首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
An initial study of a collection of fossil conifer wood is reported from the late early Miocene Yallourn Clays, an interseam unit intergrading into the base of the early to middle Miocene Yallourn seam of the LaTrobe Valley, Victoria in southeastern Australia. The fossil wood shares characteristics with the modem genera Dacrycarpus and Dacrydium. On the basis of contiguous, uniseriate tracheid pitting and 1–2 podocarpoid cross field pits, it is placed in the form genus Podocarpoxylon, and the new species P. latrobensis. The wood is compared with extant Podocarpaceae and other Australian fossil woods. Its ring anatomy is consistent with low temperature or rainfall seasonality in the early Miocene.  相似文献   

2.
Fragments of diadematoid echinoids from the early and middle Miocene, and late Miocene–Pliocene, respectively, of Java, Kalimantan and Sulawesi, Indonesia, are identified as diadematid spp. indet. (radioles from all sites) and Centrostephanus sp. (an interambulacral plate; early Miocene, Java). The radioles are probably a mixture of Diadema ± Centrostephanus ± Echinothrix. This is the first report of identifiable fossil diadematoid remains from Indonesia and demonstrates that these echinoids, so common in modern reef environments, were present in the Neogene of the region. Even though classified in open nomenclature, Centrostephanus sp. nevertheless provides further evidence for the Cenozoic record of a genus in which the only nominal species are of Late Cretaceous and Holocene age.  相似文献   

3.
Five isolated molars from two localities in the Northern Territory, the middle Miocene Bullock Creek and late Oligocene Kangaroo Well sites, are assigned to the new miralinid genus Barguru, which includes the three new species: Barguru kayir, Barguru maru and Barguru kula. The Miralinidae was previously thought to be restricted to the late Oligocene and early Miocene, but the occurrence at Bullock Creek extends the time range of this family into the middle Miocene. Analysis of metaloph development in the Miralinidae suggests that loph formation in this family followed a different trajectory to that of phalangerids.  相似文献   

4.
Durudawiri anfractus sp. nov. (Marsupialia: Miralinidae) is described from Riversleigh. This, the second described species of the genus, is very similar in morphology to, but much larger than, D. inusitatus. Durudawiri anfractus and D. inusitatus are found at similar sites, all early Miocene. The Miralinidae remains one of the most time-restricted families of marsupial, being found so far in only the late Oligocene and early Miocene.  相似文献   

5.
Seven species of marine bivalves, including six new taxa, are described from the Cape early Miocene Melville Formation which crops out on the Melville Peninsula, King George Island, West Antarctica. The bivalve assemblage includes representatives of the families Nuculidae, Ennucula frigida sp. nov., E. musculosa sp. nov.; Malletidae, Neilo (Neilo) rongelii sp. nov.; Sareptidae, Yoldia peninsularis sp. nov.; Limopsidae, Limopsis psimolis sp. nov.; Hiatellidae, Panopea (Panopea) sp. cf. P. regularis; and Pholadomyoida (Periploma acuta sp. nov.). Species studied come from four sedimentary sections measured in the upper part of the unit. Detailed morphologic features of nucloid and arcoid species are exceptionally well preserved and allow for the first time reconstruction of muscle insertions as well as dentition patterns of Cenozoic taxa. Known geological distribution of the species is in agreement with the early Miocene age assigned to the Cape Melville Formation. The bivalve fauna from Cape Melville Formation is the best known from Antarctic Miocene rocks, a time of complex geologic, paleogeographic and paleoclimatic changes in the continent. The new fauna introduces new taxonomic and palaeogeographic data that bear on the question of opening of sea gateways and distribution of Cenozoic biota around Antarctica.  相似文献   

