Re: Parts & Non-Recreation (was: Ceratonykus)

[Augusto Haro <augustoharo@gmail.com>]

2011/5/1 Jaime Headden <qi_leong@hotmail.com>:
>
> I'm jumping on a limb here. Both Augusto and Tom below sent emails that 
> included an address with a listproc identifier, but these did not show up in 
> the archives for the dates sent. I will presume they were intended for the 
> list. Otherwise, I apologize.
>
No need in my case, I just tried to post to the DML and failed. Thanks
for the courteous manners however.
>
> Augusto Haro wrote:
>
> <May that be due to their their phylogenetic inheritance? I mean, if you have 
> a bear with bunodont ancestors that starts eating more insects, you will find 
> an ant-eating bear with smaller bunodont teeth. If you have some coelurosaur 
> with blade-like teeth, and then dental reduction operates because of social 
> insect feeding habits, then I would expect seeing animals with reduced blades 
> instead of reduced bunodont teeth.>
>
>    While I would agree in general principle that the relevance of phylogeny 
> matters here, such that *Ceratonykus oculatus* itself inherited an 
> opisthopubic pelvis, this sin't true for alvarezsaurids as a whole: 
> *Haplocheirus sollers* has a propubic pelvis, and *Patagonykus puertai* 
> either propubic, mesopubic, or just slightly opisthopubic. None of them are 
> remotely as odd as the ornithischian-level of "parvicursorines" where the 
> pubis and ischium are in contact for nearly their entire lengths, thin, 
> slender, and fairly short. In *Patagonykus puertai,* for example, the arm is 
> highly modified from the condition in *Haplocheirus sollers,* as is the 
> pelvis, based on the preserved fragements; yet the pubis is not attenuated or 
> modified into the splint-like rods of "parvicursorines." Based on its 
> curvature, and I think that alone, I suspect the pubis is procurved and 
> mesopubic, which is the inverse of what is usually depicted...
>
Sorry if not clear enough in my responses (and thanks for the
information about the alvarezsaur pelvis!) but my point was directed
towards teeth. I mean, you brought into consideration the shape of the
teeth of alvarezsaurs while (apparently) dismissing the possibility
that they were myrmecophagous. I just attempted to say that the teeth
reduction seemed concordant with myrmecophagous habits, and its
carnivorous theropod-like features such as being blade-like may be
explained just because of phylogenetic heritage (the true adaptation
being thus the reduction).