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1.
本文研究了产于滇西腾冲上新世芒棒组一种被子植物叶型化石垂丝紫荆（比较种）Cercis cf．racemosa Oliv．，归于豆科紫荆属。揭示了该种叶表皮构造特征：上表皮无气孔器，表皮细胞为多边形，垂周壁平直；下表皮具环列型气孔器，表皮细胞为多边形，垂周壁平直；上下表皮有相同类型的毛基，毛基的根部由多细胞组成，毛基部的细胞特化成辐射状。该化石表皮微细构造的分析为恢复腾冲上新世古环境提供了古植物证据。 相似文献
2.
对福建永安市下白垩统坂头组保存较好的真蕨类营养叶化石枝脉蕨Cladophlebis进行了叶片形态及角质层微细构造特征的分析, 该化石至少二次羽状分裂, 末二次羽轴粗, 小羽片小, 全缘, 排列紧密, 中脉明显, 侧脉密集, 多数一次分叉; 上表皮无气孔器, 细胞轮廓不清晰, 偶见表皮毛; 下表皮具气孔器, 呈纵向带状排列; 表皮细胞长方形或呈条带状; 垂周壁加厚, 较直; 平周壁波状突起; 气孔器近圆形, 具明显拱盖, 保卫细胞弱角质化, 副卫细胞分化不明显.对当前化石小羽片解剖学特征的分析填补了该属植物化石叶片角质层微细构造特征的空白, 进一步将其与现生紫萁Osmunda joponsica以及部分真蕨类化石的表皮特征进行对比, 结合宏观形态和角质层特征的分析及其与相似种类的比较, 将永安的标本命名为一新种, 永安枝脉蕨Cladophlebis yonganensis Dai et B. N. Sun, sp. nov., 并且推断当前化石代表了某一类已经灭绝的真蕨类植物. 相似文献
3.
通过对新疆准噶尔盆地白杨河地区中侏罗世奥勃鲁契夫银杏(Ginkgo obrutschewii Seward)模式产地及其邻区该种叶化石表皮构造的研究,笔者认为应以采自白杨河模式产地的化石材料作为认定该种主要特征的依据。尽管G.obrutschewii的外部形态和叶表皮构造可能具有一些变异特征,但综合而言,该种叶表皮构造主要特征似应为:表皮气孔器特征通常为下气孔式,上下表皮细胞均普遍发育强度不同的角质化丘状或低缓的乳状突起,垂周壁略直或微弯;气孔器单唇式,保卫细胞近孔缝处唇状加厚强烈,副卫细胞通常强烈角质化,表面常发育瘤状或团块状角质化加厚。目前对该种叶化石的采集及其表皮构造的研究尚不充分,相关研究有待进一步深入。近年来,俄罗斯学者归于本种的产于新疆福海的银杏叶片化石,及其对本种叶表皮构造特征的补充等,尚值得商榷。 相似文献
4.
《地学前缘》2017,(1):65-77
在云南腾冲上新统芒棒组发现了角质层保存完好的侧柏化石。通过与已知化石种及最近亲缘种的宏观形态和微细构造特征对比,建立一新种Platycladus tengchongensis P.Deng et B.N.Sun sp.nov.。基于当前新种与现生种Platycladus orientalis和化石种Platycladus yunnanensis在宏观形态及角质层特征的相似性,统计了3个种的气孔密度和气孔指数,并用气孔比率法重建了云南腾冲上新世晚期和云南梁河晚中新世的古大气CO_2浓度分别为417.9×10~(-6)(386.5×10~(-6)~471.3×10~(-6))和409.9×10~(-6)(392.2×10~(-6)~433.3×10~(-6)),结果与Berner全球碳平衡模型中CO_2浓度变化曲线上的变化范围基本相符,故表明Platycladus tengchongensis和Platycladus yunnanensis叶片可以作为测量古大气CO_2浓度变化的生物指标。根据文中恢复的云南西部上新世晚期和晚中新世古大气CO_2浓度平均值均高于现在,推测新近纪时期云南西部的气候比现在温暖。综合云南腾冲地区已有的古气候研究与化石和现生叶片角质层特征的对比分析,认为云南腾冲上新世晚期气候较为温暖湿润。此外,文中化石的发现为侧柏属自然分布的研究提供了宝贵的材料。 相似文献
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归于壳斗科栎属的一种植物化石黄毛青冈(亲缘种)Quercusaff.delavayi Franch采于浙江天台中新统下南山组。该化石不仅具有与现生黄毛青冈Quercus delavayi Franch相似的叶形态结构,而且两者表皮微细构造亦颇为一致,宏观和微观特征表明,当前材料与现生黄毛青冈具有一定的亲缘关系。通过研究不同时间、不同地点现生黄毛青冈的表皮微细特征,发现黄毛青冈毛基的个体发育重演了青冈亚属毛基的系统演化。进一步比较化石与现生材料的毛基参数及其他表皮特征,推论浙江天台中新世的古气候较现在温暖湿润,根据现生与化石黄毛青冈气孔比率计算出浙江天台中新世古大气CO2体积分数为(395.22±5.61)×10-6。 相似文献
6.
