Heart Fossilization Is Possible And Informs The Evolution Of Cardiac Outflow Tract In Vertebrates

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Elucidating cardiac evolution has been frustrated by lack of fossils. One celebrated enigma in cardiac evolution involves the transition from a cardiac outflow tract dominated by a multi-valved conus arteriosus in basal actinopterygians, to an outflow tract commanded by the non valved, elastic, bulbus arteriosus in higher actinopterygians. We demonstrate that cardiac preservation is possible in the extinct fish Rhacolepis buccalis from the Brazilian Cretaceous. Using X-ray synchrotron microtomography, we show that Rhacolepis fossils display hearts with a conus arteriosus containing at least five valve rows. This represents a transitional morphology between the primitive, multivalvar, conal condition and the derived, monovalvar, bulbar state of the outflow tract in modern actinopterygians. Our data rescue a long-lost cardiac phenotype (119-113 Ma) and suggest that outflow tract simplification in actinopterygians is compatible with a gradual, rather than a drastic saltation event. Overall, our results demonstrate the feasibility of studying cardiac evolution in fossils.5Coordenacao de Aperfeigoamento de Pessoal de Nivel Superior [01P-03488/2014]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [2012/05152-0]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico [481983/2013-9]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Géopatrimoine et biopatrimoine, à la croisée entre conservation et développement. Une approche des trajectoires patrimoniales dans le Cariri du Ceará (Nordeste brésilien)

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