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1.
The so-called Hundsheim rhinoceros, Stephanorhinus hundsheimensis, was a very common faunal element of the Early to early Middle Pleistocene period in the western Palaearctic. In this study, individuals from two different central European populations of the Hundsheim rhinoceros were analysed in order to determine whether their local dietary signals could reflect differing food availability between the two populations, and whether such information could provide a better understanding of the ecological role of S. hundsheimensis within corresponding faunal assemblages, and of its principal subsistence strategy in the western Palaearctic. The mesowear traits observed in the studied S. hundsheimensis populations have been interpreted as representing biome-specific signals, indicating grassland vegetation at the site of Süßenborn, and dense to open forests at Voigtstedt (both localities in Germany). The analyses performed on the fossil rhino material demonstrate the most pronounced dietary variability ever established for a single herbivorous ungulate species by mesowear studies. This variability ranges from an attrition dominated grazing regime, to a one of predominantly browsing, and characterises S. hundsheimensis as the most ecologically tolerant rhinoceros of the Palaearctic Plio-Pleistocene. Although such dietary flexibility proved an effective enough subsistence strategy over a period of 600–900 ka (1.4/1.2–0.6/0.5 Myr) in the western Palaearctic, the situation changed dramatically after 0.6 Myr BP, when the new species of rhinoceroses, Stephanorhinus hemitoechus and Stephanorhinus kirchbergensis, appeared and started to compete for both the grass and the browse. For the generalist S. hundsheimensis, this bilateral interference was detrimental to its success in all of its habitats. The successful competition of specialised forms of rhinoceroses, which might have originated as a result of the development of 100 ka periodicity in the global climatic record, is proposed as the main reason for the extinction of S. hundsheimensis during the early Middle Pleistocene. 相似文献
2.
The dietary regime of Equus capensis from the Middle Pleistocene of South Africa is investigated by mesowear analysis. Results indicate that the mesowear signature of this species resembles that of two extant mixed feeders, the Grant's Gazelle (Gazella granti) and the Thomson's Gazelle (Gazella thomsoni), suggesting a mixed feeding dietary strategy for E. capensis. The mesowear signature of a contemporaneous population of Equus mosbachensis from Europe (Arago, France) is also determined for comparative purposes and has a typical grazing signature. In general, all extant species of Equus are believed to be almost exclusively grazers. However, a considerable degree of dietary flexibility is recently reported. The dietary signal of E. capensis is considered to be the result of feeding on the unique fynbos vegetation, which was beginning to establish itself at this time in southwestern South Africa. Grasses are a minor component of this floral kingdom. Our findings thus provide further evidence for the unexpected flexibility in feeding strategies of Equus, the most widely distributed equid taxon in the Quaternary. They highlight the potential use of the attrition–abrasion wear equilibrium as a habitat indicator, by mirroring the availability of food items in mammalian herbivore ecosystems. 相似文献
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4.
In Mexico, just 54% of the reported Pleistocene Bison material has been identified to species. Current paleontological research in northwestern Oaxaca, southern Mexico, has allowed collection of several specimens of Bison antiquus that are part of the Viko Vijin Local Fauna. B. antiquus had a very wide geographic distribution, from lowlands to mountainous landscapes of North and Central America. The B. antiquus record from southern Mexico links their former records from central Mexico and middle Central America and confirms this wide geographic distribution. The univariate mesowear score of the B. antiquus specimens from Oaxaca is in the lower extreme of grazers and the upper end of mixed-feeders, suggesting that they had a less abrasive diet than the modern plains Bison, as has been observed in other samples of this species from diverse parts of North America. The presence of B. antiquus in the Viko Vijin L. F. constrains the age of this fossil assemblage within a range from 60 Ka to 11.7 Ka. 相似文献
5.
