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Post by DinoLord on Jul 3, 2011 1:08:35 GMT
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Post by Griffin on Jul 3, 2011 3:42:42 GMT
Great now one more nitpicky thing to nail every artist's rendition of a theropod on...
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Post by Himmapaan on Jul 3, 2011 11:23:31 GMT
Huh, strangely enough, I'd only just been wondering about this. I sometimes think we get a little over-keen on folding them too far like modern birds.
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Post by arioch on Jul 3, 2011 17:23:41 GMT
Great now one more nitpicky thing to nail every artist's rendition of a theropod on... But you just love doing that, do you? ;D |
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Post by sid on Jul 3, 2011 18:24:37 GMT
IMHO it means that bigger dromies like Deinonychus, not being able to completely fold their arms like modern birds, had shorter arm feathers than more little and/or basal guys like Microraptor, or they would have touched the ground getting dirty (the feathers, i mean)... OR, they placed their arms in a manner their wing feathers didn't touch the ground (pulling the elbow up?).
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Post by arioch on Jul 3, 2011 20:52:00 GMT
They could have placed their arms forward as default, or more horizontally and the feathers wouldn´t have touch the ground despiting their lenght.  ;D |
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Post by Griffin on Jul 3, 2011 21:18:20 GMT
Great now one more nitpicky thing to nail every artist's rendition of a theropod on... But you just love doing that, do you? ;D You have no idea how harshly I get critiqued on my stuff by the bio coordinator at my school. All the "That body part can't bend that way" is from him critiquing my stuff first. I blame him for any anal tendencies I have.  And regarding the feathers on the arms. I have a feeling the arm feathers, especially on the larger non-arboreal dromaeosaurs, probably werent as long as people like to imagine. |
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Post by sid on Jul 3, 2011 22:19:02 GMT
And regarding the feathers on the arms. I have a feeling the arm feathers, especially on the larger non-arboreal dromaeosaurs, probably werent as long as people like to imagine. My thoughts exactly! |
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Post by dinoguy2 on Jul 4, 2011 12:42:17 GMT
And regarding the feathers on the arms. I have a feeling the arm feathers, especially on the larger non-arboreal dromaeosaurs, probably werent as long as people like to imagine. My thoughts exactly! I wouldn't be so sure about that. Birds like ostriches can't really bend their wrists *at all*. Here's an ostrich wing. The hand is the lumpy part at the end. You can see it's barely bent compared to the arm. Yet it has incredibly long feathers compared to the length of the arm. 2.bp.blogspot.com/-YJHdQPXuOgY/TVnUTl9shnI/AAAAAAAAAxk/kXtGi1qZwOQ/s1600/46371158.RL06.jpg |
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Post by sid on Jul 4, 2011 17:58:50 GMT
Yeah, but an Ostrich doesn't have the long, grasping and fully functional hands a medium-sized dromeosaurid had  |
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Post by Griffin on Jul 4, 2011 19:42:25 GMT
Not really the same as a dromaeosaur's arm though. |
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Post by zopteryx on Jul 5, 2011 0:00:00 GMT
Does anyone else think we could use this new info to help us better understand which dinosaurs were closest to birds? Assuming we can, that would mean dromeosaurs are not as close to birds as we thought; therizinosaurs would be closer and oviraptors would be the closest. Although this theory may be nothing new, as I recall the same organization in the Princeton Dino Field Guide.
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Post by eriorguez on Jul 5, 2011 13:14:13 GMT
Wrist bending degree is something that can be attributed to convergent evolution.
No seriously, there is a ton of evidence pointing to the monophyletic nature of Paraves, like Archaeopteryx looking like a mini Dromie.
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Post by dinoguy2 on Jul 5, 2011 23:52:02 GMT
Yeah, but an Ostrich doesn't have the long, grasping and fully functional hands a medium-sized dromeosaurid had True to some degree, but I wouldn't call them fully functional. They would have been more like semi-mobile grappling hooks. And Senter showed that the feathers would not get in the way of predation, because they are perpendicular to the plane of the digits and claws. Does anyone else think we could use this new info to help us better understand which dinosaurs were closest to birds? Assuming we can, that would mean dromeosaurs are not as close to birds as we thought; therizinosaurs would be closer and oviraptors would be the closest. Although this theory may be nothing new, as I recall the same organization in the Princeton Dino Field Guide. Some people have suggested that oviraptorosaurs are avialans, but this hasn't been supported by most analyses. And it's possible, even likely IMO, that the limited folding of large, hypercarnivorous eudromaeosaurs is a secondary loss of folding ability. Basal dromies seem to have been able to bend the wrists more than Deinonychus. |
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Post by Horridus on Jul 6, 2011 15:32:58 GMT
So Matt, you agree with Greg Paul that the larger dromaeosaurs are likely secondarily flightless? I thought he made a convincing case, but then other palaeontologists fervently disagree.
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Post by Griffin on Jul 6, 2011 21:31:34 GMT
"but then other palaeontologists fervently disagree. "
Is Greg Paul a paleontologist?
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Post by Horridus on Jul 6, 2011 22:45:45 GMT
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Post by dinoguy2 on Jul 6, 2011 23:44:28 GMT
So Matt, you agree with Greg Paul that the larger dromaeosaurs are likely secondarily flightless? I thought he made a convincing case, but then other palaeontologists fervently disagree. No, but I think they were possibly ancestrally gliding and probably ancestrally arboreal, both behaviors that would favor greater wrist flexibility in basal forms. There's no evidence that the ancestors of dromaeosaurs could actively fly. Heck, there's no anatomical evidence that Confuciusornis could actively fly! It's hard to flap if you can't lift your wings above shoulder level. |
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Post by Horridus on Jul 7, 2011 15:31:31 GMT
Ah, I see. I always forget about the limb articulation issue, mostly because I'm so used to seeing pretty images of flapping Microraptors, Confuciusorniseses et al...the curse of attractive but innacurate palaeoart strikes again!
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Post by sid on Jul 8, 2011 11:26:32 GMT
True to some degree, but I wouldn't call them fully functional. They would have been more like semi-mobile grappling hooks. Mmh... I'm not really convinced about that; if i look at the hand of a typical derived dromeosaurid like Deinonychus, Velociraptor and such, i see well-developed fingers, robust claws and other elements which suggest me that in life it was quite, ehr, dexterous (not as a monkey like us, obviously, but more like a parrot or any other bird who uses his feet like they'd be hands). |
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