The Permian pandemic ammonoids in Nanpanjiang Basin (41 genera, including two new genera Glenisteroceras and Fusicrimites, and 56 species, including 21 new species) are systematically described and/or discussed. New species described in this paper are Agathiceras sequaxilirae n. sp., Akmilleria parahuecoensis n. sp., Aristoceras liuzhaiense n. sp., Bamyaniceras nandanense n. sp., Bamyaniceras yangchangense n. sp., Bransonoceras longyinense n. sp., Difuntites furnishi n. sp., Emilites globosus n. sp., Eoaraxoceras spinosai n. sp., Eumedlicottia kabiensis n. sp., Fusicrimites nanpanjiangensis n. gen. n. sp., Glenisteroceras sidazhaiense n. gen. n. sp., Metaperrinites shaiwaensis n. sp., Miklukhoceras guizhouense n. sp., Neocrimites guizhouensis n. sp., Neopronorites leonovae n. sp., Popanoceras ziyunense n. sp., Properrinites gigantus n. sp., Stacheoceras shaiwaense n. sp., Svetlanoceras uraloceraformis n. sp., and Synartinskia meyaoense n. sp. A relatively complete Permian basinal ammonoid sequence with six zones has been newly recognized in South China, in ascending order, Properrinites gigantus-Svetlanoceras serpentinum, Svetlanoceras uraloceraformis-Prothalassoceras biforme, Popanoceras kueichowense-Medlicottia orbignyanus, Metaperrinites shaiwaensis-Popanoceras ziyunense, Waagenoceras sp.-Propinacoceras beyrichi, and Eoaraxoceras spinosai-Difuntites furnishi. The upper three zones are close to being duplicated from the Permian of Las Delicias, Coahuila, Mexico and west Texas, USA; while the lower three zones compare well to those of the Lower Permian in South Urals. The Eoaraxoceras-Difuntites assemblage, as an index fauna of the upper Capitanian in Coahuila, has been found from the Claystone (3rd) Member of the Shaiwa Formation with the commonly accepted Lopingian stratigraphic age. The updated Permian ammonoid biostratigraphy in South China reveals a possible overlap between the basinal Guadalupian from North America and the platform-based Lopingian from South China.

Well-preserved microfossils occur in abundance through more than 1000 m of lower Mesoproterozoic siliciclastic rocks composing the Roper Group, Northern Territory, Australia. The Roper assemblage includes 34 taxa, five interpreted unambiguously as eukaryotes, nine as possible eukaryotes (including Blastanosphaira kokkoda new genus and new species, a budding spheromorph with thin chagrinate walls), eight as possible or probable cyanobacteria, and 12 incertae sedis. Taxonomic richness is highest in inshore facies, and populations interpreted as unambiguous or probable eukaryotes occur most abundantly in coastal and proximal shelf shales. Phylogenetic placement within the Eukarya is difficult, and molecular clock estimates suggest that preserved microfossils may belong, in part or in toto, to stem group eukaryotes (forms that diverged before the last common ancestor of extant eukaryotes, or LECA) or stem lineages within major clades of the eukaryotic crown group (after LECA). Despite this, Roper fossils provide direct or inferential evidence for many basic features of eukaryotic biology, including a dynamic cytoskeleton and membrane system that enabled cells to change shape, life cycles that include resting cysts coated by decay-resistant biopolymers, reproduction by budding and binary division, osmotrophy, and simple multicellularity. The diversity, environmental range, and ecological importance of eukaryotes, however, were lower than in later Neoproterozoic and Phanerozoic ecosystems.

Since 1986, samples with a total mass of more than 14,000 kg, mainly from three key sections in western Hunan, South China, have been processed for conodonts. Previous work mainly focused on biostratigraphy, but the taxonomy has been performed only on the faunas of the middle Cambrian. Described herein are conodonts of the upper Cambrian (Furongian Series) through lowermost Ordovician from Hunan, South China. Conodonts of the middle Cambrian are redescribed, based on material that has been recovered for more than three decades. The fauna consists of 82 species belonging to 36 genera. Newly established genera are Lugnathus n. gen., Miaognathus n. gen., Millerodontus n. gen., Tujiagnathus n. gen., Wangcunella n. gen. and Wangcunognathus n. gen. New species are Coelocerodontus hunanensis n. sp., Furnishina wangcunensis n. sp., Laiwugnathus hunanensis n. sp., Laiwugnathus transitans n. sp., Lugnathus hunanensis n. gen. n. sp., Miaognathus multicostatus n. gen. n. sp., Millerodontus intermedius n. gen. n. sp., Prosagittodontus compressus n. sp., Tujiagnathus gracilis n. gen. n. sp., Wangcunella conicus n. gen. n. sp., Wangcunognathus elegans n. gen. n. sp., Westergaardodina dimorpha n. sp., Westergaardodina gigantea n. sp., and Westergaardodina sola n. sp. The taxonomy of some conodont genera is revised. In the light of histological investigation, genera are assigned to euconodonts, paraconodonts, or protoconodonts. The 13 conodont zones previously proposed in the middle Cambrian through lowermost Ordovician remain the same, but taxa within these conodont zones are documented more clearly because of the revised taxonomy proposed herein.

