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1.
New palm leaves from the Oligocene Ningming Formation are placed into the morphogenus Sabalites because of their costapalmate leaf shape. Four taxa are described on the basis of leaf compressions with cuticular structure. S. guanxiensis sp. nov. is characterised by hypostomatic leaf blades with a stout costa and a symmetrical base. Sabalites cf. asymmetricus has amphistomatic leaf blades with a long, delicate costa and an asymmetrical base. Sabalites sp. 1 has amphistomatic leaf blades with a long, massive costa and wide segments. Sabalites sp. 2 is characterized by hypostomatic leaf blades with a prominent costa and an asymmetrical base. The four new palm taxa expand our understanding of the floristic elements and features of the Oligocene Ningming flora. Together with the other three palm taxa that were previously reported from the Ningming Formation, our material indicates that the Oligocene Ningming flora had a rich diversity of costapalmate palms. The relatively high species diversity of palms and other plants corroborate that the Oligocene Ningming flora represents a warm and humid climate.  相似文献   

2.
The genus Burretiodendron Rehder is currently endemic to an area near the China–Vietnam border and the limestone mountains of Thailand and Myanmar. The fossil records of this genus were previously found only from the Miocene of Yunnan, Southwest China, and the Oligocene of Guangxi, South China. Here, we describe fossil fruits and associated leaves of Burretiodendron, which were discovered in the lower Oligocene Shangcun Formation of the Maoming Basin, Guangdong, South China. Morphological comparison with extant and fossil Burretiodendron taxa indicates that fruit fossils belong to the species Burretiodendron parvifructum J. Lebreton Anberrée & Z. K. Zhou. This is one of the earliest fossil records of the genus, providing additional evidence for the early biogeographic history of this genus and supporting the inference that the genus originated in South China. According to the habitat conditions of modern species, we speculate that there were limestone mountains around the Maoming Basin in the early Oligocene.  相似文献   

3.
The genus Calocedrus Kurz is characterized by flattened branches covered with decussate and dimorphic leaves. In this study, we describe fossil foliage of Calocedrus discovered in the Shangcun Formation (early Oligocene) of the Maoming Basin, South China. The fossils have wedge‐shaped branchlet segments and scale‐like strongly dimorphic leaves, similar to the fossil species Calocedrus lantenoisi (Laurent) Tao. There have been no detailed studies of the morphological features and cuticle structures of C. lantenoisi. Therefore, a newly emended diagnosis of the species C. lantenoisi is given based on a detailed study of leaf morphology and cuticular characters exhibited by the Maoming fossils. This is one of the earliest fossil records of Calocedrus in the world, providing additional evidence for the early biogeographic history of this genus and supporting the inference that eastern Asian Calocedrus is primitive among all the living species. The extant species of Calocedrus are mainly distributed in mountainous regions. On the basis of the “nearest living relative” analysis, we propose that the Maoming Basin was adjacent to a mountainous region during the early Oligocene.  相似文献   

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5.
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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7.
The ring‐cupped oaks (Quercus subg. Cyclobalanopsis) characterized by united and concentric ring‐cupped acorns, are mainly distributed in broad‐leaved evergreen forests in tropical and subtropical regions of East and Southeast Asia. Their geological history has been traced from the middle Eocene to Pleistocene. Most reports of the subgenus have been on the basis of leaves, whereas the acorns or cupules, more valuable evidence for the inter‐ and intrageneric classifications, have been relatively poorly documented. Here, we describe a new species, Quercus shangcunensis sp. nov., based on a ring‐cupped fossil acorn and pollen on the acorn, as well as Quercus sp. associated leaves, recovered from the early Oligocene Shangcun Formation of Maoming Basin, Guangdong Province, South China. The morphological and anatomical structures of these fossils confirm their attribution to the subg. Cyclobalanopsis. Quercus shangcunensis sp. nov. represents the world's first Oligocene fossil acorn and the earliest fossil acorn in China for the subgenus, indicating that the subg. Cyclobalanopsis arrived in the low latitude area of South China at least by the early Oligocene. Our fossil provides evidence that the subgenus was present in one of its modern distribution centers in the Oligocene, suggesting that the modern distribution patterns of the subg. Cyclobalanopsis most likely originated during or prior to the Oligocene.  相似文献   

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Icacinaceae are well represented in the modern tropical flora of East Asia, but this family has no confirmed macrofossils from this region. Most of the unambiguous fossils (e.g., endocarps) are from the Paleogene of North America and Europe, where the family is no longer present. Here we report a fossil endocarp of the liana genus Iodes from the Oligocene Wenshan flora, southwestern China. The fossil is relatively large (ca. 20 mm length, 11 mm width) and documents a vascular bundle inside the endocarp wall, a pattern of ridges enclosing few areoles, and an asymmetrical apex and rounded base. On the basis of these characteristics, we described a new species, Iodes elliptica, which represents the first Icacinaceae fruit fossil record from Asia. This fossil, consistent with recent reports of Iodes pollen from the Eocene of Hainan, indicates a long-standing presence of the genus in SE Asia, dating back to the Paleogene. Based on the climatic data of modern Iodes, and other fossil occurrences from Wenshan, we hypothesize that the climate in the region was subtropical during the Oligocene, supporting a rainforest, with an overall mixed regional flora of subtropical and tropical elements.  相似文献   

