问:高中生物课本地质年代表中的代和纪是什么意思?为什么表中只有第三、四纪,而没有第一、二纪?各纪的名称是怎样得来的?

答:“代”是地质年代划分的二级时间单位.一级时间单位是“宙”.隐生宙表示生命的早期阶段和保留在地层中的化石极稀少的一个地层时期,包括太古代和元古代.显生宙表示地层中开始出现大量动物化石的寒武纪及其以后的各阶段,包括古生代、中生代和新生代. “纪”是次于“代”一级的地质年代的时间单位.在地质学上,最早曾有人把地层自老而新划分为四部分:古生代为第一纪、中生代为第二纪、新生代为第三纪和第四纪.后来由于第一纪和第二纪的地层很厚,化石种类繁多,又把古生代分为六个纪,把中生代分为三个纪.因此,现在的地质年代表中没有第一纪和第二纪. 因为近代科学首先在欧洲兴起,所以地质时代的名称,最早是欧洲人根据他们的发现而命名的,后来成为全世界统一的名称. 震旦纪:“震旦”原是古代印度人对我国的称呼.震且纪这个名称,是研究了我国河北省燕山地区的元     

世界中生代竹节虫目昆虫化石研究

昆虫分类学发展早期将竹节虫归于直翅目,现多数学者认其为1个独立的目.有关竹节虫目的化石记录大都来源于中生代.本文详细回顾和综述了世界中生代竹节虫目昆虫化石研究简史,列出已发表的化石种类名录、分布及年代,描述了中生代不同地质时期竹节虫目化石的分类单元以及分布特点,初步分析了目前该类群研究中所存在的一些问题,并对今后的研究工作进行了展望.     

中国直翅目昆虫化石研究现状

截至目前,中国古昆虫学家已研究了分布于中国14省区的50件直翅目化石标本,发表新属38个,新种48个.通过图表提供了我国已发现的直翅目化石名录并介绍了其分布和年代.直翅目化石的研究对昆虫的起源、昆虫与植物的协同演化及古气候的演变等研究提供线索.中国已发现的直翅目化石主要分布于辽、冀、内蒙古三省区,其地质时代大部分为中生代.提出了在化石研究中存在的问题.     

中国晚古生代轮藻化石组合

本文综述了数十年来中国晚古生代轮藻化石研究成果。与全球其它地区相比较,中国古生代轮藻化石较为丰富,可归纳为九个轮藻化石组合及三个轮藻化石层位。依据轮藻植物组成特点、演化特征以及伴生其它门类化石,论证各组合的地质时代,其中两个组合地质时代相同,属于不同的生物地理区系。     

中国古生代化石昆虫研究回顾

自林启彬先生1978年命名了我国第一个古生代昆虫至今, 中国学者共发表20余篇分类学论著, 描述鉴定我国古生代昆虫共61种, 归属于9目（总目）。这些标本分布于西北、 西南、 华东等9省区, 其中石炭纪47种, 二叠纪14种。本文统计了我国已发现的古生代化石昆虫属种名录以及它们的分布和地质年代, 总结了国内古生代化石昆虫当前的研究状况和发展趋势, 并分析了研究中存在的问题。其中关于化石昆虫普遍存在的脉序差异问题需给予足够的重视, 高级阶元的建立应更加慎重。研究表明我国古生代昆虫已经高度分异, 古翅类、 新翅类均已出现, 且代表着有翅昆虫辐射演化的重要阶段。     

昆虫的起源和进化(续)

中生代——恐龙盛极一时,昆虫欣欣向荣中生代昆虫区系最引人注意的特点是古生代的各目化石昆虫大都没能延续到中生代,其中只有一个目(舌鞘目)例外,但也只延续到中生代早期的三叠纪,以后很快也就消失了。三叠纪已经开始发现一些原始的膜翅目和半翅目昆虫化石。到了侏罗纪,虽然庞大的爬行动物仍然统治着世界,翼龙仍然支配着天空,     

中国南方第四纪啮齿动物研究的一个里程碑──简介《川黔地区第四纪啮齿类》

啮齿类是目前地球上种类和数量最多、分布最广的哺乳动物类群,第三纪早期在地球上出现。由于它适应性广,繁殖力强和演化速度快,分布广,化石数量多,在生物地层对比、哺乳动物演化及动物地理区系的划分等方面具有重要的意义,因而颇受地层学家、古脊椎动物学家、进化生物学家以及动物地理学家的青睐。中国啮齿类化石的研究历史较长,发现材料与研究成果在国际学术界占有重要地位。1927年,我国已故著名古脊椎动物学家杨钟健先生发表了《中国北方的啮齿类化石》OosslleNagetlereausNord－China）,对当时中国北方发现的啮齿类化石进行了…     

保护化石与保护地球历史

保护化石与保护地球历史潘江众所周知,地球历史的划分为：显生宙（宇）、隐生宙（宇）;太古代（界）、元古代（界）、古生代（界）、中生代（界）;寒武纪（系）、奥陶纪（系）、志留纪（系）……第三纪（系）及第四纪（系）。其主要依据仍是古生物化石。地球从形成至今...     

