A new species of polycotylid, Dolichorhynchops herschelensis, is described based on a well-preserved skeleton from the Upper Cretaceous (Campanian–Maastrichtian) Bearpaw Formation of Herschel, Saskatchewan. Its small size as an adult, the sharp rise in front of the parietal crest, and the straight ilium with narrow dorsal end are diagnostic features of this taxon. This is the first polycotylid plesiosaur described from the Bearpaw Formation, deposited during the critical period when polycotylids were disappearing from the Western Interior of North America.

The trochid archaeogastropod Margarites (Pupillaria) columbiana n. sp., the mytilid bivalve Modiolus (Modiolus) willapaensis n. sp., and the vesicomyid bivalve Calyptogena chinookensis n. sp. are described from the earliest known fossil communities associated with subduction-related methane seeps. The communities are in very localized limestones of late middle to late Eocene age along the southwestern margin of Washington. These limestones contain large numbers of chemosynthetic bivalves and worm tubes, as well as other macrobenthos, that colonized around cool-temperature methane seeps along the landward slopes of an ancient subduction-zone complex.

Calyptogena chinookensis n. sp.is the earliest known species of this genus, which was previously known from Miocene to Recent.

Taphofacies have been based on the likelihood that considerable variability exists in taphonomic processes between different environments and that this variability produces predictable variations in taphonomic signature between assemblages. Three stations above storm wave base that differed little in sediment texture and depth were sampled on the inner continental shelf of central Texas. Taphonomic analysis revealed subtle gradients in sediment grain size and water depth that would not be revealed by most other analyses. These gradients may exist over very small spatial scales, equivalent to those within a single extensive outcrop. Not all taphonomic attributes are equally likely to be preserved in the fossil record. Those varying with depth in our study area, such as fragmentation and articulation, are more likely to be preserved than those documenting changes in sediment texture, such as variation in the frequency of dissolution features on the shells. Nevertheless, siting and sampling protocols are important when characterizing a taphofacies because within-habitat variation is potentially as large as between-habitat variation. Description of the average taphofacies for an environment must include documentation of the variation in taphonomic attributes within the sampled area because few conservative taphonomic attributes exist. Fragments, even those that are unidentifiable, retain significant taphonomic information and should not be ignored. Careful sampling should permit the simultaneous description of general taphofacies as well as the detection of important but unsuspected gradients in the environment.

Light microscopy studies on new materials and museum collections of early Cambrian organic-walled microfossils, informally called acritarchs, provide the observations on phenetic features that permit a comparison to certain Modern microalgae and the recognition of various developmental stages in their life cycle. the microfossils derive from various depositional settings in Estonia, Australia, Greenland, Sweden, and Poland. the exceptionally preserved microfossils reveal the internal body within the vesicle, the endocyst, and the process of releasing the endocyst from the cyst. Vegetative cells, cysts, and endocysts are distinguished, and the hypothetical reconstruction of a complex life cycle with the alternation of sexual and asexual generations is proposed. Acritarchs from the Skiagia-plexus are cysts, and likely zygotes in the sexual generation, which periodically rested as “benthic plankton.” Some microfossils of the Leiosphaeridia-plexus that are inferred to be vegetative cells were planktonic and probably haplobiontic. These form-taxa may belong to a single biological species, or a few closely related species, and represent the developmental stages and alternating generations in a complex life cycle that is expressed by polymorphic, sphaero- and acanthomorphic acritarchs. the morphological resemblance and diagnostic cell wall ultrastructure with the trilaminar sheath structure known from earlier studies suggest that the early Cambrian microfossils are the ancestral representatives and/or early lineages to the Modern class Chlorophyceae and the orders Volvocales and Chlorococcales.

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.

African wild dogs (Lycaon pictus) occupy an ecological niche characterized by hypercarnivory and cursorial hunting. Previous interpretations drawn from a limited, mostly Eurasian fossil record suggest that the evolutionary shift to cursorial hunting preceded the emergence of hypercarnivory in the Lycaon lineage. Here we describe 1.9—1.0 ma fossils from two South African sites representing a putative ancestor of the wild dog. the holotype is a nearly complete maxilla from Coopers Cave, and another specimen tentatively assigned to the new taxon, from Gladysvale, is the most nearly complete mammalian skeleton ever described from the Sterkfontein Valley, Gauteng, South Africa. the canid represented by these fossils is larger and more robust than are any of the other fossil or extant sub-Saharan canids. Unlike other purported L. pictus ancestors, it has distinct accessory cusps on its premolars and anterior accessory cuspids on its lower premolars—a trait unique to Lycaon among living canids. However, another hallmark autapomorphy of L. pictus, the tetradactyl manus, is not found in the new species; the Gladysvale skeleton includes a large first metacarpal. Thus, the anatomy of this new early member of the Lycaon branch suggests that, contrary to previous hypotheses, dietary specialization appears to have preceded cursorial hunting in the evolution of the Lycaon lineage. We assign these specimens to the taxon Lycaon sekowei n. sp.

