by Staff Writers
London, UK (SPX) Jan 18, 2013
A new fossil discovered in Tunisia represents the oldest known ancestor of modern-day sea cows, supporting the African origins of these marine mammals. The find is described in research published in the open access journal PLOS ONE by Julien Benoit and colleagues from the University of Science and Technology in Montpellier, France.
Some fossils of sea cow ancestors have been found in Jamaica, but the Tunisian fossil is more primitive and pre-dates these, revealing an older ancestor for sea cows that emerged at the same time as other modern mammals. Unlike whales and dolphins, the evolutionary origins of the sea cow family have been obscure.
They share an ancestor with elephants, and it is thought that their oldest relatives were terrestrial animals that gradually adapted to an aquatic life. The last common ancestor of the two species may have lived in freshwater swamps well before the time that the new species described in this study lived.
Though this specimen may not have been the common link between modern day sea cows and elephants, the authors' analyses suggest that this new species lived in fresh water, not sea waters.
Benoit J, Adnet S, El Mabrouk E, Khayati H, Ben Haj Ali M, et al. (2013) Cranial Remain from Tunisia Provides New Clues for the Origin and Evolution of Sirenia (Mammalia, Afrotheria) in Africa. PLoS ONE 8(1): e54307. doi:10.1371/journal.pone.0054307
Public Library of Science
Explore The Early Earth at TerraDaily.com
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement|