Palaeomagnetic ages of late cretaceous and tertiary weathered profiles in the Eromanga Basin,Queensland

Two iron-enriched weathered profiles, both widely distributed in the Eromanga and Surat Basins of Queensland, have been investigated palaeomanetically. Normal and reversed polarities have been obtained from each profile, indicating that the weathering events spanned at least one reversal of the geomagnetic field. The minimum duration of weathering for the older of the two profiles is estimated as 10,000 years. The palaeomagnetic directions when compared with the Late Cretaceous and Cainozoic apparent polar wander curve for Australia give a Maastrichtian to Early Eocene age for one profile and an approximately Late Oligocene age for the other. These ages are consistent with times of high palaeotemperature indicated by oxygen isotope analysis of marine fossils of the Southeast Indian Ocean. The pole position for the younger profile is not significantly different from pole positions obtained in previous palaeomagnetic investigations of weathered rocks in Western Australia, South Australia and the Northern Territory, supporting the long-held view of a mid-Tertiary continent-wide weathering event in Australia.     

Biogeographical and geological evidence for a smaller, completely-enclosed Pacific Basin in the Late Cretaceous

Aim To use biogeographical, palaeomagnetic, palaeosedimentary, and plate circuit data from Late Cretaceous regions in and around the Pacific to test the plate tectonic hypothesis of a pre‐Pacific superocean. Location East Asia, Australia, Antarctica, the western Americas, and the Pacific. Methods Literature surveys of the distributions of Cretaceous, circum‐Pacific taxa were compared with palaeomagnetic and palaeosedimentary data. Uncontroversial plate motions based on seafloor spreading data were also used to test the results of the biogeographical and palaeomagnetic analyses. Results The distributions of Cretaceous terrestrial taxa, mostly dinosaurs, imply direct, continental connections between Australia and East Asia, East Asia and North America, North America and South America, South America and Antarctica, and Antarctica and Australia. Palaeomagnetic, palaeosedimentary, and basic plate circuit analyses require little to no latitudinal motion of the Pacific plate with respect to the surrounding continents. Specifically, the data implies that western North America, East Asia, and the Pacific plate all increased in latitude by roughly the same amount (c. 11 ± 5°) since the Campanian – and that the Pacific Ocean Basin has increased in length north‐to‐south. Main conclusions Each of the analyses provides independent corroboration for the same conclusion: the Late Cretaceous Pacific plate was completely enclosed by the surrounding continents and has not experienced significant latitudinal motion with respect to North America, East Asia, or the Bering land bridge. This contrasts significantly with the plate tectonic history of the Pacific, implying instead that the Pacific plate formed in situ, pushing the continents apart as the plate and basin expanded. These results also substantiate recent biogeographical analyses that have concluded that a narrower Pacific Ocean Basin in the Mesozoic and early Tertiary provides the most reasonable explanation for the great number of trans‐Pacific disjunctions of poor dispersing taxa.     

柴达木盆地第四系介形类化石带与磁性柱

柴达木盆地东部晚上新世－全新世湖相沉积巨厚,无明显间断,微体化石丰富。区内已建厚度超过２０００ｍ的第四系磁性柱中,记录了布容、松山和高斯极性时带。由于有剖面上部的同位素测年数据和剖面中、下部的介形类化石带序列的对比成果配合验证,布容、松山极性时下限的确定和布拉克、莫纳、琵琶湖、奥尔杜威、马默思等亚极性时的鉴别依据充足可信。据此极性年表标定的晚上新世－第四纪介形类化石带序列中１２个标准化石的时限得以识别。古生态研究与壳体元素分析的资料表明,始见于距今３０５万年的Ｍｉｃｒｏｌｉｍｎｏｃｙｔｈｅｒｅｓｉｎｅｎｓｉｓ指示低温水体,该化石带的出现标志着中新世以来柴达木盆地古气候的首次明显变冷。     

A morphometric analysis of the Late Pleistocene Human Skeleton from the Moh Khiew Cave in Thailand.

