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Based on the fossil record, we explore the macroevolutionary relationship between species richness and gigantism in cowries (Cypraeidae), the best-studied family of gastropods, with a global diversity distribution that parallels that of tropical corals, mangroves and seagrasses. We introduce Vicetia bizzottoi sp. nov. based on a Priabonian fossil found in northeastern Italy, the largest documented cowrie found so far and the youngest of a lineage of Eocene Gisortiinae species. The Gisortiinae stratigraphic record in western Europe indicates that species selection favoured large size and armouring of the shell. Palaeoecology and per-stage species richness suggest that gigantism occurred in peripheral habitats with respect to diversity hotspots, where smaller species were favoured. The Eocene–Oligocene boundary was marked by a turnover and the Chattian global warming favoured small-sized species of derived clades. Species selection leading to gigantism is further documented in Miocene lineages of Zoila and Umbilia, in the southern hemisphere, two extant genera distributed at the periphery of modern diversity hotspots, suggesting that the negative relationship between size and diversity is a recurring pattern in the evolutionary history of cowries. This palaeontological evidence is projected onto the existing hypotheses that explain analogous biogeographic patterns in various other taxa. Likewise, body size-species richness negative relationship was possibly driven in cowries by physiological, ecological and life history constraints.

1. The microgranular/agglutinated imperforate larger foraminifera (ILF, chiefly “lituolids”) of Mesozoic shallow marine carbonate shelves are a polyphyletic group of K-strategists, ecologically homogeneous inhabitants of the photic zone (nutrient poor) and hosting symbionts as their larger porcelaneous recent equivalents. They contrast with deeper water “lituolid” taxa and other deeper marine dwellers (hyaline perforate and planktonics r-strategists). They are narrowly linked to the carbonate platform history and evolution, birth and demise (correlated to paleotectonics or sea-level variations), and global climatic or volcanic events, OAE, etc. 2. General principles used in evolutionary sciences can be applied to decipher some morphological pathways among foraminifera through time to reconstruct phylogenetical arborescences, e.g., embryology (heterochronies of development), recapitulation law (Haeckel), size increase (Deperet), parallel evolution, and biostratigraphy. 3. Iterative evolution is the main mode of morphological variation through time and biostratigraphy helps to reconstruct the time repartition of diverging advanced homeomorphic taxa and their distinction. The new characters are issued from a constant, more tolerant stock of smaller and simpler primitive atavic forms by the transformation of previous structures or the addition of new ones. Advanced homeomorphic taxa are temporarily preserved and their morphological innovations linked probably to (epi)genetic constraints and symbiotic history increasing their energy efficiency in a rather stable (but cyclical) environment. 4. Morphological innovations appear slowly during the Jurassic and more rapidly (and frequently) during the Cretaceous following a probable saltative and allopatric mode of evolution during favorable periods after main environmental crisis, anoxia, and sea-level changes. The Cretaceous is a time of great diversification (adaptive radiation of microgranular lituolids and larger porcelaneous tests). 5. Morphological changes at a scale of one or two stages in one evolutive bioseries (general trend: size and internal complications increase) cannot be linked to global events or other abiotic factors (e.g., the orbitopsellids in the Pliensbachian) but are rather driven by internal epigenetic factors related to algal symbiosis and coevolution. The constancy of the model (text Fig. 8.2) through time in variable clades could be explained that way. The structural incompatibility between pseudokeriotheca/alveolae within the wall and marginal microstructures (radial partitions or hypodermic network) could be explained by a biological incompatibility of bacterial symbionts to live aside with larger microalgae as dinoflagellates. Local discontinuous events like cyclic (metric) parasequences are common on carbonate platforms but have no apparent influence on morphogenesis or population composition. 6. Conversely, global environmental crises affect deeply the larger foraminifera (chiefly advanced larger tests) and population compositions at a higher taxonomic rank (families, etc.), replacing in the aftermath the larger solid tests by smaller forms with a fragile (thin) test during anoxic crisis (T/J—Late Pliensbachian—Late Cenomanian, etc.). Larger forms are too specialized and complicated in their architecture and are particularly sensitive to environmental changes (Hallock, Paleobiology 11(2):195–208, 1985). They cannot adapt their test morphology (“retrograde evolution,” Guex, Retrograde Evolution During Major Extinction Crisis, 2016) back to some kind of more tolerant simpler form because their low reproduction rates impede a rapid reaction to environmental stress, even for minor adjustments. Major sea-level and facies changes (deeper water conditions or large-scale emersions) cause the brutal disappearing of this very sensitive group of foraminifera. However, some large discoid taxa and other smaller siphovalvulinids-valvulinids cross the K/T environmental crisis, interpreted as survivors in the Paleocene. 7. Moreover, gigantism is probably a disadvantage against physical perturbations like tidal currents and storms in an otherwise stable carbonate environment. In a first evolutionary step, increasing of test size and flattening of chambers are selective advantages in terms of energy (increasing of chemical exchanges with more symbionts) and stability on flat surfaces; but near the end of the evolutive bioseries, the same traits become a drawback concerning test anchorage and risk of displacement in unfavorable microenvironments.