The thallus of a new noncalcified dasycladalean alga, Wiartonella nodifera n. gen. n. sp., from the mid-Silurian Eramosa Lagerstätte of Ontario, Canada, comprises a narrow main axis with laterals in whorls (euspondyl). Laterals branch to the second order and show a distinct expansion (node) at the termination of first-order lateral segments. Morphologic differences between specimens are interpreted as ontogenetic stages similar to those displayed by extant Dasycladales, including late-stage shedding of higher-order lateral segments. Examination of reproductive functional morphology using biophysical modeling indicates that the expanded terminations of the first-order lateral segments probably are not homologous with gametophores, and that reproduction instead was either endospore or cladospore, with details of the ontogenetic sequence pointing to the latter. The distinctive lateral morphology displayed by this species adds to the list of morphological innovation achieved by dasycladalean algae during a significant burst of evolutionary activity that unfolded between the Middle Ordovician and late Silurian.

A reassessment of the taxonomic relationships of North American gigantopterids is presented in light of an examination of large populations of specimens housed in the US National Museum of Natural History. Variations in venation and subtle aspects of leaf shape facilitate refined understanding of the relationships and diversity of the North American gigantopterid species leading to an improved understanding of the taxonomic and biogeographic relationships of this group, which are found most abundantly in western equatorial Pangea and Cathaysia. Current literature suggests that there are eight North American genera, however, this study has revealed a morphological overlap of several previously defined genera, leading to the conclusion that Gigantopteridium encompasses the species previously treated as Cathaysiopteris yochelsonii as well as a new species, Gigantopteridium utebaturianum. The transfer of C. yochelsonii to Gigantopteridium yochelsonii suggests that Cathaysiopteris may represent a genus endemic to Cathaysia, limiting the biogeographical connection between the regions to Zeilleropteris, Gigantopteridium, Euparyphoselis, and Gigantonoclea.

The fixing organ of the Precambrian macroalga was briefly described by most researchers as a holdfast or rhizoid, suggesting a fixation structure and/or tissue differentiation. An Ediacaran macroscopic alga, Discusphyton whenghuiensis n. gen. n. sp., with a complex disc-like holdfast and an unbranching thallus, has been collected, together with abundant and diverse macrofossils (i.e., the Wenghui biota) in black shales of the upper Doushantuo Formation (~560–551 Ma) in northeastern Guizhou, South China. The Wenghui biota lived in a relatively low-energy marine environment and was preserved in situ or nearby their growth position. Morphologically, the macroalgal thallus, including the compressed lamina and cylindrical stipe, might have been suspended in the water column for photosynthesis. Its holdfast, a rare fixing form, is complex in structure and construction, consisting of a globular rhizome and a discoidal rhizoid. The large-sized discoidal rhizoid is regarded as a flat-bottomed and dome-shaped organ to attach the macroalga on the water-rich muddy seafloor. The globular rhizome, expanded by a thallus on the substrate, was originally harder and spherical nature within the dome-shaped rhizoid. It may have been an important organ as a steering knuckle to connect between the stipe and the rhizoid. The macroscopic metaphyte D. whenghuiensis n. gen. n. sp. shows the appearance of complex holdfast in morphology and bio-functions. However, not enough is known, in the absence of more information, to decipher the phylogenetic affinity of D. whenghuiensis n. gen. n. sp. and the origin of a discoidal rhizoid.