6.
New bird fossils from the Santa Cruz Formation (lower–middle Miocene), Santa Cruz Province, Patagonia, Argentina, are described. They represent an indeterminate species of the extinct anhingid Macranhinga and a new genus and species of basal Anatidae Ankonetta larriestrai. The record of the giant darter Macranhinga constitutes the southernmost record for the family, and expands the known stratigraphic range of the genus, previously restricted to the upper Miocene. Based on an analysis of the fossil anhingid record from South America, we hypothesize that giant darters disappeared from South America in the early Pliocene due to climatic deterioration, regression of marine and freshwater environments, the arrival of placental carnivorous mammals, and also probably by competition with phalacrocoracid cormorants. The new anatid Ankonetta is based on an incomplete but informative tarsometatarsus, with superficial similarities to extant Dendrocygna. A brief overview of several fossil ducks from the Patagonian Cenozoic concludes that most pre-Pliocene examples belong to non-anatine taxa, indicating that plesiomorphic ducks were the dominant anseriforms in those times, a pattern also evident on other continents.  相似文献   

7.
Qianyu Li & Brian Mcgowran, 1994:03:28. Evolutionary morphological changes in the new genus Duoforisa: implication for classification and habit of the unilocular Foraminifera. Alcheringa 18, 121–134. ISSN 0311-5518.

Unlike other unilocular foraminifera, the new genus Duoforisa from the Late Oligocene to Early Miocene possesses a kidney-shaped test with two apertures on its distal ends. It contains two distinct and successional species, both new, and differentiated by their apertural details. In Duoforisa rima the apertures are slit-like, and become radial in the descendant D. diducta. Intermediate forms have transitional apertural configurations between the slit type and radial type, accompanied also by a change of the test outline from subtriangular to compactly U-shaped. The evolution of the lineage occurred during a period of enhanced upwelling in the Early Miocene and it was terminated just before the global warming at the Early-Middle Miocene boundary. This example suggests evolution of the unilocular foraminifera through successional morphological changes in test shape and in the aperture. Unilocular taxa have tended to flourish or speciate in cool or upwelling environments. Their contraction in the latest Early Miocene to early Middle Miocene was probably due to global warming and well oxygenated conditions which were widespread in the neritic domains of southern Australia.  相似文献   

8.
Campanile rupicolum sp. nov. is described from the early Miocene Upper Maude Limestone Member of Maude, Victoria. The genus has not hitherto been recorded from Victoria, a part of the Southeast Australian biogeographic Province, and was thought to be characteristic of the Austral-Indopacific Province. This is the oldest occurrence of the genus so far recorded from Australia.  相似文献   

9.
Conran, J.G., Bannister, J.M. & Lee, D.E., 2013. Fruits and leaves with cuticle of Laurelia otagoensis sp. nov. (Atherospermataceae) from the early Miocene of Otago (New Zealand). Alcheringa 37, 496–509. ISSN 0311-5518.

Laurelia otagoensis sp. nov. Conran, Bannister & D.E. Lee (Laurales: Atherospermataceae) is described from the earliest Miocene Foulden Maar diatomite deposit, Otago, New Zealand. The new species is represented by mummified fossil leaves with well-preserved cuticle and associated clusters of achenes bearing persistent, long plumose styles. This basal angiosperm family is of significance because of its classic southern disjunctions and ecological importance in extant Gondwana-type rainforests, but has a very sparse fossil record. The present study describes one of very few convincing leaf fossils for Atherospermataceae and the only definitive fossil fruits. The presence of fossil Laurelia in Oligo–Miocene New Zealand combined with fossil leaf impressions from the late Eocene, Miocene dispersed cuticle and pollen from the Oligocene to Holocene shows that the family has had a long history in Cenozoic New Zealand. These new fossils also support palaeoclimatic data suggesting warmer conditions in the earliest Miocene of New Zealand.

John G. Conran [john.conran@adelaide.edu.au], Australian Centre for Evolutionary Biology & Biodiversity and Sprigg Geobiology Centre, School of Earth and Environmental Sciences, Benham Bldg DX 650 312, The University of Adelaide, SA 5005 Australia; Jennifer M. Bannister [jennifer.bannister@xtra.co.nz], Department of Botany, University of Otago, PO Box 56, Dunedin, New Zealand; Daphne E. Lee [daphne.lee@otago.ac.nz], Department of Geology, University of Otago, PO Box 56, Dunedin, New Zealand. Received 17.12.2012; revised 9.4.2013; accepted 15.4.2013.  相似文献   

10.
An upper molar of a small bat, here described from an early Miocene freshwater lime-stone deposit at Riversleigh, northwestern Queensland, is the oldest record in Australia of the microchiropteran family Vespertilionidae. The new taxon is referred to the cosmopolitan genus Leuconoe, but it does not appear to be closely related to the two extant Australian species of this genus.  相似文献   

