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1.
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   

2.
Bin Bai 《Palaeontology》2017,60(6):837-852
The Eocene perissodactyl family Palaeotheriidae has traditionally been considered to be a nearly endemic European group within Equoidea, but a few palaeotheres have been reported from Asia. Here, I reanalyse a maxilla containing M1–3 from the Lunan Basin, Yunnan Province, China. This element was initially assigned to a new tapiromorph species, Lophialetes yunnanensis, but is here placed in a new genus Lophiohippus within Pachynolophinae based mainly on the absence of mesostyles, the strongly oblique metalophs, the strong development of lophodonty, parastyles overlapping metastyles of preceding teeth and situated mesial to the paracone, and the fact that M3 is longer than wide and has a large and buccally deflected metastyle. Lophiohippus differs from European Anchilophus and Paranchilophus in that the parastyles are situated mesial or even slightly lingual, rather than mesiobuccal, to the paracones, and M3 is markedly relatively larger than M1. I further reanalyse Qianohippus magicus from the Shinao Basin of Guizhou Province, China, in which the complete dentition is known. Qianohippus is characterized by a molariform P2 and non‐molariform P3–4; a relatively high degree of lophodonty; the absence of mesostyles; an angular bending in the protoloph on P3‐M3 and the metaloph on M1–3 at the paraconule and metaconule, respectively; and weakly developed ‘metastylid’ on the lower cheek teeth. A cladistic analysis supports a close relationship between Lophiohippus yunnanensis and Paranchilophus, and suggests that Qianohippus is closely related to some derived pachynolophs. The appearance of the pachynolophins Lophiohippus and Qianohippus in China supports the existence of a biogeographical connection between Europe and Asia in the Middle‐Late Eocene, and the dispersal route was probably along the Tethyan microcontinents in the south.  相似文献   

3.
Fossil plants from the Upper Devonian (Frasnian) of northern Timan are studied. The sporangia contain well-preserved spores, which were studied in transmitted light using a scanning electron microscope. The genus Gutzeitia S. Snigirevsky, gen. nov. is established. Macroremains and in situ spores of G. timanica (Petros.) S. Snig., comb. nov. and ?Cephalopteris mirabilis (Nath.) Nath. are described. Microspores in Dimeripteris gracilis Schmalh. are identified, and microspores and megaspores in ?Cephalopteris mirabilis are studied for the first time.  相似文献   

4.
The genus Woodwardia, which together with the genera Anchistea and Lorinseria comprise the subfamily Woodwardioideae of Blechnaceae, has a disjunct distribution across Central and North America, Europe and the temperate to tropical areas of Asia. Fossil records of Woodwardia occur throughout the Paleogene and Neogene of North America, Europe and Asia. However, well-preserved fertile pinna fossils of this genus have not yet been reported in South China. In this paper, a new species, W. changchangensis Naugolnykh et Song, sp. nov. is described from the middle Eocene of the Changchang Basin, Hainan Island, South China. Macromorphological and micromorphological features of the fertile pinna show a straight pinna rachis, alternate, subtriangular pinnules, acute pinnule apices, almost entire or slightly undulate pinnule margins, long-ovoid sori, stalked sporangia and spores with wing-like folds on the surface, which are characterised in detail. Overall, the present fossil is most similar to the extant species Woodwardia japonica, which mostly grows in warm and moist environments. The discovery of this new species from the Changchang Basin of Hainan Island indicates that this genus has been distributed in the low-latitude tropical regions of South China from as early as the middle Eocene. Based on this find, and previous studies of other ferns from the same site, we infer that the climate of the Palaeo-Hainan landscape during deposition of the Changchang Formation was warm and humid, similar to conditions prevailing today across this region.  相似文献   

5.
A new species of Nageia, Nageia maomingensis sp. nov., is described from the Late Eocene of Maoming Basin, Guangdong Province, South China. According to its cuticular characteristics, the present fossil species is assigned to N. sect. Dammaroideae, showing the most resemblance to the extant species N. motleyi (Parl.) de Laub. At present, this section is mainly distributed in the Pacific islands region from South Asia to New Guinea. The discovery of N. maomingensis demonstrates that plants of this section inhabited South China at least by the Eocene. The distribution and living habitat of extant N. sect. Dammaroideae imply that South China was warmer during the Late Eocene than today, and may represent one of the centers for early diversification of Nageia and its section Dammaroideae during the Eocene. In addition, we postulate that plants of sect. Dammaroideae migrated southward in response to climate cooling after the Eocene.  相似文献   

