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1.
Two new fossil charophyte species from middle Miocene lacustrine deposits of Moneva (Ebro Basin, NE Spain) are described and illustrated. Sphaerochara miocenica nov. sp. is represented by medium sized gyrogonites with a characteristic spheroidal shape and ornamented with numerous small and regularly spaced tubercles arranged along the spiral cells. Several specimens show an unusual carbonate encrusted layer that covers completely or partially the gyrogonite. Psilochara monevaensis nov. sp. is characterized by large gyrogonites, with typical prolate shape and protruding apical poles. A second population of S. miocenica nov. sp. from a distant early upper Miocene lacustrine basin located in the Middle East (Bekaa Valley, Lebanon), identified in a previous study as Sphaerochara sp., is described and illustrated here, allowing the comparison of these distant populations. Ecologically, the associated fauna and facies from both localities suggest that these taxa grew in very shallow athalassic lakes. Interestingly, S. miocenica nov. sp. having a wide geographic distribution in peri-Mediterranean lakes with variable salinity, may become a fossil guide for the Miocene, providing at the same time important palaeoecological information.  相似文献   

2.
Post-Cretaceous examples of Electridae, a primitive family of cheilostome bryozoans, are poorly represented in the fossil record, probably because of their thinly calcified zooids and preference for nearshore environments. Two new electrid species are here described from the Lower Miocene (Burdigalian) of Pontpourquey, Aquitaine, France: Electra triaurata nov. sp. and Electra aquitanica nov. sp. Both species belong to extant species groups, the E. indica and E. biscuta groups, respectively, that presently occur in the Indo-Pacific; both are the only fossil examples of these species groups. Whereas E. triaurata nov. sp. has uniserial colonies, zooids with porous gymnocysts, three flattened spines and basal windows allowing etching of the substrate to produce the trace fossil Leptichnus, E. aquitanica nov. sp. has multiserial colonies and zooids with a proximal gymnocyst bearing 2 to 5 spines.  相似文献   

3.
The mass occurrence of turritelline gastropod shells from the Lower Miocene of southern Germany allows for detailed studies of their palaeoecology, transport mechanisms, preservation potentials and the reconstruction of nutrient regimes. Changes in the fabric of the gastropod-dominated beds are used to reconstruct a generally deepening environment corresponding to the Lower Miocene transgression within the Upper Molasse Sea of the North Alpine Foreland Basin. The sedimentary succession ranges from chaotically arranged, densely packed and near-shore transported; wave-influenced deposits showing bimodal shell orientations; more widely dispersed shells showing a uni-directional orientation; and dispersed shells showing diverse orientations. The shells often show damage to the apex and aperture though it is not clear whether this is due to predation events, pagurisation or abrasion due to transport. An outstanding feature is the replacement of aragonite shells by calcite leading to internal vugs as well as modulating the outer shell surface morphology. The high density of turritelline gastropods indicates a nutrient-rich palaeoenvironment at the northern edge of the Molasse Sea.  相似文献   

4.
The Late Miocene Italian brackish Loxoconchidae are herein discussed and illustrated. Three genera and two subgenera have been recognized in the brackish Italian basins: Loxoconcha, Loxocorniculina, Loxoconchissa (Loxoconchissa) and Loxoconchissa (Loxocaspia). Taking into account the diagnostic characters of several Loxoconchidae genera, in this paper Loxocorniculina is raised at a generic rank, Loxocaspia is confirmed as a subgenus within genus Loxoconchissa and several new species are established: Loxoconchissa (Loxoconchissa) kinoi nov. sp., Loxoconchissa (Loxocaspia) cosentinoi nov. sp., Loxoconchissa (Loxocaspia) nuda nov. sp., Loxoconchissa (Loxocaspia) punctata nov. sp., Loxoconchissa (Loxocaspia) reticulata nov. sp., Loxoconchissa (Loxocaspia) tuberosa nov. sp. and Loxoconchissa (Loxocaspia) velonae nov. sp. Loxocorniculina is a typical Paratethyan genus which widespread into the Palaeo-Mediterranean during the late Messinian Lago-Mare event. Loxoconchissa was known to be widespread only in the Paratethyan realm and in this paper it is signalled for the first time in the Late Tortonian-early Messinian of Italy. The palaeobiogeography of these genera is discussed and the observed continuous distribution of Loxocorniculina against the disjunct distribution of Loxoconchissa leads to suggest that this latter genus underwent a passive dispersal via aquatic birds.  相似文献   