化石采自浙江天台嵊县组.该地层含丰富被子植物压型化石及少量裸子植物化石.利用叶结构分析法,依据叶脉、叶尖、叶基等稳定性特征,对一种樟科植物化石的宏观形态进行了详细的研究;结合表皮特征分析,发现该化石与现生Cinnamomum bejolghota(Buch-Ham.)Sweet在叶形、叶脉特征以及表皮脉络细胞特征、气孔器类型和毛基特征等方面均很相似,因而将当前化石定名为Cinnamomum cf.bejolghota(钝叶桂相似种).通过分析化石钝叶桂的角质层微细构造特征,结合现生钝叶桂的分布范围和生存环境恢复了浙东地区中新世的古气候和古环境特征,推测当时的气候比现在更为炎热多雨,同时认为钝叶桂从中新世至今有南迁的趋势. 相似文献
7.
对浙江天台中新统下南山组6块叶片压型化石——天台润楠Machilus tiantaiensis Ding S. T. et Sun B. N. sp. nov.,并对其叶结构和表皮构造特征进行了详细的研究.其主要特征为:叶椭圆形,全缘,顶端渐尖,基部楔形,侧脉羽状;表皮细胞垂周壁浅波状,单细胞毛基多集中于脉络区;气孔下生式,气孔器短平列型,副卫细胞1~2个.通过与现生植物进行对比分析,发现当前标本的叶结构和表皮构造特征与樟科润楠属(Machilus)十分一致.利用PAST(palaeontological statistics)软件对我国润楠属68种植物叶片的形态特征进行聚类分析,结果表明当前化石与M. pingii Cheng ex Yang最为接近;角质层分析也表明二者的表皮构造最为相似.利用化石与其现存最近亲缘种M. pingii的气孔比率,恢复了天台晚中新世的古大气CO2体积分数为407.9×10-6.此外,依据现生润楠属主要分布于亚洲东南部和南部的热带、亚热带地区,推断天台地区中新世的古气候较为温暖湿润. 相似文献
8.
角质层微细构造特征是化石植物鉴定的重要依据,实验研究了云南腾冲新近系樟科润楠属薄叶润楠Machilus leptophylla和长梗润楠(近似种)Machilus cf. longipedicellata两个化石种的表皮微细构造特征,并与现存对应种类进行了表皮构造和叶结构特征的对比分析,补充证实了两化石种均属于自然分类属性。丰富了我国樟科润楠属化石记录。鉴于大气CO2浓度与植物叶片气孔指数呈负相关关系,Machilus叶片可以作为大气CO2浓度的生物指示器。研究表明,利用该类化石叶片气孔参数可推测地史时期古大气CO2浓度,揭示了新近纪滇西地区为温暖湿润性气候。 相似文献
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10.
报道了产自黑龙江嘉荫晚白垩世太平林场组的两种银杏化石:具毛银杏(Ginkgo pilifera Samylina)及太平银杏(新种)(Ginkgo taipingensis sp.nov.)。新种以双面气孔式、上表皮具一定数量的气孔、普通表皮细胞垂周壁厚而弯曲、平周壁具毛状体散布以及下表皮普通表皮细胞垂周壁弯曲等特征,区别于其他已知银杏化石种。 相似文献
11.
A new species of Phoenicopsis subgenus Windwardia(Florin) Samylina, Phoenicopsis neimengguensis sp.nov., is recognized from the Middle Jurassic Zhaogou Formation in the Shiguai Basin, a Jurassic coal-bearing sedimentary basin in Inner Mongolia, China. Linear leaves are in bundles of six to eight and are attached on a short shoot. The leaf is amphistomatic with one or two irregular rows of longitudinally oriented stomata in each intercostal zone on the upper epidermis and three or four(occasionally six) rows of stomata in each intercostal zone on the lower epidermis. Each stomata is surrounded by four to six subsidiary cells with unevenly developed papillae. The anticlinal walls of epidermal cells are straight. Cuticular thickenings or papillae are present on the outer surface of the periclinal walls. This is the first time that Phoenicopsis subgenus Windwardia(Florin) Samylina is recognized from the Middle Jurassic of Inner Mongolia, China. The occurrence of the new species is noteworthy because it extends the geological and geographic distribution of Phoenicopsis subg. Windwardia in China and Eurasia. The discovery is significant as it increases our knowledge of Phoenicopsis subg. Windwardia by providing new data on morphological and epidermal features. 相似文献
12.
