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Natural Science Forum / Biology / Paleontology / May 2005Feathered Dinosaur?
Hi everybody. I wanted to know, has any really, truly, non-speculated feather been found on a Dinosaur? BIrds theoretically descended from Maniraptors, but how can we be sure unless feathers were found on these things? The feather is a highly derived and extremely specialized character, it can be the telltale sign to early ancestors of birds. I wish a missing link between Maniraptors and Birds would be found, maybe in Utah? Any help would be apreciated. ~albaradru > Hi everybody. > [quoted text clipped - 5 lines] > link between Maniraptors and Birds would be found, maybe in Utah? > Any help would be apreciated. Archaeopteryx is only distinguishable from small theropods by being feathered. One specimen was misidentified as a small theropod for decades. Also a whole flock of feathered dinosaurs have been found in western China in the last 15 years or so. Ken > Hi everybody. > > I wanted to know, has any really, truly, non-speculated feather been > found on a Dinosaur? Yes, many of them. My favorite is Microraptor gui, but Caudipteryx is also nice. There are others. See these for a start: Xu, X., Z. Zhou, X. Wang, X. Kuang, F. Zhang, and X. Du. 2003. Four-winged dinosaurs from China. Nature 421:335-340. Ji, Q., P. J. Currie, M. A. Norell, and S.-A. Ji. 1998. Two feathered dinosaurs from northeastern China. Nature 393:753-761. > BIrds theoretically descended from Maniraptors, > but how can we be sure unless feathers were found on these things? There is no single, magic-bullet character. We can recognize bird relationships without regard to feathers. However, there are indeed known, feathered maniraptorans, including Microraptor gui and "Dave" a probable juvenile Velociraptor. > The > feather is a highly derived and extremely specialized character, it can > be the telltale sign to early ancestors of birds. I wish a missing > link between Maniraptors and Birds would be found, maybe in Utah? > Any help would be apreciated. The links are not missing. Feathers, though unnecessary to establish relationships, are nevertheless known from a wide sampling of theropods, including several dromaeosaurs, oviraptorids, tyrannosaurids, compsognathids, and others. >> The >> feather is a highly derived and extremely specialized character, it can >> be the telltale sign to early ancestors of birds. I wish a missing >> link between Maniraptors and Birds would be found, maybe in Utah? >> Any help would be apreciated. >The links are not missing. Feathers, though unnecessary to establish >relationships, are nevertheless known from a wide sampling of theropods, >including several dromaeosaurs, oviraptorids, tyrannosaurids, >compsognathids, and others. One thing I am curious about is how we managed to miss finding feathered dinosaurs for so long. I mean, people have been enthusiastically seeking out dinosaur fossils since at least the 19th century, and for almost all of that time nobody found feathers. Now suddenly -- in the last decade or so -- we seem to be finding feathered dinosaurs all over the place. So what's up with that? On a somewhat separate note, would you happen to know what is the most un-birdlike dinosaur definitely known to have been feathered? How about tentatively? And has any sort of covering -- downy, hairy, or whatever -- ever been found on any ornithischian dinosaurs?  SignatureJohn Brock jbrock@panix.com >>>The >>>feather is a highly derived and extremely specialized character, it can [quoted text clipped - 13 lines] > Now suddenly -- in the last decade or so -- we seem to be finding > feathered dinosaurs all over the place. So what's up with that? We aren't finding them all over the place. We're finding them in one fairly small area of China, where the preservational conditions seem to have been just right for the preservation of feathers. > On a somewhat separate note, would you happen to know what is the > most un-birdlike dinosaur definitely known to have been feathered? > How about tentatively? And has any sort of covering -- downy, > hairy, or whatever -- ever been found on any ornithischian dinosaurs? There's a psittacosaur with some kind of fibrous integument in its tail. Aside from that, Sinosauropteryx is the most "un-birdlike", meaning most distantly related to birds. >> One thing I am curious about is how we managed to miss finding >> feathered dinosaurs for so long. I mean, people have been >> enthusiastically seeking out dinosaur fossils since at least the >> 19th century, and for almost all of that time nobody found feathers. >> Now suddenly -- in the last decade or so -- we seem to be finding >> feathered dinosaurs all over the place. So what's up with that? >We aren't finding them all over the place. We're finding them in one >fairly small area of China, where the preservational conditions seem to >have been just right for the preservation of feathers. Ah, that was pretty much the impression I had gotten. Another possible answer might have been "feathers were there all along, but we didn't see them because we weren't expecting to see them," or