Daniel Perea Matías Soto Gerardo Veroslavsky Sergio Martínez Martín Ubilla 《Journal of South American Earth Sciences》2009,28(2):168-179
The Tacuarembó Formation has yielded a fossil assemblage that includes the best known body fossils, consisting of isolated scales, teeth, spines, and molds of bones, recovered from thin and patchy bonebeds, from the Botucatu Desert, Parana Basin, South America. The remains are preserved in the sandstones widespread around the city of Tacuarembó. We propose a new formalized nomenclature for the Tacuarembó Formation, naming its “Lower” and “Upper” members as the Batoví (new name) and Rivera (new rank) members, respectively. An assemblage zone is defined for the Batoví Member (fluviolacustrine and aeolian deposits). In this unit, the freshwater hybodontid shark Priohybodus arambourgi D’Erasmo is well represented. This species was previously recorded in Late Jurassic–Early Cretaceous units of the Sahara and the southern Arabian Peninsula. Globally considered, the fossil assemblage of this member (P. arambourgi, dipnoan fishes, Ceratosaurus-like theropods, and conchostracans) is indicative of a Kimmeridgian–Tithonian age, which in combination with the stratigraphic relationships of the Tacuarembó Formation with the overlying basalts of the Arapey Formation (132 My average absolute age) implies that the latter was deposited during the Kimmeridgian–Hauterivian interval. 相似文献
6.
The Upper Cretaceous succession outcropping in the Anamas–Akseki Autochton, consists of approximately 500 m thick purely platform carbonate sediments. It begins with Cenomanian limestones intercalated with limestone breccias (Unit-1) containing mainly Pseudorhapydionina dubia, Pseudonummoloculina heimi, Spiroloculina cretacea (Assemblage I) and unconformably overlies the Lower Cretaceous (Barremian–Aptian) limestones with Vercorsella laurentii, Praechrysalidina infracretacea and Salpingoporella hasi. The Cenomanian limestones include foraminiferal packstone–wackestone, peloidal packstone–wackestone and mudstone microfacies deposited in restricted platform conditions. The Cenomanian succession is truncated by an unconformity characterised by locale bauxite deposits. Immediately above the unconformable surface, dolomitic limestones and rudistid limestones (Unit-2) are assigned to the upper Campanian based on the benthic foraminiferal assemblage (Assemblage II) comprising mainly Murciella gr. cuvillieri, Pseudocyclammina sphaeroidea, Accordiella conica, Scandonea samnitica and Fleuryana adriatica (smaller-sized populations). The upper Campanian limestones composed of dominantly foraminiferal-microbial packstone–wackestone microfacies deposited in shallow water environment with low energy, restricted circulation. The following limestones of the Unit-2 is characterised by sporadic intercalation of “open shelf” Orbitoides, Omphalocyclus, Siderolites assemblage (Assemblage III), assigned to the Maastrichtian, in addition to pre-existing “restricted platform” species. In the upper part of this biozone, the Rhapydionina liburnica/Fleuryana adriatica concurrent range subzone (Assemblage IIIb) is distinguished by the presence of Valvulina aff. triangularis, Loftusia minor as well as the nominal species. The Maastrichtian limestones with sporadically open marine influence consist of bioclastic (rudist-bearing) packstone–floatstone, foraminiferal packstone–wackestone with rudist fragments and peloidal/intraclastic packstone–wackestone microfacies deposited in shallow subtidal–subtidal (lagoonal) environments. The Upper Cretaceous succession passes upwardly into 70 m thick limestones and clayey limestones (Unit-3) which do not contain rudists and pre-existing foraminiferal assemblage with one exception Valvulina aff. triangularis. Variable amounts of ostracoda, discorbids, miliolids, dasycladacean algae and Stomatorbina sp. (Assemblage IV) occur into mud-rich microfacies suggesting restricted conditions with low water energy. A probable Danian age is proposed for the Unit-3 based on the occurrence of Valvulina aff. triangularis and Stomatorbina sp. which were previously recorded from Danian of peri-Tethyan platforms. 相似文献
7.
