tag:blogger.com,1999:blog-9107291904794625632.post7520218900286809080..comments2023-10-29T06:50:22.166-04:00Comments on Love in the Time of Chasmosaurs: Deinonychus, a Cretaceous Rodeo RiderUnknownnoreply@blogger.comBlogger29125tag:blogger.com,1999:blog-9107291904794625632.post-16762964165817776062012-07-17T03:52:11.083-04:002012-07-17T03:52:11.083-04:00This comment has been removed by a blog administrator.Anonymoushttps://www.blogger.com/profile/10372309577029399989noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-19889126872565664372011-12-19T11:22:30.968-05:002011-12-19T11:22:30.968-05:00@Denver Fowler
"Incidentally, I appreciate t...@Denver Fowler<br /><br />"Incidentally, I appreciate this discussion. It's making me thing about claw morphology again."<br /><br />Glad I could help.Hadiazhttps://www.blogger.com/profile/10805346627826158173noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-76346216541615870952011-12-18T14:24:40.391-05:002011-12-18T14:24:40.391-05:00@henrique - Doesn't that depend on the keratin...@henrique - Doesn't that depend on the keratinous sheath, though? Interested to see the research Denver refers to in yesterday's comment.<br /><br />@Denver - I also appreciate this; it's really my highest hope when I write a post.davorhttps://www.blogger.com/profile/04970830405883835452noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-42406882132924695102011-12-18T14:08:57.545-05:002011-12-18T14:08:57.545-05:00@Hadiaz
Osprey claws aren't circular. I think...@Hadiaz<br /><br />Osprey claws aren't circular. I think what the writer at thefez.com is trying to enunciate is that typical falcon & hawk claws are arched (agreed) in cross section, whereas Ospreys' are rounded.<br /><br />Some pictures (not brilliant, but I am not at the museum, so I can't shoot photos of our own foot):<br />http://upload.wikimedia.org/wikipedia/commons/thumb/5/57/Pandion_haliaetus_-Sanibel_Island,_Florida,_USA_-feet-8.jpg/800px-Pandion_haliaetus_-Sanibel_Island,_Florida,_USA_-feet-8.jpg<br />http://www.sciencephoto.com/image/429085/530wm/C0108563-Osprey_foot,_museum_display-SPL.jpg<br />http://dyfiospreyproject.com/uploads/default/files/Ringing_2006s.jpg<br /><br /><br />Again, in this sense, dromaeosaur D-II claws are more like ospreys than hawks. I suspect hawks may have the arched cross section as they do more holding down of prey than piercing, whereas ospreys just pierce fish. this looks like I am contradicting myself, since we say that deinonychus is doing pinning. What I mean is that the D-II claw of dromaeosaurs is used for anchoring into the prey (hence it needs to pierce), but that the other digits are adapted to maintain hold, using the bodyweight to pin down the prey (ie. RPR).<br /><br />This would all need testing. Maybe some FEA of an arched cross section vs. a narrow one. Manning put a ?velociraptor manus ungual through FEA and they are similarly narrow (like most theropod manus unguals). Or just repeat the stabbing experiments.<br /><br />Incidentally, I appreciate this discussion. It's making me thing about claw morphology again.Dr. Denver Fowlerhttps://www.blogger.com/profile/04642242652389286832noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-82400747695558326332011-12-18T13:51:17.764-05:002011-12-18T13:51:17.764-05:00One moment, please. I might have read it wrong but...One moment, please. I might have read it wrong but slashing motions for D-II claws are unlikely since eudromaeosaurs didn’t have a suitable cutting edge.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-59338602465277006602011-12-17T21:45:37.439-05:002011-12-17T21:45:37.439-05:00@Denver Fowler
I'm not saying that eudromaeos...@Denver Fowler<br /><br />I'm not saying that eudromaeosaur D-2 claws didn't have multiple functions: Like cat hind claws, they were probably used for hanging onto relatively large prey & climbing (in addition to slashing); Also, as I implied in my 1st comment, small basal paravians probably used their D-2 claws to pin relatively small prey & microraptorines/eudromaeosaurs later exapted their D-2 claws for arboreality/big game hunting (respectively). I'm just saying that 1 of their functions was probably slashing, given their striking resemblance to cat hind claws (As Naish pointed out, cat hind claws resemble eudromaeosaur D-2 claws even more than cat front claws), the cat-like hunting technique of eudromaeosaurs (Grapple-&-slash: http://www.dinosauria.com/jdp/trex/hunting.htm ) & the preference of eudromaeosaurs for relatively large prey.<br /><br />BTW, aren't Osprey talons "nearly circular in cross section" ( http://www.thefez.net/osprey/articles/naturalhistory.htm ) as opposed to teardrop shaped in cross section like eudromaeosaur D-2 claws?Hadiazhttps://www.blogger.com/profile/10805346627826158173noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-16708967962373357102011-12-17T13:30:10.779-05:002011-12-17T13:30:10.779-05:00@Hadiaz
