They died out approximately 85 million years ago in the Western Interior Sea , where a majority of them were found .
Such species are Ptychodus mortoni , P. decurrens , P. marginalis , P. mammillaris , P. rugosus and P. latissimus to name a few .
few died out approximately 85 million years ago in the Western Interior Sea , where a majority of them were found .
Such species are Ptychodus mortoni , P. decurrens , P. marginalis , P. mammillaris , P. rugosus and P. latissimus to name a few .