5.
Tao Deng 《Geobios》2008,41(6):719
Ningxiatherium euryrhinus sp. nov. is a relatively large elasmothere rhino from the Linxia Basin in northwestern China found in the early Bahean, which corresponds to the early Vallesian (MN 9), ca. 11.1 Ma. It is much larger than the extant Ceratotherium simum and has a single horn. Ningxiatherium is similar to the late Miocene Parelasmotherium from Gansu and Shanxi, but differs in having partially ossified nasal septum, terminal nasal horn boss, shallower nasal notch above the P3/P4 boundary, and much shorter premolars. N. euryrhinus sp. nov. differs from N. longirhinus from the late Miocene of Zhongning, Ningxia in northwestern China by its larger size, relatively wider nasals, shallower nasal notch, and sub-quadrangular occlusal surface of M3. In the Linxia Basin, the other early late Miocene (Bahean or Vallesian) elasmotheres are known from complete skulls or isolated teeth. They include two genera and three species: Parelasmotherium linxiaense, P. simplum, and Iranotherium morgani. They lack a nasal septum, but Ningxiatherium has one. The age of N. euryrhinus is early late Miocene based on direct association with biochronologic indicator taxa, such as Dinocrocuta gigantea, Hipparion dongxiangense, and Chilotherium primigenius. N. euryrhinus is more primitive than N. longirhinus sp. nov. in having a sub-quadrangular M3, a shallower nasal notch, and the presence of DP1 in adults.  相似文献   

6.
Seven bryozoan species belonging to the Order Rhabdomesida and Order Cystoporida are described from the Permian deposits exposed near the small town of Deh-e Mohammad, Shotori Mountains (northeastern Iran): Rhabdomeson cf. consimile Bassler, Pamirella nitida Gorjunova, Clausotrypa conferta Bassler, Streblotrypa (Streblotrypa) elegans Sakagami, Streblotrypa (Streblascopora) supernodata nov. sp., Cystodictya sp., and Filiramoporina cf. kretaphilia Fry and Cuffey. The described fauna identifies the age of the Jamal Formation at the locality near Deh-e Mohammad as Lower Permian. It displays palaeobiogeographic connections to the Lower Permian of Pamir (Tajikistan), Indonesia, Thailand and Kansas (North America).  相似文献   

7.
Willmer  Bernd J.  Rasser  Michael W. 《Facies》2022,68(4):1-31
Facies - The Devonian to Carboniferous (DC) transition coincided with a green-to-ice house climatic shift, anoxia, disappearance of lower latitude carbonate banks, and turnover from warm-to-cool...  相似文献   

8.
Anatomic modification in evolution process of mammals was closely correlated with the environmental changes, and become the powerful evidence for reconstructing the palaeoenvironment shaped their evolution. Rhinocerotid fossils are important indicators of the ecosystems inhabited by the mammalian faunas. Here, we first described remains of two rhinocerotids from the terminal Miocene Zhaotong Basin, the most recent hominoid locality in South China, including Acerorhinus lufengensis and Rhinocerotini gen. et sp. indet. New remains of A. lufengensis display a short crochet and antecrochet, expanded lingual cones, and rounded labial wall of the trigonid and talonid. These characteristics demonstrate its feeding habits of grazing brush and high grass. The limb bones of Rhinocerotini gen. et sp. indet. enable to live in an open habitat in having the following characteristics: the Mc II facet of Mc III is large, oval, flattened, and nearly vertical in direction; the femur exhibits a very large trochanter tertius and two nearly parallel asymmetrical ridges of the distal patella trochlea. The rhinocerotid fossils described herein provide a substantial evidence of the presence of mosaic environment, and the grassland should patches within or along the margin of the forest in the terminal Miocene Shuitangba locality.  相似文献   

