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1.
Catagonus wagneri has the most restricted geographical distribution among extant Tayassuidae and inhabited semi-arid thorny forests of dry Chaco in Paraguay, Bolivia and Argentina. Until now, C. wagneri has only been recorded in archaeological, pre-Hispanic deposits from the Santiago del Estero Province, Argentina. A new partially complete skull from the Sopas Formation (Late Pleistocene; Uruguay) is identified as C. wagneri. This is the only fossil record of the species which extends its biochron until the late Pleistocene, and the first one substantially far from its current range; the first fossil record of the species in Uruguay; the most complete fossil material of the species; and it provides relevant ecological and climatic information. According to the ecological and climatic available information of C. wagneri, the presence of this mammal in the late Pleistocene of northern Uruguay indicates a warm climate and arid to semi-arid environments. Even though not associated with the fossil remains of C. wagneri, some mammals included in the sedimentary levels of the Sopas Formation also suggest arid to semi-arid environments. Climatic changes, in particular in the late Pleistocene and Holocene, could be invoked to explain modifications of its geographic range.http://zoobank.org/ECF04BCF-8246-4F11-AAB8-5FAA9F437BDA  相似文献   

2.
Additions to the knowledge on fossil rodents of Uruguay (Mammalia: Rodentia). — This paper brings new information on fossil rodents of Uruguay. Four new species are described:Microcavia (M.) aua n. sp. (Caviidae),Ctenomys mesorhinus n. sp. (Octodontidae),Isostylomys intermedius n. sp. andIsostylomys magnus n. sp. (Dinomyidae), the latter from Argentina. Apart from this,Palmiramys waltheri Kraglievich, 1932, illustrated here for the first time, is considered a Lower Oligocene (Deseadan) ?Dasyproctidae. The first records for Uruguay ofEucardiodon cf.marshi (Ameghino) (Hydrochoeridae), and +Holochilus brasiliensis (Desmarest) are reported.  相似文献   

3.
4.
Mariano Verde 《Ichnos》2013,20(1-2):77-80
Continental tetrapod coprolites from Uruguay are described for the first time. These remains come from the Piedra Pintada locality (Artigas Department), northern Uruguay, where the Sopas Formation crops out (Upper Pleistocene, Lujanian Stage). It was possible to identify several attributes indicative of a coprolitic origin, such as anisopolar shape, extrusion marks, pointed ends, sutures, gas bubbles, and inclusions. These specimens are assigned to carnivorous mammals, probably large felids, based on morphological attributes and inclusions of rodent bones and teeth.  相似文献   

5.
A new fossil species,Hemiptelea mikii, is described on the basis of fruits from the Pleistocene of central Japan. It is distinguished fromH. davidii, the only extant species of the genus restricted to Korea and China, in having shorter fruits. Fossil woods discovered from the same horizon differ from the extant one in some anatomical characteristics, and are assigned to the new fossil species. Taken together with earlier records of fossil fruit occurrence in the early and the middle Pleistocene of central Japan, the latest finding of fossil fruits and woods from the last glacial sediments (ca. 50,000 years ago) at Kita-egota site of Tokyo suggests thatH. mikii was widespread in central Japan throughout the Pleistocene and survived until as late as the Last Glacial age.  相似文献   

6.
王惠基 《古生物学报》1995,34(3):370-374
报道河南郑州三李西沟更新世马兰组、潞王坟组的腹足类化石4种:Physaassuturalissp.nov,Indoplanorbisexustus(Deshayes),Cathaica(Pliocathaica)richthofeni(Marten),C.(Eucathaica)fasciola(Draparnaud)。认为潞王坟组沉积时的水域可能比马兰组沉积时广宽,其时代归入早更新世,沉积环境与现代相似,气候比现代温暖。  相似文献   

7.
8.
Coevolution was studied in six species of rodents of the genus Ctenomys and their parasitic nematodes of the genus Paraspidodera , collected in Bolivia. Representatives of the families Octodontidae and Caviidae were used as outgroups for the mammals, and nematodes from caviids were used as outgroups of the nematodes from ctenomyids. For the nematodes, quantitative and qualitative morphological characteristics of both males and females and electrophoretic characters of both sexes were used to generate phylogenetic hypotheses of evolutionary relationships of the OTUs occurring in hosts of different species. Concordance estimates of cladograms generated from biochemical—genetic and morphological data of the nematodes show a percentage incongruence (Mickevich-Farris Incongruence Statistic or I MF) of 8.23% in the character sets. Parsimony mapping, testing concordance of topologies between the trees derived from both analysis of both morphological and biochemical—genetic data indicates an overall agreement of 82.3°. Comparisons of topologies of the host and parasite cladograms, as measured with parsimony mapping, showed 70.8% concordance, indicating substantially more cospeciation than host-switching in the Ctenomys-Paraspidodera host-parasite system. Nematodes of the genus Paraspidodera appear to have invaded the Ctenomys lineage from an origin in caviids sometime before the ctenomyids began to diversify in early Pleistocene time.  相似文献   

