

Re: Sapeornis and other Mesozoic Birds

It is close to Gauthier and de Queiroz' (2001) definition of Avialae, which does follow PhyloCode rules: "The clade stemming from the first panavian with feathered wings homologous with those of Aves (Vultur gryphus) and used for powered flight."

There is the additional issue that traits such as "used for powered flight" are difficult to demonstrate. Granted, the ability to use powered flight is something that we've gotten better at detecting (I've been working on a method that refines such analyses further, in fact), but it still seems a cumbersome trait to use in clade definitions.


--Mike Habib