The fossil record of solemydid turtles is primarily based on isolated fragments collected from Late Jurassic to Late Cretaceous sediments throughout North America and Europe and little is therefore known about the morphology and evolutionary history of the group. We here provide a detailed description of the only known near-complete solemydid skeleton, which was collected from the Lower Cretaceous (Aptian–Albian) Antlers Formation of Texas during the mid-twentieth century, but essentially remains undescribed to date. Though comparison is limited, the skeleton is referred to Naomichelys speciosa, which is based on an isolated entoplastron from the Lower Cretaceous (Aptian–Albian) Kootenai (Cloverly) Formation of Montana. The absence of temporal emarginations, contribution of the jugals to the orbits, and a clear subdivision of the middle and inner cavities, and the presence of elongate postorbitals, posteriorly expanded squamosals, a triangular fossa at the posterior margin of the squamosals, an additional pair of tubercula basioccipitale that is formed by the pterygoids, foramina pro ramo nervi vidiani (VII) that are visible in ventral view, shell sculpturing consisting of high tubercles, a large entoplastron with entoplastral scute, V-shaped anterior peripherals, and limb osteoderms with tubercular sculpture diagnose Naomichelys speciosa as a representative of Solemydidae. The full visibility of the parabasisphenoid complex in ventral view, the presence of an expanded symphyseal shelf, and the unusual ventromedial folding of the coronoid process are the primary characteristics that distinguish Naomichelys speciosa from the near-coeval European taxon Helochelydra nopcsai.

The terminal Neoproterozoic Sheepbed and Blueflower Formations at Sekwi Brook in northwestern Canada have yielded two additional taxa, both of them new to North America. Hiemalora cf. H. pleiomorphus Vodanjuk is a tentaculate disc that most likely represents a semi-infaunal polyp. Windermeria aitkeni n. gen. and sp. is an ovate, bilaterally symmetrical, segmented fossil similar to the dickinsoniids; these fossils characterize Neoproterozoic faunas of Australia and the Russian Platform, but had not previously been reported from Laurentia.

The dyrosaurids of the Iullemmeden Basin (West Africa) are mainly represented by two genera, Hyposaurus and Rhabdognathus. Hyposaurus has been recognized in the Paleocene of Mali and Nigeria with two species, H. nopcsai and H. wilsoni. Diagnostic characters given by previous authors for these species do not enable their distinction from each other, nor from North American species. It is therefore reasonable to consider H. nopcsai and H. wilsoni as nomina dubia. in 1930, Swinton erected the new genus and species Rhabdognathus rarus on the basis of mandibular remains, and Buffetaut referred a skull to this species in 1980. A new skull was described in 2002 by Brochu et al., and referred to Rhabdognathus sp. Unfortunately, it is impossible to refer either skull to the type species, the mandibular remains having no diagnostic characters at the specific level. Thus, R. rarus is a nomen dubium, and two new names are erected for the two skulls: R. keiniensis n. sp. and R. aslerensis n. sp., all the mandibular remains being referred to Rhabdognathus sp. the species Rhabdognathus compressus is reassigned to the genus Congosaurus, since its mandible is higher than that of Hyposaurus, shorter than that of Rhabdognathus, and the lateromedially compressed teeth demonstrate that C. compressus and C. bequaerti are closely related.

Phosphatized, three-dimensional cuticle fragments of the palaeoscolecids Houscolex lepidotus new genus and new species, Houscolex species indeterminate, and an unidentified form are described from the Lower Cambrian Qiongzhusi Formation of Shaanxi, China. These segmented worms, characterized by regularly arranged simple plates and platelets, small circular pores and fine pits, and irregularly distributed nipplelike protuberances, are unique among known palaeoscolecids. The occurrence of such cuticles as seemingly persistent elements of phosphatized faunas suggests that wormlike organisms achieved a fairly high diversity and widespread geographic distribution during the Early and Middle Cambrian.