10.
A new pearleye species of the alepisauroid family Scopelarchidae, Scopelarchoides neamticus sp. nov., is described herein based on two specimens from the Oligocene Lower Dysodilic Shales Formation, cropping out in the Pietricica Mountain, Romanian Eastern Carpathians. The new species described herein exhibits a unique combination of features (including head length about 25% of SL; coracoid remarkably expanded; both preorbital and postorbital lengths larger than orbit diameter; 50 or 51 vertebrae; dorsal fin with nine or ten rays; anal-fin with 28 rays; length of anal fin base about 30% of SL; preanal distance almost 60% of SL; pelvic fin insertion located just under the second dorsal fin ray; pectoral fins only slightly longer than pelvic fins; caudal fin with 19 principal rays plus 14 upper and 13 lower procurrent rays) that justifies its recognition as a new species of the genus Scopelarchoides. Both morphological and meristic features suggest a certain degree of similarity between S. neamticus sp. nov. and the extant species Scopelarchoides signifer. The fossils of the new Oligocene species described herein represent the oldest known skeletal record of Scopelarchidae.  相似文献   

11.
《Palaeoworld》2014,23(3-4):370-382
Two fossil leaves identified as Castanopsis presclerophylla n. sp. collected from a diatomite bed in the upper Pliocene (3.3–2.8 Ma) in Tengchong County, Yunnan Province, Southwest China, are characterized by elliptic laminar shapes with acuminate apex, convex base, simple trichome bases and cyclocytic stomata. The cuticles of extant leaves from six selected Castanopsis species that are similar to the Pliocene fossil leaves in laminar shape were examined in detail for the comparison. Based on the analysis of leaf architecture and cuticular characteristics, the present fossil leaves most closely resemble the extant leaves of Castanopsis sclerophylla (Lindl.) Schott., which prefers a subtropical climate. The published fossil records of Castanopsis also indicate that it was once widely distributed in North America, Europe and Asia before the Pliocene, and then rapidly retreated to the East and Southeast Asia as a result of the Pleistocene glaciation.  相似文献   

12.
中国云南元谋上新世千屈菜科紫薇木属一新种   总被引:1,自引:0,他引:1  
报道了来自中国云南元谋新华土林上新世地层的木化石新种——元谋紫薇Lagerstroemioxylon yuanmouensis Y.M.Cheng,C.S.Li,X.M.Jiang&Y.F.Wang。目前紫薇属Lagerstroemia分布于亚洲至澳大利亚北部的热带森林中,其中有一些种在我国的西南部和台湾省也有分布。在印度、缅甸、印度尼西亚和德国的第三纪地层中曾报道有紫薇属木化石的存在,这表明该属在第三纪分布的范围比现代更广。  相似文献   

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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   

15.
? 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   

16.
易同培  杨林 《植物研究》2006,26(6):641-643
绵竹榆的花秋季开放,翅果柱头面被毛,其两侧的翅较果核为窄,果核位于翅果上端接近缺口处,与榔榆(Ulmus parvifolia Jacq.)相似,但树皮深灰色,不规则鳞块状浅裂,叶片先端渐尖,花被片裂至基部,宿存,边缘上部生纤毛,翅果狭椭圆形,中部最宽,向两端渐变窄,果梗与花被等长,长约2 mm,果序梗长约1 mm,而明显不同。  相似文献   

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18.
《Palaeoworld》2014,23(3-4):336-356
Lauraceae is among the largest and floristically most important woody plant families in subtropical and tropical zones. However, the Cenozoic fossil records of Lauraceae are mostly from mid-latitude regions. Here we described eight lauraceous species from the Oligocene of Ningming, Guangxi, South China on the basis of leaf compressions with cuticular structure, providing new evidence for high diversity of Lauraceae in the low latitude region of the northern hemisphere during the late Paleogene. The extant genera to which the Ningming Oligocene fossils are possibly closely related include Cinnamomum, Neolitsea, Litsea, Alseodaphne, Laurus, and Beilschmiedia. All of these extant genera except Laurus still exist in Guangxi today, whereas Laurus is currently distributed in the Mediterranean and adjacent regions. A cladistic analysis based on leaf architectural and leaf cuticular characters for Paleogene Lauraceae species in the world indicated a possible relationship between European and East Asian Paleogene species.  相似文献   

19.
记述了产自广西南宁盆地渐新世早—中期的鲤科鲤亚科一新属种——伍氏南宁鲤(+Nanningocyprinus wui gen.et sp.nov).化石材料包括一些咽喉骨和咽齿.这些咽喉骨和咽齿的以下特征组合明显不同于其他鲤科鱼类:齿式-3·2·1,主行第一枚咽齿大小是第二枚的3~4倍,第二枚咽齿及第二行第一枚咽齿咀嚼面上各仅有一条沟纹,咽骨前角很发育.该属种的发现进一步证明鲤亚科是鲤科中较早的分支,中国南方很有可能是鲤亚科的起源和分化中心.  相似文献   

20.
The species Proconsul (Xenopithecus) hamiltoni was based on two weathered molars in a maxillary fragment from the Erageleit beds, Lothidok, Turkana District, Kenya. New fossils from Lothidok show a unique suite of features indicating generic distinction of this taxon from other known large early catarrhines. A new generic diagnosis is given. The new genus, although still poorly known, may be the first Oligocene hominoid from East Africa. It retains many primitive features, but the few derived ones hint that it may be related to the Afropithecus group.  相似文献   

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