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The morphologic radiation of Early Jurassic ammonites following the near extinction at the end of the Triassic is analyzed from 436 species of 156 genera that form a representative sample of morphs occurring worldwide in the first three stages of the Jurassic (Hettangian, Sinemurian, Pliensbachian: 36 subzones, 24 m.y.). Morphologic diversity is analyzed independently of taxonomy by processing 18 shape parameters using multivariate analysis and clustering techniques. The morphospace thus defined indicates that morphs fall readily into two groups made up of four and five adjacent morpho-subsets. The temporal pattern of morphospace occupation in the 36 Lower Jurassic subzones displays diversification, depletion (sometimes total), and displacement of successive parts of the morphospace, reflecting a complex history in which morphologic radiation appears to be more than a process of diffusion. The history of the morphologic evolution is tentatively related to sea-level changes and there is a suggestion that morphologic diversity increases during second-order transgressive periods.

Conservation biologists and palaeontologists are increasingly investigating the phylogenetic distribution of extinctions and its evolutionary consequences. However, the dearth of palaeontological studies on that subject and the lack of methodological consensus hamper our understanding of that major evolutionary phenomenon. Here we address this issue by (i) reviewing the approaches used to quantify the phylogenetic selectivity of extinctions and extinction risks; (ii) investigating with a high-resolution dataset whether extinctions and survivals were phylogenetically clustered among early Pliensbachian (Early Jurassic) ammonites; (iii) exploring the phylogenetic and temporal maintenance of this signal. We found that ammonite extinctions were significantly clumped phylogenetically, a pattern that prevailed throughout the 6.6 Myr-long early Pliensbachian interval. Such a phylogenetic conservatism did not alter – or may even have promoted – the evolutionary success of this major cephalopod clade. However, the comparison of phylogenetic autocorrelation among studies remains problematic because the notion of phylogenetic conservatism is scale-dependent and the intensity of the signal is sensitive to temporal resolution. We recommend a combined use of Moran's I, Pearson's ϕ and Fritz and Purvis' D statistics because they highlight different facets of the phylogenetic pattern of extinctions and/or survivals.

A two-step "naked-eye" screening of selective metal-based chemosensors for biologically important anions such as cyanide, phosphate, and oxalate from commercially available metal indicators and metal ions has been developed. Applications in food safety control have been demonstrated.

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Aim: To test for the phylogenetic conservatism of geographic range size and to explore the effect of the environment on this potential conservatism.Location: The western Tethys Ocean and its surroundings (present-day Europe, the Middle East and North Africa) during the early Pliensbachian (Early Jurassic).Methods: Using 104 localities and 1,765 occurrences of ammonite species, we estimated geographic range sizes using the extent of occurrence and the latitudinal range.The phylogenetic conservatism of range sizes was tested using Moran's I index which measures phylogenetic autocorrelation, and Pagel's k which indicates whether a phylogeny correctly predicts covariance patterns among taxa on a given trait according to a Brownian evolution model. We conducted these analyses for two neighbouring provinces with contrasting environmental features (Mediterranean and Northwest European). We also explored scale effects by considering the whole western Tethys and two temporal resolutions (chronozone and sub-stage).Results: A marked difference in phylogenetic signal is observed between Mediterranean (MED) and Northwest European (NWE) species; the range size of MED species is more frequently phylogenetically conserved than that of NWE species. No phylogenetic conservatism of species range size is observed during the last chronozone of the early Pliensbachian which is characterized by numerous palaeoclimatic and palaeoenvironmental changes.Main conclusions: Species range size may be partly determined by phylogeny, but this phylogenetic conservatism is modulated by spatio-temporal environmental stability. The phylogenetic signal of species range size may be labile through time within the same lineage and may differ between contemporaneous species of the same group. This lability stems from the fact that species range size results from a complex interplay of intrinsic and extrinsic factors. K E Y W O R D S ammonites, Early Jurassic, environment, phylogenetic conservatism, phylogeny, provincialism, species range size

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