The E‐OBS precipitation gridded data set v.10.0 is used to detect very long dry spell (VLDS) events over the entire Mediterranean Basin for the 1957–2013 period, during the wet season (September to April). The main objective is to characterize these events as climatic objects, in terms of location, spatial extent, duration, and temporal variability. In this study, 76 VLDS events were detected in the Mediterranean Basin and grouped into four spatial patterns: scattered localized (with 25 events), northeast Mediterranean (11 events), West Mediterranean (15 events), and southeast Mediterranean (25 events). Each pattern shows seasonality in events. Most of the scattered localized, northeast, and southeast events begin in September, at the beginning of the wet season. In contrast, most of the West Mediterranean events begin in the middle of the wet season. Over time, there is a slight but not significant increase in the cumulative number of days per season affected by VLDS events.

Several typologies of urban surface properties have been proposed, in recent years, for urban heat island studies and climate modeling. Some were specifically developed for cities and urban climate issues, like the Urban Climate Zones, and the more recent Local Climate Zones. The initial objective of this paper is to evaluate the capacity of these two typologies to identify thermal environments in and around cities, and to determine which typology best captures the daily spatio-temporal patterns of surface and urban canopy heat islands. To simulate urban climate with a model, LULC data based on a given typology are required. To avoid circularity, we combined the Corine Land Cover database, with data for the whole of Europe, and the BD TOPO database, for France, to form a new tool, CLC_USGS, which we used as input for the WRF limitedarea model, with a 150-m grid resolution. The capacity of each typology to identify coherent thermal zones was estimated for Dijon, a medium-sized French city, during a three-week heat wave, over a 24-hour period, in conditions favorable to urban heat island development. The comparison was based on hourly air temperatures directly output from the WRF model, those obtained from the purpose-built MUSTARDijon 47-sensor meteorological network, and NDVI values and land surface temperatures estimated from Landsat images for 11 July 2015 at 1030 UTC. Typical diurnal variations and spatial contrasts of surface and air temperatures were identified in both simulations and observations. As both typologies show significant capacity for identifying thermally coherent intra-urban areas, this study suggests that they could both be useful for urban climate applications. The typology that is most generally applicable in worldwide contexts is Local Climate Zones. 1. Introduction Urbanization and urban expansion linked to demographic growth produce diverse mosaics of built and non-built surfaces. This diversity results in very different surface energy budgets and Urban Heat Island (UHI) effects, induced by impermeable, heat-storing

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Tooth number in rodents is an example of reduction in evolution. All rodents have a toothless diastema lacking canine and most premolars present in most other mammals. Whereas some rodent lineages retained one premolar (p4), many others lost it during evolution. Recently, an 'inhibitory cascade' developmental model (IC) has been used to predict how the first molar (m1) influences the number and relative sizes of the following distal molars (m2 and m3). The model does not, however, consider the presence of premolars, and here we examine whether the premolar could influence and constrain molar proportions during development and evolution. By investigating a large data set of both extinct and extant rodent families over more than 40 million years, we show that the basal phenotype is characterized by the presence of premolars together with equally sized molars. More recent rodent families, with and without premolar, show more unequal molar sizes. Analysing molar areas, we demonstrated that (i) rodents harbour almost all the molar proportions known in mammals, and the IC model can explain about 80% of taxa in our data set; (ii) proportions of molars are influenced by the presence or absence of p4; and (iii) the most variable teeth in the dental row are m1 and m3, whether p4 is present or not. Moreover, m1 can represent up to half of the total molar area when p4 is absent. We hypothesize that p4 loss during evolution released the constraint on m1 development, resulting in a more variable size of m1 and thereby having an indirect effect on the evolution of the whole molar row.