J. Tyler Faith 《Quaternary Research》2011,75(1):159-165
The Cape grysbok is endemic to southern Africa's Cape Floral Region where it selectively browses various species of dicotyledonous vegetation. Fossil evidence indicates that the grysbok persisted under glacial and interglacial conditions throughout the late Quaternary and inhabited a range of environments. This study employs mesowear analysis to reconstruct grysbok diets over time and in response to changing environments at Nelson Bay Cave, Die Kelders Cave 1, Klasies River Mouth, and Swartklip 1. Results indicate that the amount of grasses (monocots) versus leafy vegetation (dicots) included in the diet fluctuated over time and largely in agreement with changes in faunal community structure. The case for dietary flexibility is particularly clear at Nelson Bay Cave, where there is a significant trend from mixed feeding towards increased browsing from the late Pleistocene (~ 18,500 14C yr BP) through the Holocene. Dietary shifts at Nelson Bay Cave are consistent with the hypothesis that declining grassland productivity is responsible for the terminal Pleistocene extinction of several large ungulates in southern Africa. Furthermore, the short-term dietary shifts demonstrated here (100s to 1000s of years) provide an important caution against relying on taxonomic uniformitarianism when reconstructing the dietary preferences of fossil ungulates, both extant and extinct. 相似文献
8.
Satish J. Patel Bhawanisingh G. Desai 《Journal of the Geological Society of India》2009,74(2):233-259
Animal-sediment relationships of two benthic communities (Crustaceans and Polychaetes) were studied around Mandvi coast in
the Gulf of Kachchh, Western India. This coast consists of many micro-geomorphic landforms in which benthic communities are
inhabited and select their niches and produce endemic biogenic structures. Five intertidal subfacies have been described and
four types of grounds are identified, based on substrate consistency. 18 species of crustaceans, 15 species of polychaetes
and unsegmented worm nemertea have been identified. Crustacean behavioural activities were observed in dunes, beaches and
ridge-runnel in the form of burrowing, pellet making, feeding and crawling traces. Pelleted wall lining burrows of the suspension
feeder stomatopodean species of Oratosquilla striata are also abundant in runnels. Motile, deposit feeder polychaetes are abundant on the ridges and are occasionally found on
the lower reaches of the beaches, while suspension and filter feeders are found in the runnels. Lagoons consist of mainly
grouped funnel branched burrows of Oniphus eremita which is identical to ichnogenus Balanoglossites. Nemertea, which are opportunistic algal grazers, have exploited restricted niches for dwelling-feeding purposes and constructed
vertical burrow with pentamerous conical mound. The shore platform consists of cemented, calcareous tubes of filter feeder
Serpula along with symbiotic encrusters like Ostrea and barnacles. Ichnocoenoses are discussed and three-dimensional ichno-sedimentologic models are reconstructed for Beach,
Ridge, Runnel and Lagoon of the Mandvi intertidal zone. 相似文献
9.
The origin of the genus Bos is a debated issue. From ∼ 0.5 Ma until historic times, the genus is well known in the Eurasian large mammal assemblages, where it is represented by Bos primigenius. This species has a highly derived cranial anatomy that shows important morphological differences from other Plio-Pleistocene Eurasian genera of the tribe Bovini such as Leptobos, Bison, Proamphibos-Hemibos, and Bubalus. The oldest clear evidence of Bos is the skull fragment ASB-198-1 from the middle Pleistocene (∼ 0.6-0.8 Ma) site of Asbole (Lower Awash Valley, Ethiopia). The first appearance of Bos in Europe is at the site of Venosa-Notarchirico, Italy (∼ 0.5-0.6 Ma). Although the origin of Bos has traditionally been connected with Leptobos and Bison, after a detailed anatomical and morphometric study we propose here a different origin, connecting the middle Pleistocene Eurasian forms of B. primigenius with the African Late Pliocene and early Pleistocene large size member of the tribe Bovini Pelorovis sensu stricto. The dispersal of the Bos lineage in Western Europe during middle Pleistocene times seems to coincide with the arrival of the Acheulean tool technology in this continent. 相似文献
10.
