-Carbon stable-isotope variation through the Cenomanian-Santonian stages is characterized using data for 1769 bulk pelagic carbonate samples collected from seven Chalk successions in England. The sections show consistent stratigraphic trends and δ 13 C values that provide a basis for highresolution correlation. Positive and negative δ 13 C excursions and inflection points on the isotope profiles are used to define 72 isotope events. Key markers are provided by positive δ 13 C excursions of up to + 2 ‰: the Albian/Cenomanian Boundary Event; Mid-Cenomanian Event I; the Cenomanian/Turonian Boundary Event; the Bridgewick, Hitch Wood and Navigation events of Late Turonian age; and the Santonian/Campanian Boundary Event. Isotope events are isochronous within a framework provided by macrofossil datum levels and bentonite horizons. An age-calibrated composite δ 13 C reference curve and an isotope event stratigraphy are constructed using data from the English Chalk. The isotope stratigraphy is applied to successions in Germany, France, Spain and Italy. Correlation with pelagic sections at Gubbio, central Italy, demonstrates general agreement between biostratigraphic and chemostratigraphic criteria in the Cenomanian-Turonian stages, confirming established relationships between Tethyan planktonic foraminiferal and Boreal macrofossil biozonations. Correlation of the Coniacian-Santonian stages is less clear cut: magnetostratigraphic evidence for placing the base of Chron 33r near the base of the Upper Santonian is in good agreement with the carbon-isotope correlation, but generates significant anomalies regarding the placement of the Santonian and Campanian stage boundaries with respect to Tethyan planktonic foraminiferal and nannofossil zones. Isotope stratigraphy offers a more reliable criterion for detailed correlation of Cenomanian-Santonian strata than biostratigraphy. With the addition of Campanian δ 13 C data from one of the English sections, a composite Cenomanian-Campanian age-calibrated reference curve is presented that can be utilized in future chemostratigraphic studies.The Cenomanian-Campanian carbon-isotope curve is remarkably similar in shape to supposedly eustatic sea-level curves: increasing δ 13 C values accompanying sea-level rise associated with transgression, and falling δ 13 C values characterizing sea-level fall and regression. The correlation between carbon isotopes and sea-level is explained by variations in epicontinental sea area affecting organic-matter burial fluxes: increasing shallow sea-floor area and increased accommodation space accompanying sea-level rise allowed more efficient burial of marine organic matter, with the preferential removal of 12 C from the marine carbon reservoir. During sea-level fall, reduced seafloor area, marine erosion of previously deposited sediments, and exposure of basin margins led to reduced organiccarbon burial fluxes and oxidation of previously deposited organic matter, causing falling δ 13 C values. Additionally, drowning of carbonate platforms during...

The term Anthropocene, proposed and increasingly employed to denote the current interval of anthropogenic global environmental change, may be discussed on stratigraphic grounds. A case can be made for its consideration as a formal epoch in that, since the start of the Industrial Revolution, Earth has endured changes sufficient to leave a global stratigraphic signature distinct from that of the Holocene or of previous Pleistocene interglacial phases, encompassing novel biotic, sedimentary, and geochemical change. These changes, although likely only in their initial phases, are sufficiently distinct and robustly established for suggestions of a Holocene-Anthropocene boundary in the recent historical past to be geologically reasonable. The boundary may be defined either via Global Stratigraphic Section and Point ("golden spike") locations or by adopting a numerical date. Formal adoption of this term in the near future will largely depend on its utility, particularly to earth scientists working on late Holocene successions. This datum, from the perspective of the far future, will most probably approximate a distinctive stratigraphic boundary.

Post‐Palaeozoic asteroids share a large number of derived characters of the ambulacral column and the mouth frame, and constitute the crown group of the monophyletic group Asteroidea. This crown group is here called the Neoasteroidea (new subclass). The stem species of the crown group lived in the Permian or early Triassic and so the evolution of the asteroids parallels that of the echinoids. Character distribution within the Neoasteroidea, especially morphology of the skeleton, digestive system, larvae and tube feet, allows subdivision into four orders (Paxillosida, Notomyotida, Valvatida, Forcipulatida). The latter three orders possess the synapomorphy of suckered tube feet and are united as the Surculifera (new superorder); the Paxillosida are their primitive sister group. Palaeozoic asteroids represent the stem group of the class, and may be divided into plesions according to the order of appearance of synapomorphies with the crown group. Classification of Palaeozoic asteroids requires much further study. The appearance of new characters within the crown group asteroids, such as suckered tube feet, implies that these were absent in the stem group. The range of life‐habits possible in Palaeozoic asteroids can thus be partly deduced from evidence provided by living asteroids. Palaeozoic asteroids are deduced to have lacked suckered tube feet and were presumably unable to evert the stomach; hence they were precluded from life on hard substrates and extraoral feeding on epifaunal organisms. It is suggested that they lived on soft substrates by deposit feeding, scavenging and predation on small benthos.

The association between mass extinction in the marine realm and eustatic sea-level change in the Mesozoic is well documented, but perplexing, because it seems implausible that sea-level change could actually cause a major extinction. However, large-scale cycles of sea-level change can and do alter the ratio of shallow to deep marine continental-shelf deposits preserved in the rock record both regionally and globally. This taphonomic megabias alone could be driving patterns of first and last occurrence and standing diversity because diversity and preservation potential both change predictably with water depth. We show that the Cenomanian/Turonian faunal event in western Europe has all the predicted signatures expected if taphonomic megabias was the cause. Grade taxa terminating in pseudoextinction and Lazarus taxa are predominantly found in the onshore facies that disappear for extended periods from the rock record. Before other mass extinctions are taken at face value, a much more careful analysis of biases in the rock record needs to be carried out, and faunal disappearances need to be analyzed within a phylogenetic framework.