9.
One of the most striking components of the modern assemblage of South American mammals is the semiaquatic capybara (Caviidae, Hydrochoerinae), the biggest rodent in the world. The large hydrochoerines are recorded from the middle Miocene to the present, mainly in high latitudes of South America. Although less known, they are also recorded in low latitudes of South America, and in Central and North America. We report the first record of capybaras from the late Pliocene of Colombia, found in deposits of the Ware Formation, Guajira Peninsula in northeastern Colombia. We analyze the phylogenetic position within Caviidae, the possible environmental changes in the Guajira Peninsula, and the implications of this finding for the understanding of the Great American Biotic Interchange. The morphological and phylogenetic analyses indicate that the hydrochoerine of the Guajira Peninsula is a new species, ?Hydrochoeropsis wayuu, and this genus is most closely related to Phugatherium. According to the latest phylogenetic results, this clade is the sister group of the lineage of the recent capybaras (Neochoerus and Hydrochoerus). ?Hydrochoeropsis wayuu is the northernmost South American Pliocene hydrochoerine record and the nearest to the Panamanian bridge. The presence of this hydrochoerine, together with the fluvio-deltaic environment of the Ware Formation, suggests that during the late Pliocene, the environment that dominated the Guajira Peninsula was more humid and with permanent water bodies, in contrast with its modern desert habitats.  相似文献   

10.
Cythere japonica was proposed by Hanai (1959) as a new species of the genus Cythere , from the Pleistocene Sawane Formation in Sado Island, Niigata Prefecture, Japan. The characters of carapace were already known, but the appendages have not been previously described. The authors formerly considered that this species should be separate from the genus Cythere sensu stricto because it has twice as many sieve-type pore systems as typical Cythere species, and a markedly higher carapace. The existence of living Cythere japonica in the tidal zone of north-west Japan is confirmed, and its taxonomic position re-examined on the basis of its appendages and the ontogeny of pore systems. The appendages, except for the copulatory organ, are almost identical with those of other Cythere species, and their pore systems share the same pattern in and before the A-4 moult stage. On the basis of these features this species should be retained in the genus Cythere. Phylogenetic relationships are considered on the basis of the ontogeny of pore systems.
The abdominal segments of podocopid Ostracoda, which have always been regarded as difficult to observe because of their fusion, are shown clearly by the SEM.  相似文献   

11.
A new ichnotaxon, attributed to earthworm aestivation chambers, is described from paleosols of the Sopas Formation (Upper Pleistocene) of northern Uruguay. This ichnofossil consists of a spherical chamber with a constructed wall of imbricated faecal pellets and a filling of rounded to meniscate pellets arranged in winding strings. The strings may also be connected to specimens of Taenidium serpentinum in the paleosol, resulting in a compound trace fossil. Castrichnus incolumis igen. et isp. nov. is interpreted as an earthworm aestivation chamber based on its morphological similarity to the chambers produced by extant earthworms. As such, C. incolumis is considered an indicator of subaerial exposure, and also of seasonal climate. C. incolumis is the second trace fossil that can be attributed with certainty to earthworms. In addition, the CastrichnusT. serpentinum compound specimens indicate that in paleosols, earthworms can be the producers of T. serpentinum. Aestivation chambers would represent a new ethological category.  相似文献   

12.
A new species of the huananaspidiform galeaspid genus Sanqiaspis is reported from the Lochkovian Si Ka Formation of northern Vietnam and is somewhat older than the previously recorded occurrences of this genus, from the Pragian Posongchong Formation of southern China. This species provides new information about the anatomy of the head shield in the Sanqiaspididae and notably provides evidence of a complete endoskeletal and dermal postbranchial wall, like in osteostracans. The various types of vertebrate assemblages defined in the Lower Devonian of China are discussed, by comparison to the vertebrate faunas hitherto recorded from the Lower Devonian of Vietnam, and it is suggested that their composition is strongly influenced by environmental factors.  相似文献   