The La Parte (Asturias) northern Spain site contains a cold-adapted mammal faunal assemblage that corresponds to a level radiometrically dated to a minimum age of 150 ka. It represents the most ancient site with cold resistant fauna in the Iberian Peninsula.Among the species recorded in La Parte, Coelodonta antiquitatis and Rangifer tarandus represent the typical cold-adapted large mammal association.The presence of the woolly rhino at La Parte provides relevant environmental information about the Mammoth Steppe. This species was not as abundant in the Middle Pleistocene as during the Late Pleistocene, when its cold-adapted features can be studied from an evolutionary perspective. The remains attributed to R. tarandus suggest an open steppe ecosystem.The presence of Marmota sp. is also confirmed in La Parte. A first interpretation would suggest an alpine or periglacial ecosystem, but based on recent results which do not support the correlation between phylogeny and climatic tolerance for extant species of Marmota (López and Cuenca, 2002. Palaeogeography, Palaeoclimatology, Palaeoecology 186, 311), we propose the presence of this rodent suggests an open landscape with cold conditions.The rest of the taxa included in the La Parte assemblage (Crocuta crocuta, Panthera leo, Cervus elaphus, Megaloceros cf. giganteus, Bison priscus and Equus caballus) are usually associated with typical cold-adapted faunas, but they are also found in woody temperate zones so they do not characterize by themselves a cold period. The faunal association from La Parte suggests a combination of steppic and open woodland ecological conditions. 相似文献
11.
Perissocytheridea Stephenson is characteristic of brackish water facies. In 57 samples from the Upper Oligocene to Lower Miocene, from five localities, Pirabas Formation, Pará State, Brazil eleven species have been identified. Among these species, four are new reports: Perissocytheridea punctoreticulata n. sp., Perissocytheridea largulateralis n. sp., Perissocytheridea colini n. sp. and Perissocytheridea pirabensis n. sp.; five species in open nomenclature: Perissocytheridea sp. 1, P. sp. 2, P. sp. 3, P. sp. 4, and P. sp. 5 and two species left in “aff.” abbreviation: Perissocytheridea aff. Perissocytheridea pumila and Perissocytheridea aff. Perissocytheridea brachyforma subsp. excavata. The distributional pattern of the Perissocytheridea combined with the occurrence of foraminifera Elphidium and Ammonia in the studied sections supports the presence of the brackish water facies to the respective layers. Their quantitative variation through the studied sections indicate more than one phase of salinity reduction (about >5 and <30 ppm) and/or the decrease of the sea level, forming lagoon along the Pirabas Formation. This genus has a wide paleobiogeographical occurrence and stratigraphic distribution ranging from the Cretaceous to Recent, and already been recorded in the northern of South America, especially in the Neogene of Solimões Basin, but this is the first report of a neotropical genus to the Oligo-Miocene deposits of Pirabas Formation, northern Brazilian Coast, Pará State. 相似文献
12.
Mawsoniids are a lineage of extinct fresh/brackish water coelacanth fishes, common in Cretaceous Godwanan deposits of South America, North and West Africa and Madagascar. Here we formally describe mawsoniid remains from the fluvio-lacustrine Missão Velha Formation (Lower Cretaceous) of the Araripe Basin, North-East Brazil. The examples from the Missão Velha Formation are here described as Mawsonia cf. gigas, based mainly on elements of the lower jaw and opercular series. The occurrence of M. cf. gigas in the Missão Velha Formation expands the stratigraphic and geographical ranges of the type species. 相似文献
13.
Middle Pleistocene climate and habitat change at Zhoukoudian, China, from the carbon and oxygen isotopic record from herbivore tooth enamel 总被引：1，自引：0，他引：1
The Pleistocene deposits at Zhoukoudian, often referred to as the “Peking Man” site, contain dental remains from a diverse group of herbivores, including Equus sanmeniensis, Cervus elaphus, Cervus nippon, Megaloceros pachyosteus, Sus lydekkeri, and Dicerorhinus choukoutienensis. The carbon and oxygen isotopic compositions of structural carbonate within the enamel of these teeth are used to reconstruct the paleodiet and paleoenvironment of the mammals. The δ13C values of enamel from Zhoukoudian range from −2.3‰ to −13.0‰, indicating that these mammals consumed between 25% and 100% C3 plants. The presence of significant amounts of C4 plants in the diets of some herbivore species indicates that at the onset of the Middle Pleistocene local habitats included mixed C3/C4 vegetation. By approximately 470,000 yr ago, C3 plants dominated the diets of herbivores studied, suggesting that the abundance of C4 flora had decreased in the area. For all deer analyzed in this study, the values of δ13C and δ18O decrease substantially from about 720,000 to 470,000 yr ago. This trend may be due to a strengthening of the winter monsoon during the Middle Pleistocene. 相似文献
14.