Longstanding scientific efforts have been dedicated to answer why and how our particular intelligence is generated by our brain but not by the brain of other species. However, surprisingly little effort has been made to ask why no other species ever developed an intelligence similar to ours. Here, I explore this question based on genetic and paleontologic evidence. Contrary to the established view, this review suggests that the developmental hurdles alone are not high enough to explain the uniqueness of human intelligence (HI). As an additional explanation I propose that HI is normally not retained by natural selection, because it is, under most conditions, an intrinsically unfavourable trait. This unfavourableness, however, cannot be explained by physical constraints alone; rather, it may also be rooted in the same emotional and social complexity that is necessary for the development of HI. Thus, a major obstacle towards HI may not be solely the development of the required physical assets, but also to cope with harmful individual, social and environmental feedback intrinsically associated with this trait.

International audience; Synthesis of ultrawideband (UWB) antennas by means of a particle swarm optimizer (PSO)-driven spline-based shaping approach is described. In order to devise a reliable and effective solution, such a topic is analyzed according to different perspectives: 1) representation of the antenna shape with a simple and efficient description; 2) definition of a suitable description of the UWB Tx/Rx system; 3) formulation of the synthesis problem in terms of an optimization one; 4) integration of the modelling of the UWB system into a computationally efficient minimization procedure. As a result, an innovative synthesis technique based on the PSO-based iterative evolution of suitable shape descriptors is carefully detailed. To assess the effectiveness of the proposed method, a set of representative numerical simulations are performed and the results are compared with the measurements from experimental prototypes built according to the design specifications coming from the optimization procedure. To focus on the main advantages and features of the proposed approach, comparisons with the results obtained with a standard parametric approach are reported, as well

International audience; Late Bajocian to Early Bathonian ammonites, now attributed to Benatinites and Lugariceras, and Late Bathonian Hemigarantia, previously considered as cryptogenic taxa, share very similar sutural and ornamentation characters, suggesting their derivation from the stephanoceratid stock, most probably from the Cadomites–Polyplectites line. The palaeogeographical distribution of these taxa is limited to the North-Western African and European margins of Western Tethys. Palaeontologically, they represent the result of the iterative evolution rather than a poorly known lineage.

Molecular recognition is one of the major challenges of supramolecular chemistry. Here, we present the design, synthesis and study of helical capsules properties self-organised by aromatic oligoamide folding. These receptors consist of oligomeric chains that fold into a helical conformation and comprise of a sequence of units which code for different diameters. Oligomeric folding defines a cavity which can recognize guests. The great modularity of the sequences has allowed a controlled evolution of foldamer structure resulting in the selective and predict recognition of biological substrates. The phenomenon of encapsulation was demonstrated in solution by NMR and CD spectroscopy and in the solid state by X-ray diffraction., La reconnaissance moléculaire constitue l’une des questions fondamentales les plus discutées dans le domaine de la chimie supramoléculaire. Cette thèse présente la conception, la synthèse et l’étude des propriétés de capsules hélicoïdales auto-organisées par repliement d’oligoamides aromatiques. Ces récepteurs sont constitués d’une chaîne oligomérique se repliant en hélice et comprenant une séquence d’unités codant pour des diamètres différents. Le repliement de l’oligomère donne naissance à une cavité pouvant accueillir des molécules invitées. La grande modularité des séquences, permettant une évolution contrôlée des structures des foldamères, donne lieu à la reconnaissance sélective et anticipée de substrats d’intérêts biologiques. Le phénomène d’encapsulation a été mis en évidence en solution par spectroscopie RMN et CD, et dans le solide par diffraction des rayons X.