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1.
After becoming nearly extinct during the Permian, the ferns began a slow recovery during the Triassic as the climate of the earth moderated. As a result, a considerable number and variety were present and widely distributed during the Jurassic and Early Cretaceous. However, with the rapid expansion of the angiosperms during the Late Cretaceous, the ferns once again became reduced in variety and greatly restricted in distribution. Some of the Mesozoic ferns are rather primitive and obviously are closely related descendants of Paleozoic taxa. Such ferns are assigned mostly to the Marattiaceae, Guaireaceae, Osmundaceae, and Gleicheniaceae. The majority of the Mesozoic ferns, however, are distinctive and appear to have originated during that era. These fossil ferns generally fit into modern orders and families such as the Matoniaceae or the Dipteridaceae. In some cases, it is difficult to clearly distinguish some of the Mesozoic ferns from living genera. A portion was presented as an invited paper to the symposium: Evolution of pteridophytes and gymnosperms at the XV International Botanical Congress, Yokohama, Japan (1993).  相似文献   

2.
The stratigraphic distribution and peculiarities of burial of caddis cases from 293 Mesozoic localities in Eurasia are analyzed. An attempt is made to analyze and interpret the co-occurrence of trichopteran cases and adults in the major localities. The main stages in the evolution of the building behavior of trichopteran larvae in the Mesozoic have been elucidated.  相似文献   

3.
中国中生代的鸟类:介绍及综述   总被引:4,自引:0,他引:4  
周忠和  张福成 《动物学报》2004,50(6):913-920
最近十来年 ,中国辽宁发现的早白垩世的鸟类化石超过了世界上其它任何一个地区。中国的中生代鸟类化石代表了始祖鸟化石之后鸟类历史上第一次显著的分异。它们不仅包括了带有明显恐龙祖先特征的长尾的鸟类 ,而且还包括了许多进步或特化的种类 ,如早白垩世最大的鸟类 ,最原始的反鸟类 ,以及保存最好的、飞行结构和现生鸟类几乎一样的今鸟类。这些早期鸟类在诸如飞行、大小和食性等所反映的演化、形态和生态学特征等方面出现了重大的分异。具有长尾骨骼的原始基干鸟类热河鸟和驰龙类具有的相似性 ,进一步支持了鸟类起源于恐龙的学说。中国发现的早白垩世的鸟类以及树栖的恐龙化石还为鸟类飞行的树栖起源假说提供了十分重要的证据。“恐龙下树”的假说结合了鸟类起源于恐龙的学说和鸟类飞行的树栖起源学说 ,因此也得到了化石证据的支持。由于多种恐龙带有羽毛 ,因此羽毛不一定代表了恒温。恒温的鸟类可能到了早白垩世的进步鸟类中才开始出现  相似文献   

4.
The paper examines recent information on the history of the ‘southern hemisphere’ conifer family Araucariaceae and gives supplementary notes to previously published monographs. Important data from the Mesozoic fossil record are presented and summarized to describe the ancient diversity and distribution of Araucariaceae. Information on the origin of the family and oldest fossil records of the present-day genera are assembled. Existing models on phylogenetic relationships within the family inferred from molecular data are compared with relationships between the genera determined from morphological data. Reasons for disappearance of representatives of this conifer family in the latest Cretaceous in North America and Europe are briefly discussed.  相似文献   

5.

Background

It is conventionally accepted that the lepidopteran fossil record is significantly incomplete when compared to the fossil records of other, very diverse, extant insect orders. Such an assumption, however, has been based on cumulative diversity data rather than using alternative statistical approaches from actual specimen counts.

