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RE: eggshells, therizinosaurs & tyrannosaurs



Thomas wrote:
We do have to remember, though, that even within clades (such as Squamata or
Aves) you can get different shell structure morphology.


But from what little I have gathered so far, these differences are just variations of the broader types. The neognath bird type is apparently a distinctive variation of the ornithoid type.
The overall ornithoid morphology is apparently distinctive enough to be of important phylogenetic value, one which I am surprised dinosaurologists don't emphasized more strongly. To me this evidence seems more clearcut and less vulnerable to counterargument than something like digit homologies or even the semilunate carpals (ooops, probably will get criticized for saying that, but right now I am more impressed by the eggshells).
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You mean "sensu Sereno". Maniraptora sensu stricto is "modern birds and all
taxa closer to modern birds than to Ornithomimidae": see Gauthier 1986.
I just meant that Maniraptora "sensu Sereno" is "sensu stricto" (in the least inclusive sense), whereas "sensu Gauthier" would be sensu lato (a more inclusive sense, at least using Sereno's phylogeny).
Sereno does not seem to follow Gauthier's definition of Maniraptora, and instead uses a new clade name, Tyrannoraptora. Apparently another case of cladistic disunity on what definitions to use!!?? In any case, I guess it would be better to say sensu Sereno (it would have admittedly been less confusing if I had said that).
Cheers, Ken Kinman
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