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1.
New fossil remains of the proboscidean genus Anancus are described. Among them, a complete skull allows us to revisit for the first time the entire Chadian Anancus fossil record. This genus occurred in the Old World from the late Miocene up to the early Pleistocene. The analysis of dental and cranial characters was allowed individual variations from specific characters to be distinguished. In this study we show that Anancus kenyensis and Anancus osiris are very likely synonym taxa which leads us to emend the diagnosis of A. kenyensis. In addition, this study shows that dental characters in anancines lineage are of little significance for biostratigraphical inference, by contrast to previous works. This study brings new data about the phylogenetical and palaeobiogeographical history of the African anancines.  相似文献   

2.
Stanford, S. D. 2009: Onshore record of Hudson River drainage to the continental shelf from the late Miocene through the late Wisconsinan deglaciation, USA: synthesis and revision. Boreas, 10.1111/j.1502‐3885.2009.00106.x. ISSN 0300‐9483. Fluvial and glacial deposits in New Jersey, Long Island, and the Hudson valley provide a record of Hudson River drainage since the late Miocene. Late Miocene fluvial deposits record southerly flow across the emerged inner New Jersey shelf. In the late Miocene–early Pliocene this drainage incised, shifted southwesterly, and discharged to the shelf south of New Jersey. During late Pliocene or Early Pleistocene glaciation, discharge to the shelf in the New York City area was established. This drainage incised and stabilized in the Early and Middle Pleistocene and remained open during pre‐Wisconsinan (Oxygen Isotope Stage 6? (OIS‐6?)) and late Wisconsinan (OIS‐2) glacial advances. During late Wisconsinan retreat, moraine deposits dammed the valley at the Narrows to form Lake Albany. From 19 to 15.5 kyr BP (all dates in 14C yr), Hudson drainage was directed eastward into the Long Island Sound lowland. Drainage of Lake Wallkill into Lake Albany at 15.5 kyr BP breached the Narrows dam and initiated the unstable phase of Lake Albany, which was controlled by eroding spillways, first on the moraine dam, then on emerged lake‐bottom in the mid‐Hudson valley. Marine incursion between 12 and 11 kyr BP limited fluvial incision of the lake bottom, stabilizing the Quaker Springs, Coveville, and upper Fort Ann spillways. Lowering sea level between 11 and 10 kyr BP allowed incision from the upper to lower Fort Ann threshold. Sediment eroded by lake outflows between 15 and 10.5 kyr BP was trapped in the glacially deepened lower valley. Little inland sediment reached the shelf after 20 kyr BP.  相似文献   

3.
Pterospermumocarpon (Type: P. kalviwadiensis), a new morphogenus of fossil fruits showing resemblance with fruits of extant Pterospermum Schreb. (Malvaceae s.l.), is described from the Sindhudurg Formation (Miocene) at the Kalviwadi Village, Sindhudurg District, Maharashtra, India. Diagnostic feature of the fossil taxon is the dehiscent pentalocular capsule with five distinct sutures and imprints of winged seed-like structures in the locules. Recent modifications in the systematics of the Malvales, their fossil record, and the distribution and migration of Pterospermum and other malvalean taxa in the context of the Indian subcontinent are discussed.  相似文献   

4.
This is the first record of a representative of the organic-walled dinoflagellate cyst genus Palynodinium from the New Zealand region. Previously, Palynodinium grallator has been reported from two sites in offshore Tasmania during Ocean Drilling Program, Leg 189. The new species Palynodinium minus is found consistently in latest Maastrichtian? and earliest Danian strata (latest Haumurian–earliest Teurian) in two sections located along the mid-Waipara and Grey rivers, North Canterbury, South Island. It occurs in a narrow stratigraphic interval at the Cretaceous–Paleogene transition and is potentially a stratigraphically important index species in the region. Its range coincides with that of the global earliest Danian index fossil Carpatella cornuta and a basal Danian acme interval of Trithyrodinium evittii, and is correlated to ca. 65.5–65.2 Ma. Its highest occurrence is at the base of an acme interval of Palaeoperidinium pyrophorum. It has only been recorded from sections composed of siliciclastic shelf sediments, suggesting that it might have had a palaeoecological preference for relatively near-shore environments.  相似文献   

