Over the last few years, the morphology, taxonomy and systematics of the cartilaginous fish taxa of the two main sites of the Bolca Lagerstätte, Italy, (Pesciara and Monte Postale sites) have been extensively discussed in a series of papers, resulting in a complete revision of this neglected component of the Eocene Tethyan ichthyofauna. Here, we provide a comprehensive overview of the diversity, palaeoecology and palaeoenvironmental significance of the two chondrichthyan assemblages of the Pesciara and Monte Postale sites. The assemblages include 14 shark species (Lamniformes and Carcharhiniformes) and batoids (Torpediniformes, Rhinopristiformes, Myliobatiformes, Platyrhinidae and Zanobatidae), as well as a single putative chimaeriform. The Pesciara and Monte Postale sites are characterized by eight chondrichthyan taxa each, but the taxonomic compositions are distinctly different reflecting the dissimilarities in the overall composition of both fish assemblages. Palaeoecological interpretations and habitat preferences of the two chondrichthyan assemblages are consistent with previously hypothesized palaeoenvironmental settings based on sedimentological, palaeontological and geochemical evidence. The chondrichthyan assemblages of the two sites appear to be constituted by ecologically vicariant taxa, with both characterized by a predominance of benthic species with durophagous/cancritrophic feeding modes. Taxonomic composition, habitat preferences and palaeobathymetric analyses support the hypothesis that both assemblages occupied tropical marine shallow waters (likely up to 50 m deep) of the inner portion of the Lessini Shelf. The taxonomic composition of both sites is considerably different from that of any other contemporaneous Tethyan and Boreal chondrichthyan assemblages.

Recent data indicate one or more moderately nearby supernovae in the Early Pleistocene, with additional events likely in the Miocene. This has motivated more detailed computations, using new information about the nature of supernovae and the distances of these events to describe in more detail the sorts of effects that are indicated at the Earth. This short communication/review is designed to describe some of these effects so that they may possibly be related to changes in the biota around these times.

The deposits of the Carnian Kasımlar Formation within the Taurus Platform Units of south-western Turkey represent an important archive of a Late Triassic ecosystem. New palaeontological information was obtained by analysing the mass occurrence, located within the Kasımlar Formation and named after the Lower Carnian (Julian) ammonoid genus . This is the dominant taxon (> 94%) within the mass occurrence: nearly 775 million ammonoids and 50 million gastropods were extrapolated for the whole extension (at least 5 km) of the beds. This calculation is one of the main findings within this study, as it is the first time that such a fossil mass occurrence was quantified. Additionally, orientation measurements of the planispiral ammonoids and the helical gastropods enabled reconstructing the history of the mass occurrence and interpreting the underlying transport mechanisms. Further taphonomic aspects (e.g. biofabric, preservation, bioerosion or genetic classification) as well as comparisons with samples of the same acme zone from different localities near Aşağiyaylabel (AS IV, KA I-II) point to a two-phased genetic history. Accordingly, local mass mortality within the fauna due to oxygen fluctuations or methane degassing may have initially led to a primary accumulation. These deposits were then reworked and redeposited basinward by gravity flows to create the present-day secondary allochthonous concentrations.

Phosphorites of the late Neoproterozoic Doushantuo Formation exposed in the vicinity of Weng'an, Guizhou Province, and Chadian, Shaanxi Province, South China, contain exceptionally well-preserved algal thalli, acritarchs, and globular microfossils interpreted as animal embryos. Combined optical microscopic and SEM observations provide insights into the taphonomy of phosphatized fossils. Algal cells and tissues are variably resistant to decay, and within preserved populations permineralization began at varying stages of degradation. In consequence, there is a spectrum of quality in cellular preservation. Algal cell walls, acritarch vesicles, and embryo envelopes are commonly encrusted by an isopachous rim of apatite, with cell interiors filled by collophane and later diagenetic dolomite. In contrast, blastomere surfaces of animal embryos are encrusted primarily by minute phosphatic spherules and filaments, possibly reflecting an immediately postmortem infestation of bacteria that provided nucleation sites for phosphate crystal growth. Thus, the same processes that gave rise to Phanerozoic phosphatized Lagerstatten--phosphatic encrustation, and impregnation, probably mediated by microbial activity--effected soft-tissue preservation in the Doushantuo Lagerstatte. It remains unclear how phosphatic ions and organic macromolecules interact at the molecular level and to what extent specific microbial metabolisms or microenvironmental conditions control the phosphatization of soft tissues. New observations of phosphatized Doushantuo fossils include: a second locality (Chadian) for Wengania globosa, interpreted as an algal thallus and previously known only from Weng'an; microtunnels in Weng'an phosphorites interpreted as pyrite trails; and new taxa described from Weng'an: Meghystrichosphaeridium reticulatum (acritarch), Sarcinophycus radiatus (algal thallus), and one unnamed problematic form.

Populations of the multi-trichomous microbial fossil Eoschizothrix composita n.gen. et sp. are preserved in growth position in silicified stratiform stromatolites of the Gaoyuzhuang Formation, Hebei Province, northern China. The microbial fossils consist predominantly of preserved sheaths, although several specimens retain shriveled remains of trichomes within sheaths. Comparisons with modern morphological counterparts, including shape, growth habit and orientation, degradational sequences, and habitat, support the interpretation of the multi-trichomous microfossils as cyanobacteria, which acted as frame-builders of ancient stromatolites. The distribution and orientation of multi-trichomous microfossils within a synsedimentary context reveal their behavioral responses to sedimentation regime. Horizontally spread, interwoven mats formed during periods of sedimentary stasis. During periods of rapid sediment influx, the filaments assumed an upright orientation, possibly to avoid accumulating particles. This is the first record of fossil stromatolite-building multi-trichomous cyanobacterial which underscores early morphological and functional diversification in cyanobacterial evolution.

Two methods are used to examine feeding strategies in graploloids; the first profiles different sets of zooids on the colony, the second treats the colony as a whole. Both of these techniques have advantages. The choice between them brings into question our concepts of the degree of coloniality shown by graptoloids. Using a whole colony model. graptoloids can be shown to have sampled the water with variable efficiency. as defined in this paper. Planar forms were relatively inefficient, generally sampling less than 10% of the available water. Inclined forms frequently approached 75% efficiency. Biserial forms and strdight monograptids roulinely exceeded 100%. sampling each unit of water more than once. Rotation of the rhabdosome during movement increased the efficiency of horizontal and inclined forms. It reduced the efficiency of scandent biserials and straight monograptids. These were both advantageous effects. Astogenetic changes in colony size and form would have had a profound effect on feeding efficiency.□.

The genus Archaeoellipsoides Horodyski & Donaldson comprises large (up to 135 micrometers long) ellipsoidal and rod-shaped microfossils commonly found in silicified peritidal carbonates of Mesoproterozoic age. Based on morphometric and sedimentary comparisons with the akinetes of modern bloom-forming Anabaena species, Archaeoellipsoides is interpreted as the fossilized remains of akinetes produced by planktic heterocystous cyanobacteria. These fossils set a minimum date for the evolution of derived cyanobacteria capable of marked cell differentiation, and they corroborate geochemical evidence indicating that atmospheric oxygen levels were well above 1% of present day levels 1,500 million years ago.