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1.
Several traces of biological interaction were found on penguin bones from the basal levels (Aquitanian) of the Miocene Gaiman Formation in the lower Chubut valley of the Provincia del Chubut, Argentina. The fossil-bearing beds were deposited in littoral to sublittoral environments within sediments of mostly pyroclastic origin. We interpret many traces to have been produced by predators and/or scavengers while the penguins were still in a breeding area. Many bones show cracking marks due to aerial exposure. The material is disarticulated as is usual in recent breeding areas. Potential predators were coeval terrestrial mammals, most probably marsupial carnivores. After a marine transgression, these bones were buried or exposed on the sea bottom where they could be colonized by algae, sponges, cnidarians, and other benthic organisms. We identified sponge borings in several bones. Other traces are interpreted to have been produced by echinoderms feeding on sponges or algae. No evidence of other invertebrate predators such as muricid or naticid gastropods, or decapods was found. Finally, other traces appear to have been generated by shark and possibly teleostean vertebrates feeding on epibionts. One coracoid is interpreted to have been marked by a shark that is common in the Gaiman Formation, the carcharhiniform Galeocerdo aduncus. From an ethological (Seilacherian) classification, traces on bones from the Gaiman Formation include Domichnia (sponge perforations), Praedichnia (terrestrial marsupials, sharks, teleosteans) and Pasichnia (echinoderms). Remarkably, remains of marine organisms with skeletons made of calcium carbonate are very poorly preserved in the Gaiman Formation. Only large oysters, sparse shell fragments, skeletal moulds, and bioturbation is evident. The fossil assemblage is mainly composed of phosphatic (e.g. teeth, bones, crustacean parts) and siliceous (sponge spicules, diatoms) remains. 相似文献
2.
Thulborn, R.A., 2013. Lark Quarry revisited: a critique of methods used to identify a large dinosaurian track-maker in the Winton Formation (Albian–Cenomanian), western Queensland, Australia. Alcheringa, http://dx.doi.org/10.1080/03115518.2013.748482 A remarkable assemblage of dinosaur tracks in the Winton Formation (Albian–Cenomanian) at Lark Quarry, a site in western Queensland, Australia, has long been regarded as evidence of a dinosaurian stampede. However, one recently published study has claimed that existing interpretation of Lark Quarry is incorrect because the largest track-maker at the site was misidentified and could not have played a pivotal role in precipitating a stampede. That recent study has identified the largest track-maker as an ornithopod (bipedal plant-eating dinosaur) similar or identical to Muttaburrasaurus and not, as formerly supposed, a theropod (predaceous dinosaur) resembling Allosaurus. Those iconoclastic claims are examined here and are shown to be groundless: they are based partly on misconceptions and partly on fabricated data that have been assessed uncritically using quantitative measures of questionable significance. Such ill-founded claims do not reveal any substantial flaw in the existing interpretation of the Lark Quarry dinosaur tracks. 相似文献
3.
The Taebaeksan Basin occupies the central-eastern part of the Korean peninsula and was a low-relief shallow marine carbonate shelf on which the Cambro-Ordovician Choson Supergroup was deposited. In the Taebaeksan Basin trilobites are among the most dominant fossil groups in the Lower Ordovician, but they become less important in Middle Ordovician faunal assemblages. The Early Ordovician trilobite faunas of the Taebaeksan Basin are characterised by the common occurrence of pandemic genera such as Jujuyaspis, Leiostegium, Asaphellus, Protopliomerops, Hystricurus, Apatokephalus, Shumardia, Asaphopsoides, and Kayseraspis. Biogeographically significant trilobite taxa include Yosimuraspis, Dikelokephalina, Koraipsis, and Chosenia. These Ordovician trilobite faunas, which thrived in shallow marine environments, show a remarkable similarity with faunas from North China, implying that the Taebaeksan Basin was connected through contiguous shallow waters to North China. These Sino-Korean faunas exhibit a close biogeographic connection with Australian faunas, with which they share some endemic genera, whereas they are more distantly related to the faunas of South China, South America, and North America. Based on these palaeobiogeographical features, it is suggested that in the early Palaeozoic much of the present Korean peninsula including the Taebaeksan Basin belonged to the Sino-Korean block, while part of the peninsula was derived from the Yangtze block. 相似文献
4.