In Europe, fossil fruits and seeds of Rhodoleia (Hamamelidaceae) have been described from the Upper Cretaceous to the Miocene, whereas no fossil record of Rhodoleia has been reported in Asia, where the modern species occur. Herein, 21 fossil leaves identified as Rhodoleia tengchongensis sp. nov. are described from the Upper Pliocene of Tengchong County, Yunnan Province, Southwest China. The fossils exhibit elliptic lamina with entire margins, simple brochidodromous major secondary veins, mixed percurrent intercostal tertiary veins, and looped exterior tertiaries. The leaf cuticle is characterized by pentagonal or hexagonal cells, stellate multicellular trichomes, and paracytic stomata. The combination of leaf architecture and cuticular characteristics suggests that the fossil leaves should be classified into the genus Rhodoleia. The fossil distributions indicate that the genus Rhodoleia might originate from Central Europe, and that migrated to Asia prior to the Late Pliocene. Additionally, insect damage is investigated, and different types of damage, such as hole feeding, margin feeding, surface feeding, and galling, are observed on the thirteen fossil leaves. Based on the damage frequencies for the fossil and extant leaves, the specific feeding behavior of insects on Rhodoleia trees appears to have been established as early as the Late Pliocene. The high occurrence of Rhodoleia insect herbivory may attract the insect-foraging birds, thereby increasing the probability of pollination. 相似文献
13.
《International Geology Review》2012,54(2):214-217
The genus Podozamites ranges from Late Triassic to Late Cretaceous and is widely distributed geographically. The epidermal pattern of the leaves of only two of the several species is clearly known. Collections from the Late Jurassic and Early Cretaceous strata in the Bureya basin have brought to light a number of Poclozamites species: P. lanceolatus (L. et H.) Schimp. , P. angustifolius (Eichw.) Schimp., P. aff. eichwaldii Schimp. , P. gramineus Heer, and P. ellipsoides Saporta. Among these collections only one form, P. aff eichwaldii, has the epidermal pattern preserved. Thus information on a third species of Podozamites is now available. The cuticle in this species is very thin. The leaf is hypostomatous. Epidermal cells on the upper surface are large, rectangular, in fairly distinct rows, and have straight, unevenly cutinized walls. The lower surface consists of alternating stomatal and astomatal bands, each band comprising six or seven rows of cells in width. The stomata are oriented at right angles to the veins and are not sunken. The cuticle of the material from the Bureya depression compares in general types with that of P. punctatus and P. cf. distans from Greenland. --F. M. Hueber. _ 相似文献
14.
拱拜孜逆断裂-背斜为秋里塔格背斜带西延部分,由拱拜孜线状背斜构造及逆断裂组成.背斜北翼宽缓,南翼陡倾甚至倒转,为典型断层扩展褶皱构造.拱拜孜背斜变形方式和发展演化具阶段性变化特点,背斜强烈隆起,在中更新世末,为中晚第四纪背斜构造.拱拜孜断裂发育于背斜核部南翼,为拱拜孜逆断裂-背斜主要控制性断裂,其形成与发展控制着拱拜孜背斜形成与发展.断层造成背斜南翼上新统库车组直立甚至向北倒转,膝折现象明显.利用插分GPS测得断层两测Ⅱ级阶堆积底界不整合面高差为2.8 m,晚第四纪以来断裂垂直滑动速率为0.25 mm/a,地壳缩短速率为0.65 mm/a. 相似文献
15.
Conifers are common in the Lower Cretaceous Zhonggou Formation of Jiuquan Basin, Gansu Province, NW China. The excellent preservation of plant fossils allows detailed investigations of the leaf epidermis by light microscope (LM) and scanning electron microscope (SEM). Based on the leaf morphology and epidermal features, two Brachyphyllum species, B. ningshiaense and B. obtusum are described. They closely resemble one another in foliar morphology and epidermal features, but have different leaf apices, cuticle features, stomatal shape and the number of subsidiary cells. The specimens consist of leafy axes with imbricate, spirally arranged, scale-like leaves. Epidermal analysis shows rectangular, pentagonal or rhomboidal unspecialized epidermal cells and abaxially longitudinally arranged stomatal rows except for the marginal areas, as well as well-developed papillae, sunken stomata and Florin rings of subsidiary cells with papillae on the inner surfaces. The imbricate and spirally arranged leaves with rather thick cuticle in both species indicate an Araucariaceae (Araucaria) or Cheirolepidiaceae affinity. However, epidermal features and the presence of Classopollis pollen in the sediments indicate a cheirolepidiaceous affinity. The morphological and anatomical characters of both taxa are interpreted as adaptations to a warm seasonally and temporarily dry palaeoclimate. 相似文献