In which case they aren't dinosaurs at all, because dinosaurs are defined node-basedly. BTW, this opinion seems to have become quite rare in the last few years. For example, it has turned out that 2 sacral vertebrae, not 3, are plesiomorphic for dinosaurs.
P. S.: You might like to join the PhyloCode mailing list where people like HP Jonathan R. Wagner, Kevin de Queiroz and Philip Cantino discuss how the current draft of the PhyloCode could/should be improved...
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