Few Late Pleistocene human remains have been found in Southeast Asia and the morphological features of the people of that age are still largely unknown due to the virtual lack of human remains in the area. Recent excavations at the Moh Khiew Cave in Thailand resulted in the discovery of a Late Pleistocene human skeleton in a relatively good state of preservation. An AMS radiocarbon date on the charcoal sample gathered from the burial gave a result of 25,800 +/- 600 BP, implying that the inhabitants of Moh Khiew Cave resided in a part of Sundaland during the last glacial age. In debates on the population history of Southeast Asia, it has been repeatedly advocated that Southeast Asia was occupied by indigenous people akin to present-day Australo-Melanesians prior to an expansion of migrants from Northeast Asia into this area. Morphometric analyses were undertaken to test the validity of this hypothesis. In the present study, cranial and dental measurements recorded from the Moh Khiew remains are compared with those of early and modern samples from Southeast Asia and Australia. These comparisons demonstrate that the Moh Khiew specimen resembles the Late Pleistocene series from Coobool Creek, Australia in both cranial and dental measurements. These results suggest that the Moh Khiew skeleton, as well as other fossil remains from the Tabon, Niah and Gua Gunung sites, represents a member of the Sundaland population during the Late Pleistocene, who may share common ancestry with the present-day Australian Aborigines and Melanesians.     

Significance of Devonian-Carboniferous radiolarians from accretionary terranes of the New England orogen, eastern Australia

Radiolarians provide age constraints for many previously undated terranes in the New England Orogen (NEO), a tectonic collage developed along the eastern margin of Australia.Djungati terrane, the age range of which was previously unknown, contains two distinctive siliceous sedimentary lithofacies. The oldest is a thick sequence of red, ribbon-bedded cherts which probably accumulated in a deep ocean-floor setting far from land. Middle Silurian through Late Devonian radiolarians have been recovered from these cherts. Green tuffaceous cherts which contain a latest Devonian (Famennian) radiolarian fauna depositionally overlie the lower red ribbon-bedded chert sequence. These cherts are intercalated with volcaniclastic sediments and the fauna which they contain can be used to constrain the timing of accretion of older rocks into a subduction complex.Anaiwan terrane, which was also previously undated, contains thin ribbon-bedded cherts which are depositionally overlain by tuffaceous chert, siliceous siltstones and volcaniclastic sediments. Latest Devonian (?late Famennian) and Early Carboniferous radiolarians have been recovered from these cherts and tuffaceous siltstones.Radiolarians also occur in fine-grained siliceous sediments of the Yarrimie Formation, part of the Gamilaroi terrane. These radiolarians are of Late Devonian (Frasnian) affinity and their presence indicates that blocks of limestone, which contain Givetian conodonts and corals and were previously thought to indicate the age of the Yarrimie Formation, are allochthonous.     

U-series evidence for widespread reef development in Shark Bay during the last interglacial

Field observations and U-series ages reveal that Shark Bay, Western Australia (WA) has been inundated by the sea on at least three occasions during the Late Pleistocene/Holocene, resulting in a succession of marine deposits around the Bay. The exact age of these deposits has until now been problematic due to a lack of reliable and accurate age data. This study reports 16 new U-series coral dates from emergent reef deposits around Shark Bay, and point to an extended period of coral reef development during the peak of the last interglacial, marine isotope stage (MIS) 5e. This is attributed to enhancement of marine circulation within the reaches and basins, a result of higher sea levels and an absence of major sill and bank structures. Stromatolites are absent from the geological record within Shark Bay until the late Holocene, suggesting that sea levels and marine sedimentary processes that have operated during the present sea-level highstand are unique to this period. There is little direct evidence of fossil reef development occurring during interglacials of the middle/late Pleistocene (MIS 9/11).     

Historical biogeography of the hyperdiverse hidden snout weevils (Coleoptera,Curculionidae, Cryptorhynchinae)