something like that. >> On a somewhat separate note, would you happen to know what is the >> most un-birdlike dinosaur definitely known to have been feathered? >> How about tentatively? And has any sort of covering -- downy, >> hairy, or whatever -- ever been found on any ornithischian dinosaurs? >There's a psittacosaur with some kind of fibrous integument in its tail. >Aside from that, Sinosauropteryx is the most "un-birdlike", meaning most >distantly related to birds. I guess what I wanted to know was whether it was still possible for an opponent of the idea that birds are descended from dinosaurs to squint, turn his head sideways, and convince himself that these are all really flightless birds of some sort, and not dinosaurs at all. More directly, are Feduccia & co., or anybody, still contesting that these are really feathers, or really dinosaurs? (And is there anything new in the "finger" controversy, which always struck me as the most troubling argument against the bird/dinosaur connection. Was that ever definitely resolved, or did it just peter out?) SignatureJohn Brock jbrock@panix.com >>>One thing I am curious about is how we managed to miss finding >>>feathered dinosaurs for so long. I mean, people have been [quoted text clipped - 26 lines] > are all really flightless birds of some sort, and not dinosaurs at > all. That's a different question. Of course it's possible. There is no point at which that becomes impossible as long as the person involved is sufficiently resolute. > More directly, are Feduccia & co., or anybody, still contesting > that these are really feathers, or really dinosaurs? (And is there > anything new in the "finger" controversy, which always struck me > as the most troubling argument against the bird/dinosaur connection. > Was that ever definitely resolved, or did it just peter out?) Feduccia's position disintegrated a few years ago, and I don't know if it ever re-congealed. He was in the creationist position of disagreeing with himself about which fossils were dinosaurs and which were birds. I haven't seen that the line has become firm again. And I don't know that there would be any way to resolve the 5-finger question. But the recent evo-devo evidence seems pretty good. See Vargas, A. O., and J. F. Fallon. 2004. Birds have dinosaur wings: The molecular evidence. J. Exp. Zool. [sorry, don't have page numbers handy; I have a PDF only]. >More directly, are Feduccia & co., or anybody, still contesting >that these are really feathers, or really dinosaurs? Speaking of Feduccia, can anybody tell me if The Origin and Evolution of Birds is worth using? I am in the middle of reading it, and it was written before any feathered dinosaurs had been found I think. I am writing a formal essay for International Baccaleureate and I would appreciate any tips. ~albaradru >>More directly, are Feduccia & co., or anybody, still contesting that >>these are really feathers, or really dinosaurs? [quoted text clipped - 4 lines] > writing a formal essay for International Baccaleureate and I would > appreciate any tips. If you ignore the first three chapters related to bird origin, the rest of the book is pretty good with some excellent pictures of the fossils. Of course, the book is a bit out of date (2nd edition 1999) but no more so than any other science book of the same age. SignatureGautam Majumdar Please send e-mails to gmajumdar@freeuk.com >>>More directly, are Feduccia & co., or anybody, still contesting that >>>these are really feathers, or really dinosaurs? [quoted text clipped - 10 lines] > than any other science book of the same age. > And there is as yet no adequate replacement. If you want to know much about bird paleontology, there is no single source that will tell you nearly as much. If you're interested in Mesozoic birds, there are a couple of substitutes, though. Try Chiappe, L. M., and L. M. Witmer (eds.). 2004. Mesozoic birds: Above the heads of dinosaurs. University of California Press, Berkeley. For Paleogene birds, there's nothing comparable, and there are a lot of new discoveries in the last 10 years. In particular, look up the name Gerald Mayr for a host of new birds from the Messel Shale. >>>The >>>feather is a highly derived and extremely specialized character, it can [quoted text clipped - 18 lines] > How about tentatively? And has any sort of covering -- downy, > hairy, or whatever -- ever been found on any ornithischian dinosaurs? Most of the feathered dinosaurs have come from western China. An area not very well explored in the past. As I understand it these fossils are coming from a very fine grained stone much like the deposits in Germany where the Archy fossils are from. These sorts of matrix preserve soft tissue impressions much better than coarser sedimentary rocks. A lot of the other feathered fossils can be attributed to improvements in collection and preparation of fossils. >Hi everybody. > [quoted text clipped - 7 lines] > >~albaradru It only gets worse: More Gaps http://pharyngula.org/index/weblog/comments/uh_oh_evolutionists_discover_two_mor e_gaps_in_the_fossil_record/ dunk |
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