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1.
In the lignite sediments of Pietrafitta (Tiberino Basin, Umbria, Central Italy), a rich fossil assemblage of vertebrate, invertebrate and plant remains belonging to the Farneta Faunal Unit (Late Villafranchian, Early Pleistocene) was collected. Among them fossil beaver cranial remains are relatively abundant. Western-Central Europe Villafranchian beaver remains were assigned to C. plicidens by some authors because molar occlusal surface patterns show complex enamel crenulations. Several recent authors have classified them as C. fiber while analysing other morphological patterns. Our samples have been compared to Plio-Pleistocene fossil remains and to living European populations of the genus Castor. New morphometric parameters on molar occlusal surfaces have been defined and statistical analyses (One-Way MANOVA, Principal Component Analysis and Canonical Discriminant Analysis) have been performed on them. The results point out a subspecific separation between the Late Villafranchian beaver of Pietrafitta, Quarata and San Giovanni in Valdarno (Umbria and Tuscany) and C. fiber populations. St. Vallier (France) Late Pliocene and Mosbach 2 (Germany) Middle Pleistocene beavers classified respectively by Viret and Friant as C. plicidens, show a C. f. fiber molar teeth pattern. Therefore, C. fiber plicidens did not occur in Central-Western Europe and this subspecific name may be used only for the local populations of Valdarno and Tiberino Basin (San Giovanni in Valdarno, Quarata, Pietrafitta and a few localities of the same area), at that time peripheral populations, probably semi-isolated during the Late Villafranchian, and at the southern limit of the geographic range of C. fiber.  相似文献   

2.
Octodontoidea is the most diverse group of caviomorph rodents. The systematics of most of the fossil representatives has been essentially based upon dental characters. Described here is an almost complete skull with dentition assigned to Prospaniomys Ameghino based upon its dental morphology. The specimen comes from the Sarmiento Formation at Pampa de Gan Gan (central Patagonia, Argentina), assigned to the Colhuehuapian SALMA (early Miocene). The most remarkable features are in the posterior portion of the skull, some of them shared with the modern octodontids and interpreted as specialized by previous authors, which contrast with the generalized dental morphology. These combined features were not previously known in other octodontoids. The comparisons with other fossil and extant members of the superfamily suggest that the characters traditionally used to associate Prospaniomys with the echimyids are very probably plesiomorphies. Prospaniomys would represent an early diverging lineage more closely related to modern octodontids than to echimyids, in which cranial structures evolved more rapidly than dental and mandibular ones.  相似文献   

3.
The rhynchonellid brachiopod species Cryptopora lovisati(Dreger, 1911) has been identified in the Middle Miocene sandy deposits of France, and its ontogeny and variability are described. This is the first record of the genus Cryptopora Jeffreys from France, although several species of Cryptopora have been already reported from other regions of Europe. Being known since the Lower Palaeocene, Cryptopora is widely distributed in modern seas, ranging from about 60 m down to over 4000 m, and is represented by six extant and about 12 fossil species. C. lovisati has been interpreted as relatively shallow water species living attached to the sediment by a long pedicle. The affinity between C. lovisati and Recent C. curiosa Cooper is discussed.  相似文献   

4.
Hypsosteiromys is the only New World porcupine that shows a tendency to hypsodonty. It is recorded exclusively from the Colhuehuapian Age (Early Miocene) of central Patagonia (Argentina). In addition to the type species, a second one, Hypsosteiromys nectus(AMEGHINO, 1902), is recognized, from the southern cliff of Colhuehuapi Lake (Chubut province). It differs from the type species in the lesser development of the anterolabial and posteroflexid notches of the m1-3, shorter p4 and dp4, and more slender incisors. Dental morphology suggests that the species of Hypsosteiromys lived in more open areas than most fossil and living Erethizontidae.  相似文献   

5.
A new species of Firmiana Marsili is recognized and described based on capsules from the Late Miocene Lincang flora of Yunnan, China. Firmiana yunnanensis nov. sp. is represented by opened, dehiscent, membranous follicles with a weak, sinuous midvein, obtuse secondary veins and thick marginal vein. The follicles conform in shape and venation with those of extant species of Firmiana, a genus now distributed in eastern Africa, Indo-Malaysia, and eastern and southeastern Asia. This fossil species occurred within the native distribution of extant Firmiana species. It provides new information on fossil history, paleoecology, as well as on the plant diversity of the Lincang flora.  相似文献   