Results

We reviewed documented specimens of the lepidopteran fossil record, currently consisting of 4,593 known specimens that are comprised of 4,262 body fossils and 331 trace fossils. The temporal distribution of the lepidopteran fossil record shows significant bias towards the late Paleocene to middle Eocene time interval. Lepidopteran fossils also record major shifts in preservational style and number of represented localities at the Mesozoic stage and Cenozoic epoch level of temporal resolution. Only 985 of the total known fossil specimens (21.4%) were assigned to 23 of the 40 extant lepidopteran superfamilies. Absolute numbers and proportions of preservation types for identified fossils varied significantly across superfamilies. The secular increase of lepidopteran family-level diversity through geologic time significantly deviates from the general pattern of other hyperdiverse, ordinal-level lineages.

Conclusion

Our statistical analyses of the lepidopteran fossil record show extreme biases in preservation type, age, and taxonomic composition. We highlight the scarcity of identified lepidopteran fossils and provide a correspondence between the latest lepidopteran divergence-time estimates and relevant fossil occurrences at the superfamily level. These findings provide caution in interpreting the lepidopteran fossil record through the modeling of evolutionary diversification and in determination of divergence time estimates.

Electronic supplementary material

The online version of this article (doi:10.1186/s12862-015-0290-8) contains supplementary material, which is available to authorized users.  相似文献   

6.
Eleven representatives of the superorder Amphiesmenoptera (Trichoptera + Lepidoptera) were examined for sex chromatin status. Three species represent stenopsychoid, limnephiloid and leptoceroid branches of the Trichoptera; eight species belong to the primitive, so-called nonditrysian Lepidoptera and represent the infra-orders Zeugloptera, Dacnonypha, Exoporia, Incurvariina, Nepticulina and Tischeriina. The female-specific sex chromatin body was found in the interphase somatic nuclei of Tischeria ekebladella (Bjerkander 1795) (Lepidoptera, Tischeriina). The sex chromatin was absent in all investigated Trichoptera species as well as in all representatives of the nonditrysian Lepidoptera except Tischeria ekebladella . The sex chromosome mechanism of Limnephilus lunatus Curtis 1834 (Trichoptera, Limnephilidae) is Z/ZZ. The sex chromosome mechanism of Tischeria ekebladella (Lepidoptera, Tischeriina) is ZW/ZZ including the W chromosome as the largest element in the chromosome set. The data obtained support the hypothesis that the Z/ZZ sex chromosome system, the female heterogamety and the absence of the sex chromatin body in interphase nuclei are ancestral traits in the superorder Amphiesmenoptera. These ancestral characters are probably kept constant in all the Trichoptera and in the most primitive Lepidoptera. The W sex chromosome and the sex chromatin evolved later in the nonditrysian grade of the Lepidoptera. It is proposed that the sex chromatin is a synapomorphy of Tischeriina and Ditrysia.  相似文献   

7.
中国中生代昆虫化石研究新进展   总被引:6,自引:0,他引:6  
任东 《昆虫学报》2002,45(2):234-240
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。  相似文献   

8.
This paper presents eight ephedroid palynomorphs from the Lower Cretaceous (Upper Albian) of Hokkaido, Japan. The ephedroid palynomorphs are ellipsoid and polyplicate pollen grains that show a wide range of variation in pollen size, shape, and plication. These ephedroid palynomorphs suggest a wide range of diversity in Gnetales at mid- or high-paleolatitude in the eastern side of Lauresia during the Upper Albian.  相似文献   

9.
A fossil scorpion belonging to a new family, genus and species, Chaerilobuthus complexus gen. n., sp. n., is described from Cretaceous amber of Myanmar (Burma). This is the third species and the fourth scorpion specimen to have been found and described from Burmese amber. The new family seems quite distinct from the family Archaeobuthidae Lourenço, 2001 described from Cretaceous amber of Lebanon.  相似文献   