11.
12.
A functional-adaptive study of the postcranium of two late Miocene sabretooth borhyaenoid specimens (Mammalia, Metatheria) is presented. Thylacosmilus atrox developed a longer neck than in non-sabretooth borhyaenoids and was capable of strong flexion of the head. The lower back is well-stabilized and more rigid than in the other borhyaenoids. The forelimb appears well-suited for manipulating and capturing prey, with a probably well-developed deltoid and pectoral musculature. Compared with other Miocene borhyaenoids, the hip joint of Thylacosmilus is modified to allow greater postural flexibility (e.g. possibility of erect stances). The low greater femoral trochanter, the short and sigmoid tibia, and the semiplantigrade hind foot of Thylacosmilus precluded fast running. Thylacosmilus killed by stabbing, a peculiar mechanism that evolved in parallel in many other sabretooth taxa. This technique has significant functional-adaptive consequences on the postcranial skeleton, superimposed on the generalized morphological pattern reflected in its non-sabertooth relatives. The superficial similarities observed between Thylacosmilus and Smilodon overshadow real differences (at the level of joint patterns and muscular groups involved in particular movements), a condition that suggests the development in the marsupial form of a morphological type unique to the thylacosmilid lineage within Borhyaenoidea.  相似文献   

13.
Park, T. & Fitzgerald, E.M.G. September 2012. A late Miocene–early Pliocene Mihirung bird (Aves: Dromornithidae) from Victoria, southeast Australia. Alcheringa 36, 427–430. ISSN 0311-5518.

An incomplete tarsometatarsus identified as an indeterminate species of Dromornithidae is described from the upper Miocene–lower Pliocene shallow marine Black Rock Sandstone at Beaumaris, Victoria, Australia. This isolated specimen represents one of the few pre-Pleistocene dromornithids with a well-constrained geologic age. Additionally, it is one of the few pre-Quaternary dromornithid fossils recorded from southeast Australia. Comparisons with known dromornithid taxa suggest that the Beaumaris dromornithid is distinct from previously established species. This hitherto unknown species of dromornithid in the late Neogene of southeastern Australia cautions against deriving evolutionary patterns solely on the basis of fossils from northern Australia.  相似文献   

14.
The occurrence of Apatopygus gaudensis sp. nov. in the upper part of the late Oligocene (Chattian) Lower Coralline Limestone division, and the lower part of the early Miocene (probably late Aquitanian) Lower Globigerina Limestone division of the Maltese Islands (Central Mediterranean), is the first confirmed record of Apatopygus outside the Australia-New Zealand region. Apatotygus vincentinus (Tate, 1891) from the middle to late Eocene of southern Australia is the earliest known occurrence of the genus, possibly suggesting that Apatotygus may have evolved earlier in the Australasian region, or merely that it is yet to be discovered in pre-Oligocene strata in the Mediterranean area.  相似文献   

15.
Palynological studies of Cenozoic sediments from borehole PGD-1A in the easternmost extension of the Damodar Basin, West Bengal, India, provide important new palynological data from this basin, where previous data are rare. The palynoassemblage includes Striatriletes, Crassoretitriletes, Bacutriporites, Cauveripollis, Cheilanthoidspora, Palaeomalvaceaepollis, Tricollareporites, Pinuspollenites and Tsugaepollenites which suggest a late Oligocene - early Miocene age. Dinocyst genera such as Selenopemphix, Tuberculodinium, Hystrichokoipoma and Thalasiphora, recorded from the borehole, also support this age assignment. The assemblage indicates a tropical to subtropical humid climate with high rainfall. Deposition of the studied strata took place in a delta under shallow marine influence; this is the first evidence that a marine transgression extended into the Damodar Basin and that mangrove forest developed in the area.  相似文献   

