Eocrinoids from the Cambrian Mantou Formation of Dalian, Liaoning

Cambrian echinoderms,especially eocrinoids,have been reported recently from Guizhou and Yunnan provinces of China,such as the Kaili,Balang,and Guanshan faunas.The present paper reports abundant well-preserved eocrinoids from the Cambrian Mantou Formation of Dalian,Liaoning Province.This new discovery provides additional data on the early evolution of Echinodermata.It also gives us a clue as to where to seek the Cambrian soft-bodied fauna on the margin of the North China Platform.     

贵州台江早寒武世台江动物群的发现及意义

贵州台江八郎凯里组剖面中下部中、下寒武统界线之下厚达１５米左右的粉砂质泥岩、页岩中存在着一个类似凯里动物群的台江动物群,由８个门类３９个属组成,核心为蠕形动物,三叶虫数量很多。形成于内陆棚浅海环境。时代为早寒武世末期,介于著名的早寒武世早期澄江动物群和中寒武世早期凯里动物群之间,对于早期后生动物的演化研究具有重要的意义。     

凯里动物群与我国早期后生动物演化的初步研究

作者所发现的中寒武世凯里动物群,属于带软躯体化石的布吉斯页岩型的动物群,是继云南澄江动物群之后我国发现的又一个早期后生动物群。它和新近发现的晚震旦世庙河生物群,分别填补了晚震旦世、中寒武世我国带软躯化石生(动)物群的空白,形成了我国多时期带软躯化石的生(动)物群体系。对于研究我国及世界早期后生动物演化并不断揭示其演化规律有重要意义。     

Sponge fossil assemblage from the Early Cambrian Hetang Formation in southern Anhui

Abundant well-preserved large articulated sponge fossils and isolated spicules have been reported from the Early Cambrian Hetang Formation, southern Anhui Province. This unique epifaunal fossil assemblage dominated by articulated sponge fossils is called the Xidi Sponge Fauna. The sponge fauna lived in a quiet oxygenic environment below the storm wave base. Bloom of phytoplankton and rapid sedimentation rate resulted in the deposition of the black shales. Sufficient food supply, lack of other competitors, abundant ecological niches, and demand for oxygen during early Cambrian were in favor of the diversification and evolution of large sponges in the Early Cambrian.     

A Chengjiang-type fossil assemblage from the Hongjingshao Formation （Cambrian Stage 3） at Chenggong,Kunming, Yunnan

A new Chengjiang-type fossil assemblage is reported herein from the lower part of the Hongjingshao Formation at Xiazhuang village of Chenggong,Kunming,Yunnan.The fossil assemblage,named as Xiazhuang fossil assemblage,yields predominantly soft-bodied fossils,including arthropods,brachiopods,priapulids,lobopods and some problematic taxa,with arthropods being the most dominant group.Preservation and composition of the fossil assemblage are very similar to the typical Chengjiang biota,which is preserved in the middle Yu’anshan Formation in the large area of eastern Yunnan.The associated trilobites demonstrate that the soft-bodied fossil assemblage belongs to the late Qiongzhusian in age(Stage 3,Cambrian),suggesting that the Hongjingshao Formation is probably a diachronous lithostratigraphic unit ranging from the upper Qiongzhusian to the lower Canglangpuan stages in eastern Yunnan.The fossil assemblage from the Xiazhuang area fills up the missing link between the typical older Chengjiang biota and the younger Malong and Guanshan biotas,making eastern Yunnan a unique area in the world to reveal the early evolutionary history of animals and palaeocommunity dynamics during the‘‘Cambrian explosion’’.     

Possible developmental mechanisms underlying the origin of the crown lineages of arthropods

The extraordinarily preserved, diverse arthropod fauna from the Lower Cambrian Maotianshan shale, central Yunnan (southwest China), represents different evolutionary stages stepping from stem lineages towards crown arthropods (also called euarthropods), which makes this fauna extremely significant for discussion of the origin and early diversification of the arthropods. Anatomical analyses of the Maotianshan shale arthropods strongly indicate that     

A venomous arthropod in the Early Cambrian Sea

A number of recently evolved animals possess poison glands for feeding and/or defense.However,examples of such animals are rare in the fossil record.We report a fossil arthropod Isoxys curvirostratus from the Early Cambrian Chengjiang biota of China.This species is regarded as the oldest known venomous arthropod based on the presence of venomous glands in its head region.The adult animal is 2-5 cm long and the body is covered entirely with a carapace.The presence of large stalk eyes and a pair of stout grasping appendages with a terminal spine suggest it was raptorial.Interestingly,the two pear-shaped,three-dimensionally preserved objects that are present in the head region and at the base of the grasping appendages closely resemble the venom glands of some living arthropods in size,shape,and position.These features indicate that the presence of venomous predators could date back 520 million years.Furthermore,our observations suggest that the feeding strategies and organs adapted for this purpose had already reached a high level of diversity and anatomical sophistication in the Early Cambrian ecosystems.     