6.
A systematic revision of Italian Messinian Prolagus findings has been performed, evidencing the presence of four different species. Comparative analyses allowed their separation in two groups corresponding to two different palaeobioprovinces characterized by distinct faunal affinities, source areas and tempos and modes of colonization. Such considerations allowed to cast a new light on the palaeobiogeography and the migration pathways of continental vertebrate faunas in the Mediterranean area during Messinian, and to give a new importance to the genus Prolagus as a palaeobiogeographical marker.  相似文献   

7.
Remains of Albertona balkanica from the Early Miocene clays of eastern Serbia have shifted the range boundary of this species in direction of Central Europe. The peculiarities in tooth morphology were used for comparison and defining of the possible evolutionary connection with other representatives of fossil Ochotonidae. Due to the similarity with fauna of Aliveri in Greece, the association of small mammals of Snegotin (which includes Albertona) was included in the MN4 zone.  相似文献   

8.
9.
The dP4 of Desmanella engesseri Ziegler, 1985 from a maxillary which includes the P2 and P3 in crypt, the P4 in eruption and fully erupted dP4 and M1, is described from Petersbuch 28 (Germany; Lower Miocene, MN3/4). The maxillary was studied using X-ray microtomography to make detailed images of the internal and external features of the sample. This is the first record of a dP4 from Desmanella Engesser, 1972. Its shape is unique for fossil talpids, possessing the apomorphic feature of replacing the protocone with a large lingual cingulum. The functional use of deciduous teeth and the process that led to the complete loss of milk teeth in extant talpids are discussed.  相似文献   

10.
Among the 14 small mammal species from the early Miocene locality of the northern area of the Junggar basin (northern Xinjiang, China), four species are cricetids (Rodentia): unnamed species of Cricetodon and Eumyarion, and two new species, Karydomys debruijni nov. sp. and Megacricetodon beijiangensis nov. sp. Some aspects of the morphology of Cricetodon sp. are shared by Eucricetodon from the late Oligocene, suggesting that these specimens could be of intermediate form between Eucricetodon and Cricetodon. One tooth of Eumyarion sp. was found, making its determination uncertain, but its morphology is clearly differentiated from the one of Cricetodon sp. The species K. debruijni nov. sp. is established based on its primitive features compared to the species known in Europe and Anatolia, and its specific association of characters compared to Karydomys dzerzhinskii. M. beijiangensis nov. sp. shows many plesiomorphic features compared to the species already described in the middle Miocene of China. Based on both the whole assemblage of rodents and the species of cricetids, the biochronologic position and the age of the locality are discussed. The locality appears to be biochronologically very close to the fauna from the Chul’adyr Formation in Aktau Mountains, but we propose an age slightly older than the one proposed for this fauna, probably equivalent to the MN3 biozone in Europe.  相似文献   

11.
The siliceous valves from species of Tetracyclus (Bacillariophyceae) have variable but characteristic shapes. In this paper, species characterised by having valves with a central constriction are discussed. This distinctive shape occurs during only a period of its lifecycle. Tetracyclus constrictus and Tetracyclus celatom have been applied to fossil specimens occurring in deposits from the west coast of the USA and the east coast of Russia. Do these names apply to two closely related species or are they one and the same taxon? Two further species, Tetracyclus javanicus and Tetracyclus peragalli, have been involved in the identity of T. constrictusT. celatom. T. constrictus M. Peragallo is the correct name and author for specimens of the extinct Miocene, circum-Pacific (or northern) fossil species with valves panduriform with rounded poles; T. javanicus refers to a species found living on Java only; fossil specimens usually referred to T. javanicus (Java) belong to a new taxon, Tetracyclus bradburyii (USA); T. peragalli is an extinct Miocene fossil, with a northern hemisphere distribution; small (≤10 μm) circular/elliptical fossil specimens, found alongside other specimens, are difficult (if not impossible) to determine to species level.  相似文献   

12.
Didier Merle 《Geobios》2005,38(4):505
Jsowerbya, nov. gen. (Gastropoda: Muricidae) includes three species from the Eocene of the Paris and Hampshire basins. It increases the number of extinct muricid genera, which curiously represent a very small fraction of the described genera. The species of Jsowerbya, often mistaken for the muricopsine genus Muricopsis, possess a unique combination of characters shared with the subfamilies Ocenebrinae and Ergalataxinae. A cladistic analysis, based on structural homologies of the spiral sculpture, however, suggests that Jsowerbya is closely related to the Ocenebrinae. Thus, Jsowerbya is here regarded as one the most basal Ocenebrinae.  相似文献   

