Southern Hemisphere Paleobiogeography of Triassic-Jurassic Marine Bivalves

DAMBORENEA, S.E.; ECHEVARRÍA, J.; ROS, S.

Springer

Lugar: Dordrecht; Año: 2013 p. 141

978-94-007-5097-5

Bivalves have proven to have a great potential for paleobiogeographic analyses due to their relatively complete fossil record, especially for Mesozoic and Cenozoic times. Being mostly benthonic, they have a large variety of life habits which should be taken into account, particularly in detailed paleobiogeographic studies. We will analyze marine bivalve distribution in the southern hemisphere during several successive time-slices within the Triassic and Jurassic, an epoch marked by critical geologic and biotic events. This period covers both the biotic recovery after the harshest diversity crisis ever (the Permian/Triassic extinction event), and later also the biotic reaction to another severe crisis at the Triassic/Jurassic boundary. This allows the opportunity to evaluate the response of paleobiogeographic patterns to such events. Earth configuration drastically changed from a concentration of land masses in a unique supercontinent (Pangea) and two oceans (Tethys and Panthalassa), to a fragmented series of continental land masses. These began to disperse, opening sea corridors which largely affected not only the global distribution of biotas but paleoclimate and sea paleocurrents as well. This dynamic paleogeography adds an interesting ingredient to the study of past distributions of benthic organisms making it possible to frame them into a physically and biologically changing scenario.