W ang, Z.H., B ergström, S.M., Z hen, Y.Y., C hen, X. & Z hang, Y.D., 2013. On the integration of Ordovician conodont and graptolite biostratigraphy: New examples from Gansu and Inner Mongolia in China. Alcheringa 37, 510–528. ISSN 0311-5518.Few Ordovician successions in the world contain both biostratigraphically highly diagnostic conodonts and graptolites permitting an integration between standard biozones based on these fossil groups. The Sandbian Guanzhuang section in the vicinity of Pingliang in the Gansu Province has an outstanding graptolite record through most of the Nemagraptus gracilis and Climacograptus bicornis graptolite biozones. Calcareous interbeds in the succession yield biostratigraphically important conodonts, including some species used for biozonations in Baltoscandia and the North American Midcontinent. Likewise, the middle–upper Darriwilian Dashimen section in the Wuhai region of Inner Mongolia hosts both diverse graptolites of the Pterograptus elegans, Didymograptus murchisoni and lowermost Nemagraptus gracilis biozones, and conodonts of Midcontinent and Baltoscandic types. The distribution patterns of these index fossil groups provide an unusual opportunity to closely correlate conodont and graptolite biozones in the middle to upper Darriwilian to Sandbian interval. For instance, the base of the C. bicornis Biozone is approximately coeval with the base of the Baltoscandic B. gerdae Subbiozone and a level near the middle of the North American P. aculeata Biozone. Zhi-hao Wang [zhwang@nigpas.ac.cn] Xu Chen [xu1936@gmail.com], and Yuan-dong Zhang [ydzhang@nigpas.ac.cn], Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China; Stig M. Bergström [stig@geology.ohio-state.edu], School of Earth Sciences, Division of Earth History, The Ohio State University, Columbus, OH 43210, USA; Yong Yi Zhen [yongyi.zhen@austmus.gov.au], Australian Museum, 6 College Street, Sydney NSW 2010, Australia. 相似文献
5.
M cC obb, L.M.E., B oyce, W.D., K night, I. & S touge, S., 2014. Lower Ordovician trilobites from the Septembersø formation, North-East Greenland. Alcheringa 38, 575–598. ISSN 0311-5518.The informally named Septembersø formation is a 76 m thick succession of microbial and peritidal shelf carbonates deposited on the North-East Greenland shelf of Laurentia. The formation, assigned to the lower part of the Cape Weber Formation in all previous studies, lies disconformably upon the Skullrockian Antiklinalbugt Formation (revised) and conformably below the Tulean to Blackhillsian Cape Weber Formation (revised) in the Fimbulfjeld Group. With the exception of Randaynia, the modest trilobite fauna recovered from the Septembersø formation consists exclusively of bathyurids, and all represent new species. Both Chapmanopyge knudseni sp. nov. and Punka adamsi sp. nov. are represented by sufficient material to merit specific names. The remaining taxa, belonging to Bolbocephalus, Peltabellia, Randaynia and Chapmanopyge are left in open nomenclature. The trilobite genera present suggest that the Septembersø formation is referable to the Tulean Stage of the Ibexian Series, latest Tremadocian/earliest Floian in Global Standard terms. Lucy M. E. McCobb [lucy.mccobb@museumwales.ac.uk], Department of Natural Sciences, National Museum of Wales, Cathays Park, Cardiff CF10 3NP, UK; W. Douglas Boyce [dougboyce@gov.nl.ca] and Ian Knight [ianknight@gov.nl.ca], Geological Survey, Newfoundland and Labrador Department of Natural Resources, PO Box 8700, St. John’s, NL, Canada A1B 4J6; Svend Stouge [svends@snm.ku.dk], Natural History Museum of Denmark (Geological Museum), Øster Voldgade 5–7, DK-1350 Copenhagen K, Denmark. 相似文献
6.
Study of the taxonomy, evolution and distribution of Tremadoc graptolites and their sequences in China and other representative sections around the world indicates that five graptolite diversity events can be recognised during the Tremadoc interval. The taxonomic validity of the suborder Graptodendroidina is advocated. 相似文献
7.
T urvey, S.T. & S iveter, D.J., June 2007. Assignment of the South Chinese Ordovician trilobite Calymene paronai to Neseuretus. Alcheringa 31, 173‐183. ISSN 0311-5518. Calymene paronai Pellizzari, 1913 Pellizzari, G. 1913. Fossili Palaeozoici antichi dello Scensi (Cina). Rivista Italiana di Palaeontologia, 19: 33–47. [Google Scholar] was described on the basis of an almost complete enrolled specimen from the Ordovician (probably the early Llanvirn Yangtzeella poloi Biozone) of southern Shaanxi, China. It represents one of the first Chinese trilobite species to have been established, but has been almost completely ignored by subsequent workers. This species is redescribed and reassigned to the Gondwanan inner shelf indicator calymenid Neseuretus, compared with other South Chinese taxa previously assigned to this genus, and interpreted as a senior synonym of N. concavus Lu, 1975 Lu, Yanhao. 1975. Ordovician trilobite faunas of central and southwestern China. Palaeontologica Sinica, New Series B, 11: 1–463. (in Chinese and English) [Google Scholar]. 相似文献
8.