Cherts and silicified dolostones of the ca. 1600 Ma Dahongyu Formation (uppermost Changcheng Group) from North China contain well-preserved microfossils. Cyanobacteria filaments and coccoids dominate the studied Dahongyu microbiota in the Jixian section. These microfossils show the characteristics of endobenthic, epibenthic, and allochthonous microfossils, which illustrated well a vertical distributional view of an intertidal microbiota. Large numbers and size of allochthonous microfossils are the distinguishing characteristics of this new microbiota. A few of these possess ornaments or odd morphology, which suggest their potential eukaryotic nature. Through regional comparisons, it is revealed that there was significant regional disparity within the Yanshan Basin of microbiotas during deposition of the Dahongyu Formation. The newly studied Dahongyu microbiota is similar to the microbiota from the underlying Changcheng Group, with only slight differences. The absence of typical eukaryotes and the emergence of unique microfossils (especially small fusiform microfossils) make the Dahongyu Formation and the subsequent strata of the Jixian Group distinct from contemporaneous eukaryote-bearing strata.

In the Dahongyu assemblage, 19 species were recognized, six species were identified informally and seven species were identified in open nomenclature. One new taxon of microfossil was described: Xiaohongyuia sinica Shi and Feng new genus new species.

The problematic calcified cnidarian Cambroctoconus is described from the Henson Gletscher Formation (Cambrian Series 2, Stage 4–Series 3, Stage 5) of North Greenland, representing the first record from Laurentia of a genus otherwise recently described from China, Kyrgyzstan, and Korea. Internal molds produced by penetrative phosphatization mirror the pervasive pore system of the calice walls and septa. The pore system is compared to the network of gastrodermal solenia that distributes nutrients between polyps and surrounding stolon tissues in present day octocorals. In conjunction with the octagonal form of the individual coralla and eight-fold symmetry of septa, the pore system promotes assignment of Cambroctoconus to the Octocorallia, a basal clade in cnidarian phylogeny. Octocorals (‘soft corals’) are diverse in present day seas, but have a poor fossil record despite the general development of distinctive calcareous spicules. New taxa: Order Cambroctoconida new; Cambroctoconus koori new species.

Plagioptychids are a conspicuous, although minor, component in uppermost Cretaceous rudist-bearing outcrops of the Caribbean Province, where other rudist families are more abundant and diverse. In the Chiapas Central Depression, the plagioptychid rudist fauna includes the following taxa: Plagioptychus antillarum (Douvillé) and Mitrocaprina sp. from the middle Campanian Suchiapa Formation, Plagioptychus muellerriedi Alencáster from the early Maastrichtian Ocozocoautla Formation, and Plagioptychus fragilis Chubb and Mitrocaprina tschoppi (Palmer) from the late Maastrichtian Angostura Formation. These five species are described in detail and some probable synonymies are discussed. Analysis of the literature on American plagioptychids reveals that the characters of too many taxa are still insufficiently known to attempt any thorough phylogenetic analysis. Other lines of evidence also seem to indicate that American Plagioptychidae diversity is probably higher than recognized today, which might result in a more significant difference to Plagioptychidae of the Mediterranean Tethys.

Three gravity cores (LZK1, ZKA4, and CSJA6) from the incised Yangtze paleo-valley comprise a thick sequence of the post-glacial deposit. Nineteen genera (26 species) of the benthic foraminifers are described from these cores, with detailed down-core foraminiferal variations to investigate their paleoenvironmental implications. Three foraminiferal assemblages are recognized for the lower, middle, and upper parts of the cores respectively. The lower part is dominated by Ammonia beccarii var. and Florilus decorus with lower abundance and diversity. In the middle part, the foraminifers are abundant and diverse, dominated by both Ammonia beccarii var. and Elphidium advenum. Cavarotalia annectens, Pararotalia nipponica, and porcellaneous benthic foraminiferal forms are always present, sometimes abundant. The upper part is characterized by the Ammonia beccarii-Elphidium magellanicum assemblage, except for the Core ZKA4, which is barren of foraminifers in this interval. AMS 14C dates and foraminiferal assemblages both confirm that the transgression-regression sequence in these cores belongs to the “Ammonia transgression” during the Holocene. In addition to documenting the post-glacial sea-level fluctuations, the benthic foraminifers also reflect a warmer climate during the early–middle Holocene. The foraminiferal differences among the three cores can be used to interpret the influence of seawater during the post-glacial sea-level fluctuations. The area in the vicinity of Core ZKA4 was affected by marine water only during the middle Holocene, which was much shorter than the areas of the other cores.

