modern genera had been present. The
oldest fagaceous fossils represent subfamily Fagoideae with affinities to the extant genus
Trigonobalanus. The leaf fossil genus Berryophyllum, with affinities to Quercus subg. Cyclobalanopsis, has been documented by the early Eocene and might have occurred earlier than
other fossils assignable to Quercus. The appearance of evergreen sclerophyllous Ouercus
with entire leaves might have occurred earlier than those with toothed leaves. Deciduous, urticoid-leaved oak fossils (Quercus subg. Quercus sect. Quercus) had not appeared until the
Miocene. Fossil equivalents of Trigonobalanus, Castanopsis and Lithocarpus had occurred
in Europe and North America by the early Tertiary, suggesting that continuous distributions
were achieved via the northern hemisphere land bridges. Three groups of evergreen sclerophyllous oaks of apparent close phylogenetic relationships occurred in the Hengduan mountains, the Mediterranean area and northwestern North America. Their fossil forms have become dominant elements of those vegetation zones since the Miocene. A shared fossil history
indicates a possible biogeographic boundary formed by the ancient Mediterranean. The evidence suggests that the oaks might arrive in North America during two distinct geologic periods: evergreen sclerophyllous entire-leaved oaks appeared by the Early Tertiary, whereas thedeciduous oaks with urticoid leaves appeared in the Late Tertiary. 相似文献
15.
Zhou Zhe-kun 《植物学报(英文版)》1992,34(12)
Evergreen sclerophyllous oaks (Quercus subg. Quercus sect. Brachylepides and part of sect. Engleriana) were dominant in Hengduan Mt., south west China, since the Late Tertiary. About 17 species from China have been recorded hitherto. However, some mistakes and confusion were made in their taxonomy and nomenclature. Therefore the nomenclature of the fossil would also be incorrect. An attempt is made in present paper, to revise such mistakes and contusion. 14 species of sect. Brachylepides were reduced to 7 and 3 species of sect Engleriana to one. In addition, the key to these fossil species was made. 相似文献
16.
MichelleTCASANOVA AdrianaGARCIA MoniqueFEIST 《微体古生物学报》2003,20(2):118-128
轮藻植物属Lychnothamnus(Rupr.)Leonh.自晚始新世即有化石代表,在上新世繁盛且分布广泛,此后分异度降低、分布范围缩减,延续至今仅存1种:L.barbatus(Meyen)Leonh.。上世纪末叶前该种还曾广泛分布于欧洲、印度、中国、巴布亚新几内亚和澳大利亚,而后该种在澳大利亚曾经留有记录的产地消失,直到1996年才被再次发现。本文描述了澳大利亚L.barbatus的居群特征,包括植株、卵囊球和藏卵器形态特征以及萌发生态学的实验研究结果。讨论该种的野外生态学、共生种、全球范围的分布与丰度特征,探讨该种衰落的原因并提出植物保护方案。 相似文献
17.
壳斗科的地质历史及其系统学和植物地理学意义 总被引:43,自引:1,他引:42
在收集整理现有壳斗科化石资料的基础上,讨论了壳斗科及其各属的起源时间、地史分布和地史
演替过程以及这些化石资料在系统学和植物地理学上的意义。白垩纪尚无壳斗科可靠的大化石记录,
微化石需要进一步研究才能确定亲缘关系以及古新世壳斗科已经分化出两个类群。从以上这些事实推
论壳斗科起源于白垩纪晚期,而壳斗科现代各属出现的时间应不晚于古新世。最早发现的壳斗科化石和现代栗亚科和水青冈亚科在形态结构上非常相似,这一事实表明,壳斗科分为两个亚科的观点更接近客观事实。在水青冈亚科中,三棱栎类的化石最早出现;在栎属中,青冈亚属更接近祖先类群;在地史中全缘栎类较具齿栎类出现早,粗齿的落叶栎类出现最晚。三棱栎属、栲属和石栎属的化石在老第三纪出现于北美和欧洲的事实说明,北美、欧洲和东亚在老第三纪时有一个相通的壳斗科植物区系。南美的三棱栎是通过北美进入南美的。中国横断山、欧洲地中海沿岸和北美西北部有一类形态特征相似、亲缘关系相近的硬叶栎类,它们之间有相同的地质演替历史,它们现代分布边界可能就是古地中海的边界。美洲的栎类有两个来源,常绿硬叶栎类是通过古地中海沿岸而经北美-欧洲陆桥到达的,落叶栎类则是在中新世以后通过白令海峡到达的。 相似文献
18.
María Jimena Franco 《Historical Biology》2018,30(5):646-660
Two new wood types from the Late Cenozoic of the Ituzaingó Formation, La Plata Basin, Northeast Argentina add to our knowledge of South American Cenozoic plants. The materials were preserved by siliceous cellular permineralization, and they were prepared for microscopic examination by surface polishing and in thin sections. The anatomy of these new species was described. The relationship and comparison with the nearest living relatives (NLRs) are discussed. Maytenoxylon perforatum Franco gen. and sp. nov. is described as the first fossil wood referable to Celastraceae from South America. This new fossil species is related to extant Maytenus Molina. The other fossil twig, Ruprechtioxylon breae Franco sp. nov., has features of the Polygonaceae family and particularly resembles the extant specie Ruprechtia laxiflora Meisn. The occurrence of these fossil woods in south-eastern South America suggests that a relatively warm and dry to seasonally dry climate prevailed over this region of Gondwana during the Upper Cenozoic. It also provides new evidence for the hypothesis of the more wide distribution of Seasonally Dry Tropical Forest (SDTF) during the Upper Cenozoic. 相似文献
19.
20.
Xiaoyuan He 《Review of Palaeobotany and Palynology》2010,162(2):159-167
A new species of Nelumbo Adanson is described from the Eocene of the Changchang Basin, Hainan Island, South China. This is the first comprehensive report on a fossil Nelumbo species from the Eocene of the Changchang Basin, Hainan Island. The co-occurrence of fruits, tubers, rhizomes with numerous adventitious roots, leaves, and receptacles indicates that the plants grew where they are preserved. These specimens, combined with palynological assemblage and other macrofossils, indicate a tropical or subtropical humid climate in the Changchang Basin from the late early Eocene to early late Eocene. 相似文献