V andenB erg, A.H.M. & M aletz, J., April 2016. The holotype of Pseudisograptus manubriatus manubriatus (Hall, 1914)—implications for the identification of Pseudisograptus manubriatus subspecies. Alcheringa 40, xxx–xxx. ISSN 0311-5518The holotype of Pseudisograptus manubriatus manubriatus (Hall, 1914) has been rediscovered in the collections of Museum Victoria and is recognized to belong to Pseudisograptus manubriatus harrisi as described by Cooper & Ni (1986). This taxon becomes a junior synonym of P. m. manubriatus. The selected neotype of Pseudisograptus manubriatus manubriatus (Hall, 1914) can be referred to Pseudisograptus manubriatus texanus Cooper & Ni, 1986. The proximal development in all known relief specimens of Pseudisograptus and their descendants indicates that a symmetrical development of the manubrium must be regarded as the rule, and the interpretation of a strong asymmetry in Pseudisograptus manubriatus texanus is rejected. Alfons H.M. VandenBerg [avandenberg@museum.vic.gov.au, lanceolatus@hotmail.com], Geology, Museum Victoria, GPO Box 666, Vic 3001, Australia; Jörg Maletz [yorge@zedat.fu-berlin.de], Department of Earth Sciences, FU Berlin, Malteserstrasse 74-100, D-12249 Berlin, Germany. 相似文献
9.
The first Chinese Ordovician series was erected by Lee & Chao (1924). Since then, many regional Ordovician series and stage names have been established and mostly published in Chinese. The present study is a review of these regional units with a discussion of their definitions and correlation to the international standard. Among them, the Ichang series, Neichiashan series, Chientangkiang series, Yushanian stage and Dawanian Stage are most important; all regarded as regional stage divisions in China. The Lower, Middle and Upper Ordovician Series with their new definitions (Webby 1998) are now accepted in China. The global stage names, which have been approved (Tremadocian and Darriwilian), and “Caradocian” and “Ashgillian”, which are potentially to be part of the global standard, should be formally used in China. The Darriwilian Stage is defined in a global stratotype section near Huangnitang, Changshan, SE China. Only two regional stage names, the Yushanian and Dawanian, still remain since the international correlation of these two units has not yet been resolved. The main type Ordovician successions of China are identified, revised and regional correlations briefly outlined. 相似文献
10.
The rostroconch mollusc Eopteria aiteneria sp. nov. is described from the Late Ordovician Angrensor Formation of north-eastern Central Kazakhstan; it is the first and only known representative of this group from the Ordovician of central Asia. By the beginning of the Late Ordovician Eopteria and the family Eopteriidae were on the verge of extinction and the new Kazakhstan species represents the youngest preserved record of the family in the Ordovician. It is likely that the group found a refuge in the diverse, but rather conservative, faunal assemblage of the Hiberno-Salairian type associated with Late Ordovician carbonate algal build-ups and mud mounds which spread widely during the late Caradoc to mid Ashgill across Kazakhstanian volcanic island arcs and microplates. 相似文献
11.
A rich benthic and planktonic graptolite fauna is associated with encrusting rhabdopleuran hemichordates and chitinous hydrozoans in the late Arenig (Ordovician) part of the Katkoyeh Formation at Banestan, east-central Iran. New taxa described here are the dendroid graptolites Callograptus huckriedei sp. nov. and Dictyonema bitubulata sp. nov. Other dendroid graptolites Dendrograptus sp. cf. D. flexuosus J. Hall, 1865; Acanthograptus divergens Skevington, 1963; and Thallograptus ?succulentus Ruedemann, 1904 are described. The tuboid graptolite Galeograptus sp., the rhabdopleuran hemichordates Rhabdopleura sp. aff. R. primaevus (Kozlowski, 1967) and Kystodendron sp., and the chitinous hydroid Palaeotuba sp. are also described. Graptoloid graptolites described here are Aulograptus? sp., Didymograptus incertus Perner, 1895, Undulograptus formosus (Mu & Lee, 1958), and Yutagraptus sp. cf. Y. mantuanus Riva, 1994. All but two species-level taxa are described from Iran for the first time. The fauna is confirmed as being late Arenig or, less likely, early Llanvirn and thus probably correlates with the early part of the Darriwilian stage. It resembles the Atlantic cold water faunas in lacking isograptids and sinograptids. 相似文献
12.
A new genus Webbyites from the Lower and Middle Ordovician of Bohemia is described. Its planar, feather-like benthic colonies (or their parts) display possible hydrozoan affinites. Webbyites is interpreted as an inhabitant of the littoral and sublittoral environment, with high energy, oscillating to current zones. 相似文献
14.