The extraxial axial theory is used to investigate homology of ambulacral and oral plating because it predicts terminal branching and terminal addition of plates in the axial skeleton, although exceptions to the former may occur in some Paleozoic echinoderms. The variety of morphological designs and anomalous individuals also provide tests of plate homology. Homology of ambulacra is generally accepted, with the hydropore and/or single gonopore in Carpenter’s CD interray. In the 2-1-2 ambulacral pattern the unbranched ambulacrum is always in Carpenter’s A ray. All ambulacral morphology requires just three instructions: ‘grow,’ ‘branch,’ and ‘stop.’ The range of variation in echinoderms with fewer than five ambulacra implies that both the ‘branch’ and ‘stop’ instructions acted independently in all five rays. Numbers of ambulacra may or may not correlate with numbers of orals. Two basic patterns of ‘cystoid’ oral plating occur; with a single radial (circum-oral, CO) plate from each ambulacrum plus a sixth in the CD interray, and with all six interradial peri-oral (PO) plates, with two in the CD interambulacrum. Five ‘orals’ may involve loss of PO3 or PO6. Erect ambulacral structures are lost first in taphonomy and so poorly known. All ambulacral skeletal elements bear the same topological relationship to ambulacral soft tissues. Where branched ambulacra occur, the trunk or flooring plates are often modified first brachiolars or pinnulars. Both brachioles and pinnules may arise from facets developed on one or two flooring plates. Terminal addition of plates, spacing of brachioles/pinnules, and lack of musculature to open cover plates all suggest that ‘cystoids’ had extensions of the water vascular system in their ambulacra.

New samples of fusulinids collected in the Tengchong Block, western Yunnan, China, are systematically studied and presented here. The fusulinid fauna from the Xishancun section in the Shanmutang area is dominated by Chusenella and Nankinella, whereas that from the Shuangheyan area is composed mainly of Chusenella and Schwagerina. Both faunas are dated as Roadian–Capitanian (middle Permian). These new findings are integrated with fusulinid taxa reported earlier from the block to demonstrate the taxonomic features and paleogeographic significance of Permian fusulinids. The low generic diversity through early and middle Permian and the paucity of middle Permian neoschwagerinids and verbeekinids in the block confirm its Gondwana-affinity attributes. Moreover, the Permian fusulinids of the Tengchong Block are depauperate; i.e., consisting of a limited number of species with abundant individuals. This particular feature commonly suggests an inhospitable environment, and carbonates of varied facies containing these faunas in the Tengchong Block suggest a facies-independent factor as the reason, most likely the relatively low temperature of seawater.

Vase-shaped microfossils (VSMs) occur in dolomitic extraclasts of indeterminate provenance within the basal diamictite of the Neoproterozoic Urucum Formation (Jacadigo Group) of west-central Brazil, having an age constrained between 889±44 Ma (K-Ar; basement rocks) and 587±7 Ma (40Ar/39Ar age of early metamorphic cryptomelane in overlying manganese ore). Early isopachous carbonate cement entombed these VSMs, preserving rare direct evidence of original wall composition that is carbonaceous (now kerogenous) in practically all specimens. Some tests are siliceous or composed of a quartz-kerogen mixture; secondary replacement explains some features of these tests, but original biomineralization seems more likely for others. This interpretation, coupled with test morphology, suggests affinity to arcellinid testate amoebae. Five VSM taxa are recognized in the deposit: Cycliocyrillium simplex Porter, Meisterfeld, and Knoll, 2003, and C. torquata Porter, Meisterfeld, and Knoll, 2003, originally described in the Chuar Group (USA), and three new monospecific genera—Palaeoamphora urucumense n. gen. n. sp., Limeta lageniformis n. gen. n. sp., and Taruma rata n. gen. n. sp. Most of the taxonomically important characteristics of these VSMs occur also in extant testate amoebae, but the combinations of some characters, such as organic-walled tests having exceptionally long necks that exhibit terminal apertures (L. lageniformis n. gen. n. sp.), are evidently novel additions to the known diversity of Neoproterozoic VSMs. Evidence of glacially influenced deposition in the conformably overlying Santa Cruz Formation may indicate that the Urucum Formation slightly preceded or was penecontemporaneous with a major Neoproterozoic glaciation, although the VSM-hosting extraclasts must be older, possibly rivaling the age of the testate amoebae of the Chichkan Formation (766±7 Ma) that are currently regarded as the oldest record of protists in the geological record.

