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1.
The Upper Cretaceous Bagh Beds yield many biota of which ammonoids are particularly well known. Previously Bagh ammonoids were grouped into many genera and species within several families. The present study, however, shows that failure to recognize dimorphism and a wide range of interspecific variation within the single genus Placenticeras perhaps results in taxonomic oversplitting. Specific dimorphism in P. mintoi has been established. 相似文献
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《International Geology Review》2012,54(9):1655-1658
Two species of subtriangular, trilete spores assigned to a new form genus, Acritosporites, occur in Cenomanian and Turonian sandstones and silty clays of central U. S. S. R. Three proximal, interradial, oval "lacunae" and one distal, circular "lacuna" characterize the genus. The author, in disagreement with Bolkhovitina, prefers not to ally A. sibiricus (Bolkh.) comb. nov. with Lygodium. — D. C. McGregor. 相似文献
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One new osmylid genus and species, Burmaleon magnificus, and one new nymphid genus and species Rafaelnymphes cratoensis are described, respectively based on inclusions in the Cretaceous Burmese amber and on a compression fossil from the Crato Formation in Brazil. The nymphid Araripenymphes seldeni, from the Crato Formation, is redescribed on the basis of a new specimen, showing possible sexual dimorphism in wing coloration, a feature extremely rare among the Neuroptera. In a recently published phylogenetic analysis of the family, the attribution to the fossil taxa (versus rejection) of the larval characters proper to the modern nymphids, has a crucial impact on the resolution of the phylogeny. The compression fossils currently attributed to the Nymphidae should be revised because their wing venation alone is not really sufficient for an accurate family attribution to Nymphidae rather than to another family of Neuroptera (viz. Osmylidae). 相似文献
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《International Geology Review》2012,54(9):1534-1542
This short section of Skarlato's monograph, Bivalve Mollusks of the Far Eastern Seas of the U. S. S. R. (Order Dysodonta), discusses the genus Arvella Bartsch, 1940 ms. The genus includes the species formerly assigned to Crenella. Diagnostic features of the species included in genus Arvella Bartsch are given. Vilasina Bartsch, 1940 ms is discussed, also The author states that the hinges of Vilasina clearly assign the species to the genus Crenella. The form and position of the umbo relate the species closely to the genus Arvella, though. The almost entirely smooth laminated surface distinguishes Vilasina from both genera, as does the finely serrated ventral edge of the shell. The last section discusses the genus Modiolus Lamarck, 1799. — A. W. Bellais. 相似文献
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Samuel Giersch Eberhard Frey Wolfgang Stinnesbeck Christina Ifrim José Manuel Padilla Gutierrez 《Swiss Journal of Geoscience》2011,104(1):73-84
A new species of the clupeid genus Scombroclupea is described from the Upper Cretaceous (Cenomanian) Plattenkalk locality “Loma la Mula” in Coahuila, northeastern Mexico. The material provides new osteological data for the genus, which clarify its systematic position. The Mexican Scombroclupea points to an occurrence of the genus in the western Tethys and indicates a vicariant event between S. macrophthalma from Lebanon and Croatia and the new species described herein. The analysis of the functional morphology of Scombroclupea supports the reconstruction of an oscillatory locomotion mode in this genus. 相似文献
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D. N. Kiselev 《Stratigraphy and Geological Correlation》2017,25(2):188-228
