Walk, Wade, or Swim? Vertebrate Traces on an Early Permian Lakeshore Swanson, B. A. ; Carlson, K. J. Abstract Publication: Palaios Pub Date: April 2002 DOI: 10.1669/0883-1351(2002)017<0123:WWOSVT>2.0.CO;2 Bibcode: 2002Palai..17..123S