13.
The Proterotheriidae (Early Palaeocene-Late Pleistocene) were small to medium sized cursorial native South American ungulates (Order Litopterna), having had its diversity peak in the Miocene. During the Pleistocene, the proterotheriid diversity decreased to a single species, Neolicaphrium recens Frenguelli (1921), and few specimens are available from a relatively narrow area at medium latitudes of South America. The first study using stable isotopes (δ13C and δ18O) as proxies is provided here, in order to known dietary preferences and testing previous environmental inferences. The analysed specimens belong to outcrops with OSL ages of 40–30 ka (Late Pleistocene, Sopas Formation of northern Uruguay). The δ13C results of both specimens suggest that at this latitude and tempo, N. recens had browser-feeding preferences, mostly a C3 diet of open canopy forest in an environment of semi-open woodland or forested savannahs and that C4 vegetation would have had a small fraction in their diet. δ18O data suggests a diet composed mostly by fruits, follow by floor plants, with few indication of a folivore diet. The specialized forest browsing diet does not significantly vary based on its site of origin, since both specimens remain in the same isotopic range.  相似文献   

14.
Lihoreau, F., Blondel, C., Barry, J. & Brunet, M. (2004). A new species of the genus Microbunodon (Anthracotheriidae, Artiodactyla) from the Miocene of Pakistan: genus revision, phylogenetic relationships and palaeobiogeography. — Zoologica Scripta , 33 , 97–115.
New unpublished remains of small Anthracotheriinae are described. First, materials from the upper Oligocene (MP 30) locality of La Milloque, southwest France, permit a review of the species Microbunodon minimum . Thereafter, fossils from the middle and late Miocene of the Potwar Plateau, Pakistan are attributed to the European genus Microbunodon . Microbunodon milaensis sp. n. from the Nagri Formation (between 10.3 and 9.2 Ma), Pakistan, is described and the species M. silistrensis from the Lower Manchar Formation (between 16 and 15 Ma) and from the Chinji Formation (between 12.7 and 11.5 Ma), Pakistan, is reviewed. The new species represents the last occurrence of the subfamily Anthracotheriinae, around 9.3 Ma. Similar materials from the Bugti and Siwalik Hills were previously considered as a small Anthracotherium . Comparisons with M. minimum from the European late Oligocene lead to a complete revision of the genus and permit definition of a new set of characters, which separate Microbunodon from Anthracotherium . A cladistic analysis reconsiders phylogenetic relationships among Anthracotheriinae, separating an Anthracothema–Anthracotherium clade and an Anthracokeryx–Microbunodon clade. Microbunodon appears to stem from the Asian late Eocene–lower Oligocene genus Anthracokeryx . These results imply a new distribution of the genus Microbunodon showing exchanges between Europe and Asia during the late Oligocene and probably the lower Miocene.  相似文献   

15.
Abstract: A new genus and species of basal non‐Viverravidae Carnivoramorpha, Dawsonicyon isami, is named and described. This new taxon is based upon DMNH 19585, an almost complete skeleton, which was collected from the Black’s Fork Member (informal ‘Bridger B’ subunit) of the Bridger Formation in southwestern Wyoming, USA. The specimen is incorporated into an existing craniodental data matrix, and the associated phylogenetic analyses support the identification of this species as a new basal carnivoramorphan. This new taxon is dentally compared to all known genera of non‐viverravid basal carnivoramorphans, as well as with all known species of the problematic genus Miacis. Postcrania are compared in detail with other described specimens of non‐viverravid basal carnivoramorphans and more generally with known postcrania of viverravids. Preliminary functional interpretations of a scansorial locomotor mode are offered for this new taxon. Its implications for the diversity of middle Eocene basal carnivoramorphans is briefly discussed, including expansion of the already high diversity in the Black’s Fork Member of the Bridger Formation (at least 11 species in 8 genera).  相似文献   

16.
The Somuncurá Plateau is a Protected Natural Area located in the middle of the northern extra-Andean arid Patagonia. Inhabited by at least 20 small mammal species, is the place with the uppermost species richness in Patagonia. The aim of this study was to examine the parasite remains from micromammal coprolites collected in association with a bone sequence recovered at the east of the Somuncurá Plateau (site “Alero Las Lechuzas”). Coprolites came from the four temporal units previously defined: unit I (4790?±?100?yrs. 14C B.P.), unit II, unit III (7840?±?120?yrs. 14C B.P.) and unit IV. Each coprolite was processed, rehydrated, homogenized, processed by spontaneous sedimentation and examined using a light microscope. Coprolites and eggs were described, measured and photographed. Samples were positive for two nematode species: Helminthoxys caudatus Freitas, Lent & Almeida, 1937 (Oxyurida, Oxyuridae) and Trichuris spp. (Trichinellida: Trichuridae). This is the first paleoparasitological study developed for the Somuncurá Plateau Protected Area. Moreover, this is the first time that the genus Helminthoxys is reported from ancient times worldwide. Coprolites were attributed to the mountain cavy Microcavia australis (Rodentia, Caviidae).The presence of H. caudatus for the Middle Holocene of northern Patagonia contributes to the study of the history of the histricomorphs and pinworms relationships.  相似文献   