13.
Here, a partial skeleton of Prodeinotherium bavaricum from Unterzolling (Southern Germany) is documented. The following elements are preserved and described for the first time: cervical vertebrae 1-2 and 5-7, the first thoracic vertebra, one lumbar vertebra, trapezium, metacarpals 1-5, tibia, calcaneus, endo- and mesocuneiform, cuboid, the fourth metatarsal, and some phalanges. Comparisons with the skeletons of Pbavaricum from Franzensbad (Czech Republic) and Deinotherium giganteum from Eserovo (Bulgaria) show osteological differences that are described and discussed.  相似文献   

14.
Size and shape changes in the skull of the genus Gerbillus were investigated using geometric morphometrics. Six species from Tunisia were studied (G. gerbillus, G. campestris, G. nanus, G. tarabuli, G. simoni and G. latastei). Statistical analyses of shape variability allowed us to discriminate three morphological groups which are congruent with the three groups suggested by previous morphological and molecular studies. However, our results contrast with previous molecular investigations. In fact, according to results obtained by the use of principal component analysis, canonical variate analysis and UPGMA, we found a higher degree of divergence between the subgenus Dipodillus and the other two subgenera Gerbillus and Hendecapleura. This fact suggests that the morphometric differences observed among species within the genus Gerbillus are not mainly related to phylogeny. To reconciliate the molecular and morphological approaches, we propose a hypothesis of differential rates of phenotypic evolution in the genus Gerbillus. In this view, the species belonging to the subgenus Dipodillus evolved apomorphic features of the skull likely related to a higher degree of habitat specialization. By contrast, the more generalist Gerbillus and Hendecapleura subgenera show less differentiated plesiomorphic morphology.  相似文献   

15.
The genera Haplocytheridea and Cytheridea have Tethyan origins and a wide paleobiogeographic and stratigraphic distribution, ranging from the Cretaceous to Recent. Both of them have been recorded in northern South America, but only Cytheridea has been found in the northern Cretaceous basins of Brazil. The genus Haplocytheridea is recorded, for the first time, in the Early Miocene deposits of the Pirabas Formation of northern Brazil, from a 20 m-thick succession of carbonate and argillaceous rocks deposited in lagoonal and restricted platform environments. Among the ten Haplocytheridea species identified, four are new: H. variopunctata n. sp., H. sandbergi n. sp., H. pirabasensis n. sp. and H. sinuosa n. sp. In addition, three new species of Cytheridea are also described: C. coimbrai n. sp., C. pirabasensis n. sp. and C. purperae n. sp. The highest frequencies and abundances of both genera, in the studied section, are thought to be associated with nearshore to brackish water settings.  相似文献   

16.
A revision of Chamaeleo caroliquarti Moody and Ro?ek is presented. The comparisons of the holotypic left dentary with those of specimens subsequently assigned to C. caroliquarti and of the Recent species of Chamaeleo, Furcifer and Calumma is carried out. It is shown that the type dentaries of C. caroliquarti include two different morphotypes with the absence of unique features. Within the Recent chameleons, the exact determination of the individual species merely on the basis of the dentaries is impossible. The holotypic dentary of C. caroliquarti is basically identical with that of C. calyptratus. However, the same morphology of the dentary as present in C. caroliquarti is also present in other species of different genera such as Calumma globifer and Furcifer pardalis. The paratypic dentaries of C. caroliquarti have a different morphology to the holotype and are indistinguishable from that in the Recent C. chamaeleon. On the other hand, a new species of the genus Chamaeleo, C. andrusovi, is described on the basis of isolated cranial elements, which possess clear autapomorphic features. This material comes from the Lower Miocene (Ottnangian) zone MN 4 in the Dolnice locality of the Czech Republic, and it differs from Recent and fossil chameleons in the following combination of characters: (1) its typically developed strongly pustular ornamentation and its distribution on the external surfaces of the skull roofing bones; (2) the frontoparietal suture is digitiform with a well-developed, anteriorly directed mesial spine, and (3) the parietal bone narrows posteriorly at its midlength, it is not bowed dorsally and it does not contribute posteriorly to a dorsal sagittal crest. This new material expands our knowledge of the cranial anatomy of Lower Miocene chameleons.  相似文献   

