Giant stem tetrapod was apex predator in Gondwanan late Palaeozoic ice age.

Current hypotheses of early tetrapod evolution posit close ecological and biogeographic ties to the extensive coal-producing wetlands of the Carboniferous palaeoequator with rapid replacement of archaic tetrapod groups by relatives of modern amniotes and lissamphibians in the late Carboniferous (about 307 million years ago). These hypotheses draw on a tetrapod fossil record that is almost entirely restricted to palaeoequatorial Pangea (Laurussia). Here we describe a new giant stem tetrapod, Gaiasia jennyae, from high-palaeolatitude (about 55° S) early Permian-aged (about 280 million years ago) deposits in Namibia that challenges this scenario.

Earliest evidence of herd-living and age segregation amongst dinosaurs.

Sauropodomorph dinosaurs dominated the herbivorous niches during the first 40 million years of dinosaur history (Late Triassic-Early Jurassic), yet palaeobiological factors that influenced their evolutionary success are not fully understood. For instance, knowledge on their behaviour is limited, although herding in sauropodomorphs has been well documented in derived sauropods from the Late Jurassic and Cretaceous. Here we report an exceptional fossil occurrence from Patagonia that includes over 100 eggs and skeletal specimens of 80 individuals of the early sauropodomorph Mussaurus patagonicus, ranging from embryos to fully-grown adults, with an Early Jurassic age as determined by high-precision U-Pb zircon geochronology.

[Mortality excess analysis for year 2015 in Palermo Province (Sicily Region, Southern Italy)].

Background: a death number increment compared to the previous years was observed in Italy for the year 2015; its causes are under study.

Objectives: to verify if the mortality occurred in Palermo Province (Sicily Region, Southern Italy) for the year 2015 was greater than the one observed in the previous period (years 2009-2014) and to find which death causes it would be attributable to.

Design: observed number of deaths in 2015 were compared with expected numbers calculated with the traditional analysis of direct adjusted rates, and with a 90% predictive interval estimated fitting a Generalized Additive Model (GAM), via a quasi-Poisson distribution of the observed deaths in the period 2009-2014; various measures of the environmental temperature were used as regressor.

The precise temporal calibration of dinosaur origins.

Dinosaurs have been major components of ecosystems for over 200 million years. Although different macroevolutionary scenarios exist to explain the Triassic origin and subsequent rise to dominance of dinosaurs and their closest relatives (dinosauromorphs), all lack critical support from a precise biostratigraphically independent temporal framework. The absence of robust geochronologic age control for comparing alternative scenarios makes it impossible to determine if observed faunal differences vary across time, space, or a combination of both.

[Mortality in relation to individual- and area-level socioeconomic status in Palermo (Italy): a multilevel analysis].

Objective: to assess whether compositional (education, income index, number of family members) and contextual (area socioeconomic index) risk factors independently predict all cause and specific mortality.

Design: a multilevel (hierarchic) logistic regression model was applied to the individual data of a cohort followed up from 01.01.

[Mortality in areas with different socioeconomic characteristics in Palermo].

Objective: To assess whether mortality rates differ among areas with different values of a socioeconomic index.

Design: Ecological mortality study; mortality rates were compared among four areas joining census tracts categorized by quartiles of a socioeconomic status index. This index was calculated using individual 2001 census data in a factorial analysis.