9.
Quantitative and qualitative analyses based on planktonic foraminifera of two sections (Oued Derdoussa and Djebel Meni) from lower Chelif basin (northern Algeria) enable us to identify for the first time a sequence of bioevents calibrated with the geomagnetic polarity time scale. The identified bioevents of late Miocene formations are useful for a high-resolution correlation in the whole western Mediterranean at local and regional scales. In particular, this work reveals that the sequence covers an interval of time that extends from the upper Tortonian up to the pre-evaporite Messinian period. Indeed, the base of the succession starts with a change in the coiling direction (from dextral to sinistral) of Neogloboquadrina acostaensis as the first bioevent. This later corresponds to the bioevent (1–8) assigned to the Tortonian sediments. This period is marked by the presence of Globorotalia menardii in sinistral coiled form that was substituted gradually with dextral coiled. The Tortonian/Messinian (T/M) boundary coincides to some extent with a sharp replacement of G. menardii group (I and II) with the first common occurrence (FCO) of Globorotalia miotumida plexus few meters below the development of the Tripoli diatomite formation (bioevent 9). This later is dominated mainly by highly convex species (G. miotumida plexus) marked by the presence of Globorotalia mediterranea in contrast with the marly formation at the base of the section. In this part, the recorded bioevents (10 to 17) are assigned to the Messinian sediments. Thus, the Tripoli formation shows the influx of Globorotalia nicolae and a small incursion of the dextrally coiled of Globorotalia scitula at the top of Oued Derdoussa section as a local bioevent that may be related to the local palaeoenvironment. We notice the absence of the change in the coiling from sinistral to dextral of N. acostaensis during the upper Messinian, this may be due to the coincidence of this bioevent with the barren levels.  相似文献   

10.
From the Bavarian Early/Middle Miocene (MN5) site Sandelzhausen, nine species of carnivoran mammals are identified including the hemicyonine ursid Hemicyon stehlini, the amphicyonids Amphicyon cf. major and Pseudarctos bavaricus, the mustelids Ischyrictis zibethoides and Martes cf. munki, the mephitid Proputorius pusillus, the viverrid Leptoplesictis cf. aurelianensis, the felid Pseudaelurus romieviensis, and finally the recently described barbourofelid Prosansanosmilus eggeri. With these taxa present, Sandelzhausen shows a carnivoran community typical, though deprived, for the Lower to Middle Miocene of Europe, but different from roughly contemporary Mediterranean faunas such as those from Çandir or Pa?alar in Turkey.  相似文献   

11.
The construction of the Neufeld tunnel in Bern city (2006–2008) led to the discovery of fossil mammals in the vicinity of the historical site of Engehalde. The study of the whole available sample led to the distinction of two mammal assemblages: (1) the historical level with the rhinocerotids Diaceratherium lemanense and D. aginense, and the ruminant Andegameryx cf. laugnacensis; (2) the Neufeld level with the artiodactyls Dremotherium feignouxi and Cainotherium sp., the carnivore Plesiogale angustifrons, and the glires Eucricetodon cf. aquitanicus, Peridyromys sp., and Prolagus vasconiensis. These two assemblages attest to a latest Aquitanian age (MN2b) for the last deposits of the ‘Lower Freshwater Molasse’ in the area. The palaeoecological analysis of the faunas indicates either the co-occurrence or the very short-termed succession of assorted terrestrial environments, ranging from forested habitats nearby water bodies or nearby steady rivers to open well-drained habitats within the hinterland.  相似文献   

