INVESTIGADORES
CASADIO Silvio Alberto
capítulos de libros
Título:
Paleobiogeography of Cretaceous and Paleogene decapod crustaceans from Southern South America: the link with Antarctica
Autor/es:
FELDMANN, R.; AGUIRRE URRETA, BEATRIZ; CHIRINO, L.; CASADÍO, S.
Libro:
The Antarctic Region: Geological Evolution and Processes
Editorial:
Terra Antartica
Referencias:
Lugar: Siena; Año: 1997; p. 1007 - 1016
Resumen:
Comparison of Cretaceous and Tertiary decapod crustacean faunas from New Zealand, Antarctica, and Chile has corroborated the observations, made previously´using molluscan faunas, that continental shelf settings in southern high latitudes served as a site of origin and dispersal of numerous taxa now occupying lower latitude and deeper water settings. These relationships, although clearly demonstrated in the southern circum-Pacific, are far less pronounced in the Atlantic Basin. In the Atlantic basin, fossil decapod faunas are dominated by thoracotreme and heterotreme crabs whose congeners are known from lower latitude regions in the North and South Atlantic as well as the Tethys. There are no podotreme (primitive) crabs, although podotremes are the dominant forms in Antarctic and Chilean faunas. Fossil lobsters and mudshrimp from the Neuquen Basin, Argentina, tend to have global distributions and are known from James Ross Basin, Antarctica. Heterotreme crabs, with origins in the low latitudes, have now been recognized as far south in Argentina as the San Jorge Basin. However, farther south, in the Austral Basin, the Cretaceous decapod fauna consists only of lobster species and mudshrimp, all of which are congeners of forms known from contemporaneous rocks in the James Ross Basin, and all occur in the fossil record of New Zealand. In addition, a single endemic crab species was also collected in the Austral Basin. The Cenozoic decapod fauna of the Atlantic Basin was not influenced by southern high latitude introductions to the same extent as was the Pacific Basin, probably owing to differences in directions of current circulation resulting in different thermal regimes. There Ls no evidence that the Cretaceous extinction event affected the decapod fauna in any part of this region; rather, the origin of many Paleogene genera can now be extended back into the Late Cretaceous.