The claws do narrow ventrally, but the ve...@Hadiaz <br />The claws do narrow ventrally, but the ventral edge is still rounded, much like Osprey unguals and claws. The fact that Ospreys have claws this shape is telling (they only impale). A survey of birds with narrow claws might be informative. IIRC woodpeckers have pretty narrow claws: again used for impaling (wood). Some owls have narrow claws (usually not all claws though; D-I IIRC).<br /><br />The physical features that would aid slashing (ie. a narrow claw) may also aid piercing (for impaling). Some physical experimentation may help with this question (repeating Manning's experiments maybe). Barrett's tetzoo comments are correct in asking how to test the slashing hypothesis. Do extant big cats rally slash with their claws? Exclusively? No modern birds slash with their foot claws, but the Seriema (see our sup) does hook-and-pull at flesh.<br /><br /> <br />The claws are obviously useful for different purposes. I wouldn't be surprised if dromeosaurs (et al) used the claws for pulling food apart, or helping climb (as we point out in the supp, all birds use claws to climb). The question is which function(s) is/are being actively selected for? We present accipitrids as the closest modern analogue, which also happens to be in a bird (ie. within the EPB; not a requirement, but it helps). Maybe we're wrong, but noone has considered this before, and it matches up with other aspects of pedal morphology and the evolutionary trends that we observe. Our paper is not supposed to be a conclusive answer / closed book. Rather, we present a new analogue, posit a few ideas that match up with the morphology, and invite others to investigate the hypotheses. Asking what the additional narrowness does functionally is a good question to try and test.<br /><br />On a related note, there is someone (not Burnham; I don't agree with his recent paper at all) currently working on the growth of the keratinous sheath and how it may be related to ungual shape . It might inform a bit on this subject. Hopefully that work is on its way to publication.Dr. Denver Fowlerhttps://www.blogger.com/profile/04642242652389286832noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-80077980135183512472011-12-17T10:10:16.967-05:002011-12-17T10:10:16.967-05:00@Matthew Martyniuk
"That would be quite an M...@Matthew Martyniuk<br /><br />"That would be quite an M.C. Escher like animal indeed."<br /><br />How so? IIRC (If not, then please correct me), Qilong's Velociraptor ( http://qilong.deviantart.com/gallery/5004780?offset=48#/deq286 ) has hands that extend beyond the feathers, yet the feathers are still long enough to brood w/. In any case, Senter basically said that while some dromaeosaur hands (E.g. Those of Microraptor) had long feathers, others (E.g. Those of Bambiraptor) extended beyond the feathers ( http://www.newscientist.com/article/dn11047-birdlike-dinosaur-boasted-opposable-fingers.html ).<br /><br />@Denver Fowler<br /><br />"The lateral compression that you see in dromaeosaur D-II unguals is diferent from accipitrids."<br /><br />1stly, many thanks for taking my concerns seriously.<br /><br />2ndly (as others have pointed out elsewhere), eudromaeosaur D-2 claws aren't just narrow, they're "narrowest ventrally" (See the 27th comment: http://scienceblogs.com/tetrapodzoology/2008/06/glut_supp_5_review.php?utm_source=sbhomepage&utm_medium=link&utm_content=channellink#comment-933916 ).Hadiazhttps://www.blogger.com/profile/10805346627826158173noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-53485015523327549172011-12-17T01:43:19.678-05:002011-12-17T01:43:19.678-05:00This comment has been removed by the author.Hadiazhttps://www.blogger.com/profile/10805346627826158173noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-80808366496157527202011-12-16T20:02:59.552-05:002011-12-16T20:02:59.552-05:00I may be wrong, but I think this is the first time...I may be wrong, but I think this is the first time an author popped in to comment on a post about a new paper. Thanks for commenting, Denver!davorhttps://www.blogger.com/profile/04970830405883835452noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-4698530803662239602011-12-16T19:00:53.559-05:002011-12-16T19:00:53.559-05:00@Denver The 'Fighting Dinosaurs' show a dr...@Denver The 'Fighting Dinosaurs' show a dromaeosaur using its 'sickle claw' in a stabbing/impaling fashion.Marc Vincenthttps://www.blogger.com/profile/01894846069567096349noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-82826456162596421282011-12-16T17:53:53.940-05:002011-12-16T17:53:53.940-05:00Thanks, I appreciate the blog post.