10.
11.
《Palaeoworld》2016,25(2):263-286
The extant family Dipteridaceae is a remarkable leptosporangiate fern because it includes only one genus with a restricted distribution to tropical regions. The fossil record of this family has been widely reported from the Mesozoic strata in Eurasia, America, Australia, and Greenland. In China, numerous fossils of the Dipteridaceae have been documented, in total, about 74 species of 6 genera. Geographically, they are distributed both in the Southern and Northern Floristic Provinces, and were particularly well developed in the Southern Floristic Province during the Late Triassic and the Early Jurassic intervals. Fossil diversity of Dipteridaceae varies in the different episodes of the Mesozoic in China. It is shown that Dipteridaceae has undergone a diversity development process and a distinct turnover during the Mesozoic. They appear to have diversified in the warm and humid Late Triassic–Early Jurassic, but declined sharply as aridity developed in the Middle Jurassic, and became extinct at the end of the Early Cretaceous. The diversity variation and tempo-spatial distribution pattern is suggested to be linked with paleoclimatic variations during the Mesozoic.  相似文献   

12.
扁甲总科隶属于鞘翅目多食亚目扁甲系,目前包含25个现生科和3个化石科,其中10个科仅分布于南半球,特别是澳大利亚、新西兰和南美。当前的分子系统发育学研究显示扁甲总科的起源时间为晚三叠世至早侏罗世,而冈瓦纳古陆与劳亚古陆的分离也发生在早侏罗世约1.8亿年前。因此对中生代扁甲总科化石的研究是解释扁甲总科如今分布格局的重要基础,也有助于研究扁甲总科的演化历史。本文简要回顾了现生扁甲总科的研究历史,并对其中生代的化石研究进行了概述,迄今在中生代地层发现有12科54种扁甲总科化石。  相似文献   

13.
Larvae of the sister orders Trichoptera and Lepidoptera are characterized by silk secretion from a pair of labial glands. In both orders the silk filament consists of heavy (H)- and light (L)-chain fibroins and in Lepidoptera it also includes a P25 glycoprotein. The L-fibroin and H-fibroin genes of Rhyacophila obliterata and Hydropsyche angustipennis caddisflies have exon/intron structuring (seven exons in L-fibroin and two in H-fibroin) similar to that in their counterparts in Lepidoptera. Fibroin cDNAs are also known in Limnephilus decipiens, representing the third caddisfly suborder. Amino acid sequences of deduced L-fibroin proteins and of the terminal H-fibroin regions are about 50% identical among the three caddisfly species but their similarity to lepidopteran fibroins is <25%. Positions of some residues are conserved, including cysteines that were shown to link the L-fibroin and H-fibroin by a disulfide bridge in Lepidoptera. The long internal part of H-fibroins is composed of short motifs arranged in species-specific repeats. They are extremely uniform in R. obliterata. Motifs (SX)n, GGX, and GPGXX occur in both Trichoptera and Lepidoptera. The trichopteran H-fibroins further contain charged amphiphilic motifs but lack the strings of alanines or alanine-glycine dipeptides that are typical lepidopteran motifs. On the other hand, sequences composed of a motif similar to ERIVAPTVITR surrounded by the (SX)4-6 strings and modifications of the GRRGWGRRG motif occur in Trichoptera and not in Lepidoptera.
František SehnalEmail:
  相似文献   

14.
Pterosaurs, a Mesozoic group of flying archosaurs, have become a focal point for debates pertaining to the impact of sampling biases on our reading of the fossil record, as well as the utility of sampling proxies in palaeo‐diversity reconstructions. The completeness of the pterosaur fossil specimens themselves potentially provides additional information that is not captured in existing sampling proxies, and might shed new light on the group's evolutionary history. Here we assess the quality of the pterosaur fossil record via a character completeness metric based on the number of phylogenetic characters that can be scored for all known skeletons of 172 valid species, with averaged completeness values calculated for each geological stage. The fossil record of pterosaurs is observed to be strongly influenced by the occurrence and distribution of Lagerstätten. Peaks in completeness correlate with Lagerstätten deposits, and a recovered correlation between completeness and observed diversity is rendered non‐significant when Lagerstätten species are excluded. Intervals previously regarded as potential extinction events are shown to lack Lagerstätten and exhibit low completeness values: as such, the apparent low diversity in these intervals might be at least partly the result of poor fossil record quality. A positive correlation between temporal patterns in completeness of Cretaceous pterosaurs and birds further demonstrates the prominent role that Lagerstätten deposits have on the preservation of smaller bodied organisms, contrasting with a lack of correlation with the completeness of large‐bodied sauropodomorphs. However, we unexpectedly find a strong correlation between sauropodomorph and pterosaur completeness within the Triassic–Jurassic, but not the Cretaceous, potentially relating to a shared shift in environmental preference and thus preservation style through time. This study highlights the importance of understanding the relationship between various taphonomic controls when correcting for sampling bias, and provides additional evidence for the prominent role of sampling on observed patterns in pterosaur macroevolution.  相似文献   