5.
In eastern North Island New Zealand, oblique subduction of the Pacific Plate beneath the Australian Plate is associated with strain partitioning. Dextral along-strike component of displacement occurred first at Early Miocene major faults within the eastern fore-arc domain. These faults were active from Early Miocene to Pliocene times. Since Pliocene times, most of the movement occurs at western faults such as the Wellington Fault. The latter joins the back-arc domain to the north. The jump of wrench faulting is related to the oblique opening of the back-arc domain. Both phenomena are impeded southwards by the Hikurangi oceanic plateau entering the subduction zone. To cite this article: J. Delteil et al., C. R. Geoscience 335 (2003).  相似文献   

6.
New Mesozoic Mesopsychidae(Mecoptera)from Northeastern China   总被引:2,自引:2,他引:0  
<正>The Mesozoic family Mesopsychidae Tillyard,1917 presently consists of seven described genera and 13 species from the mid-Triassic to the Early Cretaceous of Australia,South Africa and Eurasia.In the present paper one new genus and three new species of fossil mesopsychids are described that add significant distributional and stratigraphic extensions to the family.This finding documents the first formal record of fossil Mesopsychidae in China.Both Lichnomesopsyche gloriae gen.et sp.nov.and L.daohugouensis gen.et sp.nov. were found from the Middle Jurassic Jiulongshan Formation of Inner Mongolia,whereas Vitimopsyche kozlovi sp. nov.,of mid Early Cretaceous age,was collected from the Jehol Biota of northern Hebei Province.This new,well-preserved material from China reveals complete and previously unknown body features,including head, antennae,mouthparts,legs and abdomen.The delicate and long proboscides of these new taxa indicate that they were feeding on externally exposed,nutrient-rich fluids of gymnospermous ovulate fructifications,and incapable of piercing surface epidermis-attributable principally to the absence of stylets.These proboscides originated, perhaps multiply,among basal Mecoptera and are functionally and structurally convergent with equivalent mouthparts borne by fossil and extant Diptera,Lepidoptera,Neuroptera and Coleoptera.  相似文献   

7.
A new genus and species of fossil elaterid namely Clavelater ningchengensis gen. et sp. nov. assigned to the subfamily Protagrypninae based on one specimen from the Middle Jurassic Jiulongshan Formation near Daohugou Village, Ningcheng County, Inner Mongolia, northeastern China is described and illustrated. This specimen displays a pair of large antennae that easily differs from those of most Mesozoic elaterids. There are around 36 species within 20 genera referred to elateroids described from the Early Jurassic to Miocene of China, with another three species within three genera reviewed, but the taxonomic assignment of at least seven species within three genera is doubted. The systematic position of fossil elateriform beetles reported from China is reviewed and the evolution of Mesozoic elateroids briefly discussed.  相似文献   

8.
Twelve fossil species of Proteaceous pollen, predominantly attributable to Proteacidites and Beaupreaidites, were recovered from the Maastrichtian-Paleocene sedimentary succession of the Garden Cove Formation on Campbell Island, the southernmost landmass of the Zealandia continent. Among these are two new species, Proteacidites campbellensis and Proteacidites hortisinus. The high diversity of Proteaceae pollen in the sediments encompassing the Cretaceous-Paleogene boundary on Campbell Island is consistent with the fossil record from neighbouring landmasses but strongly contrasts with the impoverished record of the family in the extant New Zealand flora. Examples of Beauprea- and Knightia-like pollen in the Campbell Island assemblages confirm the presence of these lineages on Zealandia by the end of the Cretaceous and suggest that their present endemism in New Caledonia and New Zealand can be explained in terms of relictual vicariant distributions, perhaps modified by northward tracking of warmer climates on Zealandia through the Cenozoic.  相似文献   