6.
Abstract: A species of water‐penny beetles is recorded from larval instars from the Middle Eocene Messel pit fossil site in Germany. This species clearly belongs to the psephenid subfamily Eubrianacinae, but its precise systematic affinities remain unclear. It is the second fossil species of this taxon recorded from Europe. The holotype of the first fossil species, Eubrianax vandeli Bertrand and Laurentiaux, 1963, is lost. The high number of fossil specimens from Messel allowed discussion of stratigraphic and spatial occurrence of the eubrianacine species in the Messel pit, but its larval ontogeny could not be unravelled. Because of the high number of fossils and their wide occurrence, it is inferred that the species from Messel gen. sp. 1 was an autochthonous faunal element of the Eocene Lake Messel, which might indicate that some parts of the former Lake Messel had a shore area with stones. The analysis of the phylogenetic position of both Eocene eubrianacine species showed that their phylogenetic placement cannot be resolved because preservational influences limit the evaluation of characters. The historical biogeography of Psephenidae and Eubrianacinae is analysed and discussed. The fossil record shows that psephenid beetles have fossil members occurring outside their current distribution range, so interpretations of their biogeography based only on extant members can be misleading.  相似文献   

7.
The rich fossil vertebrate record from the Beaufort Group, Main Karoo Basin, provides a global standard for mid‐Permian to Mid‐Triassic continental faunas. However, recent studies have demonstrated variability in the composition of contemporaneous faunas across Gondwana. This raises the question of how much the vertebrate faunas differ within the Karoo, where the taxonomic composition of vertebrate assemblage zones (AZs) is mostly considered to be uniform. Although fossil material is known from across the outcrop of the Beaufort Group, the lowest Beaufort strata have received little attention, particularly north of S31°10′. Here, we report two fossil tetrapod assemblages from the lowest Beaufort Group in the southern Free State Province, which represent the northernmost point at which the lowest Beaufort has been targeted for collecting. The lower assemblage is characterized by an abundance of the small dicynodont Eosimops and can thus be attributed to the Tapinocephalus AZ (Guadalupian), but the absence of dinocephalian or pareiasaurian material is unlike contemporaneous assemblages found further south. This suggests that the Tapinocephalus AZ was not uniform across the entire basin and highlights that the abundance, distribution and taxonomic composition of Karoo biozones may vary more than currently appreciated. The upper assemblage, characterized by the dicynodonts Oudenodon, Aulacephalodon and Dinanomodon, is attributable to the upper Cistecephalus AZ to lower Daptocephalus AZ. The juxtaposition of the lower Tapinocephalus AZ and upper Cistecephalus\lower Daptocephalus AZ in the southern Free State implies a stratigraphic gap from the Middle to Late Permian of up to 6 million years.  相似文献   

8.
We present here the earliest known Asian fossil records of the Menispermaceae based on fossil fruits from Paleocene and Eocene localities in South China. A new genus and species, Paleoorbicarpum parvum sp. nov., and two new species of Stephania Loureiro, S. ornamenta sp. nov. and S. geniculata sp. nov., are recognized from Paleocene deposits of the Sanshui Basin, Guangdong, and a new occurrence of the widespread Eocene species Stephania auriformis (Hollick) Han & Manchester is recognized from the Maoming Basin, Guangdong. The Paleocene Stephania specimens described here represent the earliest fossil endocarp record of the Menispermaceae in eastern Asia. This discovery shows that the moonseed family had arrived in tropical and humid South China by at least the middle Paleocene, which provides important evidence for the origin and phytogeographic history of the family.  相似文献   

9.
We describe tarsal remains of primates recovered from the Middle Eocene (approximately 45 mya) Shanghuang fissures in southern Jiangsu Province, China. These tarsals document the existence of four higher-level taxa of haplorhine primates and at least two adapid species. The meager and poorly preserved adapid material exhibits some similarities to European adapines like Adapis. The haplorhine primates are divided into two major groups: a "prosimian group" consisting of Tarsiidae and an unnamed group that is anatomically similar to Omomyidae; and an "anthropoid group" consisting of Eosimiidae and an unnamed group of protoanthropoids. The anthropoid tarsals are morphologically transitional between omomyids (or primitive haplorhines) and extant telanthropoids, providing the first postcranial evidence for primates which bridge the prosimian-anthropoid gap. All of the haplorhines are extremely small (most are between 50-100 g), and the deposits contain the smallest euprimates ever documented. The uniqueness of this fauna is further highlighted by the fact that no modern primate community contains as many tiny primates as does the fauna from Shanghuang.  相似文献   