15.
The first Mesozoic scutigeromorph centipede (Myriapoda: Chilopoda), Fulmenocursor tenax gen. et sp. nov., is described from the Lower Cretaceous (Aptian) Crato Formation of north-east Brazil. Previously described fossil Scutigeromorpha are known from Dominican and Baltic amber, the Carboniferous (Westphalian D) Francis Creek Shale of Mazon Creek, Illinois, the Silurian and Devonian of Britain, and the Devonian of New York State.  相似文献   

16.
通过扫描电镜重新研究了产自俄罗斯维特奴河流域下三叠统维特奴宽网叶肢介(Loxomegaglypta wetlugiana Novo-jilov, 1958)的正模标本。扫描电镜成像揭示了光学照相无法分辨的重要分类学新特征, 其中包括: 生长带饰有圆形、角状或椭圆形小筛坑状装饰(直径15–25 μm), 筛坑被不同形状的隆起包围。均匀分布的针孔(直径4–6 μm)不但出现在筛坑里, 而且布满了筛坑周围的隆起。这种装饰与该属建立时描述的多角状大网格装饰区别较大。在此基础上,本研究修订了宽网叶肢介属生长带的装饰特征。  相似文献   

17.
武春生  方承莱 《昆虫学报》2009,52(5):561-566
系统整理了中国眉刺蛾属的全部种类,共9种及1亚种,包括1新种--黄眉刺蛾Narosa pseudopropolia Wu et Fang及1新纪录种--齐眉刺蛾N. propolia Hampson。编制了本属中国已知种的检索表,提供了成虫和外生殖器特征照片。新种模式标本保存在中国科学院动物研究所。  相似文献   

18.
武春生  方承莱 《昆虫学报》2003,46(3):351-358
系统整理了中国胯舟蛾属(Syntypistis Turner)的全部种类共20种,包括1新种黑胯舟蛾Syntypistis melana Wu et Fang,sp. Nov. 和2中国新记录种:篱胯舟蛾 Syntypistis hercules (Schintlmeister) comb. Nov.与防胯舟蛾 Syntypistis defector (Schintlmeister) comb. Nov.,后2种均为新组合。文中提供了分种检索表,新种形态描述和外生殖器特征图。模式标本保存在中国科学院动物研究所动物标本馆。  相似文献   

19.
武春生  方承莱 《昆虫学报》2009,52(6):684-690
系统整理了中国球须刺蛾属的全部种类,共8种,包括1新种--双带球须刺蛾Scopelodes bicolor Wu et Fang。显脉球须刺蛾S. kwangtungensis Hering从亚种提升为种级阶元。编制了本属中国已知种的检索表,提供了成虫和外生殖器特征照片。新种模式标本保存在中国科学院动物研究所。  相似文献   

20.
The encrusting genus Lithocodium Elliott, widespread in Tethyan Triassic-Cretaceous carbonate platforms and interpreted in the past as a codiacean alga, is presently regarded as a colony of calcified cyanobacteria, a microorganism incertae sedis or a loftusiacean foraminifer. The absence of apertures connecting neighbouring cavities, as well as the very irregular form and arrangement of these hollows within a frequently massive micritic matrix, excludes assigning Lithocodium to the foraminifers, but could rather suggest colonies of calcified cyanobacteria.  相似文献   

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