The first dated phylogeny of the weevil subfamily Cryptorhynchinae is presented within a framework of Curculionoidea. The inferred pattern and timing of weevil family relationships are generally congruent with previous studies, but our data are the first to suggest a highly supported sister-group relationship between Attelabidae and Belidae. Our biogeographical inferences suggest that Cryptorhynchinae s.s. originated in the Late Cretaceous (c. 86 Ma) in South America. Within the ‘Acalles group’ and the ‘Cryptorhynchus group’, several independent dispersal events to the Western Palaearctic via the Nearctic occurred in the Late Cretaceous and Early Paleogene. A second southern route via Antarctica may have facilitated the colonization of Australia in the Late Cretaceous (c. 82 Ma), where a diverse Indo-Australian clade probably emerged c. 73 Ma. In the Early Eocene (c. 50–55 Ma), several clades independently dispersed from Australia to proto-New Guinea, i.e. the tribe Arachnopodini s.l., the ‘Rhynchodes group’ and the genus Trigonopterus. New Zealand was first colonized in the Late Palaeocene (c. 60 Ma). Divergence time estimations and biogeographical reconstructions indicate that the colonization of New Guinea is older than expected from current geological reconstructions of the region.     

Dispersal,vicariance, and the Late Cretaceous to early tertiary land mammal biogeography from South America to Australia

A review of paleontological, phyletic, geophysical, and climatic evidence leads to a new scenario of land mammal dispersal among South America, Antarctica, and Australia in the Late Cretaceous to early Tertiary epochs. New fossil land vertebrate material has been recovered from all three continents in recent years. As regards Gondwana, the present evidence suggests that monotreme mammals and ratite birds are of Mesozoic origin, based on both geochronological and phyletic grounds. The occurrence of monotremes in the early Paleocene (ca. 62 Ma) faunas of Patagonia and of ratites in late Eocene (ca. 41-37 m.y.) faunas of Seymour Island (Antarctic Peninsula) probably is an artifact of a much older and widespread Gondwana distribution prior to the Late Cretaceous Epoch. Except for South American microbiotheres being australidelphians, marsupial faunas of South America and Australia still are fundamentally disjunct. New material from Seymour Island (Microbiotheriidae) indicates the presence there of a derived taxon that resides in a group that is the sister taxon of most Australian marsupials. There is no compelling evidence that dispersal between Antarctica and Australia was as recent as ca. 41 Ma or later. In fact, the derived marsupial and placental land mammal fauna of Seymour Island shows its greatest affinity with Patagonian forms of Casamayoran age (ca. 51–54 m.y.). This suggests an earlier dispersal of more plesiomorphic marsupials from Patagonia to Australia via Antarctica, and vicariant disjunction subsequently. This is consistent with geophysical evidence that the South Tasman Rise was submerged by 64 Ma and with geological evidence that a shallow water marine barrier was present from then onward. The scenario above is consistent with molecular evidence suggesting that australidelphian bandicoots, dasyurids, and diprotodontians were distinct and present in Australia at least as early as the 63-Ma-old australidelphian microbiotheres and the ancient but not basal australidelphian,Andinodelphys, in the Tiupampa Fauna of Bolivia. Land mammal dispersal to Australia typically has been considered to be at a low level of probability (e.g., by sweepstakes dispersal). This study suggests that the marsupial colonizers of Australia included already recognizable members of the Peramelina, Dasyuromorphia, and Diprotodontia, at least, and entered via a filter route rather than by a sweepstakes dispersal.To whom correspondence should be addressed.     

Permian, Jurassic and Early Cretaceous palynofloral assemblages from subsurface sedimentary rocks in Chuperbhita Coalfield, Rajmahal Basin, India

The results of a palynological analysis of the sedimentary sequence of Borehole RCH-151, Chuperbhita Coalfield, Rajmahal Basin, Bihar are presented here. The borehole penetrated the Rajmahal Formation (comprising two traps sandwiching an intertrappean bed), the thinly represented Dubrajpur Formation and in its lower part, the Coal Measures. The coal-bearing interval is associated with Scheuringipollenites barakarensis, Faunipollenites varius, Densipollenites indicus, Gondisporites raniganjensis and Densipollenites magnicorpus Assemblage Zones. The presence of these biostratigraphic units indicates correlation with the Barakar Formation (Early Permian) and the Barren Measures and Raniganj Formations (both Late Permian). This is the first record, in the Chuperbhita Coalfield, of Late Permian strata, which appear to represent a condensed sequence. Prior to the present study, the Permian succession was thought to have been associated entirely with the Barakar Formation. The overlying Dubrajpur Formation yielded a distinct spore-pollen assemblage (in association with the first report of dinoflagellate, Phallocysta), which is assigned to the newly identified Callialasporites turbatus palynozone of latest Early to early Middle Jurassic age. The diverse spore-pollen flora of the intertrappean bed (Rajmahal Formation) incorporates several age marker taxa, viz. Undulatisporites, Leptolepidites, Klukisporites, Ruffordiaspora, and Coptospora. The assemblages from intertrappean beds are correlated with the Ruffordiaspora australiensis palynozone of Australia. Thus the palynodating indicates Permian, latest Early to early Mid-Jurassic and Early Cretaceous age for the strata studied. This is the first record of definite Jurassic microfossils from the non-marine sequence of Rajmahal Basin, India.     