Bathynotus --A key trilobite taxon? for global stratigraphic boundary correlation between Cambrian Series 2 and Series 3

The Cambrian trilobite Bathynotus is a special morphology of Redlichiid, which is characterized by a wider thorax axis and an 11th macropleural segment bearing a long, backwardly directed spine. Additionally, its 12th and 13th pleural segments are narrow and they terminate at a fulcrum where they fuse together and to the posterior edge of the long macropleural spine. The genus is widely distributed, occurring in North America, Siberia, the Altay-Sayan fold belt of Russia, South China, the Tarim Basin of China, and Australia. It occurs primarily in deposits of the upper part of the continental slope, at the transition between stable platform settings and subsiding margins of the late Early Cambrian. Here, we recognize three species of Bathynotus from China, including B. holopygus which is widespread around the world. Although six species of Bathynotus have been reported from Siberia and the Altay-Sayan fold belt area of Russia, data presented here suggest that only three of these species are valid. Bathynotus exhibits a short geological range, with its first occurrence late in the unnamed Cambrian Series 2 and the last appearance datum of Bathynotus at the boundary of Cambrian Series 2 and Cambrian Series 3. The late appearance datum (LAD) of Bathynotus provides an important global stratigraphic marker of the boundary between Cambrian Series 2 and Cambrian Series 3.     

Bathynotus: A key trilobite taxon for global stratigraphic boundary correlation between Cambrian Series 2 and Cambrian Series 3

The Cambrian trilobite Bathynotus is a special morphology of Redlichiid,which is characterized by a wider thorax axis and an 11th macropleural segment bearing a long,backwardly directed spine.Additionally,its 12th and 13th pleural segments are narrow and they terminate at a fulcrum where they fuse together and to the posterior edge of the long macropleural spine.The genus is widely distributed,occurring in North America,Siberia,the Altay-Sayan fold belt of Russia,South China,the Tarim Basin of China,and Australia.It occurs primarily in deposits of the upper part of the continental slope,at the transition between stable platform settings and subsiding margins of the late Early Cambrian.Here,we recognize three species of Bathynotus from China,including B.holopygus which is widespread around the world.Although six species of Bathynotus have been reported from Siberia and the Altay-Sayan fold belt area of Russia,data presented here suggest that only three of these species are valid.Bathynotus exhibits a short geological range,with its first occurrence late in the unnamed Cambrian Series 2 and the last appearance datum of Bathynotus at the boundary of Cambrian Series 2 and Cambrian Series 3.The late appearance datum (LAD) of Bathynotus provides an important global stratigraphic marker of the boundary between Cambrian Series 2 and Cambrian Series 3.     

扬子地台早寒武世早期小壳动物的古生态及其生物分区初探

文章讨论了早寒武世早期小壳动物的生存条件及几类常见软舌螺(Microcornus, Actinotheca, Neogloborilus, Paragloborilus, Adyshevitheca, Sulcavitus等)的生活环境及生存方式,并在古生态分析的基础上,对扬子地台早寒武世早期小壳动物的地理分区进行了探讨,提出扬子地台自西向东可分为三个不同的生物地理区,即底栖生物区;浮游、游泳、底栖生物混生区;浮游、游泳动物区。其分区界线大致与三叶虫的分区界线相吻合。     

New discoveries from the classic Quaternary mammalian fossil area of Yanjinggou, Chongqing, and their chronological explanations

Yanjinggou in Wanzhou District of Chongqing is one of the earliest reported and most famous Quaternary mammalian fossil areas in China. The fauna from this area used to be taken as a benchmark for the biochronological comparison of Quaternary paleontology of South China, but the chronology of this fauna has many controversies for the lack of exact locational and stratigraphical records. The present article, on the basis of recent investigations and discoveries, discusses and explains the distribution and biochronology of the mammalian faunas in the Yanjinggou area. The newly discovered Dayakou fissure fauna, including Rhizomys troglodytes, Homotherium sp., Panthera pardus, Stegodon orientalis, Dicerorhinus sumatrensis, Hesperotherium sinense, Sus sp., Cervavitus fenqii, Cervus sp. and Muntiacus sp., is correlated to the middle Early Pleistocene. The presence of Early Pleistocene mammalian fauna in the Yanjinggou area is therefore confirmed. The “Wanhsien fauna” or “Yenchingkou (=Yanjinggou) fauna” as a Mid-Late Pleistocene biostratigraphical datum should be abandoned. The Dayakou fauna and the Upper Cave fauna of Pingba, both in the Yanjinggou area, are correlated to the middle Early Pleistocene and the early Middle Pleistocene in age, respectively.     