The distinctive, branched thrombolite, Favosamaceria cooperi new group and form, is found widely in the Great Basin, USA, where it is restricted to the Late Cambrian Saukia trilobite Zone. This thrombolite is distinguished by a hedgerow, mazelike organization of ridges similar to garden walls (maceriae) in plan view, branching of ridges into daughter ridges and columns, the polymorphic nature of dark, 1–4 mm mesoclots, and the relative consistency of maceria width (approximately 1 cm). As a group, Favosamaceria is found elsewhere in Upper Cambrian strata of the Argentine Precordillera, Appalachians, and Upper Mississippi Valley, as well as in Lower Ordovician deposits of the Canadian Arctic and Newfoundland. The distribution of the group around Laurentia illustrates the use of microbialites in biogeographic studies.

Eutherian tarsal bones of Late Cretaceous age are reported for the first time from sedimentary beds intercalated with the Deccan Traps of peninsular India. The tarsal bones, represented mainly by calcanea and astragali, occur in association with dental elements of palaeoryctid mammals: Deccanolestes hislopi Prasad and Sahni and D. robustus Prasad, Jaeger, Sahni, Gheerbrant, and Khajuria. Two size variants in the tarsals correlate well with the teeth of D. hislopi and D. robustus. Morphologically, the tarsal complex of Deccanolestes is quite different from that of other Cretaceous eutherians for which the relevant anatomy is known (Protungulatum and Procerberus). Rather, the tarsals of Deccanolestes exhibit a close affinity to the tarsal morphology of Archonta. A large number of tarsal characters indicate a highly arboreal mode of life for these animals. Presence of such specialized animals as early as the Cretaceous suggests that mammals had already diversified their locomotor adaptations by this time.

The Chattanooga Shale of the southern Appalachian Basin contains a diverse conodont fauna of the high Givetian, Frasnian, and Famennian. The predominantly fine-grained strata were deposited in an offshore setting where depositional packages are separated by unconformities. Conodonts allow regional and global correlation of these strata, recognition of the Frasnian-Famennian boundary, and narrow biostratigraphic constraint of two Frasnian ash beds, MN Zone 8 for the Belpre Ash and upper MN Zone 13 for the Center Hill Ash. Three new Frasnian palmatolepid conodonts are described in open nomenclature, and the holotype of Palmatolepis regularis Cooper is reillustrated.

The early terrestrial fossil record contains numerous Siluro-Devonian problematic Thallophyta which have morphological and habitat characteristics intermediate between the algae and the embryophytic plant kingdom. Three new species of the genus Nematothallus Lang (N. taenia, N. lobata, and N. elliptica) are described from a coaly lens in the Bloomsburg Formation (Ludlow). They are included in the order Nematophytales, which is placed in a new informal taxonomic group, Paraphyta, intended to include enigmatic, terrestrial plant-like fossils. These species designations are based upon the gross morphology of carbonized thalli which consist of an underlying anatomy of flattened tubular elements. The association and attachment of cuticles and axes of ?Prototaxites to Nematothallus is clearly demonstrated in these collections. The morphological and anatomical variety expressed in the numerous fragments of thalli from the deposit implies moderate levels of organic diversity in a “flora” of nonvascular, terrestrial plant-like thallophytes which predates the adaptive radiation of the embryophytes.

A model for crinoid plate circlet homologies is proposed based on a tricyclic (four-circlet) aboral cup, with Aethocrinus the characteristic tricyclic crinoid. The plate circlets in the aboral cup of Aethocrinus, from bottom to top, are lintels (named herein), infrabasals, basals, and radials. In this model, traditional interpretation is maintained for the aboral cup plates of most crinoids. Cladids, flexibles, articulates (primitively), and diplobathrid camerates are dicyclic and are composed of infrabasal, basal, and radial circlets. Monobathrid camerates are monocyclic, and they have basal and radial circlets. Disparid plate circlet homologies are reinterpreted. Among disparids, “basals” are lintels, “inferradials” and “radials” are infrabasals, and “superradials” are radials.

The “Law of Wachsmuth and Springer” is judged to be a relationship that has most fidelity applied to lumen angles. This “law” is considered to be only a consequence of development and not an invariable basis by which to determine plate homologies. In the model presented here, plates cannot be shifted around after the juvenile calyx is sutured, and arms may grow on either radials or infrabasals, whichever plates are at the top of the cup when arms begin to grow.