中国双翅目化石研究现状

我国特别是北方诸省的中生代侏罗世到新生代中新世地层保存有大量的双翅目昆虫化石,国内外许多专家都从事过该类群的分类研究工作。迄今为止,我国已知双翅目化石达45科136属共216种。本文试就目前中国双翅目化石的分类情况、产地与地层分布特点、研究成果及其存在问题等方面加以综述。     

北京下白垩统芦尚坟组叶肢介的生物地层学北大核心CSCD

叶肢介化石是我国北方中生代生物群的重要成员之一,对古环境恢复和生物地层对比具有重要意义。北京西下白垩统芦尚坟组含丰富的昆虫、介形虫、植物、孢粉等化石,还发现了鱼和恐龙等脊椎动物化石,但叶肢介化石以前并无正式报道。芦尚坟组及其上覆夏庄组的昆虫化石组合被称为"芦尚坟昆虫群",对京西地区早白垩世中晚期的古生物学和古生态学研究具有重要意义。本文描述产自北京市丰台区贺照云村附近芦尚坟组第四段的Eosestheria(东方叶肢介)1新种,认为芦尚坟组的叶肢介群落为衰落型Eosestheria群,与上覆夏庄组的Yanjiestheria(延吉叶肢介)群差异较大,与辽西阜新组的叶肢介群落联系紧密。我们认为芦尚坟组和阜新组时代接近,约为Aptian晚期。     

ESTABLISHMENT OF FOSSIL ENTOMOFAUNAS AND THEIR EVOLUTIONARY SUCCESSION IN NORTH CHINA*

Abstract According to a systematic study of large numbers of fossil insects collected from the Paleozoic, Mesozoic and Tertiary strata in North China, three evolutionary mega-stages of fossil insects including 14 fossil entomofaunas and 29 entomassemblages have been established. These insect faunas reflect their order or law of evolution—the history of their rise and fall, and form their evolutionary succession in North China. Such a history provides an important reference not only for understanding fossil insects through time, but also showing for stratigraphical correlation.     

中国中生代昆虫化石研究新进展

回顾了1990年以来中国中生代昆虫化石研究的新进展,简述了我国学者在古昆虫分类学、昆虫内部形态学、昆虫系统学、古生态学、昆虫生物地层学、昆虫区系的历史演变、生物古地理学、昆虫与植物的关系等8个方面取得的突出贡献,并给出了我国发现的世界最低层位昆虫科级类群表。     

A golden orb-weaver spider (Araneae: Nephilidae: Nephila) from the Middle Jurassic of China

Nephila are large, conspicuous weavers of orb webs composed of golden silk, in tropical and subtropical regions. Nephilids have a sparse fossil record, the oldest described hitherto being Cretaraneus vilaltae from the Cretaceous of Spain. Five species from Neogene Dominican amber and one from the Eocene of Florissant, CO, USA, have been referred to the extant genus Nephila. Here, we report the largest known fossil spider, Nephila jurassica sp. nov., from Middle Jurassic (approx. 165 Ma) strata of Daohugou, Inner Mongolia, China. The new species extends the fossil record of the family by approximately 35 Ma and of the genus Nephila by approximately 130 Ma, making it the longest ranging spider genus known. Nephilidae originated somewhere on Pangaea, possibly the North China block, followed by dispersal almost worldwide before the break-up of the supercontinent later in the Mesozoic. The find suggests that the palaeoclimate was warm and humid at this time. This giant fossil orb-weaver provides evidence of predation on medium to large insects, well known from the Daohugou beds, and would have played an important role in the evolution of these insects.     

