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re: Pterosaur origins again, Hone and Benton 2007
Scott Selberg wrote:
This may seem to split hairs, but if I understand correctly this doesn't
say that dromaeosaurs were NOT secondarily flightless, just hat they were
not secondarily flightless BIRDS. Do I have it?
Yes, that seems to be the gist of it. Senter (2007) was refuting a previous
phylogeny that placed _Confucusornis_ inside the Dromaeosauridae.
Nevertheless, dromaeosaurids like _Velociraptor_ and _Deinonychus_ might
indeed have been secondarily flightless, given that _Rahonavis_ was
recovered by Senter inside the Dromaeosauridae, as a unenlagiine.
Something else that occurred to me after reading Senter's paper... Aside
from _Coelurus_ and _Tanycolagreus_, how many other small to medium-sized
coelurosaurs may also turn up inside the Tyrannosauroidea once they are run
through this kind of analysis. For example, _Nqwebasaurus_, or even
little_Scipionyx_. I think tyrannosauroid affinities have already been
suggested for _Proceratosaurus_, but I can't place the source. I don't want
to go too far with this, given that (so far) this position for coelurids has
only been found by one analysis. Not surprisingly, Senter does give credit
to "intermediate tyrannosauroids" such as _Dilong_ and _Eotyrannus_ for
pulling _Coelurus_ inside the Tyrannosauroidea. _Tanycolagreus_ also played
David Peters wrote:
And if its not the Macrocnemus > Longisquama clade, then can we assume that
the various apparent synapomorphies found in various members of that clade
-- including the elongated naris, antorbital fenestra, multi-cusped teeth,
elongated cervical ribs, deep dorsal ribs, high sacral count, attenuated
caudal series, elongated scapula, tall coracoid, sternal complex (sternum +
keeled interclavicle + clavicles), magnified deltopectoral crest, migrated
centrale, elongated fourth finger, reduced fifth finger, elongated ilium,
fused ischium+pubis, prepubis, sprawling femora, attenuated fibula,
mesotarsal ankle, elongated lateral toe, and uropatagia -- are ALL
convergent with pterosaurs?
Out of interest, just how many of the above features are evident in
_Longisquama_? It was my impression that it was not too many.
Also nice to know those tiny lateral fingers and toes will somehow become
Stranger things have happened. After all, the elongated hallux that allows
birds to perch in trees evolved from one tiny lateral toe in terrestrial
theropods. It's amazing what natural selection can achieve, irrespective
of our own personal credulity.
Anthony Docimo wrote:
that'd be...irony, right?
people used to think birds evolved from crocs....and now we may be on the
verge of confirming that the croc family gave rise to pterosaurs?
We're along way from that point, I would say. BTW, the idea that birds
evolved from crocs (by which was meant "basal crocodylomorphs" like
_Sphenouchus_) never really had much support. Even then, the idea was more
about birds and "crocs" sharing an especially close relationship to the
exclusion of all other archosaurs (including dinosaurs), rather than a
straight ancestor-descendent relationship. The origianl idea was Alick
Walker's, and even he changed his mind a few times on the matter of
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