Phylogeny, biogeography and diversification patterns of side-necked turtles (Testudines: Pleurodira)

Pleurodires or side-necked turtles are today restricted to freshwater environments of South America, Africa– Madagascar and Australia, but in the past they were distributed much more broadly, being found also on Eurasia, India and North America, and marine environments. Two hypotheses were proposed to explain this distribution; in the first, vicariance would have shaped the current geographical distribution and, in the second, extinctions constrained a previously widespread distribution. Here, we aim to reconstruct pleurodiran biogeographic history and diversification patterns based on a new phylogenetic hypothesis recovered from the analysis of the largest morphological dataset yet compiled for the lineage, testing which biogeographical process prevailed during its evolutionary history. The resulting topology generally agrees with previous hypotheses of the group and shows that most diversification shifts were related to the exploration of new niches, e.g. littoral or marine radiations. In addition, as other turtles, pleurodires do not seem to have been much affected by either the Cretaceous– Palaeogene or the Eocene–Oligocene mass extinctions. The biogeographic analyses highlight the predominance of both anagenetic and cladogenetic dispersal events and support the importance of transoceanic dispersals as a more common driver of area changes than previously thought, agreeing with previous studies with other non-turtle lineages.Fil: Ferreira, Gabriel S.. Universidade de Sao Paulo; Brasil. Senckenberg Centre For Human Evolution And Palaeoenvironment; Alemania. Universität Tübingen; AlemaniaFil: Bronzati Filho, Mario. Bayerische Staatssammlung für Paläontologie und Geologie; AlemaniaFil: Langer, Max C.. Universidade de Sao Paulo; BrasilFil: Sterli, Juliana. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Chapada Do Araripe: A Highland Oasis Incrusted into the Semi-arid Region of Northeastern Brazil

Located inside the Brazilian northeast, the Chapada do Araripe represents a prominent testimony of the regional evolution extending as a residual relief in the form of flat and elongated tableland with over 8,000 km2 and an altitude close to 1,000 m, elevated up to 500 m from the Cariri Valley floor. Evolution by escarpment retreats influenced by gravitational processes developed piedmont deposits, marked by pediments and flat recessed areas, where urban centres have settled. Its sedimentary record includes Paleozoic and Mesozoic depositional sequences with exceptional fossil record. With high local rainfall and high permeability sandstones, the region is rich in water and lush natural vegetation and has a mild climate, characterised also as a regional centre of culture and economic development, begun in mid-eighteenth century and active to the present day. Those aspects that led the progress are assigned to miracles of Padre Cícero, patron saint of the region.Departamento Petrologia e Metalogenia São Paulo State UniversityDepartment of Applied Geology São Paulo State UniversityDepartamento Petrologia e Metalogenia São Paulo State UniversityDepartment of Applied Geology São Paulo State Universit