Waggle dance behavior associated with seasonal absconding in colonies of the African honey bee,Apis mellifera scutellata

Summary Waggle dance activity associated with seasonal absconding (migration) was investigated in two colonies of the African honey bee. Prior to absconding, waggle dances regularly communicated distances up to 10–20 km from the nests. However, compared to waggle dances observed during nonabsconding periods, those occurring prior to migration were less associated with food sources, occurred during periods of little or no flight activity, and exhibited great variability in the communication of distance by consecutive waggle runs of individual bees. It is therefore unlikely that migration dances communicated the locations of, or stimulated immediate recruitment for, specific foraging or nesting sites. Rather, the dances may have functioned to establish a general route of travel. The majority of migration dances observed were oriented in an easterly direction, and upon departure both colonies traveled towards the E-SE. The orientation of migration dances occurred independently of the directions communicated by waggle dances associated with past foraging success or the sampling of alternate foraging areas. Migration dance orientation may have been affected by prevailing wind directions, because during the migration period winds blew primarily from the east. However, it is unlikely that wind direction was the only factor influencing migration dance orientation. The lack of immediate flight activity associated with migration dance performance suggests the dances may have gradually prepared colonies for migratory movement by conveying a message to fly for a long, but unspecified distance in a certain direction. Waggle dances associated with migration may therefore function differently from those associated with foraging and nest site selection, which convey both the distance and direction to specific locations.     

Cambrian biostratigraphy of the Bowers back-arc basin,Northern Victoria Land,Antarctica — A review

The Bowers Mountains in Northern Victoria Land contain the richest Cambrian Series 3 (Miaolingian, middle Cambrian) and Cambrian Series 4 (Furongian, late Cambrian) fossiliferous successions in Antarctica. Almost all the fossils are found within the Bowers Supergroup, which outcrops within the Bowers Terrane, a fault-bounded northwest-southeast oriented strip in Northern Victoria Land. The fossils provide the main age control on the history and evolution of the Bowers volcanic arc and back-arc basin. The great bulk of the fossils occur within the Spurs Formation. The fossil assemblages are dominated by agnostoids and polymerid trilobites with most ranging in age from Drumian to Paibian, although one fauna is of Jiangshanian age. Over 40 agnostoid taxa and over 100 polymerid trilobite taxa have been recorded from the rocks of the Bowers Supergroup. The youngest fauna occurs within the adjacent Robertson Bay Terrane, where a limited fauna of polymerid trilobites and conodonts from within a limestone olistolith have a very late Cambrian or early Ordovician age. Faunal affinities are mainly with Australia, New Zealand, North and South China and the Himalaya with lesser ties to Iran, Kazakhstan, Siberia and Laurentia.     

Late Late Cambrian Trilobites From Near Birch Inlet, South-Western Tasmania

The first late Late Cambrian basinal-facies trilobites to be described from Tasmania are from a succession exposed 8.5 km west of Birch Inlet, south-western Tasmania. Twenty-one taxa are described; the six agnostoid species include a new species of Leiagnostus, L inletensis. The polymeroids include five new species: Hedinaspis uniformis, Proceratopyge longa, Niobella birchensisSkljarella expansa and Ivshinaspis reticulata.SkljarellaIvshinaspis are described for the first time from Australia. The specimens are preserved in siltstone belonging to a basinal facies; the fauna has more in common with those of the South-East China Faunal Province than with the shallow-water carbonate-facies faunas from northern Australia. The fauna is of late Late Cambrian age (Payntonian–earliest Datsonian) on the north Australian biostratigraphic scale. The Birch Inlet fauna is correlated with those of the Siyangshan Formation of Zhejiang, the Guoziguonen Formation of Xinjiang and the Shengjiawan Formation of Hunan. There are similarities with late Late Cambrian faunas from Nevada, Kazakhstan and New Zealand. K ey words : Trilobita, Late Cambrian, Tasmania, basinal facies, biostratigraphy, palaeobiogeography.     

