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Re: New ankylosaur paper- Bissektipelta gen. nov.



Mickey Mortimer wrote:

I believe unique combinations of characters are just as
useful for supporting validity as completely unique autapomorphies.


I agree. I haven't read the _Amtosaurus_/_Bissektipelta_ paper so I won't comment on this particular example... but in general I'm curious why a given species is regarded as a _nomen dubium_ simply because it lacks autapomorphies. This has been done for the type species for _Lagosuchus_, for example. _Lagosuchus_ was described by one study as non-diagnostic because (unlike _Marasuchus_) the type specimen lacked any autapomorphies. However, it can easily be shown that _Lagosuchus_ is not the same as _Marasuchus_, or any other "lagosuchian"-grade archosaur. Thus, _Lagosuchus_ should be retained as a valid genus.

BTW, does any one know of a study that has described autapomorphies in _Archaeopteryx_? This is undoubtedly a valid genus, and it can be distinguished from any other known maniraptoran in a heartbeat. But most of _Archaeopteryx_'s characters are plesiomorphic for the bird clade, and at the moment I can't bring to mind a single autapomorphy. (Doesn't mean there aren't any - I just can't think of any.)



Tim

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