Sorin Mihai Donald A. McFarlane 《Proceedings of the Geologists' Association. Geologists' Association》2010,121(3):319-325
Tens of thousands of palaeontological and archaeological remains were collected by William Pengelly during 19th century excavations of Kents Cavern, but are now widely dispersed between museums. This has previously precluded spatial analysis. We have now assembled available museum records into a single database, and, using our previously-reconstructed Pengelly excavation map as a base, we have been able to exploit the unique Pengelly location code to set up a GIS mapping system. This allows, for the first time, the analysis of spatial patterns. In addition, the GIS serves to highlight potential problems of recording or curation in the original data. Here we report on the construction of the GIS system and its first use in the analysis of spatial distribution of bear remains. The maps demonstrate that Ursus deningeri entered the cave through a now-sealed High Level Chamber entrance at the back of the cave in the middle Pleistocene, whereas Ursus arctos accessed the cave in the late Pleistocene through the now-sealed Northeast Gallery entrance. The denning areas are reconstructed as Labyrinth/Bear's Den for U. deningeri and Vestibule/Great Chamber for U. arctos. Considerable post-mortem re-distribution of the remains of both species is indicated. 相似文献
15.
We report structural and compositional data leading to the classification of 41 iron meteorites, increasing the number of classified independent iron meteorites to 576. We also obtained data on a new metal-rich mesosiderite and on two new iron masses that are paired with previously studied irons. For the first time in this series we also report concentrations of Cr, Co, Cu, As, Sb, W, Re and Au in each of these 44 meteorites. We determined 7 of these elements (all except Sb) in 30 previously studied ungrouped or unusual irons, and obtained Cu data on 104 irons, 21 pallasites, and 3 meteorite phases previously studied by E. Scott. We show that Cu possesses characteristics well suited to a taxonomic element: a siderophile nature, a large range among all irons, and a low range within magmatic groups. For the first time we report the partial resolution of the C-rich group IIIE from its populous twin group IIIAB on element-Ni diagrams other than Ir-Ni. Cachiyuyal previously classified ungrouped and Armanty (Xinjiang) previously classified IIIAB are reclassified IIIE. Despite the addition of 3 new irons and the reanalysis of 3 previously studied irons the members of the set of 15 ungrouped irons having very low Ga (<3 μg/g) and Ge (<0.7 μg/g) contents remain individualists. The same is generally true for irons having and compositional similarities to IIICD, but A80104 increases the Garden Head trio to a quartet. Algoma is reclassified from ungrouped to IIICD-an and Hassi-Jekna and Magnesia from IIICD to IIICD-an. The metal of Horse Creek and Mount Egerton is compositionally closely related to metal from EH chondrites. We suggest that the P-rich Bellsbank trio irons formed in the IIAB core in topographic lows filled with an immiscible, P-rich second liquid. 相似文献
16.
Throughout the Cenozoic, the North American mammalian fauna has been enriched by the appearance of new taxa originating on different continents. During most of the Tertiary, the primary source area of these new taxa was Eurasia with dispersal across some version of the Bering Land Bridge. In the late Pliocene (Blancan) ca. 2.5 mya, the creation of the Panamanian Land Bridge permitted the northward dispersal of species of South American origin including ground sloths. One of these sloths was “Glossotherium” chapadmalense, which in turn gave rise to the Pleistocene species Paramylodon harlani. Mammoths first appear in North America at the beginning of the Irvingtonian ca. 1.9 mya. Despite originating on two different continents, the two species are often found together in North American Pleistocene faunas and shared a common habitat. Both of these lineages are commonly interpreted as grazers, indicative of open grassland habitat, and both of these exotic species shared this habitat with North American endemic species such as horses, also interpreted as grazers. Despite their association in North American faunas, mammoths did not disperse into South America and mylodont sloths were unable to disperse into Eurasia. This suggests there were some aspects of their ecology they did not have in common and there existed a limited zone of conditions that permitted them to share common habitat. There is no evidence that the appearance of either species in North America resulted in the extinction of any native species. The question is how these different species, immigrants and endemics, were able to avoid competition, coexist, and become integrated into a single fauna, thus enriching the overall North American Pleistocene fauna. 相似文献
17.
