Kenrick and Crane's Polysporangiophyte cladograms have been questions before; besides, there appears to be no complete Linnean classification for early polysporangiophytes that is consistent with their cladistic analysis and subsequent research.
Kenrick and Crane's cladograms have been questioned  see the Evolution section below. As of February 2011, there appears to be no complete Linnean (i.e., rank-based) classification for early polysporangiophytes that is consistent with Kenrick and Crane's cladistic analysis and subsequent research, though Cantino et al. 