江西省官山自然保护区鸟类调查初报

１９９３－１９９４年，对江西省官山片段保护我鸟类进行了调查。结果表明，已知鸟类７８种，繁殖鸟５６种，非繁殖鸟２２种，发现国家一级重点保护鸟类白颈长尾雉１种，还有国家二级重点保护鸟类１０种。     

中国的三叠纪海生爬行动物化石及其层位

对中国三叠纪海生爬行动物化石及其产出层位、产地进行了较为系统的分析研究和总结,划分出4个相关的海生爬行动物群:早三叠世南漳海生爬行动物群、中三叠世兴义海生爬行动物群、晚三叠世关岭海生爬行动物群、晚三叠世定日海生爬行动物群.进一步的研究表明,中国三叠纪海生爬行动物化石数量比较丰富,种类多样;特别是贵州关岭地区三叠纪海生化石数量多、保存完整,基本上为原地埋藏,实属国内外同期地层之罕见.中国三叠纪海生爬行动物化石地史分布从早三叠世奥伦尼克期到晚三叠世诺利期都有分布;地理分布主要分布于古东特提斯海域,具有明显的区域性.     

Hydrogen sulphide release to surface waters at the Precambrian/Cambrian boundary

Animal-like multicellular fossils appeared towards the end of the Precambrian, followed by a rapid increase in the abundance and diversity of fossils during the Early Cambrian period, an event also known as the 'Cambrian explosion'. Changes in the environmental conditions at the Precambrian/Cambrian transition (about 542 Myr ago) have been suggested as a possible explanation for this event, but are still a matter of debate. Here we report molybdenum isotope signatures of black shales from two stratigraphically correlated sample sets with a depositional age of around 542 Myr. We find a transient molybdenum isotope signal immediately after the Precambrian/Cambrian transition. Using a box model of the oceanic molybdenum cycle, we find that intense upwelling of hydrogen sulphide-rich deep ocean water best explains the observed Early Cambrian molybdenum isotope signal. Our findings suggest that the Early Cambrian animal radiation may have been triggered by a major change in ocean circulation, terminating a long period during which the Proterozoic ocean was stratified, with sulphidic deep water.     

The Homo sapiens Cave hominin site of Mulan Mountain, Jiangzhou District, Chongzuo, Guangxi with emphasis on its age

One of the most hotly debated and frontal issues in paleoanthropology focuses on the origins of modern humans. Recently, an incomplete hominin mandible with a distinctly weaker mental protuberance than modern human and a great variety of coexisting fossil mammals were unearthed from the Homo sapiens Cave of Mulan Mountain, Chongzuo, Guangxi. The mammalian fauna from the Homo sapiens Cave characterized by the combination of Elephas kiangnanensis, first occurring Elephas maixmus, and Megatapirus augustus, and strikingly different from the Early Pleistocene Gigantopithecus fauna and the Middle Pleistocene Ailuropoda-Stogodon fauna of South China could be regarded as an early representive of the typical Asian elephant fauna. Faunal analysis, biostratigraphic correlation, and, most importantly, U-series dating all consistently support an estimate of ca. 110 ka for the age of the fossil Homo sapiens and coexisting mammalian fauna, that is, the early Late Pleistocene. The fauna is mainly made up of tropical-subtropical elements, but grassland elements have a much greater variety than forest elements, which probably indicates a drier climate at that time. This discovery of early Homo sapiens at the Mulan Mountain will play a significant role in the study of the origin and its environmental background of modern humans.     

Phylogeny and life habits of Early Arthropods-Predation in the Early Cambrian Sea

We investigated two new arthropods from the Maotianshan-Shale fauna of southern China in the course of our research on life strategies, particularly predation, in Early Cambrian marine macrofaunal biota. One form clearly belongs to the so-called "great-appendage" arthropods, animals that were, most likely, active predators catching prey with their first pair of large, specialized frontoventral appendages. Based on this, we hypothesize that the new species and many others, if not all, of the "great-appendage" arthropods were derivatives of the chelicerate stem lineage and not forms having branched off at different nodes along the evolutionary lineage of the Arthropoda. Rather, we consider the "great-appendage" arthropods as belonging to a monophyletic clade, which modified autapomorphically their first pair of appendages (antennae in general arthropod terminology) into raptorial organs for food capture. The second new form resembles another Maotianshan-Shale arthropod, Fuxianhuia protensa, in sharing a head made of only two separate segments, a small segment bearing oval eyes laterally, and another bearing a large tergite, which forms a wide shield freely overhanging the subsequent narrow trunk segments. This segment bears a single pair of rather short anteriorly directed uniramous appendages, considered as the "still" limb-shaped antennae. Particularly the evolutionary status of head and limbs of these two forms suggests that both are representatives of the early part of the stem lineage toward the crown-group of Arthropoda, the Euarthropoda. These forms appear rather unspecialized, but may have been but simple predators. This adds to our hypothesis that predation was a common, if not dominant feeding strategy in the Cambrian, at least for arthropods.     