17.
In recent years there has been growing interest in analyzing the geographical variations between populations of different Phlebotomus spp. by comparing the sequences of various genes. However, little is known about the genetic structure of Phlebotomus ariasi. In this study, we were able to sequence a fragment of the mitochondrial Cyt b gene in 133 sandflies morphologically identified as P. ariasi and proceeding from a wide geographical range covering 35 locations in 11 different regions from five countries. The intra-specific diversity of P. ariasi is high, with 45 haplotypes differing from each other by one to 26 bases and they are distributed in two mitochondrial lineages, one limited geographically to Algeria and the other widely dispersed across Mediterranean countries. The Algerian lineage is characterized by having 13 fixed polymorphisms and is made up of one sole haplotype. The European/Moroccan P. ariasi lineage is characterized by being made up of a great diversity of haplotypes (44) which display some geographical structuring. This could be one of the multiple factors involved in the epidemiological heterogeneity of the foci of leishmaniasis. Phlebotomus chadlii is the sister group of European/Moroccan P. ariasi. The separation of the Algerian haplotype, H45, from the rest of the specimens, European/Moroccan P. ariasi and P. chadlii, is well supported by the bootstrap analysis.  相似文献   

18.
Haowen Tong 《Geobios》2007,40(2):219
The materials of Aeretesmelanopterus from the Tianyuan Cave, a Late Pleistocene site with human fossils recovered recently near Zhoukoudian, are the richest of this species ever reported in North China. Aeretesmelanopterus is an endemic species of China, its relationship with Petaurista and Trogopterus is still controversal. Studies based on the dental characters show that Aeretesmelanopterus resembles Petaurista more closely than Trogopterus. The earliest fossil record of Aeretesmelanopterus was found in South China in Middle Pleistocene deposits. The earliest records in the Beijing area are from Upper Cave and Tianyuan Cave at Zhoukoudian are of late-Late Pleistocene age, around 30 kyrs BP. The geographical distributions of this species are very limited. In evolution, Aeretesmelanopterus experienced both the increase and the decrease in tooth size; but its crown height of cheek teeth was continuously increasing.  相似文献   

19.
Most of the 16 currently recognized astrapothere genera are well known through numerous specimens preserving at least almost complete dentition. One of the exceptions is the enigmatic genus Isolophodon Roth, 1903, based on very scant and fragmentary materials from Paleogene levels of central Patagonia. This taxon was ruled out from almost all taxonomic lists, although its validity has not been discussed by subsequent authors. We herein re-describe and discuss the taxonomic status of the species of Isolophodon. The type species, I. cingulosus Roth, 1903, is characterized by having lower cheek teeth with a much reduced hypoflexid, resembling derived uruguaytheriines, but lower-crowned and with three lower premolars, as in the species of Astraponotus Ameghino, 1901. This is the only astrapothere nominal species attributable to the Tinguirirican South American Land Mammal Age (SALMA, Early Oligocene). Isolophodon aplanatus Roth, 1903 (Casamayoran and Mustersan SALMAs, middle Late Eocene) has proportionally more elongated lower molars and a less developed paraflexid than the type species. Isolophodon would represent an early diverging lineage of astrapotheriids, in which some dental features evolved convergently with the more derived uruguaytheriines. Additionally, we describe other fragmentary but very significant specimens from Paleogene localities in central Patagonia (Argentina) attributable to the following taxa: cf. Scaglia kraglievichorum (Barrancan? subage), based on a partial upper molar nearly 60% larger than the type of Scaglia kraglievichorum Simpson, 1957; Astrapotheriidae gen. et sp. 1 (Barrancan? Subage, Middle Eocene), based on an isolated upper molar larger than any other Eocene astrapothere; Astrapotheriidae gen. et sp. 2, based on five isolated upper cheek teeth from “La Cantera” (Gran Barranca, Early Oligocene), characterized by a large, isolated hypocone and accessory cusps on P3-P4. These taxa enlarge the known diversity of Paleogene astrapotheres and document novel evolutionary patterns for these mammals.  相似文献   

20.
This integrative taxonomy study of French pikes compares morphological characters and molecular sequence data (mitochondrial COI and nuclear Plagl2 genes). In addition to the expected E. lucius, DNA sequences and morphology both support a new species in France, E. aquitanicus sp. nov. from the Charente to the Adour drainages. It is characterized by a color pattern of sides with narrow 1–1.5-scale-wide oblique vertical bands, conferring it a marbled coat, a snout only 0.9 times larger than the postorbital length, an anal fin basis 1.1–1.2 times larger than the caudal peduncle length, 101 to 121 lateral scales, 53 to 57 vertebrae, as well as 24 diagnostic sites in the COI gene and 3 in the Plagl2 gene. Partial COI sequences (131 bp) from modern and historical specimens indicate also the presence of E. cisalpinus and E. lucius during the 19th century in Lake Geneva. Morphological and molecular data points to a possible hybridization between E. lucius with both other local pike species, representing a risk for them. Their endangerment status should be evaluated rapidly in order to take conservation measures.  相似文献   

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