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Re: Confuciusornis and other feathered beasts
At 08:51 AM 6/6/99 EDT, Barbara Saffer wrote:
>I note that "The Encyclopedia of Dinosaurs" refers to Confuciusornis as a
>'toothless bird'. In other places, I read that it is a feathered dinosaur (I
>assume this means non-avian dinosaur).
Your assumption would not be entirely correct. Unlike _Caudipteryx_ and
_Protarchaeopteryx_ (NOT _Protoarchae..._), _Caudipteryx_ is most definitely
a bird under everyone's definition.
>Could someone tell me if
>Confuciusornis (as well as Caudipteryx and Protoarchaeopteryx) are
>considered "non-avian feathered dinosaurs" by dinosaur paleontologists.
The crux here concerns the two primary different definitions of Aves used by
Definition #1: Aves = all descendants of the most recent common ancestor of
ratites, tinamous, and neognaths. In this definition, Aves = the modern
bird clade, and _Confuciusornis_, _Caudi._, and _Prot._ are all non-avian
feathered dinosaurs. Under this definition, _Archaeopteryx_, _Hesperornis_,
and such are not avians either. Instead, they are part of the more
inclusive group Avialae.
Definition #2: Aves = all descendants of the most recent common ancestor of
_Archaeopteryx_ and Neornithes (with Neornithes = Aves Definition #1 above).
In this scheme, _Confuciusornis_ is clearly within Aves, and thus an avian
feathered dinosaur. However, if the phylogenies presented at the Ostrom
Symposium are correct, neither _Caudi._ nor _Prot._ are within Aves, and are
thus still non-avian feathered dinos.
Is this clear? If not, I'll try and make things a little clearer.
>assuming Sinosauropteryx is unequivocally a non-avian dinosaur with some kind
>of feathers. Right?
Yes. (Okay, there's a few out there who think that the structures are
really a sea-snake fin...).
>Also, does anyone know if those "new" ankylosaurs from Utah have been named
>yet? The article I dug up on the Internet said they would be named for some
>of the people on the dig -- but doesn't say what the names will be.
Could you be a bit more precise WHICH new ankylosaurs? _Mymoorapelta_ and
_Gastonia_ and _Gargoyleosaurus_ have all been named, and xxxxx still isn't
formally named yet.
Thomas R. Holtz, Jr.
Vertebrate Paleontologist Webpage: http://www.geol.umd.edu
Dept. of Geology Email:email@example.com
University of Maryland Phone:301-405-4084
College Park, MD 20742 Fax: 301-314-9661