V inn, O., December 2015. Rare encrusted lingulate brachiopods from the Cambrian–Ordovician boundary beds of Baltica. Alcheringa 40, xx–xx. ISSN 0311-5518 Encrustation is rare on late Cambrian and Tremadocian brachiopods of Baltica. The encrusting fauna is represented by a single taxon, Marcusodictyon. Only Schmidtites celatus is encrusted in the Furongian of Estonia. The Marcusodictyon–Schmidtites association is the earliest example of syn vivo encrustation and symbiosis from the Baltica palaeocontinent. The encrusting faunas of the late Cambrian and Tremadocian of Baltica were unusual presumably owing to palaeogeographic reasons because the other known examples of early encrustation originate from lower palaeolatitudes. Olev Vinn [olev.vinn@ut.ee], Department of Geology, University of Tartu, Ravila 14A, 50411 Tartu, Estonia. 相似文献
15.
The discovery of an astragalus of an allosaurid theropod in southeastern Australia extends the geographic range of the Allosauridae to include all continents except Antarctica and the Indian subcontinent. In addition, it confirms the presence of this family during the Early Cretaceous. 相似文献
16.
The Ordovician diversification is marked by an increase in both marine diversity and ecospace occupation. Bivalves, like other groups, underwent a remarkable diversification in the Early Ordovician. The early phases of such a bivalve diversification took place in the Gondwanan basins of western Argentina. In the Northwestern Argentina (NWA) Basin, three clades originated during late Tremadocian–Floian times. In the Floian successions of the Famatina Basin, a probable basal arcoid is recorded. Genera from these two basins belong to 13 families. Phylogenetic analysis of the NWA heteroconchian bivalves indicates that redoniids and coxiconchinids may have originated during this radiation event. This taxonomic radiation also implies an ecological diversification. Ten guilds are recognized on the basis of bauplan, mode of life, and feeding types. Lifestyles included free endofaunal, free semi-endofaunal, semi-endobyssate, and epibyssate; feeding types included suspensivorous and detritivorous habits. Physiological changes imposed by colonization of low-salinity environments also account for guild definitions. Recent discoveries of Tremadoc to early Darriwilian bivalves from the NWA and Famatina basins indicate that the dominance of higher groups (e.g. Heteroconchia, Pteriomorphia) deviates from the patterns evident in other Gondwanan basins. This agrees with previous ideas supporting the importance of local radiations during the Ordovician diversification. Two new taxa are described, Eoredonia orientalis gen. et sp. nov. and Babinka notica sp. nov., and Coxiconchia sellaensis Sánchez & Babin is first reported from the NWA Basin. 相似文献
17.
Forty-two conodont species are documented from the Liuxia, Shijiatou and Jingshan formations in Zhejiang Province of southeast China, located palaeogeographically on the Jiangnan Slope offshore to the Yangtze Platform. From these faunas, eight successive conodont biozones of Tremadocian to middle Floian (Early Ordovician) age are recognized, including the Cordylodus lindstromi Biozone, Cordylodus angulatus Biozone, Chosonodina herfurthi Biozone, Paltodus deltifer Biozone, Paroistodus proteus Biozone, Triangulodus bifidus Biozone, Serratognathus diversus Biozone and Prioniodus elegans Biozone. Several zonal index species of the Baltoscandian succession— Paltodus deltifer, Paroistodus proteus and Prioniodus elegans—are described and illustrated in detail for the first time from South China. Co-occurrence of P. proteus and Serratognathus bilobatus in several samples below the appearance of P. elegans also confirms correlation of the S. diversus Biozone (basal Floian) with the upper P. proteus Zone of the Baltoscandian succession. These Zhejiang faunas are dominated by pandemic forms, and are similar to those of the Open-Sea Realm elsewhere, inhabiting deep, offshore environments. 相似文献
18.
Fossil eggshell fragments from a sand dune near Port Augusta are attributed to the extinct dromornithid, Genyornis newtoni Stirling & Zietz. Shell curvature measurements show that the eggs were larger than those of the Emu, Dromaius novaehollandiae. Radiocarbon dates indicate an age in excess of 40,680 BP. Holes pierced through some fragments are attributed to the action of predators. 相似文献
19.
A new genus and species of fordilloid pelecypod, Pojetaia runnegari gen. et sp. nov., is described from the lower part of the Parara Limestone, Yorke Peninsula, South Australia. Establishing the age of the sample on an international scale is difficult, as with almost all Early Cambrian formations, but evidence tends to suggest that this is the oldest pelecypod so far recorded. Clearly defined hinge teeth and sockets on both valves and on internal moulds help to confirm the pelecypod placement of fordilloids. 相似文献
20.
An assemblage of well-preserved Devonian trilobites is described from limestones in Satun Province, southern Thailand. The biogeographic implications are briefly discussed. The fauna, which is of Early Devonian age, probably Emsian, includes Decoroproetus, Cornuproetus, Platyscutellum and two species of Reedops, one of which is new. No similar fauna has been described before from the Shan-Thai block. The fauna is a typical Hercynian assemblage with close specific comparisons with Turkey, Morocco and Bohemia. 相似文献
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