The mixed carbonate-siliciclastic successions of the Cambrian Series 2–Cambrian Series 3 interval of the Great Basin are well investigated in respect to their trilobite and brachiopod fauna. In contrast, the small shelly fossils have been mostly unreported. Nine sections in eastern California and southern Nevada have produced a small shelly assemblage of low diversity, which likely reflects non-phosphatization and loss of originally calcareous remains. From the Montezuman–Delamaran stages we report Anabarella chelata Skovsted, 2006a, Costipelagiella nevadense Skovsted, 2006a, Pelagiella aff. P. subangulata (Tate, 1892), Microcornus sp., Parkula sp., Hyolithellus? sp., Allonia sp., Chancelloria sp., Archiasterella cf. A. hirundo Bengtson in Bengtson et al., 1990, Archaeooides cf. A. granulatus Qian, 1977, and undefined echinoderms and helcionelloid molluscs. The lower part of the Montezuman Stage delivered a number of lobopodian sclerites as Microdictyon rhomboidale Bengtson, Matthews, and Missarzhevsky, 1986, Microdictyon montezumaensis n. sp., and Microdictyon cuneum n. sp. The occurrence of P. aff. P. subangulata and species of Microdictyon in the lower Montezuman Stage offers a fundamental potential for correlation with the base of Cambrian Series 2/Stage 3 of South China, Siberia, and Avalonia.

Cherty limestones, marls and radiolarites are widespread in the Hallstatt Mélange of the Northern Calcareous Alps. The mélange was formed during the Neotethyan orogeny in a series of deep-water basins that progressively developed in front of the advancing nappe front. The low thermal overprint of these rocks favors the good preservation of radiolarians (polycystines) that have been used for dating and reconstructing the Jurassic tectonostratigraphy of the area. This paper describes rich Middle–Late Jurassic radiolarian faunas from four localities in the Hallstatt Mélange near Bad Mitterndorf in Austria. Two different successions, both spanning from the Bathonian to the Oxfordian, are dated. In the first succession, the radiolarites are intercalated between or occur as matrix in mass-flow deposits originating from the accretionary wedge. The second succession is nearly 100 m thick but is devoid of mass-flow deposits and documents a continuous radiolarite deposition in greater distance from the nappe stack. Both successions are ascribed to the Sandlingalm Basin, which evolved on a relatively distal continental margin during early stages of the orogeny.

The highly diverse and well-preserved radiolarian assemblages have been used for a detailed taxonomic study. Two new families are described: Minocapsidae n. fam. and Xitomitridae n. fam.; six new genera are described Doliocapsa n. gen., Crococapsa n. gen., Parvimitrella n. gen., Xitomitra n. gen., Campanomitra n. gen., and Mizukidella n. gen. In addition, one new replacement name, Takemuraella (pro Triversus), is introduced, the diagnoses of 6 genera are emended, and two new species are described: Hemicryptocapsa nonaginta n. sp. and Mizukidella mokaensis n. sp.

The subfamily Hindellinae is an early group of athyride brachiopods, characterized by a simple jugum that connects the laterally directed spiralia, which are disjunct from the crura. Four genera (Hindella, Cryptothyrella, Koigia, and Hyattidina) are reexamined on the basis of their internal structures, such as the crura and their connection to the hinge, the jugum, and spiralia. The internal brachidium and shell of the Aeronian genus Cryptothyrella differ substantially from those of Hindella. Elkanathyris pallula n. gen. n. sp. is recognized as a posteriorly ribbed hindellide of Aeronian age. These genera are transferred from the Meristellinae to the subfamily Hindellinae (family Hindellidae). On Anticosti Island, Hindella is confined to the Hirnantian (latest Ordovician): it became extinct at the end Ordovician during the last of several mass extinction events that also extinguished the Laframboise reefs at the top of the Ellis Bay Formation. Post-extinction recovery of athyrides was pioneered by small-shelled Koigia, which are abundant in the basal Silurian Becscie Formation. Hyattidina, with a simple brachidium, is abundant in the Aeronian and Telychian of Anticosti, but absent earlier. True meristellines, as envisioned here, first appeared in the Aeronian Gun River Formation. The revised taxonomy and stratigraphic ranges of these earliest athyrides shed light on the nature of the Ordovician–Silurian mass extinction and recovery, and help refine the biostratigraphy of the O-S boundary interval.