Here we describe large, complex trace fossils in the late Ediacaran Omkyk Member of the Zaris Formation, Nama Group, southern Namibia. The horizontal trace fossils are preserved on a number of talus blocks from a bedding plane of a cm-thick sandstone lens from a single stratigraphic horizon less than 100 m below an ash bed dated at 547.3 ± 0.7 Ma. The forms consist of overlapping U-shaped spreiten elements with parallel limbs surrounded by an outer tube. Individual U-shaped elements are 0.2 to 1 cm in diameter, the outer tube is less than 3 mm in diameter, and the forms as a whole range from 5 to 30 cm long and 3 to 10 cm wide. The specimens commonly show a change in direction and change in diameter. The morphology of these trace fossils is comparable to backfill structures, particularly specimens of Paleozoic Zoophycos from shallow water environments. Here we interpret these horizontal spreiten-burrows to record the grazing of the trace-maker on or below a textured organic surface. The identification of large late Ediacaran trace fossils is consistent with recent reports of backfilled horizontal burrows below the Precambrian–Cambrian boundary and is suggestive of the appearance of complex feeding habits prior to the Cambrian trace fossil explosion.

Sodium metatungstate (SMT), 3Na2WO4 · 9WO3 · H2O, is a nontoxic (Sax, 1979), high-density (1.00-3.10 g/cm3) separating compound which results in nearly neutral (pH 6) solutions of relatively low viscosity. It was presented as a medium for density gradient centrifugation by Plewinsky and Kamp (1984). Since then, investigators have used SMT (or sodium polytungstate) as a high-density medium for routine mineral separations, for recovery of conodonts from insoluble residues, for separation of various feldspar species from one another, and for segregation of inorganic mineral fractions (ash) from coal.

Most of the specimens of Myoscolex ateles Glaessner, 1979, the most abundant soft-bodied taxon in the Big Gully fauna from the Lower Cambrian Emu Bay Shale of South Australia, preserve only the phosphatized trunk muscles, in striking contrast to the organic residues that characterize other Burgess-Shale-type biotas. This is the oldest phosphatized muscle tissue and the first thus far reported from the Cambrian. The extent of phosphatization implies a source in addition to the animal itself, and this is reflected in high levels of phosphate in the Big Gully sequence compared to other shales. The apparent anomaly posed by the extensive preservation of labile muscle tissue as opposed to the more decay resistant cuticle is explained by the role of bacterial processes in the preservation of soft tissues. New specimens of Myoscolex reveal a variable number of trunk somites with possible tergites, and flap-like appendages. There is evidence for at least three eyes on the head, and a proboscis may have been present. An annelid affinity is rejected and Myoscolex is reinterpreted as an Opabinia-like animal with possible affinities with the arachnomorph arthropods.

The foraminiferal suborder Astrorhizina is reinstated for the typically monothalamous agglutinated taxa whose cementing material is solely organic, the suborder Haplophragmiina reinstated for multilocular agglutinated taxa with organic cement and simple to alveolar walls. The suborder Trochamminina is recognized for those with organic cement and simple agglutinated walls, and the suborder Textulariina is restricted to include only those with agglutinated walls containing biogenic calcareous cement, and typically canaliculate. In the latter suborder, the new genera Connemarella, type species Gaudryina rudis Wright, and Hemlebenia, type species Hemlebenia aptiensis n. sp., are described in the expanded family Pseudogaudryinidae, subfamily Pseudogaudryininae, whose geologic range thereby is extended into the Lower Cretaceous (Aptian).

The family Emuellidae Pocock, 1970 was established for Emuella Pocock, 1970 and Balcoracania Pocock, 1970 from the Lower Cambrian of South Australia. Based on their peculiar trunk tagmosis, emuellids have been interpreted as the sister group of all other trilobites with dorsal facial sutures, and classified as high as the ordinal level. Cladistic analysis with a range of exemplar taxa of the Olenellina and Redlichiina instead resolves the emuellids within the Redlichiina, with tagmosis into a prothorax and opisthothorax (“telosoma”) nonhomologous in olenellines and emuellids. A taxonomic revision of Australian species identifies Balcoracania flindersi as a junior subjective synonym of B. dailyi, whereas the two named species of Emuella are considered to be distinct. Balcoracania dailyi possesses up to 103 thoracic segments, the maximum number recorded in any trilobite.