|
Post by dinoguy2 on Apr 16, 2011 11:15:36 GMT
Some porcupine quills look about as stiff as Psittaco quills...
|
|
|
Post by sid on Apr 18, 2011 15:37:42 GMT
Cool pic. Is he (or she) a young one?
|
|
|
Post by Griffin on Apr 18, 2011 17:37:02 GMT
Are those quills or is that just the normal fur? I'm pretty sure they can keep the quills closer to the body when they are more relaxed which is what it looks like in the photo. We used to work with a North American Porcupine (I didn't personally but my boss did for a little while) and it could be pet and held pretty easily since it didnt feel threatened.
|
|
|
Post by dinoguy2 on Apr 18, 2011 18:27:39 GMT
Are those quills or is that just the normal fur? I'm pretty sure they can keep the quills closer to the body when they are more relaxed which is what it looks like in the photo. We used to work with a North American Porcupine (I didn't personally but my boss did for a little while) and it could be pet and held pretty easily since it didnt feel threatened. I'm not sure, Whatever they are they look to have the same thickness and same level of stiffness as the "quills" of Psittacosaurus and Tianyulong. Normal porcupine quills are much, much thicker and straight as an arrow. If there's a different name for this type of porcupine integument we should be using that for Psittaco instead of "quills" which can be pretty misleading.
|
|
|
Post by Griffin on Apr 18, 2011 20:09:50 GMT
Well isn't "quill" also used for a feather too? I think of the term "quill knob" on a bird's bone. But yeah I'm almost positive what you see there are not the porcupine's quills which most likely are laid down under the normal fur...which is what we see. The actual quills actually aren't that long. Check out this photo where you can see the quills and the fur. www.dnr.state.md.us/wildlife/Plants_Wildlife/rte/rtePorcupine.asp
|
|
|
Post by dinoguy2 on Apr 19, 2011 0:13:16 GMT
Well isn't "quill" also used for a feather too? I think of the term "quill knob" on a bird's bone. Sometimes (though it's very imprecise, rachis is the term I almost always see except in non-scientific contexts). But again, that usually applies to a thick, inflexible structure. The pliable rachides of down feathers aren't referred to as quills afaik.
|
|
|
Post by arioch on May 2, 2011 19:34:39 GMT
Question about dromaeosaurids: should caudal feathers cover all the tail, from base to tip, or just the very tip?
I had an arguement about this. My point was that it where fully covered like in Archaeopteryx, hence the need to be completely straight. But on the other hand, basal dromies like Microraptor or Oviraptorids only have it in the tip or the last half of the tail, right? So we probably should assume this is the default condition until we have a more clear fossil evidence.
Are my dromies reconstructions wrong, then? (check my dinosaur art thread if you havenĀ“t seen them.)
|
|
|
Post by Horridus on May 2, 2011 19:49:59 GMT
|
|
|
Post by arioch on May 2, 2011 19:58:53 GMT
I mean feathers like this: My point was that it was a bit wrong as the whole tail should be covered by medium size-long feathers (the longer being in the tip), and not small and some long ones in the tip as the picture shows. Sort of like this:
|
|
|
Post by Horridus on May 2, 2011 20:15:47 GMT
I think for species in which the exact feather patterns are unknown, there's room for a bit of artistic license.
|
|
|
Post by Griffin on May 2, 2011 20:47:02 GMT
I wouldn't worry about it. Plus keep in mind things like Microraptor were tiny tree-dwelling critters...very specialized. So using them for an exact model when reconstructing much larger ground running dromaeosaurs may not be best. In other words there is room for educated guesswork.
|
|
|
Post by paleofreak on May 2, 2011 22:21:41 GMT
But on the other hand, basal dromies like Microraptor or Oviraptorids only have it in the tip or the last half of the tail, right? The troodontid Jinfengopteryx (google it for good pictures of the fossil) had a full feathered tail, with the feathers gradually larger towards the tail tip.
|
|
|
Post by zopteryx on May 5, 2011 0:25:23 GMT
I'm thinking a fan of larger feathers at the end of the tail was probably for display, while larger feathers running the length of the tail may have also served a mechanical function, like the tail of a cheetah. Does this accurate?
|
|
|
Post by Griffin on May 5, 2011 4:52:37 GMT
Maybe? A fan on the tail could easily serve as a rudder too.
Honestly you can't go wrong with the sexual display hypothesis. It can pretty much apply for anything and not be shot down.
|
|