17.
Among the South American Pleistocene Glyptodontidae (Xenarthra, Cingulata), one of the most scarcely represented genus in the fossil record is Neuryurus Ameghino, in which the only well characterized species, until now, is Neuryurus rudis (Gervais), coming from the Ensenadan (early-middle Pleistocene) of the Pampean region, Argentina. In this contribution, we report and describe a new species of Neuryurus, coming from the Arroyo Feliciano Formation (early Lujanian; ca. 130 ka), Entre Ríos province, Argentina, in a particular palaebiogeographic context, more associated with the western sector of Uruguay and southern Brazil than the Pampean region. From a morphological perspective, this new taxon is characterized by: (a) the remarkable development of the foramina at the exposed surface of the osteoderms of the dorsal carapace, showing un aspect almost spongy; (b) the large diameter of the perforations observed in the ventral surface of the osteoderms, resembling to those present in the dorsal surface of the osteoderms of the Glyptodontidae Doedicurinae; (c) the evident thickness of the osteoderms, as in Glyptodon Owen; (d) area of contact and articulation of adjacent osteoderms very denticulate, with deep osseous interdigitating projections, as in Glyptodon and Glyptotherium Osborn, but here more evident; (e) larger osteoderms of the dorsal carapace showing, in the dorsal surface, many little conical tubercles, having some resemblance to Panochthus tuberculatus Burmeister. The presence of this new species in the early late Pleistocene of the Mesopotamic region is another element that adds to the biogeographical characterization of this particular area, especially evident during the warm and humid pulses of the late Pleistocene. In turn, this species represents the most complete record of the genus outside the Pampean region and partially complete the stratigraphic and geographic distribution of the genus.  相似文献   

18.
A new ostracod, Loxoconcha kamiyai sp. nov. in the Family Loxoconchidae, is described from the Pleistocene Omma Formation of Japan. Its geological and geographical distributions suggest that this species was once endemic to the Japan Sea, where it would have evolved until the Pliocene. Since the early Pleistocene, this species would have become extinct within this marginal sea during glacial maxima, probably due to its narrower salinity tolerances and geographical distributions than those of extant species inhabiting the euryhaline environments in other seas. The distributional patterns of pore systems in this species strongly suggest its closest phylogenetic affinities to a living species, Loxocorniculum mutsuense . These two species show a unique adult sexual dimorphism in the anterior element of the hingement. Taking the female hingement morphology as a standard, the male hingement can be explained in terms of heterochrony, i.e. paedomorphosis. Sexual hingement dimorphism with paedomorphosis occurs in only one phylogenetic group of the genus Loxoconcha , which is distinguished by the ontogenetic distributional patterns of pore systems. This morphology may represent relict primitive characters of ancient ostracods and could be an important character for evaluating the history of sexual dimorphism in ostracods since the Palaeozoic.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 153 , 239–251.  相似文献   

19.
记述新直脉蝎蛉科1新属1新种Neorthophlebopsis qishuiheensis gen.et sp.nov.,并以其Sc很长,Rs与M分支同一水平,Rs1 2分支在Pt之前,M与CuA汇合,臀区3支粗壮横脉,呈一字斜形排列等特征与已知属相区别.新属种系铜川昆虫组合的新成员,属陕西昆虫群.化石标本采自陕西铜川中三叠统铜川组下段上部灰绿色泥页岩.铜川组的时代相当欧洲拉丁尼期(Ladinian Stage).  相似文献   

20.
记述产自中国辽西的逍遥蛛科化石1新属:白垩逍遥蛛属Cretadromus gen.nov.,1新种:辽宁白垩逍遥蛛Cretadromus liaoningensis sp.nov.:这是逍遥蛛科化石在中国的首次发现,也是逍遥蛛科在晚侏罗世-早白垩世的首次报道。标本采白辽宁省凌源市大王杖子晚侏罗世-早白垩世义县组地层,现存于大连自然博物馆:  相似文献   

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