9.
The New Hebrides archipelago is a complex reversed-arc system that can be divided into four major volcanic provinces. The Western Belt is an Early to Middle Miocene extinct volcanic arc that, as a result of polarity reversal, is now incorporated into the frontal arc of the present-day configuration. The Eastern Belt initially received detritus in the early Middle Miocene from a tholeiitic arc complex but in the Mio-Pliocene became the locus of a more calc-alkaline arc volcanism. Volcanic activity then ceased in the Eastern Belt but is well-represented as a third and largely submerged Marginal Province through the Pliocene into the Early Pleistocene. The present volcanic line, the Central Chain, is essentially a continuation of the Marginal Province volcanism into Recent times.Initial tectonic events in the New Hebrides arc were associated with the regional disruption in the Middle Miocene of an east-facing system, with consequent termination of Western Belt arc volcanism. The Western Belt remained as a landmass during the lowermost Late Miocene but subsided following a Late Miocene renewal of island arc volcanism to the east. This latest phase was coeval with initial expansion of the North Fiji Basin and marked the advent of the New Hebrides as a westwards-migrating reversed-arc system. During arc migration there were apparent hiatuses in island arc volcanism, the most notable being a Middle Pliocene to Late Pleistocene period of quiescence in the central sector.Tectonism in the Early Pleistocene-Recent raised the fore-arc, brought about rifting and extension to the rear and concentrated volcanism along the presently-active Central Chain.  相似文献   

10.
张伟  高克勤 《古地理学报》2014,16(2):205-216
离龙类是一在形态和生态适应上高度特化的水生—半水生爬行动物双孔亚纲的灭绝支系。离龙目的地理分布局限于北半球,地史分布从侏罗纪一直延续到中新世。辽西是中国最为重要的离龙类化石产地,化石点主要分布于凌源、义县、朝阳和建昌4个地区,尤其以义县地区化石点的分布最为密集。目前辽西已经发现的离龙类包括3科4属5种,其中潜龙和满洲鳄2属的化石仅发现于义县组,而伊克昭龙与戏水龙2属的化石则仅见于九佛堂组。化石证据表明,白垩纪离龙类在辽西范围内的延展分布呈现一个自西向东、由南向北的地理地史演化过程。化石证据也表明辽西的离龙类在较短的时期和较窄的地域范围内经历了一个快速分异演化的过程。长颈潜龙类和短吻满洲鳄类在辽西同时首现于凌源义县组大新房子层,并先后灭绝于义县组的大康堡层和金刚山层。潜龙类最后出现的大康堡层的火山凝灰岩层密集保存了数以千计的潜龙类个体,可能代表该类群于早白垩世发生了与火山喷发活动紧密相关的集群灭绝事件。而后,短吻戏水龙和长吻伊克昭龙同时首现于九佛堂组第2段,并于该组第3段沉积时期内灭绝。整个辽西地域内的离龙类的分布从126~120Ma,在经历了大约6Ma的快速分异演化之后,均于早白垩世阿普第期灭绝。  相似文献   

11.
12.
Situated at the easternmost area of the Late Mesozoic Jehol Biota, China, abundant fossils, including invertebrates, vertebrates and plants, were collected from the Early Cretaceous Yingzuilazi Formation of the Baishan Basin, southeastern Jilin. The faunal remains from this formation distinctly belong to the Early Cretaceous Lycoptera–Ephemeropsis–Eosestheria assemblage of the Jehol Biota. Based on the gross leaf morphology and epidermal structures, two new species and one indeterminate species of genus Solenites(Czekanowskiales), S. baishanensis sp. nov., S. gracilis sp. nov. and S. sp. are described in this paper. This is the first fossil plant of Czekanowskiales reported from this new fossil locality of the easternmost area of the Late Mesozoic Jehol Biota, China. The new discovery contributes to improve our knowledge for understanding of leaf morphology, epidermal characters and diversity of this genus during the Early Cretaceous time, and extends geologic and geographic distribution of Solenites in northern China and Eurasia. Along with consideration of associated plant and faunal assemblages and sedimentology, we suggest that the regional climate was warm and moderately humid with seasonal temperature and precipitation variations in warm–temperate zone during the Early Cretaceous.  相似文献   

13.
A new marine reptile record for the Upper Cretaceous of the Chatham Islands is described from the Takatika Grit. Incomplete mosasaur and plesiosaur remains represent the first record of marine reptiles from the Chatham Islands and wider New Zealand. Present among the myriad bones are elasmosaurid plesiosaurs and mosasaurine mosasaurs. This assemblage is comparable to the New Zealand marine reptile record and represents apex predators that flourished in a zone of upwelling in a Late Cretaceous southern high-latitude ecosystem.  相似文献   