12.
Sixty-four silicified fossil woods were collected from the Early Miocene Upper Coal-bearing Formation of Janggi Group in Pohang City, the Korean Peninsula. Out of them 23 specimens were identified as gymnosperms and 27 specimens as dicotyledons. The taxa identified include Picea palaeomaximowiczii Watari, Taxodioxylon cunninghamioides (Watari) Watari, T. sequoianum (Merckl.) Gothan, Fagus hondoensis (Watari) Watari, Cercidiphyllum sp., Camellia japonoxyla Suzuki et Terada, Distylium chiharu-hirayae Suzuki et Terada, Aesculus sp., Wataria miocenica (Watari) Terada et Suzuki and W. parvipora Terada et Suzuki. All of these species are reported for the first time from the Tertiary basins of Korea. Compared with those of the Miocene Formations in Japan, most taxa we found are common between the paleo-floras in Korea and Japan during the Early to Middle Miocene.  相似文献   

13.
This paper deals with the only latest Miocene fish fauna so far recognized in Portugal and probably in western Europe through more than 10,000 teeth and many other remnants collected in the Latest Miocene, Esbarrondadoiro Formation (Alvalade basin, southern Portugal). A large number of teeth reported to the family Dasyatidae (ca. 46% among the Myliobatiforms) are described. Several forms were recognized. The concerned deposits are particularly rich in modern type, close to still extant selachian forms. This is confirmed by the presence of different species of Dasyatis. From the thermic point of view, Alvalade basin marine fishes point out to a decrease in the prevailing thermic conditions. The still abundant Dasyatis are in contrast to the rarity of Raja, a genus which suggests temperate or cold, or deeper hence colder waters. Moderately warm water conditions predominated, less than in Tortonian of Lisbon, more than exist today near the Portuguese coasts. The occurrence ratios of the taxa concerned among the exploited sites are quantitatively different. This points out to different paleoenvironmental conditions. The Dasyatis had a litoral/neritic bathymetric distribution and a benthic way of life. However, the Esbarrondadoiro pattern is very different from those from Santa Margarida and Vale de Zebro, which are nearly identical between them as far as Dasyatis gr. gigas and Dasyatis sp. are concerned: Dasyatis gr. gigas may suggest less warm waters, and this is very much compatible with other data that indicate a deeper environment and hence colder waters for Esbarrondadoiro.  相似文献   

14.
Abstract

The Neogene Fortuna Basin (Murcia Region, SE Spain) is rich in microvertebrate sites. Its continental sections include localities extended from the middle Turolian (MN12) to the early Ruscinian (MN14). However, there are few works dealing with the taxonomy of these fossil assemblages. In this paper we provide a complete taxonomic study of the rodents and insectivores from three levels (ROM-2B, ROM-2C and ROM-3A) within the Romerales section. We infer a late Turolian age (late Messinian) for these levels, among which the richest and most diverse level is ROM-C, including at least 11 different taxa. In addition, the paleoecological analysis of these fossil assemblages suggests the dominance of open herbaceous meadows under temperate climate during the formation of these sites, with a slight decrease in temperature and humidity from ROM-2B to ROM-2C.  相似文献   

15.
<正>1988年吴文裕描述了产自新疆准噶尔盆地北缘铁尔斯哈巴合地点哈拉玛盖组下部层位的一枚圆齿鼠的P4,定名为Sinomylagaulus halamagaiensis。1997年中国科学院古脊椎动物与古人类研究所新疆考察队又在铁尔斯哈巴合的哈拉玛盖组下部层位中采集到两枚p4。1988年的研究工作仅依据一枚上前臼齿(P4),标本的稀缺决定了当时研究成果的局限性。新材料无疑为认识新疆的圆齿鼠类提供了新的信息  相似文献   

