Folks, Here is help that I can provide over email in this short time. PLEASE check out other sources, too: for example, Dingus & Rowe's book The Mistaken Extinction or the notes on my dinosaur class website (esp.: http://www.geol.umd.edu/~tholtz/G104/10422arch.htm http://www.geol.umd.edu/~tholtz/G104/10423aves.htm). > Archaeopteryx: The Missing Link: > > Grounded. > > Tamzek claims that fossil theropod Dromaeosaurs (Protoarchaeopteryx and > Caudipteryx) Neither Protarchaeopteryx (note spelling) nor Caudipteryx are dromaeosaurs. They are a generalized maniraptoran and an oviraptorosaur, respectively. I've enclosed a .tif figure of a recent theropod phylogeny. On this diagram, the following groups have confirmed feathers/feather analogs: Avialae (birds) (duh...) Dromaeosauridae (Microraptor, Sinornithosaurus, and the new form mentioned in Nature this week) Alvarezsauridae (Shuvuuia) Oviraptorosauria (Caudipteryx) Therizinosauroidea (Beipiaosaurus) Compsoganthidae (Sinosauropteryx) Note that other than Shuvuuia and birds, all the discoveries are from a single Formation, the Yixan, noted for its spectacular preservation. Note also that we do not have scale impressions or any non-feather impressions for other species in these particular groups, so the simplest explanation is that their most recent common ancestor had simple feathers. > provide unequivocal evidence that birds evolved from > dinosaurs. > However, the skeptic must ask the question, is this really the case? These > are interesting fossils, but they do not provide enough evidence > to get the > dino-bird hypothesis off the ground. In fact, the heavy tails and large > bodies of theropod dinosaur bodies are the exact opposite of the type of > organism we would expect to evolve into a flier92. The dinosaurs from Tyrannosauroidea up to birds on this cladogram are noted by a reduction in the number of tail vertebrae; this is particularly true of birds and their closest relatives. > According to the report in Nature38, Protoarchaeopteryx, was a > dinosaur with > "down-like" feathers on its body, however one paleontologist called this > down "dino-fuzz, [which] really could have nothing to do with the > origin of > feathers."91 These guys are mixed up; the description they refer to sounds like Sinosauropteryx (a compsognathid). No one has questioned the feathers on Protarchaeopteryx; the only question was whether or not it was a bird. > Regardless, down feathers have no function for > flight on birds. > The only "vaned, barbed, symmetrical feathers"38 on Protoarchaeopteryx > appear on its tail--no sign of feathers for flight. Caudipteryx has a few > vaned and barbed remiges on one finger of the hand, but its arm is far > shorter than that of a bird39--too short for flight. Because > these organisms > have some body structures which are well adapted to flight, but clearly > didn't fly, these (and other) fossils have led evolutionists to > believe that > some of the primary complex structures specified for flying -- feathers, > wings, and ossified bones Neither of these guys have "wings"; they are just arms. Those of Caudipteryx, in fact, are really short compared to other oviraptorosaurs! "ossified bones" = bones made of bones. Since you and I have ossified bones, as do cats, dogs, lizards, frogs, and trout, this is hardly a flight characteristic!! > -- originated for a purpose other that flight40. > There are no elegant explanations here, but rather wishful thinking trying > to force-fit the data to an evolutionary model failing to explain > the origin > of flight. Actually, what there is is the description of the material at hand. Fossils first, guys; hypotheses second. > Reptiles of a feather, don't flock together > > In fact, feathers have been also found a non-dinosaur lizard-like > reptile90, Nope. These have been shown to be structurally disctinct from the true feathers of birds and other dinosaurs; see recent papers by Reisz and Sues. > however proponents of the dino-bird hypothesis think this feathered fossil > is completely unrelated to the origin of birds and the alleged feathered > dinosaurs. Why, then, should the alleged appearance of feathers on these > post-avian Dromaeosaurs become the definitive proof of the dinosaurian > ancestry of birds? Perhaps these "feathered dinos" are just what their > squamate Longisquama is NO squamate!!! (Squamate = lizards & snakes). It isn't a true archosaur, either, as it has traditionally been considered. Furthermore the primary evidence of the dinosaurian origin of birds is skeletal, not integumentary. See my website, among many other references. > counterparts are: reptile chimeras unrelated to birds. > > To throw some other bones into the dino-bird hypothesis, although both > theropod dinosaurs and birds both walk on 2 legs and have some skeletal > similarities, differences such as digit configuration, Identical > pubis bone, pelvis > shape, identical (and in fact the same thing: pubis bone being part of the pelvis!) in basal dromaeosaurids, basal troodontids, and basal birds. > teeth, Teeth of primitive birds, primitive troodontids, and primitive dromaeosaurids all very similar. > and internal organ setup (the avian respiratory system is > unique and far different than of reptiles) Fair to say that it is distinct from all LIVING reptiles. > have all been raised And rejected... > as > differences which challenge the dino-bird hypothesis43, 92. Wells > also notes > that cladistical methods which have established this alleged relationship > ignore the fossil record, Bullcrap. How would a cladistic analysis of forms only known from fossils ignore the fossil record? (I suspect he meant "stratigraphic record", but that is another issue) > assume an evolutionary history, Guilty. :-) > and ignore major > problems with the implications that dinosaurs evolved to fly from the > ground. ????? Phylogenetic analyses are hypotheses of relationships; they are the framework by which other studies (like flight origins or so forth) might be interpreted, but the analyses themselves are JUST the interrelationships. Thomas R. Holtz, Jr. Vertebrate Paleontologist Department of Geology Director, Earth, Life & Time Program University of Maryland College Park Scholars College Park, MD 20742 http://www.geol.umd.edu/~tholtz/tholtz.htm http://www.geol.umd.edu/~jmerck/eltsite Phone: 301-405-4084 Email: tholtz@geol.umd.edu Fax (Geol): 301-314-9661 Fax (CPS-ELT): 301-405-0796