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1.
Abstract:  Several new specimens of Protoischnurus axelrodorum Carvalho and Lourenço and Araripescorpius ligabuei Campos from the Crato Formation, Brazil, are described. The preservation and recognition of new morphological features allows a re-diagnosis of both species and a modification of their familial placement. Protoischnurus axelrodorum is the oldest species belonging to the scorpionoid family Hemiscorpiidae Pocock (= Ischnuridae Simon; = Liochelidae Fet and Bechly) and the first Cretaceous record. It was originally placed in the extinct family Protoischnuridae Carvalho and Lourenço, which is here synonymized with Hemiscorpiidae. Araripescorpius ligabuei, now assigned to Chactidae Pocock, is the first chactoid recorded for the Cretaceous of Brazil. These findings confirm that the lineages of two modern families date back at least to the Early Cretaceous and, considering their current distribution, were probably present before the break-up of the supercontinent Gondwana. Palaeoecological inferences indicate the presence of tropical habitats in the vicinity of the Crato lake/lagoon.  相似文献   

2.
The present report describes fossil evidence of insect pathogens, heretofore, almost non-existent, from six samples of amber ranging in age from 15 to 100 million years. They include a cytoplasmic polyhedrosis virus and trypanosomatid infection in an adult biting midge (Diptera: Ceratopogonidae), and a nuclear polyhedrosis virus in an adult sand fly (Diptera: Phlebotomidae), both from Early Cretaceous Burmese amber, several types of fungal thalli on the cuticle of an adult mosquito (Culicidae: Diptera), as well as a fungal growth on the prothorax of a fungus gnat (Mycetophilidae: Diptera) in Dominican amber and large tumors in the body cavity of a caterpillar (Lepidoptera) in Mexican amber. These discoveries suggest that insect polyhedrosis viruses were present 100 million years ago and present the possibility that vertebrate arboviruses (especially those in the family Reoviridae) could have evolved from cytoplasmic polyhedrosis viruses infecting biting insects. The flagellates in the Early Cretaceous biting midge represent the first fossil record of monogenetic trypanosomatid infections of arthropods.  相似文献   

3.
内蒙古海拉尔盆地白垩纪生物地层研究进展   总被引:3,自引:1,他引:2  
兴安岭群龙江组产Ephemeropsistrisetalis等热河生物群分子,九峰山组产富含Cicatricosisporites,Pilosisporites,Concavissimisporites的孢粉组合,兴安岭群龙江组、甘河组火山岩同位素年龄为105-141Ma,证实兴安岭群的时代为早白垩世早期;扎赉诺尔群中以Cypridea,Limnocypridea,Ilyocyprimorpha和Hailaeria等属为代表的介形类动物群,以Nyktericysta,Vesperopsis等属为代表的NV浮游植物群,以富含Lygopodiaceae科各属孢子,尤其是Cicatricosisporites高含量的孢粉组合,代表了中国北方早白垩世特有的动、植物群面貌,而其中Asteropollis,Tricolpites和Polyporites等被子植物花粉化石的发现,这一事实似乎暗示了扎赉诺尔群的时代为早白垩世中、晚期;青元岗组产以Talicypridea,Altanicypris,Chinocypridea和Harbinia为代表的介形类动物群,具有显著的地域性特点,可与松辽盆地四方台组对比,其时代为晚白垩世Maastrichtian期。  相似文献   

4.
Calissounemys matheroni gen. et sp. nov. (Testudines) is described on the basis of a skull and shell elements from the Upper Cretaceous of Var, southern France. This new taxon is assigned to the family Compsemydidae and characterized by a thick-boned, robust skull, a shallow temporal emargination, a crista supraoccipitalis not extending beyond the posterior edge of the skull roof, large nasals meeting along the midline for their full length; frontals retracted from the orbital margin, absence of a cheek emargination, a large jugal forming a substantial part of the orbital margin, absence of a secondary palate and an uneven upper triturating surface; and the shell with vertebral 1 clearly wider than vertebrals 2-3, with the lateral margins strongly divergent towards the anterior border and wider than long vertebrals 2-3. This find increases the diversity of the Late Cretaceous turtle fauna from southern France, and fills a stratigraphical gap in the fossil record of Compsemydidae between the Early Cretaceous and the Paleocene in Europe.  相似文献   