16.
丰富的化石记录显示中生代和新生代紫萁属在北半球广泛分布.本文描述了发现于福建中中新世佛昙群的紫萁属一新种:漳浦紫萁(Osmunda zhangpuensis Z.X.Wang and B.N.Sun,sp.nov.).化石小羽片保存完好,呈线状披针形,边缘具齿,羽状脉序.在该属现生种中,当前化石种与现生种Osmunda...  相似文献   

17.
A new fossil species of Vallisneria (V. janecekii Bogner & Kva?ek, sp. n., Hydrocharitaceae) is reported from Early Miocene freshwater lake deposits of the North Bohemian brown coal basin (Czech Republic). It is based on a single fragmentary sterile plant bearing two clusters of ribbon-shaped widely serrulate leaves on a short rhizome. It is a potential producer of seeds described from equivalent and slightly older deposits in Saxony (Germany) as Vallisneria ovalis Mai.  相似文献   

18.
We report here a new fossil primate from the middle Miocene of Argentina. The material consists of isolated teeth, mandibular fragments, and a talus. The fossils were collected in the Collón Cura formation at Cañadón del Tordillo in Neuquén Province. An age of 15.71 ± 0.07 Ma has been reported for the Pilcaniyeu Ignimbrite, which lies just below the paleosols in which the fossils were found. This material is thus the youngest occurrence of fossil primates in Argentina (hitherto documented in the Santacrucian and older land mammal ages) but still is older than the middle Miocene platyrrhine primates from La Venta, Colombia, in particular the pitheciins Nuciruptor and Cebupithecia. The material is recognized as a new genus and species of Pitheciinae, Propithecia neuquenensis. The mesiodistally compressed, high-crowned incisors are specialized and similar to species in the tribe Pithecini and to the nonpitheciin Soriacebus (early Miocene, Patagonia). We rule out a phylogenetic relationship to the latter because of differences in molar morphology. Propithecia does, however, fit well into the pattern of pitheciin evolution, being more derived than the middle Miocene pitheciin Nuciruptor but not as much as another middle Miocene taxon, Cebupithecia. As such, this makes Propithecia the oldest taxon that can be confidently placed within this modern New World monkey subfamily. By analogy with the molar structures and diets of extant platyrrhines, Propithecia has a molar structure consistent with a variety of low-fiber diets ranging from fruit and gum to seeds. Its incisors suggest seed-eating in much the same way as extant pitheciins, like Pithecia. The talus resembles that of Callicebus, suggesting arboreal quadrupedal locomotion. Am. J. Primatol. 45:317–336, 1998. © 1998 Wiley-Liss, Inc.  相似文献   

19.
Tao Deng 《Palaeontology》2004,47(6):1427-1439
A new species of the genus Alicornops, A. laogouense , from Laogou in Hezheng County, Linxia Basin, Gansu, China, is described. It is mid-sized in the subfamily Aceratheriinae, but is the largest known species of Alicornops . It represents the first discovery of the genus in Asia. The Middle Miocene fauna bearing A. laogouense is contemporaneous with the Dingjiaergou fauna of Tongxin, Ningxia, China, and its age corresponds to MN 6 in Europe. The discovery of A. laogouense in the Linxia Basin implies that Alicornops dispersed from Europe to Asia. During MN 6 times it was relatively widespread throughout Eurasia. Alicornops laogouense lived in open woodland rich in lakes and rivers.  相似文献   

20.
We report the results of quantitative and qualitative investigations of the ostracod fauna of the profundal benthos of Loch Ness, an oligotrophic lake in Scotland, UK. Six ostracod species were recorded from profundal samples: Candona angulata, C. candida, Cryptocandona reducta, Cypria ophthalmica, Cyclocypris ovum and Potamocypris smaragdina. In addition, Psychrodromus robertsoni was found in fish gut contents. The mean density of profundal ostracods was 262 individuals m2, with an average Brillouin's Diversity of 0.7. A weak inverse relationship between fish body weight and the number of ostracods eaten is reported for Arctic charr, Salvelinus alpinus.  相似文献   

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