In response t...Thanks, I appreciate the blog post.<br /><br />In response to a couple points:<br />The lateral compression that you see in dromaeosaur D-II unguals is diferent from accipitrids. We note about this (and Manning's work) in the supp info. What difference the lateral compression makes is not clear. I agree that lateral compression would make slashing easier than if they were broad, but I doubt if it would make much difference, and thus I still doubt that this would be the purpose of the claw. I suspect it is for impaling, and that the lateral compression makes it easier to impale (needs experiment). Ospreys also have laterally compressed claws, and they impale fish.<br /><br />I don't mind being called a cheerleader for Jack; he is my supervisor after all. <br /><br />I admit sometimes I get a bit highly charged about things. But then, I'm passionate about my science, and people have often been quite unreasonable about Jack's work. Jack has great ideas, and I never really understand why people object so strongly. Ontogeny is a new frontier in dinosaur paleobiology, and it has the potential to make sense of all sorts of issues. <br /><br />Anyway, thanks again for highlighting our work.Dr. Denver Fowlerhttps://www.blogger.com/profile/04642242652389286832noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-29564455834409733082011-12-16T14:24:09.322-05:002011-12-16T14:24:09.322-05:00@Hadiaz "I don't like that this paper ign...@Hadiaz "I don't like that this paper ignores the probability of eudromaeosaur hands extending beyond the feathers"<br /><br />That would be quite an M.C. Escher like animal indeed. given that the manus including the metacarpal and at least the proximal phalanges are an integral part of the aviremigian wing to which the feathers attach, it would be logically impossible for the hand to extend beyond the wing--the wing itself being an extension of the hand.Matt Martyniukhttps://www.blogger.com/profile/04220900229537564466noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-10810740009179878872011-12-16T09:59:40.293-05:002011-12-16T09:59:40.293-05:00@Holtz - We need more movies! It will be like the ...@Holtz - We need more movies! It will be like the "fast zombie" vs "slow zombie" debate. That's how we'll settle it.davorhttps://www.blogger.com/profile/04970830405883835452noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-17289542692012670832011-12-16T09:40:32.027-05:002011-12-16T09:40:32.027-05:00We've known for sometime (since the 1990s) tha...We've known for sometime (since the 1990s) that the classic dromaeosaurids (the eudromaeosaurs nowadays) were absolutely NOT speed adapted animals, based on limb proportions. If it weren't for a certain major fictional franchise hyping the exact opposite, maybe it would have sunk in.Thomas Holtzhttps://www.blogger.com/profile/05580730835586277579noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-85912256339599592042011-12-16T08:49:15.813-05:002011-12-16T08:49:15.813-05:00Ha ha, too true, Taranaich! And if you're pers...Ha ha, too true, Taranaich! And if you're persuaded by Fowler's arguments, it would almost be better to let dromies and troodontids trade names.davorhttps://www.blogger.com/profile/04970830405883835452noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-77023560070311387822011-12-16T06:24:12.211-05:002011-12-16T06:24:12.211-05:00So if I'm reading this aright, the very name D...So if I'm reading this aright, the very name Dromaeosaur is something of a misnomer?Taranaichhttps://www.blogger.com/profile/02176999342965850175noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-2965058513645179832011-12-15T22:37:05.492-05:002011-12-15T22:37:05.492-05:00Thanks for the excellent round of comments, everyo...Thanks for the excellent round of comments, everyone. A nice treat after a night of x-mas shopping. Thanks to Hadiaz and PH for those excellent observations on where the Fowler paper has some weaknesses. I hadn't thought to consider the *shape* of accipiter talons. This would be another spot that would be ripe for another piece of research.<br /><br />@Hadiaz - Good point about the Carroll drawing. The perspective on those big ol' arms is pretty comical. It is very Rey-ish. Just missing the lurid colors.davorhttps://www.blogger.com/profile/04970830405883835452noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-79825105802062399292011-12-15T20:50:40.415-05:002011-12-15T20:50:40.415-05:00Love the comments here almost as much as the artic...Love the comments here almost as much as the article. I think optimisticpainter's is my favorite. <br /><br />I have absolutely no expertise, and I know how some folks feel about Mr Fowler, so that may color mine or others' objections to the finding, but is this all that revelatory? I mean, I don't think anyone would ever have objected to the hypothesis that raptors subdued prey with their feet. His supporting hypotheses grab me even less, like flapping wings to stabilize one's self over struggling prey. Surely there are better reasons to retain wings, not to mention that wingless hunters today the same size as Deinonychus don't seem to have any trouble subduing prey without wings... Seems like if the prey's too big, two stubby-winged arms aren't going to do much good as far as holding it down. Some extra kg<br /><br />And as Hadiaz points out, accipiter claws are basically round in cross-section, not flat and blade/like. The propensity for deinonychosaur claws to "rack" sideways so easily must surely have been problematic-- dislocated toes, broken claws, etc. Only if the interior edge were very, very sharp would the utility of such a claw begin to mitigate these problems. This for me has always been the problem with dromaeosaurs, and why the function of their claw remains as inscrutable as ever.<br /><br />And Marc (and David, too)-- the "horrible dromaeosaur sculpture" one-upsmanship must stop. We can only enjoy them ironically so far before they make us physically ill;)Paul Heastonhttps://www.blogger.com/profile/13361025829815286466noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-5176816589898172882011-12-15T19:37:10.160-05:002011-12-15T19:37:10.160-05:00I almost forgot to mention the following.