中国东北中生代时期的传粉昆虫与虫媒植物

昆虫与植物的相互作用在昆虫与植物协同进化和发展中起着至关重要的作用。化石记录中发现了昆虫取食花粉、授粉滴、访问中生代裸子植物具胚珠的繁殖器官等多方面的昆虫化石证据。20世纪90年代以来,研究和报道了大量采自中国东北地区保存良好的昆虫与植物化石。例如发表于Science上的2篇具有长喙的双翅目和长翅目昆虫化石文章,暗示着它们很可能参与各种裸子植物的授粉。在本篇文章中,作者回顾了已报道的中国东北晚中生代时期的昆虫化石,并把它们与授粉或访"花"相联系。另外,作者对采自同一层位的同时代的植物化石进行了初步研究并介绍了可能涉及到与昆虫相互作用的代表性植物。今后将进一步深入研究,以期在化石中找到昆虫授粉和访花的直接证据。     

Evolutionary trends in leaf morphology and biogeography of Altingiaceae based on fossil evidence

The extant woody family Altingiaceae, consisting of only one genus Liquidambar L. with ca. 15 species, demonstrates a typical disjunctive distribution among East Asia, North America, and the Mediterranean. However, the fossil record throughout the Cenozoic indicates that Altingiaceae was once widespread in the Northern Hemisphere. After studying the abundant Altingiaceae fossil leaf collections, we revised the easily-confused fossil leaves and corrected the misidentifications. Consequently, we proposed an evolutionary history of Altingiaceae leaf morphology in consulting the modern leaf characteristics. It is revealed that the trilobated leaf morphology is the ancestral character state, whereas both the pentalobated and the undivided, pinnate-veined lineages evolved separately. The latter diverged from the trilobated ancestor in South China in Eocene. The lobed and undivided lineages represent the deciduous and evergreen, respectively. An extensive fossil database of Altingiaceae was built to reconstruct its biogeographical history. We reconfirmed that Altingiaceae developed into a temperate and a subtropical-tropical patterns and migrated across both the Bering and North Atlantic land bridges since Cretaceous, independently. It was widespread in the early Neogene of North America and Eurasia, and became extinct in the high latitude triggered by the global cooling and aridification. The modern disjunctive distribution was finally formed, with southeast Asia as its modern diversity center. This study provides new fossil evidence for understanding the morphology and biogeography of the family Altingiaceae.     

The taphonomy of colour in fossil insects and feathers

Colouration is an important multifunctional attribute of modern animals, but its evolutionary history is poorly resolved, in part because of our limited ability to recognize and interpret fossil evidence of colour. Recent studies on structural and pigmentary colours in fossil insects and feathers have illuminated important aspects of the anatomy, taphonomy, evolution and function of colour in these fossils. An understanding of the taphonomic factors that control the preservation of colour is key to assessing the fidelity with which original colours are preserved and can constrain interpretations of the visual appearance of fossil insects and theropods. Various analytical approaches can identify anatomical and chemical evidence of colour in fossils; experimental taphonomic studies inform on how colour alters during diagenesis. Preservation of colour is controlled by a suite of factors, the most important of which relate to the diagenetic history of the host sediment, that is, maximum burial temperatures and fluid flow, and subsurface weathering. Future studies focussing on key morphological and chemical aspects of colour preservation relating to cuticular pigments in insects and keratinous structures and nonmelanin pigments in feathers, for example, will resolve outstanding questions regarding the taphonomy of colour and will enhance our ability to infer original colouration and its functions in fossil insects and theropods.     

Conceptual and analytical worldviews shape differences about global avian biogeography

In a recent paper, we generated a new time tree of modern birds and integrated it with biogeographic and palaeontological information to formulate a model for their biogeographic history. We postulated that modern birds originated in West Gondwanan continents, from where they dispersed around the world. Mayr suggested that our selective use of the fossil record may have biased our ancestral area reconstructions. We argue that the use of the fossil record must be selective in order to avoid the influence of its severe geographic bias: rock formations with numerous high‐quality fossil birds are found only in North America and Europe. An indiscriminate use of the avian fossil record would bias any biogeographic analysis towards these two continents. Our biogeographic model is perfectly consistent with the existence of diverse fossil avifaunas in the Eocene of North America and Europe because dispersion out of South America occurred earlier, in the Palaeocene.     

Late Cenozoic insects of northern Eurasia

Quaternary and Late Tertiary fossil insects from different regions of Eurasia are studied. The main areas are northeastern Eurasia (Part 1) and Belarus and adjacent regions (Part 2). Paleoenvironmental and climatic reconstructions for these regions are provided and compared with other parts of Europe, Asia, and North America. Hundreds of fossil insect localities are described; thousands of insect sclerites are recognized.     

Fossils of the Fagaceae and their implications in systematics and biogeography

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.