Problems of correlation of the upper part of the middle Volgian beds of European Russia and Arctic regions with the Portlandian of England and northern France largely result from existing uncertainties in the taxonomy of the ammonite subfamily Dorsoplanitinae. The poor knowledge of the morphogenesis of this group precludes effective and stable taxonomy and recognition of parallelisms, thereby decreasing the group’s correlative-biostratigraphic potential. In Dorsoplanitinae, dimorphism is revealed in the differences in the terminal shell diameter and, to a lesser extent, in the sculpture, whereas apertural modifications characteristic of many Perisphinctoidea are not observed in members of this group. The middle Volgian Dorsoplanitinae are represented by minimorphs and macromorphs, taxonomically different at the species or genus level. The Volgian minimorphs are mainly represented by the genera Epivirgatites and Lomonossovella, whereas macromorphs are represented by Titanites s.l.; in the genus Taimyrosphinctes, micro- and macromorphs belong to different subgenera. All morphological types of Volgian Dorsoplanitinae have vicariate equivalents in the Portlandian, which can be used for the interregional correlations. 相似文献
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A new genus and species of extinct rove beetle, Procileoporus burmiticus gen. and sp. n., is described from Upper Cretaceous Burmese amber (Cenomanian; ca. 99 Ma). Due to the condition of the fossil, parts of the body could not be examined, but sufficient characteristics were visible to allow the specimen to be placed within the subfamily Tachyporinae (tribe Tachyporini). Procileoporus is most similar to the extant genus Cileoporus Campbell in having a slender abdomen, but it differs in having much shorter abdominal setae, prominent striated microreticulation on the elytra, non-lobed tergite VIII, and in other details of the male genital segments. This is the first tachyporine rove beetle from Burmese amber and the oldest record of the subfamily in amber. The evolution of sexual dimorphism in the genital segments is briefly discussed. 相似文献
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山东平邑官庄组的非海栖软体动物化石 总被引：1，自引：0，他引：1
官庄组按岩性分为上、中、下三段。软体动物化石产于该组中段。主要化石计有双壳类1属1种;腹足类11属14种,其中包括1个新属、4个新种和1个新亚种。 相似文献
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A. P. Ippolitov 《Stratigraphy and Geological Correlation》2018,26(2):179-205
Belemnites from the lower Bathonian of the Russian Plate are revised on the basis of the study of two reference sections—Pletnyovka and Sokur quarries. The first part of the study deals with the members of the family Megateuthididae. They include eight species of the genus Barskovisella gen. nov., neoendemic to the territory of the Russian Plate and originating from high Boreal taxa—species of the genus Paramegateuthis Gustomesov, 1960, which immigrated to the Middle Russian Sea in the early Bathonian via a short-lived meridional strait. The new genus includes six new species described in the present paper—Barskovisella pseudoishmensis sp. nov., B. issae sp. nov., B. variabilis sp. nov., B. barskovi sp. nov., B. gracilis sp. nov., and B. renegata sp. nov. The beds with Barskovisella, a new belemnite-based unit, corresponding to the Oraniceras besnosovi ammonite zone and including four successive phylogenetic biohorizons well comparable in resolution with ammonite-based infrazonal subdivisions, are introduced. 相似文献
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本文描述了产于吉林中部的皱纹珊瑚1新属2新种。这些珊瑚化石除具皱纹珊瑚的一般特征之外,还具有六射珊瑚的特点。它对研究六射珊瑚与皱纹珊瑚之间演化关系具有重要意义。 相似文献
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《International Geology Review》2012,54(6):1116-1120
A new species is described, Tunguskocrinus ivanovae, representing a new genus and family of the superfamily Homocrinicae. The crinoid was found in Middle Ordovician rocks in Siberia.—P. M. Kier. 相似文献