10.
戴静  陈威兆  金露露  黄亮 《生物多样性》2022,30(11):22553-48
栎属(Quercus)植物叶片化石在新生代地层中分布普遍, 对亚热带常绿阔叶林具有重要的指示意义。本文对采自云南省宜良县上新统茨营组中的栎属植物叶片化石进行角质层结构分析, 结合叶形态特征, 系统描述了4种栎属植物: 阔叶栎(Quercus latifolia)线叶栎(Q. scottii)、楔基栎(Q. simulata)和黄毛青冈相似种(Q. cf. delavayi)。通过对比化石和现生植物的叶形态和角质层特征, 本文认为叶片形状、叶基和叶尖特征、二级脉数量、表皮细胞和垂周壁特征、气孔大小和形状、气孔密度、毛基类型、形态和分布情况可以作为区分不同种类的特征, 但是不能只考虑其中的一个因素, 应该综合这些特征作为判断依据。结合宜良植物群中其他化石资料认为, 包括壳斗科柯属(Lithocarpus)、栲属(Castanopsis)以及樟科、榆科、木兰科等在内的植物, 代表了以栎属青冈组为优势树种的半湿润常绿阔叶林。宜良植物群与同时期相近纬度的植物群相比, 植被类型相似, 但是落叶成分较少。宜良植物群中的线叶栎、楔基栎和阔叶栎同晚始新世的线叶栎以及早中新世的楔基栎和阔叶栎相比, 形态并未发生大的变化, 与现生植物也非常相似, 进一步说明云南现代常绿阔叶林的主要成分来自于古老植物的承袭, 没有发生较大的改变。  相似文献   

11.
One hundred and seventy collected samples from Jebil section have been carefully studied for their ostracod content and referred to 41 species belonging to 20 genera. Their vertical distribution allowed to distinguish five successive associations of ostracod assemblages; two of which are correlated with the Early Lutetian, one with the Late Lutetian, another association with the Bartonian and the last one with the Priabonian. Community structure of the collected ostracod fauna has been studied; three indices have been calculated for each sample: Shannon (diversity), Margalef (richness) and Equitability indexes. In the lower and the middle part of the Formation, they indicate a stable environment supporting high diversity ostracod communities; whereas in the upper portion the environmental conditions were unstable characterized by low diversity. The results of a multivariate statistical method, using the cluster analysis and the Detrended Correspondence Analysis of the 41 ostracod species and the 170 samples, have led to conclude that the most effective environmental factor in the study area is the paleodepth and of less importance oxygenation and salinity. Thus, it allowed to distinguish four palaeoenvironmental intervals within the Cherahil Formation: the first one represented by taxa that are known from the shallower parts of the shelf; the second interval includes the majority of the encountered species of inner neritic shelf with normal salinity; the third one, corresponding to an outer neritic domain; and the last interval refers to a circalittoral environment, is comprised mainly of Cytherella angulata and of Soudanella laciniosa triangulata.  相似文献   

12.
发现于广西柳江的更新世晚期人类化石除1具完整的头骨外,还包含有右侧髋骨、骶骨、两段股骨及若干件椎骨。根据各方面的特征分析,初步认定这些化石属于同一个体。这一有利条件为我们比较准确地获取与该个体身体大小和形状有关的指标数据提供了可能。本文通过对柳江人头骨及复原骨盆的测量,计算了柳江人的身高、体重、身体比例、相对脑量等。在此基础上分析了柳江人的身体大小和形状。本研究发现:柳江人化石所代表的个体具有适应温暖气候环境的纤细型身体比例,代表相对脑量的EQ指数5.602大于金牛山、山顶洞等中国更新世中、晚期化石人类,而与包括港川人在内的更新世末期及现代人类的EQ指数接近。柳江人体重52.0kg小于金牛山、山顶洞、尼安德特人等生活在高纬度地区的化石人类,而与港川、非洲的KNM-ER3883、KNM-ER3733等生活在温暖环境的古人类接近。作者认为这些发现除说明柳江人生活的气候环境外,还提示柳江人身体大小、比例及相对脑量与更新世末期及现代人类接近。  相似文献   

13.
壳斗科的地质历史及其系统学和植物地理学意义   总被引:42,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   

14.
The discovery of Lufengpithecus at Yuanmou, in Yunnan Province, China, provides important clues to understanding the evolution of early hominoids in eastern Asia. However, the age and paleoecology of the fauna remain to be established. An assemblage of micromammalian fossils, collected recently by screenwashing at Leilao, one of the hominoid-bearing localities at Yuanmou, contains 41 species belonging to 16 families and 4 orders, and represents the most diverse Neogene micromammalian fauna known from southwestern China. This paper presents an analysis of the taxonomy, age, and paleoecology of the micromammalian fauna. The Yuanmou hominoid fauna is now considered older than the Lufeng fauna, and is currently thought to correspond to an age of about 9 Ma. The micromammalian fauna indicates a predominantly forested habitat, with marginal environments consisting of bush-grassland.  相似文献   