5.
Abstract:  A recent collection of actinopterygian fossil fishes from a previously unreported locality in the Cenomanian or Turonian of southeastern Morocco includes a single specimen of a macrosemiid fish. Macrosemiids are more common in Jurassic and Early Cretaceous deposits, with the previously known range of the family being Late Triassic through Aptian or Albian. This discovery therefore extends the temporal range of the family into the Late Cretaceous. Moreover, macrosemiids had not previously been reported from northern Africa or the Moroccan area of the Tethys basin; therefore, this fossil also increases the geographical range of the family. The Moroccan macrosemiid is described in a new genus and species, Agoultichthys chattertoni . A phylogenetic analysis places it basal to all other genera of the family with the exception of Notagogus . Diagnostic characters of the new species include the high number of scales laterally along the body and the greater number of dorsal fin rays than in other members of the family.  相似文献   

6.
Abstract:  The largest known flying organisms are the azhdarchid pterosaurs, a pterodactyloid clade previously diagnosed by the characters of their extremely elongate middle-series cervical vertebrae. The named species of the Azhdarchidae are from the Late Cretaceous. However, isolated mid-cervical vertebrae with similar dimensions and characters have been referred to this group that date back to the Late Jurassic, implying an almost 60 million year gap in the fossil record of this group and an unrecorded radiation in the Jurassic of all the major clades of the Pterodactyloidea. A new pterosaur from the Early Cretaceous of Liaoning Province of China, Elanodactylus prolatus gen. et sp. nov., is described with mid-cervical vertebrae that bear these azhdarchid characters but has other postcranial material that are distinct from the members of this group. Phylogenetic analysis of the new species and the Pterodactyloidea places it with the Late Jurassic vertebrae in the Late Jurassic–Early Cretaceous Ctenochasmatidae and reveals that the characters of the elongate azhdarchid vertebrae appeared independently in both groups. These results are realized though the large taxon sampling in the analysis demonstrating that the homoplastic character states present in these two taxa were acquired in a different order in their respective lineages. Some of these homoplastic characters were previously thought to appear once in the history of pterosaurs and may be correlated to the extension of the neck regions in both groups. Because the homoplastic character states in the Azhdarchidae and Ctenochasmatidae are limited to the mid-cervical vertebrae, these states are termed convergent based on a definition of the term in a phylogenetic context. A number of novel results from the analysis presented produce a reorganization in the different species and taxa of the Pterodactyloidea.  相似文献   

7.
The fossil record for neoceratopsian (horned) dinosaurs in the Lower Cretaceous of North America primarily comprises isolated teeth and postcrania of limited taxonomic resolution, hampering previous efforts to reconstruct the early evolution of this group in North America. An associated cranium and lower jaw from the Cloverly Formation (?middle–late Albian, between 104 and 109 million years old) of southern Montana is designated as the holotype for Aquilops americanus gen. et sp. nov. Aquilops americanus is distinguished by several autapomorphies, including a strongly hooked rostral bone with a midline boss and an elongate and sharply pointed antorbital fossa. The skull in the only known specimen is comparatively small, measuring 84 mm between the tips of the rostral and jugal. The taxon is interpreted as a basal neoceratopsian closely related to Early Cretaceous Asian taxa, such as Liaoceratops and Auroraceratops. Biogeographically, A. americanus probably originated via a dispersal from Asia into North America; the exact route of this dispersal is ambiguous, although a Beringian rather than European route seems more likely in light of the absence of ceratopsians in the Early Cretaceous of Europe. Other amniote clades show similar biogeographic patterns, supporting an intercontinental migratory event between Asia and North America during the late Early Cretaceous. The temporal and geographic distribution of Upper Cretaceous neoceratopsians (leptoceratopsids and ceratopsoids) suggests at least intermittent connections between North America and Asia through the early Late Cretaceous, likely followed by an interval of isolation and finally reconnection during the latest Cretaceous.  相似文献   