A late pleistocene and holocene vegetation and environmental record from Lake Wangoom, Western Plains of Victoria, Australia

Pollen, microfaunal and sedimentological evidence from the top 20 m of sediment in a closed volcanic crater lake is used to construct a detailed record of vegetation and environmental conditions through the Holocene and a substantial part of the Late Pleistocene. Radiocarbon dating suggests that the sequence covers tha last 51,000 yr or so. High lake-levels and the presence of forest or woodland vegetation indicate that the Holocene and the basal few thousand years of the record experienced wet and warm conditions. The earliest period was succeeded by a long phase of lower but variable moisture levels before more arid conditions resulted in the replacement of forest and woodland by herbaceous vegetation and frequent lake drying. Periods of slight amelioration occurred between about 27,000 and 19,000 and before 15,000 radiocarbon yr ago. Maximum aridity occurred between about 19,000 and 10,000 yr B.P., a period incorporating the height of the last glacial. During the Pleistocene, the lake became gradually more saline but has been fresh during the Holocene, even under low lake-levels.

An increase in charcoal values is recorded, probably around 20,000 years ago, and this could have resulted from increased burning as a result of the activities of Aboriginal people. This may have also caused a change in understorey vegetation from one composed largely of Asteraceae, to grassland.

The record is compared with others from southeastern Australia and there is good correspondence through the last 20,000 or 30,000 yr but, before this, problems of dating and the condensed nature of most sequences prevent detailed correlation.     

Earliest humans in Europe: the age of TD6 Gran Dolina, Atapuerca, Spain

Hominid remains found in 1994 from the stratified Gran Dolina karst-filling at the Atapuerca site in NE Spain were dated to somewhat greater than 780 ka based on palaeomagnetic measurements, making these the oldest known hominids in Europe (sensu stricto). We report new ESR and U-series results on teeth from four levels of the Gran Dolina deposit which confirm the palaeomagnetic evidence, and indicate that TD6 (from which the human remains have been recovered) dates to the end of the Early Pleistocene. The results for the other levels are consistent with estimates based mainly on microfaunal evidence, and suggest that TD8, TD10 and TD11 date to the Middle Pleistocene.     

Carnivoran remains from the Malapa hominin site, South Africa

Recent discoveries at the new hominin-bearing deposits of Malapa, South Africa, have yielded a rich faunal assemblage associated with the newly described hominin taxon Australopithecus sediba. Dating of this deposit using U-Pb and palaeomagnetic methods has provided an age of 1.977 Ma, being one of the most accurately dated, time constrained deposits in the Plio-Pleistocene of southern Africa. To date, 81 carnivoran specimens have been identified at this site including members of the families Canidae, Viverridae, Herpestidae, Hyaenidae and Felidae. Of note is the presence of the extinct taxon Dinofelis cf. D. barlowi that may represent the last appearance date for this species. Extant large carnivores are represented by specimens of leopard (Panthera pardus) and brown hyaena (Parahyaena brunnea). Smaller carnivores are also represented, and include the genera Atilax and Genetta, as well as Vulpes cf. V. chama. Malapa may also represent the first appearance date for Felis nigripes (Black-footed cat). The geochronological age of Malapa and the associated hominin taxa and carnivoran remains provide a window of research into mammalian evolution during a relatively unknown period in South Africa and elsewhere. In particular, the fauna represented at Malapa has the potential to elucidate aspects of the evolution of Dinofelis and may help resolve competing hypotheses about faunal exchange between East and Southern Africa during the late Pliocene or early Pleistocene.     