15.
考古遗址中动物粪化石中的微体植物遗存是重建过去生态环境以及人类活动的重要材料,然而对于能够指示人类活动的粪化石孢粉组合类型及其特征仍然缺乏清楚的认识。本文研究了山羊(Capra aegagrus)、绵羊(Ovis aries)、牛(Bos taurus)、骆驼(Camelus)、牦牛(Bos grunniens)和马(Equus caballus)等几种中国常见的家养食草类动物粪便中的主要孢粉和真菌孢子类型。通过分析这些动物粪便的花粉组合特征,探讨了花粉和菌孢子等微体植物遗存对生态环境及人类活动的指示意义。花粉种类丰度低、一些特征种属花粉(如禾本科、藜科)含量高是家养食草类动物粪便花粉组合的主要特征,可以用于指示人类的饲养行为。家养食草动物粪便中的粪生真菌孢子类型主要有Sporormiella,Sodaria,Pleospora,Coniochaeta,Thecaphora and Dictyosporium。研究表明真菌孢子的分布主要受到动物活动范围的影响,这使得利用粪生菌孢子(如Sporormiella)并结合其他记录来反映人类的饲养或游牧活动成为可能。  相似文献   

16.
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   

17.
《Palaeoworld》2023,32(2):287-302
Ordovician chitinozoans are as yet inadequately documented from the western Yangtze Platform, South China. Here we present a systematic study on chitinozoans from a Middle–Upper Ordovician succession at Songliang of Qiaojia, northestern Yunnan, southwestern China. Altogether 34 species of 12 genera are identified from the upper Hungshihyen and the Huadan formations. The top of the Hungshihyen Formation yields typical Early and Middle Ordovician forms, for instance, Lagenochitina obeligis and Belonechitina chenjiawuensis, with the latter only known from the lower Darriwilian in South China, thus suggesting an early Darriwilian age for this interval. The chitinozoans recovered from the Huadan Formation include Lagenochitina prussica and Spinachitina fossensis, both are mainly confined in Katian and sometimes ranging into younger strata. This indicates an age younger than the middle to late Darriwilian previously determined for the Huadan Formation. However, conflicts exist in age assignment of the Huadan Formation based on chitinozoan and other evidence, and further work is required.  相似文献   

18.
19.
胡荣  赵凌霞 《人类学学报》2015,34(3):404-416
华南和东南亚发现大量更新世的猩猩牙齿化石。本研究应用CT扫描三维重建的技术方法研究了广西更新世化石猩猩牙齿釉质厚度,并与现生类人猿、现代人、化石类人猿以及早期人类进行比较分析。结果显示:广西猩猩同类牙齿的釉质厚度与牙齿大小相关性很小;臼齿和前臼齿釉质厚度在上下颌之间不存在显著性差异;来自广西不同地区的猩猩化石牙釉质厚度无显著差异。与早期人科成员相比,广西猩猩的牙釉质相对较薄,平均与相对釉质厚度值都明显小于南方古猿、傍人。与早期人属相比,小于直立人、尼人以及非洲和欧洲的早期人属化石。与现代人和现生灵长类相比,广西化石猩猩釉质厚度明显大于大部分猴类和非洲大猿;平均釉质厚度稍大于现生猩猩,而与现代人更为接近;相对釉质厚度小于现代人,而与现生猩猩差异不大,都属于偏厚型釉质。本文讨论了釉质厚度与系统分类演化、食性适应的相关问题,作者推测釉质厚度可能是物种的特征属性,与牙齿功能适应有密切关联。  相似文献   

20.
Tarka and Tarkadectes are Middle Eocene mammals known only from the Rocky Mountains region of North America. Previous work has suggested that they are members of the Plagiomenidae, an extinct family often included in the order Dermoptera. Here we describe a new primate, Tarkops mckennai gen. et sp. nov., from the early Middle Eocene Irdinmanha Formation of Inner Mongolia, China. The new taxon is particularly similar to Tarka and Tarkadectes, but it also displays many features observed in omomyids. A phylogenetic analysis based on a data matrix including 59 taxa and 444 dental characters suggests that Tarkops, Tarka and Tarkadectes form a monophyletic group—the Tarkadectinae—that is nested within the omomyid clade. Within Omomyidae, tarkadectines appear to be closely related to Macrotarsius. Dermoptera, including extant and extinct flying lemurs and plagiomenids, is recognized as a clade nesting within the polyphyletic group of plesiadapiforms, therefore supporting the previous suggestion that the relationship between dermopterans and primates is as close as that between plesiadapiforms and primates. The distribution of tarkadectine primates on both sides of the Pacific Ocean basin suggests that palaeoenvironmental conditions appropriate to sustain primates occurred across a vast expanse of Asia and North America during the Middle Eocene.  相似文献   

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