14.
Twenty-seven moss specimens collected from the Guangfayong section (Early Miocene,22.1 Ma) of the Weichang District,North China were investigated in the present study.Based on the morphological and anatomical features of gametophytes,all specimens were found to belong to three species:Leptodictyum riparium,Drepanocladus subtrichophyllus sp.nov.,and Amblystegium varium,all of which belong to the family Amblystegiaceae.The microhabitats and living environments of fossil mosses were also investigated based on comparison with living mosses.The results suggest that these mosses grew primarily at the edges of rivers,streams,and lakes and favored being submerged in streams or lakes in the Weichang District in the Early Miocene.  相似文献   

15.
New species of a gecko of the genus Euleptes is described here—E. klembarai. The material comes from the middle Miocene (Astaracian, MN 6) of Slovakia, more precisely from the well-known locality called Zapfe`s fissure fillings (Devínska Nová Ves, Bratislava). The fossil material consists of isolated left maxilla, right dentary, right pterygoid and cervical and dorsal vertebrae. The currently known fossil record suggests that isolation of environment of the Zapfe`s fissure site, created a refugium for the genus Euleptes in Central Europe (today, this taxon still inhabits southern part of Europe and North Africa—E. europea), probably resulting from the island geography of this area during the middle Miocene. The isolation of this territory might have facilitated allopatric speciation.  相似文献   

16.
Mayflies are very rare in the British fossil record. The first nymph to be found, Schistonotorum wallisi gen. et sp. nov., is described from the non-marine Lower Cretaceous of southeast England. This Early Barremian find is from the Upper Weald Clay Formation at Smokejacks brickworks, Surrey. It is preserved as an adpression in concretionary sideritic ironstone from the upper insect bed exposed in the northeast face of the pit. The palaeoecological significance of this record is discussed.  相似文献   

17.
A new fossil leaf impression is described from the Early Miocene sediments of Kasauli–Kalka road section, Himachal Pradesh. The characteristic leaf venation pattern suggests that it has a close affinity with Ficus L., particularly with F. racemosa L. (= F. glomerata Roxb.). Its presence indicates a warm and humid climate in the region during the deposition of sediments, in contrast to the present day cooler and less humid climate.  相似文献   

18.
The first fossil echinoids are recorded from the Cayman Islands. A regular echinoid, Arbacia? sp., the spatangoids Brissus sp. cf. B. oblongus Wright and Schizaster sp. cf. S. americanus (Clark), and the clypeasteroid Clypeaster sp. are from the Middle Miocene Cayman Formation. Test fragments of the mellitid clypeasteroid, Leodia sexiesperforata (Leske), are from the Late Pleistocene Ironshore Formation. Miocene echinoids are preserved as (mainly internal) moulds; hence, all species are left in open nomenclature because of uncertainties regarding test architecture. All Miocene taxa are recorded from single specimens apart from the 27 assigned to Brissus. Schizaster sp. cf. S. americanus (Clark) is compared to a species from the Oligocene of the south‐east USA. Brissus sp. cf. B. oblongus is close in gross morphology to a taxon from the Miocene of Malta. Leodia sexiesperforata is identified from fragments with confidence, being the only extant Antillean sand dollar with elongate ambulacral petals that is limited to carbonate substrates. The Miocene echinoids of Grand Cayman, although of limited diversity, are mainly comprised of genera common in comparable mid‐Cenozoic carbonate environments. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

19.
A new fossil fruit wing of Shorea Roxb. belonging to the family Dipterocarpaceae is described from the Early Miocene sediments of Kachchh, Gujarat. It resembles best the extant species Shorea macroptera Dyer, which is a prominent member of the tropical evergreen forests of the Malayan Peninsula. The present finding, along with the other megafossil records described from the same area, indicates a typical tropical vegetation with a warm and humid climate at the time of deposition in contrast to the present day xeric vegetation in the area. As the family Dipterocarpaceae no longer exists in western India, it is essential to discuss the time of its extinction and possible causes, which may include drastic changes in the climate of the region. The present finding also supports the theory of a Malaysian origin for the family in contrast to the hypothesis of a Gondwanan origin.  相似文献   

20.
Earwigs (Dermaptera) are scarce in the fossil record. Over a hundred fossil dermapterans have been described to date, the oldest undisputed fossils dating back to the Late Triassic. Here, two new species, Phanerogramma kellyi sp. nov. and Brevicula teres sp. nov., are described from the Rhaetian and Sinemurian of England, respectively, from isolated tegmina. The features that distinguish fossil earwig fragments from other insect remains are discussed. A catalogue of fossil and subfossil Dermaptera is appended.  相似文献   

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