新疆哈密拉甫却克墓地人的颅面部测量学特征

新疆地处欧亚大陆东西方交汇处,公元前200年以后的人群迁徙、融合历程能够反映丝绸之路沿线地区不同族群的形成历史和多元文化的互动模式。拉甫却克墓地是东疆哈密地区首次发掘的历史时期墓葬群。本文基于该墓地10例成年人颅面部测量数据,采用多元统计及生物距离的方法来评估拉甫却克墓地的人群结构,并对哈密绿洲地带青铜时代晚期到历史时期的人群变迁进行初步探索。结果显示：1）拉甫却克人群呈现出明显的异质性,既有与欧亚大陆东部人群颅面部特征相近的个体,也有表现出东西方混合特征的个体;2）青铜时代晚期至早期铁器时代（公元前2000年至公元前1000年）,哈密人群在体质特征上存在连续性;而早期铁器时代到历史时期（公元前1000年以后）,随着欧亚大陆东部人群遗传贡献的增加,哈密人群体质特征发生明显变化。结合考古证据和历史记录,新的人骨标本让我们对哈密历史时期的人群迁徙和融合有了初步认识,也使后续可以针对这一问题展开更详细的多学科研究。     

Epidemiology of bovine ephemeral fever in Australia 1981-1985

Bovine ephemeral fever is an important viral disease of cattle in Australia. The disease occurred each year, principally in summer and autumn, between 1981 and 1985. Queensland and the northern half of New South Wales were areas of greatest activity with only sporadic cases being reported from the Northern Territory and the northern third of Western Australia. Since 1981, the disease has been endemic in an extensive area of eastern Australia and has tended to occur in widely scattered outbreaks rather than the north-south advancing wave form of the epidemics of 1936-37, 1967-68, 1970-71 and 1972-74. The southernmost outbreaks between 1981 and 1985 were well within the limits of these earlier epidemics. The pattern of disease appears to have become seasonally endemic rather than periodically endemic in the northern two-thirds of eastern Australia. Ephemeral fever was not recorded in Victoria, Tasmania, South Australia or the southern part of Western Australia between 1981 and 1985. The disease was most frequently reported in cattle under 3 years of age, but also occurred in older cattle.     

A review of theropod dinosaurs from the Late Jurassic to mid-Cretaceous of Southeast Asia

Several non-avian theropod dinosaurs, as well as some Mesozoic birds, have been reported from Southeast Asia. The fossils are dominantly found in northeastern Thailand, however, one bizarre theropod has been described from Laos, one theropod has been reported from Malaysia, and some avian and non-avian theropods have been recently reported from Myanmar. The temporal distribution of Southeast Asian theropods ranges from the Late Jurassic to the mid-Cretaceous. All non-avian theropod faunas from Southeast Asia consist of non-maniraptoran tetanurans. They show similarity to Chinese plus Japanese theropods during the Early Cretaceous in broad systematic terms. During this time, megaraptorans can be found only in Japan, Australia, Brazil, and possibly Thailand, whereas tyrannosauroids can be found in China, Europe, possibly Brazil and Australia. Spinosaurids, carcharodontosaurians, and some coelurosaurs such as ornithomimosaurs were almost cosmopolitan. Metriacanthosaurids, on the other hand, were endemic to Europe and Asia including China and Thailand during the Middle to Late Jurassic.     

Determinants of loss of mammal species during the Late Quaternary 'megafauna' extinctions: life history and ecology,but not body size

Extinctions of megafauna species during the Late Quaternary dramatically reduced the global diversity of mammals. There is intense debate over the causes of these extinctions, especially regarding the extent to which humans were involved. Most previous analyses of this question have focused on chronologies of extinction and on the archaeological evidence for human-megafauna interaction. Here, I take an alternative approach: comparison of the biological traits of extinct species with those of survivors. I use this to demonstrate two general features of the selectivity of Late Quaternary mammal extinctions in Australia, Eurasia, the Americas and Madagascar. First, large size was not directly related to risk of extinction; rather, species with slow reproductive rates were at high risk regardless of their body size. This finding rejects the 'blitzkrieg' model of overkill, in which extinctions were completed during brief intervals of selective hunting of large-bodied prey. Second, species that survived despite having low reproductive rates typically occurred in closed habitats and many were arboreal or nocturnal. Such traits would have reduced their exposure to direct interaction with people. Therefore, although this analysis rejects blitzkrieg as a general scenario for the mammal megafauna extinctions, it is consistent with extinctions being due to interaction with human populations.