8.
Nomenclature reappraisal, diversity pattern and palaeoclimatic implications of Jurassic, Triassic and Early Cretaceous pycnoxylic woods in India are undertaken in the present study. Among the fourteen generic names published previously, only eight are validly published and the rest are nomenclaturally illegitimate. About 51 species were reported under these genera to date. There is a gradual increase of species diversity of fossil wood from the Triassic to Early Cretaceous. The nature of the growth rings was applied to understand the palaeoclimate. The lack of distinct growth rings in the Triassic woods suggests absence of seasonality. The Jurassic woods with an inconsistency in growth rings and presence of growth interruptions suggest climate was seasonal and turbulent. During the Early Cretaceous, conifer dominated vegetation and with wider growth rings and gradual transition suggests warm environments with pronounced seasonality. The general increase in mean ring width from the Triassic to Early Cretaceous indicates ameliorating climatic conditions, particularly benign summer conditions.  相似文献   

9.
黑龙江省东部鸡西盆地早白垩世穆棱组植物化石新材料   总被引:4,自引:0,他引:4  
杨小菊 《古生物学报》2003,42(4):561-584
系统描述了最近采集的穆棱组植物化石22属23种,其中的两种被子植物叶化石均为具原始被子植物叶特征的小型叶,在该植物群中尚属首次发现。运用扫描电镜(SEM)等方法对其中的Tyrmia sp.,Nilssoniopteris sp.,Ginkgoites cf..sibirica,.Sphenobaiern sp.,Elatocladus manchurica等化石的叶角质层进行了研究。据已有的资料统计,穆棱组迄今已知有化石植物31属38种。该植物群以真蕨类占据绝对优势,裸子植物也相当丰富,其中的大多数种类主要见于早白垩世,穆棱组的地质时代应属早白垩世巴列姆期或巴列姆-阿普梯早期。植物组合中以丰富的热带及亚热带型植物为主要特点,未发现针叶类型的植物,说明早白垩世穆棱组沉积时,该地区的气候温暖湿润;另一方面,落叶的银杏类和松柏类,以及裸子植物木化石中具有清楚的生长轮,又说明该地区的古气候存在着季节变化。该植物群属于早白垩世西伯利亚植物区或加拿大-西伯利亚植物区。  相似文献   

10.
Abstract:  Bulk screening of Early Cretaceous (Barremian) strata of the Wessex Formation, exposed in sections on the south-west and south-east coasts of the Isle of Wight, southern England, has resulted in the recovery of mammal remains, the first to be obtained from Wealden Group strata since the early 1970s. The fauna comprises at least six taxa represented by isolated teeth and in addition, in the case of an as yet undescribed spalacotheriid, a partial dentary. One of the teeth, a distal premolar, is of unique tricuspid, single-rooted morphology and represents the first British record of the Gobiconodontidae. Discovery of a gobiconodontid mammal in Early Cretaceous deposits of Britain sheds further light on the palaeogeographical distribution of an apparently successful clade of Early Cretaceous mammals and together with the occurrence of a gobiconodontid in the earliest Cretaceous of North Africa calls into question recent hypotheses concerning the area of origin of the Gobiconodontidae and mechanisms of dispersal therefrom.  相似文献   

11.
黑龙江嘉荫县渔亮子组是我国最早发现爬行动物化石的层位,盛产鸭嘴龙等爬行类化石,前人认为,该组在层位上相当于北美晚白垩世马斯特里赫特期Edmonton群,HellCreek和Lance组,但孢粉化石资料提示,渔亮子组中的被子植物花粉尚未发展至上述群(组)的阶段,其层位应较之低,大致相当于北美的坎佩尼期BellyRiver群(组)或相当层位。  相似文献   

12.
Three new taxa from Albian, Early Cretaceous assemblages in Gondwana (Australia and Antarctica) and two previously described fossils from the Late Cretaceous and Eocene of North America are attributable to the heterosporous semi-aquatic fern family Marsileaceae. They are assigned to Marsileaceaephyllum, a morphotaxon erected here for sterile remains (whole plants, and isolated leaves and leaflets) of Marsileaceae. The Gondwanan taxa, Marsileaceaephyllum lobatum and Marsileaceaephyllum spp. B-C, have either a cruciform leaflet arrangement or dichotomous and anastomosing venation characteristic of modern Marsileaceae. Two previously established taxa, Marsilea johnhallii and Marsilea sp., which represent sterile Marsileaceae, are also transferred to the new genus (now Marsileaceaephyllum johnhallii and Marsileaceaephyllum sp. A, respectively). Examination of all fossil venation patterns reveals four new venation types not present in extant taxa, suggesting that most fossil Marsileaceae (leaves) are distinct from extant genera, and are likely members of extinct lineages. This is further supported by the absence of modern megaspore types in the Early Cretaceous.  相似文献   