16.
A new sthenurine taxon, Rhizosthenurus flanneryi gen. et sp. nov. from middle late Miocene deposits of Riversleigh, northwestern Queensland, is established on the basis of material previously assigned to Bulungamayinae. Postcranial remains belonging to an indeterminate basal macropodid are described. Cladistic analysis of 50 discrete postcranial characters coded for 16 ingroup and two outgroup taxa suggests that R. flanneryi is the most plesiomorphic member of a clade containing the late Miocene macropodid Hadronomas puckridgi and crown-group sthenurines. The indeterminate basal macropodid is placed as the immediate sister taxon to the bulungamayine Ganguroo bilamina and a monophyletic clade containing macropodines and sthenurines. This arrangement supports consideration of bulungamayines as ancestral to other macropodids and suggests that macropodines and sthenurines are monophyletic. However, the possibility of a diphyletic origin for Macropodinae and Sthenurinae from within Bulungamayinae cannot be dismissed.  相似文献   

17.
Stidham, T.A. & Zelenkov, N.V., September 2016. North American–Asian aquatic bird dispersal in the Miocene: evidence from a new species of diving duck (Anseriformes: Anatidae) from North America (Nevada) with affinities to Mongolian taxa. Alcheringa 41, XXX–XXX. ISSN 0311-5518.

Prehistoric intercontinental dispersals are often used to explain the modern geographic distributions of various organisms, including birds. The extant Holarctic avifauna formed largely in the Neogene, and thus dispersals of various taxa during the Miocene likely have had a strong long-lasting effect upon the geographical pattern of the extant avian communities. However, the uneven fossil record of Neogene birds prevents accurate reconstruction of the biogeographic history of many bird clades, and the present evidence on dispersal of birds in the Neogene among continents is very limited. Past dispersals are most likely to be documented by taxa that are well represented in the fossil record, including diving ducks. Although these birds have a rather substantial fossil record in Europe and Asia, they remain very poorly known from the Neogene of North America. Here we document a new species of Miocene diving duck represented by a proximal humerus and a distal tibiotarsus from the Esmeralda Formation in Nevada (USA) and describe it as a new species of the primitive diving duck genus Protomelanitta Zelenkov (Protomelanitta bakeri sp. nov.), previously known only from the middle Miocene of Mongolia. Both species (from Mongolia and Nevada) are from the ca 11–12 Ma age range during the warm (though cooling) middle Miocene after the Middle Miocene Climatic Optimum and Middle Miocene Climate Transition. Given their proposed close relationship, it appears that Protomelanitta dispersed between Asia and North America, and this instance is the first clear indication of an aquatic bird dispersal between North America and Eurasia in the middle Miocene. This palaeobiogeographical event predates the famous immigration of Hipparion horses to the Old World and the late Miocene dispersals between continental Eurasian and North American faunas in general, but likely reflects one prolonged faunal interchange related to global climatic conditions and its effects.

Thomas A. Stidham* [], Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China; Nikita V. Zelenkov [], Cabinet of Paleornithology, Borissiak Paleontological Institute, Russian Academy of Sciences, Profsoyuznaya 123, Moscow 117997, Russia.  相似文献   


18.
19.
Continental deposits of the Cullen Formation (early or middle Miocene) exposed on the northeast coast of Isla Grande de Tierra del Fuego (southernmost Patagonia) are analyzed. Twenty-four taxa of algae, and bryophyte and pteridophyte spores are identified, including three new species, which are Anthocerisporis gandolfii sp. nov., Coptospora archangelskyi sp. nov. and Ophioglossisporites cullensis sp. nov. Sedimentologic and palynological data suggest a system of meandering water channels. The diverse and abundant spore assemblage reinforces the proposed paleoenvironment indicated by pollen assemblage and stratigraphy, consisting of humid temperate forests and local occurrences of bog, freshwater and near-shore lake communities.  相似文献   

20.
This paper reports the discovery of three of the most iconic New Caledonian endemic genera, Amphorogyne, Paracryphia and Phelline, as dispersed leaf cuticle fossils in the early Miocene of New Zealand. New Caledonia's endemic angiosperm families have given it a reputation as one of the most interesting botanical regions in the world, but unfortunately it has no known pre-Pleistocene Cenozoic plant fossil record. A once more widespread distribution of its key plants in the context of a cooling and drying Neogene world suggests the current vegetation of New Caledonia is the result of contraction, or even a migration, from more southerly landmasses. Thus, New Zealand may have been a source of at least some of New Caledonia's plants.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号