The Young Argentine Sea, Its Ichthyofaunistic Colonization and Its Traumatic Evolution

FIGUEROA DANIEL E.; BELLEGGIA MAURO; BARBINI SANTIAGO; SAVADIN DAVID; SCENNA LORENA; CHIERICHETTI M; ROMÁN

Austin, TX

Congreso; Joint Meeting of Ichthyologists and Herpetologists (JMIH); 2017

American Elasmobranch Society (AES), American Society of Ichthyologist and Herpertologists (ASIH)

 At the beginning of the Mesozoic Era (140mA), the Argentine Sea did not exist, the Gondwana was probably a set of united plates with shallow water. In the middle of that Era (112Ma) the plates separate with each other allowing shallow marine intrusions, where an endemic fish fauna develops, as some coelacanths. At the end of the Mesozoic Era, in the Cretaceous period (66 Ma), the south Protoatlantic joins with the North Atlantic (Tethys Sea in part), and allows the fish fauna of Tethyan origin to colonize the south, reaching Antarctica. The opening of the Drake Passage in the Oligocene period (33 Ma), in the Cenozoic Era, enables the cold waters of the Pacific Ocean to penetrate in the south Atlantic, causing drastic effects on the thermophilic fauna. Successive glaciations in the Quaternary Period (2 Ma-10,000A), allowed the polar front to advance several times to lower latitudes, leaving the Argentine Sea within it. This traumatic development in the constitution of the southwest Atlantic is reflected in the heterogeneous composition of the Argentine marine ichthyofauna, with cosmopolitan, Tethyan, Pacific, Antarctic, Gondwanic and own lineages.