13.
Abstract: New multituberculate mammals from the Hauterivian/Barremian transition of Europe are described. They were found in the late Hauterivian‐early Barremian fossiliferous locality of La Cantalera (Josa, Teruel, Spain), one of the Early Cretaceous sites in the Aragonese branch of the Iberian Ranges, in northeastern Iberia. The fossils have been assigned to at least three taxa on the basis of nine isolated teeth: a new pinheirodontid taxon, Cantalera abadi gen. et sp. nov.; a representative of the eobaatarid Eobaatar; a taxon described as Plagiaulacidae or Eobaataridae gen. et sp. indet.; and other as Plagiaulacida indet. These fossils have increased the resolution of European Early Cretaceous multituberculate mammalian biostratigraphy and palaeobiogeography: the oldest representative of Eobaatar is described here; a taxon is assigned to ?Plagiaulacidae, in which case it would be the first of this family in the Iberian Peninsula; and the discovery of a new late Hauterivian pinheirodontid taxon demonstrates greater biodiversity and a wider distribution for these multituberculates than was previously known. The mutituberculate fauna of La Cantalera consists of endemic taxa (Pinheirodontidae), which were restricted to what is now Western Europe, and others (Eobaataridae) which have also been described in Asia. Consistent with the Iberian record of late Barremian gobiconodontid mammals, the presence of Eobaatar in Iberia with representatives from the late Hauterivian to late Barremian, as well as in the Aptian or Albian of Mongolia, indicates that faunal exchanges between Europe and Asia could have existed for most of the Early Cretaceous, either sporadically or constantly.  相似文献   

14.
The first dated phylogeny of the weevil subfamily Cryptorhynchinae is presented within a framework of Curculionoidea. The inferred pattern and timing of weevil family relationships are generally congruent with previous studies, but our data are the first to suggest a highly supported sister-group relationship between Attelabidae and Belidae. Our biogeographical inferences suggest that Cryptorhynchinae s.s. originated in the Late Cretaceous (c. 86 Ma) in South America. Within the ‘Acalles group’ and the ‘Cryptorhynchus group’, several independent dispersal events to the Western Palaearctic via the Nearctic occurred in the Late Cretaceous and Early Paleogene. A second southern route via Antarctica may have facilitated the colonization of Australia in the Late Cretaceous (c. 82 Ma), where a diverse Indo-Australian clade probably emerged c. 73 Ma. In the Early Eocene (c. 50–55 Ma), several clades independently dispersed from Australia to proto-New Guinea, i.e. the tribe Arachnopodini s.l., the ‘Rhynchodes group’ and the genus Trigonopterus. New Zealand was first colonized in the Late Palaeocene (c. 60 Ma). Divergence time estimations and biogeographical reconstructions indicate that the colonization of New Guinea is older than expected from current geological reconstructions of the region.  相似文献   

15.
甘肃玉门红柳峡早白垩世下沟组的介形类   总被引:1,自引:1,他引:0  
本文描述了甘肃玉门红柳峡下沟组的介形类化石共5属4亚属、13种。其中1新属、6个新种、1个比较种。根据介形类特征和地理分布,推测下沟组的时代为早白垩世巴列姆期;同时结合玉门红柳峡下沟组的岩性特征,认为该组为淡水微咸水河湖相沉积。  相似文献   

16.
The family Ciehlidae is a large group of tropical fishes in the order Perciformes, with an estimated number of living species exceeding 1400. The modern distribution of the family Ciehlidae is predominantly in fresh waters of Central and South America, Africa, Madagascar, India and the Middle East, with fossil members known from Africa, Saudi Arabia, the Levant, Europe, South America and Haiti. Many authors have referred to the distribution as being Gondwanan and have postulated that cichlids originated over 130 million years ago, in the Early Cretaceous. However, the suggested evidence for an Early Cretaceous origin of cichlids is equally or more compatible with a much younger age of origin. Based on the biology and distribution of modern and fossil cichlids, it is more probable that they arose less than 65 million years ago, in the Early Tertiary, and crossed marine waters to attain their current distribution.  相似文献   

