ps418

Just want to point out again that Confuciusornis is a lovely intermediate form linking Archaeopteryx to later birds. Clearly too Confuciusornis is not in any sense a 'modern bird.' Confuciusornis is more derived than Archaeoptery is being edentulous (lacking teeth), having a fully reversed hallux, having a shorter tail, and a more retroverted pubis. However, there remain numerous primitive characters as well.

For instance, the orbit is not fully confluent with the postorbital fenestra. There remain a descending process on the postorbital and an ascending process on the jugal. In dinos these two processes meet and form the anterior border of the orbit. In birds, these processes are gone and the orbit is confluent with the psoterior fenestrae. The hand (manus) is unfused as in theropods, rather than fused into a carpometacarpus as in later birds. In the hindlimbs, the tarsals and metatarsals remained unfused as in theropods, rather than fused into a tarsometatarsus as in later birds. The pelvis is more bird-like than Archaeopteryx, yet still very different from modern birds. There is no pygostyle, for instance, and the pubis is not nearly as slender as it is in modern birds. Like Archaeopteryx and theropods, but unlike later birds, Confuciusornis possessed belly ribs or gastralia (not shown in image below).



Note: the description as a 'Jurassic bird' was taken from Hou et al (1995), before Swisher et al and others proved a Cretaceous age.

Patrick

ps418

Ed, it appears you've already more or less admitted your error, only without actually admitting it. Remember, your original claim was that modern birds existed at the same time as Archaeopteryx. Now, in the face of undeniable contradictory evidence, you drop that and claim only that a bird, a very theropod-like bird at that, existed some time later, from a few million to 20 millions years, than Archaeopteryx. Well, no shit, Sherlock!

The problem is, Ed, when you replace what you actually said with what you now claim to have meant, it doesn't make any sense at all. On June 1, replying to Jack about transitional forms, you said:

But there are modern birds among archaeopteryxes.

Obviously, if you replace that with:

But there are primitive birds from a few to 20 million years after Archaeopteryx.

. . . the original claim would look silly indeed.

And let me point out another glaring contradiction that you've caught yourself in. In a post on June 9 to the E/C thread, you dismissed Microraptor on the grounds that it is 25 million years younger than Archaeropteryx. The punch line is that Microraptor comes from the same strata as Confuciusornis, which you had just claimed was the same age as Archaeopteryx. In fact, immediately after saying that Microraptor was 25 million years younger than Archaeopteryx, in your next post you stated that Confuciusornis was "almost the same age" (this is where you made the switcheroo from "among" the Archaeopteryxes to "almost the same age." Only later to you abandon "modern bird," for the senseless "100% bird").

Patrick

PS: By the way, Ed, I remind you again that there is no such thing as a 100% bird, or a 50% bird, or a 10% bird. Bird-ness is a binary thing, because taxonomy is a binary thing: either a species is classified as a member of aves, or it is not.

keyser_soze

Patrick, beautiful work. Do you mind if I quote your synopsis of the work in the future?

ps418

Thank you, and feel free to use anything I post.

Patrick