Extincion local de tiburones del genero Carcharias Rafinesque, 1810 (Elasmobranchii, Odontaspididae) en el Oceano Pacifico oriental.
Local extinction of sharks of genus Carcharias Rafinesque, 1810 (Elasmobranchii, Odontaspididae) in the eastern Pacific Ocean
Author
Cione, Alberto L.
Mennucci, Jorge A.
Santalucita, Fernando
Acosta Hospitaleche, Carolina
Full text
http://www.andeangeology.cl/index.php/revista1/article/view/V34n1-a0710.5027/andgeoV34n1-a07
Abstract
El estudio del registro paleontologico indica que la distribucion de Carcharias y posiblemente C. taurus Rafinesque, 1810, durante el Mioceno y parte del Plioceno, habria incluido la costa oeste de Sudamerica, donde hoy se encuentra ausente. Se propone que su extirpacion de esta zona habria sido provocada por el abrupto descenso de las temperaturas durante el Plioceno medio y Pleistoceno y la consiguiente caida del nivel del mar, lo que habria reducido notablemente el ambiente de plataforma, habitat natural de este taxon. Posteriormente a los 3 Ma aproximadamente, al restablecerse el nivel del mar, la recolonizacion desde el norte no habria sido posible debido al establecimiento del istmo de Panama. Fossil record has shown that the genus Carcharias and probably species C. taurus Rafinesque, 1810 occupied the western coast of South America during the Miocene and part of the Pliocene. The genus is absent in the area today. It is suggested that its local extinction was the consequence of a drop of global temperatures during the middle Pliocene and Pleistocene and the coeval lowering of sea level that shrinked the area of distribution to the northern areas and provoked the disappearance of suitable environments when the shelf area became extremely reduced. After approximately 3 Ma it would have not been possible for the species to migrate from the north to the region due to the establishment of the Panamanian isthmus.