17.
曹正尧 《古生物学报》2001,40(2):214-218
报道辽西义县组两种颇具地层意义的植物化石。Ruffordia goeppertii(Dunker)Seward和Nageiopsis exgr.samioides(Fontaine)berry,根据植物化石认为义县组的时代应属于早白垩世。  相似文献   

18.
This paper deals with evolution, classification and pollen morphology of the Hamamelidaceae, an important family in phylogeny of angiosperms. I. Pollen morphology and systematics of modern Hamamelidaceae. The pollen morphology of the family may be divided into the following four types: (1) Tricolpate: Hamamelis, Loropetalum, Mytilaria, Corylopsis, Sysopsis, and Distylum etc.; (2) Tricolpate with operculum: Disanthus; (3) Tricolporate: Rhodoleia; (4) Pantoporate: Liquidambar. The tricolpate pollen of the Hamamelidaceae is a primitive type in angiosperms, but the most ancient type is monocolpate pollen. Therefore, the family might have evolved from the Magnoliaceae of the monocolpate pollen. The pantoporate pollen is an evolutionary type in the family. It might have evolved from the tricolpate pollen. II.The fossil pollen of the Hamamelidaceae 1 .General introduction of the fossil pollen of the family Hamamelidaceae The most’ancient fossil pollen belonging to the family was found in the middle-late Early Cretaceous. Palynologists call the fossil pollen of the Hamamelidaceae Retitricolpites, which consists of three genera: Hamamelis L.,Corylopsis Sieb. et Zucc and Fothergilla Murr. Liquidambar is of an advanced type in the fossil pollen of the Hamamelidaceae. It was found in the period from the Palaeogene to the Neogene in China. 2. The geological history of the Hamamelidaceae may be divided into the following four stages: (A) The Early Cretaceous stage or origination stage. The family may be evolved from Magnoliales in the middle-late Early Cretaceous. (B)the Late Cretaceous stage or formation stage. The family is much developed in the period. (C) The Tertiary stage or development stage. The family was a much developed one among angiosperms. (D)The Neogene to modern stage or perfection stage. The evolutionary type, the Liquidambar type of the Hamamelidaceae, was much developed in the Neogene. III. The palaeopalynological evidence of evolution of the Hamamelidaceae The earliest fossil pollen of angiosperms was found in the Barremian (Early Cretaceous) in England, Israel, the United States of America etc., and was named as Clavatipollenites by Couper (1953). In recent years, Clavatipollenites was also found in the middle-late Early Cretaceous in Nei Monggol and Jiangxi Province of China. We also found Retitricolpites in the middle-late Early Cretaceous in Nei Monggol and Jiangxi Province. Retitricolpites, belonging to the Hamamelidaceae, is a primitive type among angiosperms, but it is younger than Clavatipollenites. Therefore, the pollen of Hamamelidaceae may have evoloved fromClavatipollenites, which may have evoloved in turn from that of Magnoliales.  相似文献   

19.
洪友崇1981年建立了京西早白垩世卢尚坟昆虫群,认为Xishania fusiformis(梭形西山蝽)为其中的代表类型,并由此建立1新科1新属1新种。胡世学2002年报道了昆明海口耳材村剖面澄江动物群蠕虫化石Xishania longiusula(长形西山虫),建立1新属1新种。因此,Xishania Hu,2002为Xishania Hong,1981的晚出异物同名,且Xishania fusiformis和Xishania longiusula的分类位置也存在很大争议。文中结合多年来收集的大量梭形西山蝽和长形西山虫标本对二者进行讨论,指出梭形西山蝽与Mesolygaeus laiyangensis(莱阳中蝽)存在区别,代表不同的种类。而长形西山虫属于澄江动物群中的火把虫类,但与模式种存在显著区别,可作为Facivermis(火把虫)一新种。  相似文献   

20.
Abstract:  On the basis of six articulated individuals from the middle to late Albian lithographic limestone at Tlayúa near Tepexi de Rodríguez (Puebla, Mexico), a new species of ophiuroid, Ophiactis applegatei , is described. The material adds to the rather poor record of Early Cretaceous brittlestars and represents the oldest known member of the family Ophiactidae, being based on well-preserved and articulated specimens and thus reasonably well defined morphologically. The rarity of ophiuroids, their complete preservation as well as the unnatural contortions of their arms suggest these specimens to be allochthonous, having been transported into a hostile environment where burial was rapid.  相似文献   

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