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RE: The claws of hoatzin and the "Dinosaur renaissance" article



Vladimír  Socha wrote-

2.) What is the most advanced non-avialan Maniraptoriform (standing closest to the clade Avialae)?

Depends on your definition of Avialae-
(Vultur gryphus <- Deinonychus antirrhopus) (modified from Gauthier, 1986)
All Deinonychosaurs.
(Archaeopteryx lithographica + Vultur gryphus) (modified from Gauthier and Wagner, 2001)
I'd say scansoriopterygids, Chiappe says alvarezsaurids, Novas says Unenlagia, Sereno and the TWG say deinonychosaurs, Holtz says deinonychosaurs or Protarchaeopteryx I think. But not everyone has considered all of these taxa.
(feathered wings homologous with Vultur gryphus and used for powered flight) (Gauthier and de Queiroz, 2001)
Depends on what could basally fly. I think microraptorians could fly homologously to birds, so would say enigmosaurs. Then again, basal enigmosaurs might be volant too, in which case I'd say ornithomimosaurs and alvarezsaurids. But Pelecanimimus does have a derived sternum, so I might have to go even more basal. Most people don't seem to think deinonychosaurs could fly, so might answer deinonychosaurs or scansoriopterygids. Paul would probably say some basal coelurosaur or tyrannosauroid.


3.) Is _Microraptor zhaoianus_ smallest non-avian dinosaur?

Depends on the definition of Aves-
(Struthio camelus + Tinamus major + Vultur gryphus) (modified from Gauthier, 1986)
I doubt it. Some adult enantiornithines were near certainly smaller, though my measurements are elsewhere.
(Archaeopteryx lithographica + Vultur gryphus) (modified from Chiappe, 1992)
Maybe, though Parvicursor and Caenagnathasia are about the same size.


4.) Is there a consensus yet in the actuall taxonomical position of Archie?
Yes, the consensus is that it's closer to living birds than alvarezsaurids, scansoriopterygids, deinonychosaurs and enigmosaurs, but further than avebrevicaudans, Shenzhouraptor and Rahonavis.

And in the simple words, is it the basalmost avialan known to the date?
Again, depends on your definition of Avialae-
(Vultur gryphus <- Deinonychus antirrhopus) (modified from Gauthier, 1986)
Out of the well known commonly sampled taxa, yes. But there are some taxa which various people would place in this position that aren't examined by everyone or are controversial (Scansoriopterygids, Protarchaeopteryx, Yixianosaurus, Unenlagia, alvarezsaurids, Rahonavis, Archaeornithoides, etc.).
(Archaeopteryx lithographica + Vultur gryphus) (modified from Gauthier and Wagner, 2001)
Yes, by definition.
(feathered wings homologous with Vultur gryphus and used for powered flight) (Gauthier and de Queiroz, 2001)
According to most people, yes. Though I have yet to see a good published argument for why microraptorians couldn't fly.


5.) Is _Protoavis texensis_ taken into account when considering the phylogeny of a feathered theropods?
No, except by Chatterjee.

6.) What, except toothless beak, distinguish Confuciusornithidae from Archie so that it's considered to be more advanced?
The toothless beak is actually convergent with living birds, so tells us nothing about whether confuciusornithids were closer to them than Archaeopteryx. My papers are at school, but off the top of my head- semiheterocoelous cervical vertebrae; less dorsal vertebrae; more sacral vertebrae; less free caudal vertebrae; pygostyle; shortened tail; longer coracoid; partially fused carpometacarpus; more flattened manual phalanx II-1; more opisthopubic pelvis; no obturator process; trochanteric crest; completely fused tibiotarsus; proximally fused tarsometatarsus; partially reversed hallux.

7.) What's the actuall cladistic placing of Madagascar avialan _Vorona berivotrensis_? Still outside Euornithes?

Basalmost ornithuromorph (but may be an enantiornithine- Clarke, 2002).

8.) For which clade is feathery integument a synapomorphy? Maniraptoriformes?

Around Coelurosauria, now that Dilong is known.

9.) Is _Velociraptor_ more advanced than _Deinonychus_ within Velociraptorinae?

Deinonychus is probably not a velociraptorine (Senter et al., 2004; me, http://dml.cmnh.org/2003May/msg00427.html ). And even if it was, your question would be meaningless without an agreed upon subjectively most advanced velociraptorine.


12.) How many non-avian dinosaur genera with preserved feathery integument are known to the date? And how many specimens?
Well, assuming the (Archaeopteryx lithographica + Vultur gryphus) definition of Aves, I count 11 genera (excluding possibly non-avian feather taxa). I estimate about 23 feathered specimens belonging to those genera, plus a few more in unnamed taxa.

13.) What's so special about _Rahona ostromi_? Oh, I see: a sickle claws together with traces of feathers and a bird-like sacrum. Hmm..
It's Rahonavis ostromi. There are actually no feather traces, just ulnar bumps suggesting they were present. It's special because it's mostly more birdlike than Archaeopteryx, but has a sickle claw, and lived very long after it must have diverged. It's also very well preserved.

14.) How closely resembled are the two recognized species of the genus Microraptor, and which are their synapomorphies?
They may be the same species (Senter et al., 2004). M. gui does have a shorter manual phalanx I-1l than M. zhaoianus, an enlarged biceps tubercle and fused sterna. But the latter may be ontogenetic, and the other two characters may be indiovidual variation.

16.) What are the relations between the compsognathids _Huxiagnathus orientalis_, _Sinosauropteryx prima_ and _Compsognathus longipes_?

I think Hwang et al. (2004) suggested (Huax(Sinos,Comps)). No other study has been done, though the first two taxa are usually not close to Compsognathus in my analyses.


17.) Does any other non-avian genus except _Nomingia gobiensis_ displays a pygostyle?
Beipiaosaurus.

18.) What happened to the "feathered Psittacosaurus" specimen? Thank you, in advance.
It was described in 2002 and preserves quills on the tail which may be feathers or scales.
Mayr, Gerald Mayr, D. Stefan Peters, Gerhard Plodowski and Olaf Vogel, 2002. Bristle-like integumentary structures at the tail of the horned dinosaur Psittacosaurus. Naturwissenschaften, 89(8):361-365.


Mickey Mortimer