A Reevaluation of the Morphology, Paleoecology, and Phylogenetic Relationships of the Enigmatic Walrus Pelagiarctos Boessenecker, Robert W. ; Churchill, Morgan Abstract Publication: PLoS ONE Pub Date: January 2013 DOI: 10.1371/journal.pone.0054311 Bibcode: 2013PLoSO...854311B