Post-Jurassic mammal-like reptile from the Palaeocene.

Mammal-like reptiles of the order Therapsida document the emergence of mammals from more primitive synapsids and are of unique zoological and palaeontological interest on that account. Therapsids, first appearing in the Early Permian, were thought to become extinct in the Middle Jurassic, soon after the Late Triassic origin of mammals. Here, however, we report the discovery of a therapsid from the late Palaeocene, 100 million years younger than the youngest previous occurrence of the order. This discovery nearly doubles the stratigraphic range of therapsids and furnishes their first record from the Cenozoic. The documenting fossils, an incomplete dentary containing three teeth, and four isolated teeth from other, conspecific individuals (Fig. 1), are from the Paskapoo Formation, at Cochrane, Alberta, Canada, from beds yielding a diverse mammalian fauna of early Tiffanian age. These specimens are catalogued in the collections of the University of Alberta Laboratory for Vertebrate Paleontology (UALVP) and provide the basis for a new taxon, as named and described below: (see text)     

Lower Cambrian small shelly faunas from Zhejiang (China)and their biostratigraphical implications

Despite a long history of research on the Early Cambrian in China most available data on small skeletal fossils concern fossil associations of the shallow carbonate platform. Information on skeletal fossils from marginal shelf environments of the Yangtze Platform is scanty, which may reflect the rarity of fossils in deeper sedimentary environments but is also due to limitation of carbonate distribution and outcrops, difficulties in fossil extraction, and a general research focus on the Precambrian-Cambrian boundary beds on the carbonate platform. Here we present a documentation of Meishucunian to Qiongzhusian small skeletal fossils from the lower Hetang Formation and the chert unit at its base from the Jiangshan region, Zhejiang Province, representing a relatively deep shelf environment compared to the inner shelf region. The earliest association (Meishucunian) from the chert unit underlying the Hetang Formation is mainly characterized by the occurrence of Protohertzina anabarica, P. unguliformis, Fengzuella zhejiangensis, and Kaiyangites novilis, which differs somewhat in composition from SSF-associations of typical inner shelf deposits. The enigmatic skeletal fossil Fengzuella zhejiangensis, which exhibits an unusual secretional growth mode previously unrecognized from the Early Cambrian, is described in detail. A younger (Qiongzhusian) fossil association contains numerous arthropod remains, such as disarticulated spines of arthropods (Jiangshanodus- and Kijacus-type), which have previously been considered as conodont-like fossils, and bradoriid valves.     

A giant Ordovician anomalocaridid

Anomalocaridids, giant lightly sclerotized invertebrate predators, occur in a number of exceptionally preserved early and middle Cambrian (542-501?million years ago) biotas and have come to symbolize the unfamiliar morphologies displayed by stem organisms in faunas of the Burgess Shale type. They are characterized by a pair of anterior, segmented appendages, a circlet of plates around the mouth, and an elongate segmented trunk lacking true tergites with a pair of flexible lateral lobes per segment. Disarticulated body parts, such as the anterior appendages and oral circlet, had been assigned to a range of taxonomic groups--but the discovery of complete specimens from the middle Cambrian Burgess Shale showed that these disparate elements all belong to a single kind of animal. Phylogenetic analyses support a position of anomalocaridids in the arthropod stem, as a sister group to the euarthropods. The anomalocaridids were the largest animals in Cambrian communities. The youngest unequivocal examples occur in the middle Cambrian Marjum Formation of Utah but an arthropod retaining some anomalocaridid characteristics is present in the Devonian of Germany. Here we report the post-Cambrian occurrence of anomalocaridids, from the Early Ordovician (488-472?million years ago) Fezouata Biota in southeastern Morocco, including specimens larger than any in Cambrian biotas. These giant animals were an important element of some marine communities for about 30?million years longer than previously realized. The Moroccan specimens confirm the presence of a dorsal array of flexible blades attached to a transverse rachis on the trunk segments; these blades probably functioned as gills.