@Everyb...I almost forgot to mention the following.<br /><br />@Everybody<br /><br />Am I the only 1 to notice the striking similarity btwn Carroll's Deinonychus ( http://blogs.discovermagazine.com/notrocketscience/files/2011/12/Deinonychus.jpg ) & Rey's ( http://search.barnesandnoble.com/booksearch/imageviewer.asp?ean=9780375863301&imId= )?<br /><br />@David Orr<br /><br />Welcome back!<br /><br />@Mark Vincent<br /><br />& I thought Alan Groves' sculptures were bad.Hadiazhttps://www.blogger.com/profile/10805346627826158173noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-9935817365250731152011-12-15T19:11:10.276-05:002011-12-15T19:11:10.276-05:00I have mixed feelings about this paper.
On the 1 ...I have mixed feelings about this paper.<br /><br />On the 1 hand, I like papers about what non-avian dinos (especially eudromaeosaurs) were like when alive based on comparisons w/living animals (especially eagles); I like the idea that grasping feet & stability flapping were pre-adaptations in paravians for WAIR/CFD, arboreality &/or big game hunting; & I like that I'm not the only 1 to notice the enlargement of eagle D-2 talons.<br /><br />On the other hand, I don't like that this paper ignores the blade-like morphology of eudromaeosaur D-2 claws (which suggests a slashing function); I don't like that this paper refers to "Manning et al. 2006" & "Roach & Brinkman 2007" for support despite their many problems (E.g. See the 25th comment: http://scienceblogs.com/tetrapodzoology/2008/06/glut_supp_5_review.php?utm_source=sbhomepage&utm_medium=link&utm_content=channellink#comment-933916 ) (E.g. See "Behavior": http://dixie.academia.edu/JerryHarris/Papers/171805/Behavioral_and_faunal_implications_of_Early_Cretaceous_deinonychosaur_trackways_from_China ); & I don't like that this paper ignores the probability of eudromaeosaur hands extending beyond the feathers (in reference to "Mantling and possible use of the forelimb"). It also doesn't help that 1 of the authors rubs me the wrong w/his DML posts (If I didn't know better, I'd say he's Horner's personal cheerleader).Hadiazhttps://www.blogger.com/profile/10805346627826158173noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-7204539241867196102011-12-15T19:10:39.023-05:002011-12-15T19:10:39.023-05:00Ah, David, your penchant for cowboys & dinosau...Ah, David, your penchant for cowboys & dinosaurs... :D<br /><br />@Marc: My word, those are frightful.Nateehttps://www.blogger.com/profile/15869685234493116483noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-12679685864639064242011-12-15T17:53:29.017-05:002011-12-15T17:53:29.017-05:00Actually, forget what I just said, and get a load ...Actually, forget what I just said, and get a load of THIS. http://flic.kr/p/8wRL4zMarc Vincenthttps://www.blogger.com/profile/01894846069567096349noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-50639787721248740542011-12-15T17:45:21.294-05:002011-12-15T17:45:21.294-05:00@optimisticpainter I'm not sure if it's th...@optimisticpainter I'm not sure if it's the worst ever. I've seen some very bad ones in my time. http://img.photobucket.com/albums/v484/Makron1n/Dino%20Park%201990s/Deino1.jpg<br /><br />But yeah, it's very ugly.Marc Vincenthttps://www.blogger.com/profile/01894846069567096349noreply@blogger.comtag:blogger.com,1999:blog-9107291904794625632.post-20433032338487804582011-12-15T17:33:13.084-05:002011-12-15T17:33:13.084-05:00I like how David balanced the quality of the artic...I like how David balanced the quality of the article with the worst 'raptor' sculptyre in human history.Anonymousnoreply@blogger.com