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中国的蛹状螺科（Pupinidae）迄今共报道5属,分别为拇指螺属（Pollicaria A.A. Gould, 1856、拟圆口螺属（Pseudopomatias M?llendorff, 1885）、蛹状螺属（Pupina Vignard, 1829）、小蛹螺属（Pupinella Gray, 1850）、象蛹螺属（Rhaphaulus L. Pfeiffer, 1856）和裂唇螺属（Coptocheilus Gould, 1862） （ = Schistoloma Kobelt, 1902）。除拟圆口螺属和裂唇螺属有过详细整理报道外,其他各属物种仍缺乏研究。本文对中国小蛹螺属（Pupinella）进行了分类整理。本属此前共记录3种,即具槽小蛹螺（P. sulcatus）,台湾小蛹螺（P. swinhoei）和梅山小蛹螺（P. masuhowaruensis）,仅分布于广西和台湾。笔者在整理由华南农业大学田明义教授洞穴考察团队在广西壮族自治区河池市都安瑶族自治县一喀斯特洞穴中采集的陆生贝类时,经鉴定发现小蛹螺属一新种,即田氏小蛹螺（Pupinella tiani sp. nov.）,因其壳体具蛹状管、无内沟槽、壳表肋纹明显及壳口窦开放等特征而与本属其他物种区分。根据壳体形态特征,分布于云南的勐仑蛹状螺（Pupina menglunensis） 被转移到本属,并认为Pupinella frednaggsi为其一新异名。此外,还提供了中国小螺属分种检索表。田氏小蛹螺新种 （Pupinella tiani Z.-Y. Chen, sp. nov.）模式标本:正模,广西壮族自治区河池市都安瑶族自治县龙湾乡琴棋村一号洞,23°52′19′′N,108°16′02′′E,海拔466 m,2013年12月24日,田明义、刘卫欣、尹昊旻、罗孝竹采集。副模:2个,采集信息同正模。正副模标本均保存于河北大学动物博物馆软体动物馆藏中。测量:正模标本,壳高:11.30 mm,壳宽:4.62 mm,壳口直径:3.80 mm。副模标本（n=2）,壳高:11.24~11.38 mm,壳宽:4.50~4.56 mm,壳口直径:3.64~3.82 mm。词源学:本种名源自标本主要采集人田明义教授。描述:贝壳小型,高圆锥形,有6.5个浅色且稍有光泽的螺层。胚螺层约有2.5个,粗糙,边界与下部螺层较难明显区分。主螺层有细而规则的肋纹,肋纹随着螺层的增加而逐渐明显,体螺层上每1 mm有15个肋纹;体螺层的腹侧稍扁平;壳口圆形,平直;唇缘外扩,白瓷色,边缘被一腔襞沟槽和一近壳轴沟槽;腔襞沟槽和壳轴沟槽为半圆形的开放槽,不形成管状。壳轴缺沟槽与基部龙骨相对应,在胼胝处消失。脐孔狭窄。厣形态未知。描别:本种因其开放的沟槽和壳轴沟槽内管阙如而与中国其他物种区分。台湾小蛹螺与本种在尺寸和外形上最相近,但新种可通过其细尖的壳顶和不具双唇结构而于前者区分。详见正文的检索表。附记:本种仅知分布于模式产地。模式标本从洞口土样中分离,同时发现的有微拟沼螺属（Acmella W.T Blanford, 1969）的标本。 相似文献
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CHEN Ailin FENG Hongzhen ZHU Maoyan MA Dongsheng LI Ming Department of Earth Science Nanjing University Nanjing Jiangsu E-mail: feng.h@jlonline.com Nanjing Institute of Geology Palaeontology Chinese Academy of Sciences Nanjing Jiangsu Chenjiang Fauna National Geological Park Chengjiang Yunnan Wang Si''en Xie Guanglian 《《地质学报》英文版》2003,77(3):281-287
The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite body plan and five pairs of chain-formed gill sacs, showing the general characteristics of Ventulicolia. However, the exclusive "atrial cavity" and external gill observed indicate that the new form is different from those previously described as vetulicolians, probably representing a lineage developed within deuterostomes and more primitive than urochordates. 相似文献
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XiaochiJIN XiangningYANG 《《幕》》2004,27(4):273-278
The Permian foraminifer Shanita is a genus of special paleobiogeographic importance. Current data indicate that this genus occurs in peninsular Thailand, Shan States of Burma, western Yunnan and northwestern Tibet of China, south Pamir of Tajikistan, South Afghanistan, Kuh-e Gahkum area of lran, Transcaucasus, Pinarbasi area of Turkey, and the Saiq Plateau of Oman. Studies also show that several species of Hemigordius usually coexist with Shanita, and form a peculiar Shanita-Hemigordius fauna. Localities of the Shanita-Hemigordius fauna that have been found hitherto are confined on Gondwanaderived blocks, which constitute a strip starting from peninsular Thailand and extending northwestwards and westwards to Turkey. This fauna is considered as another Permian palaeontological marker of marginal Gondwana environment. 相似文献
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《International Geology Review》2012,54(8):1435-1443
The author discusses the conceptual bases of the pelecypod family Allorismidae and of the Carboniferous genera Allorisma, Allorismiella, Edmondia, Edmondiella, and Pseudedmondia. There is an extensive discussion of the hinge line structures of Allorisma based on Russian specimens, and four species of the genus from the Carboniferous of the Moscow area are described. Astaf'yeva-Urbaitis overlooked Wilson's 1959 paper in which Allorisma was shown to be a junior synonym of Edmondia; as a result Astaf'yeva-Urbaitis' nomenclature is faulty. Wilson replaced Allorisma with the new generic name Wilkingia. — J. Pojeta, Jr. 相似文献
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Metoicoceras 《Cretaceous Research》2000,21(6):845
Species of the ammonite genus Metoicoceras are not generally strongly differentiated with respect to coiling and ornament. The present study addresses the problem of how well purely visual (subjective) identification succeeds in identifying taxonomically and hence evolutionarily relevant differences between forms. Multivariate statistical analysis, based on coiling, standard dimensions of the conch and ornamental properties, indicates that quantitative procedures reproduce traditional methods to a conspicuous degree, with the added advantage of objective repeatability. Additionally, uncertain phylogenetic relationships could be resolved by appropriate methods of multivariate statistical analysis and possible new information on dimorphism in the conch was obtained. 相似文献
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