A new occurrence of dinocysts Pseudokomewuia in continental Cenosoic (Oligocene–Miocene) rocks of the West Siberian plain is identified. A complex of palynomorphs with dominant microphytoplankton (dinocysts) was found for the first time in the lacustrine-marsh sediments of the south of Tyumen oblast. The variable composition of the complex with Pseudokomewuia aff. laevigata He and Pseudokomewuia aff. granulata He species is traced upward through the section. The layers that correspond to the maximum abundance of Pseudokomewuia (akme) are distinguished and correlated with sections studied previously, which are located in the Barabinsk lithofacial region. Sediments with dinocysts are compared with sediments of the same age from North America, Northern Europe, and Southern China. 相似文献
18.
New morphologic information permits systematic revision of trilobites from the Middle Ordovician Klimoli Formation of the Zhuozishan area, Ordos Basin, Inner Mongolia. The new assemblage is composed of 10 species of the Raphiophoridae, Nileidae, Asaphidae, and Telephinidae.? An asaphid, aff. Mioptychopyge lashachungensis (previously Paraptychopyge lashachungensis) displays an intermediate morphology between the Chinese nobiliasaphine genera Mioptychopyge and Zhenganites. The pygidial doublure is regarded as the most significant character to differentiate Symphysurus klimoliensis (previously Nileus klimoliensis) of the Nileidae from such closely allied taxa as Poronileus. A nileid, cf. Peraspis kujandensis displays typical nileid morphology, unlike the type species, Peraspis lineolata, which might turn out to be an asaphid. Ampyx gongwusuensis sp. nov. of the Raphiophoridae is the first record of the genus in the Zhuozishan area and reveals morphologic details that might be employed to resolve Ampyx taxonomy in China. Morphologic differences between A. gongwusuensis and Abulbaspis ordosensis might represent a case of sexual dimorphism. 相似文献
19.
随着地层学和年代学工作的深入开展,对萨拉乌苏河地区的地层划分愈加仔细;原含萨拉乌苏动物群的地层现在被划分为下部的萨拉乌苏组和上部的城川组。相应地,过去的萨拉乌苏动物群也被划分为萨拉乌苏动物群和城川动物群;而萨拉乌苏动物群又被进一步划分为下部组合和上部组合,下部组合含王氏水牛和诺氏古菱齿象化石,与欧洲的末次间冰期对应;上部组合以野驴和披毛犀为主,与末次冰期第一阶段对应。但对萨拉乌苏河地区晚更新世动物群中有些属种的分类命名问题,一直未达成共识,有些甚至存在错误认识。关于萨拉乌苏动物群是否含有肿骨大角鹿的问题,争论持续了近20年。最新研究表明,在萨拉乌苏组中发现的两件有肿厚现象的大角鹿下颌骨,应当归入河套中国大角鹿(Sinomegaceros ordosianus),而非肿骨大角鹿。因为,下颌骨肿厚是大角鹿类所有种的共有特征。过去很多文献中提到萨拉乌苏动物群中有"蒙古鹿",经笔者核对,该名称最早被用于"大角鹿蒙古变种"(Cervus megacerosvar.mongoliae)和"蒙古马鹿"(Cervus mongoliae);但这两个名称后来均被弃置不用。关于萨拉乌苏动物群中的恰克图转角羚羊,后来曾有人将其转入许家窑扭角羚,经笔者研究,认为萨拉乌苏河地区的转角羚羊应保持原有名称,即恰克图转角羚羊。 相似文献