tag:blogger.com,1999:blog-3049195237412585561.post75463395337761906..comments2023-11-07T12:07:59.585-08:00Comments on Pterosaurs to Birds: Pelvic Bones SummaryUnknownnoreply@blogger.comBlogger9125tag:blogger.com,1999:blog-3049195237412585561.post-88074789035328869432013-05-21T10:36:29.015-07:002013-05-21T10:36:29.015-07:00A comment was received from David Hone. But since ...A comment was received from David Hone. But since he does not accept my posts I do not accept his. Dr. Pterosaurhttps://www.blogger.com/profile/13137867768653523183noreply@blogger.comtag:blogger.com,1999:blog-3049195237412585561.post-23720430731660222102013-02-13T06:49:03.040-08:002013-02-13T06:49:03.040-08:00I was able to get my hands on a chicken carcass. U...I was able to get my hands on a chicken carcass. Unfortunately, in taking it apart, I broke the hip bones. It did appear to have a perforate acetabulum when I reassembled the broken hip bones, but I can't be sure. It did not appear to be covered with cartilage, as I had speculated. I will have better opportunity to examine this part in something larger and sturdier, like a turkey, in the future.Anonymoushttps://www.blogger.com/profile/00700525321909666545noreply@blogger.comtag:blogger.com,1999:blog-3049195237412585561.post-11152630680927970022013-02-07T09:15:12.205-08:002013-02-07T09:15:12.205-08:00For reference:
http://www.innerbird.com/ancestors_...For reference:<br />http://www.innerbird.com/ancestors_feathered_dinos/bird_ancestors.html<br />[In birds] the tips of the pubic bones are no longer fused. Because they do not form a bony ring, there is no longer a skeletal constraint on egg size.Dr. Pterosaurhttps://www.blogger.com/profile/13137867768653523183noreply@blogger.comtag:blogger.com,1999:blog-3049195237412585561.post-18520052714701195082013-01-31T06:51:55.565-08:002013-01-31T06:51:55.565-08:00I also wonder if it is a rule that pterosaurs had ...I also wonder if it is a rule that pterosaurs had imperforate acetabulum. It would be interesting to have more info on that. Dr. Pterosaurhttps://www.blogger.com/profile/13137867768653523183noreply@blogger.comtag:blogger.com,1999:blog-3049195237412585561.post-1781926194739252972013-01-31T06:50:30.304-08:002013-01-31T06:50:30.304-08:00It seems to me that the femur/acetabulum articulat...It seems to me that the femur/acetabulum articulation angle is very significant. As I understand it, it means that dinosaurs could not swivel their femur while pterosaurs could. <br />It is my understanding that birds can swivel their femur, like pterosaurs could (which dinosaurs could not do). Do you have any insight on this particular aspect?Dr. Pterosaurhttps://www.blogger.com/profile/13137867768653523183noreply@blogger.comtag:blogger.com,1999:blog-3049195237412585561.post-42319446415183099012013-01-31T06:45:13.620-08:002013-01-31T06:45:13.620-08:00The similarities and differences (cylindrical vs. ...The similarities and differences (cylindrical vs. ball-and-socket) in the hip joints of modern birds, pterosaurs, and dinosaurs sound interesting. <br /><br />Regarding the perforate acetabulum in (some?) modern birds, I wonder if there is cartilaginous material that ordinarily covers the perforation. The cartilage would decompose, leaving the perforation. <br /><br />In that case, we would have dinosaurs with perforate acetabulum, pterosaurs with imperforate acetabulum, and modern birds with a more refined, semi-imperforate acetabulum (less bone material means less weight, more cartilage means less joint friction).<br /><br />When I get a chicken to work with in a couple weeks, I'll see if the perforate acetabulum is covered by cartilage.Anonymoushttps://www.blogger.com/profile/00700525321909666545noreply@blogger.comtag:blogger.com,1999:blog-3049195237412585561.post-7334833367905212122013-01-29T10:23:43.736-08:002013-01-29T10:23:43.736-08:00So the acetabulum situation is more complicated. G...So the acetabulum situation is more complicated. Good. All the more interesting. <br />I will now research in more detail the situation with pterosaurs.<br />Dr. Pterosaurhttps://www.blogger.com/profile/13137867768653523183noreply@blogger.comtag:blogger.com,1999:blog-3049195237412585561.post-33059545266378298252013-01-29T09:54:15.170-08:002013-01-29T09:54:15.170-08:00To be more precise, the anhinga and yellow-billed ...To be more precise, the anhinga and yellow-billed hornbill pelvis photos appear to have imperforate acetabulum.<br /><br />http://www.innerbird.com/pelvic_girdle/run_swim_wade/pages/Anhinga_psd.htm<br />http://www.innerbird.com/pelvic_girdle/typical_hips/pages/Hornbill2YB_jpg.htm<br /><br />The bald eagle, western grebe, rhinoceros auklet, wood ibis, brown kiwi, common loon, humbolt penguin, hoopoe, wreathed hornbill, red-crested turaco, and pileated woodpecker pelvis photos appear to have perforate acetabulum.<br /><br />http://www.innerbird.com/pelvic_girdle/eggs_hips/pages/BAEA_jpg.htm<br />http://www.innerbird.com/pelvic_girdle/eggs_hips/pages/COLOWEGR_psd.htm<br />http://www.innerbird.com/pelvic_girdle/eggs_hips/pages/RHAU_jpg.htm<br />http://www.innerbird.com/pelvic_girdle/run_swim_wade/pages/Ibis_jpg.htm<br />http://www.innerbird.com/pelvic_girdle/run_swim_wade/pages/Kiwi01_jpg.htm<br />http://www.innerbird.com/pelvic_girdle/run_swim_wade/pages/loon_jpg.htm<br />http://www.innerbird.com/pelvic_girdle/run_swim_wade/pages/Penguin_jpg.htm<br />http://www.innerbird.com/pelvic_girdle/typical_hips/pages/hoopoe2_jpg.htm<br />http://www.innerbird.com/pelvic_girdle/typical_hips/pages/Hornbill4W_jpg.htm<br />http://www.innerbird.com/pelvic_girdle/typical_hips/pages/Turaco2_jpg.htm<br />http://www.innerbird.com/pelvic_girdle/typical_hips/pages/Woodpecker2_jpg.htm<br /><br />The other bird pelvis photos do not show the acetabulum.<br />Anonymoushttps://www.blogger.com/profile/00700525321909666545noreply@blogger.comtag:blogger.com,1999:blog-3049195237412585561.post-38308714107164090232013-01-29T07:34:09.292-08:002013-01-29T07:34:09.292-08:00Here is a gallery of some modern bird hips. Note ...Here is a gallery of some modern bird hips. Note the perforate acetabulum is visible in some of the photos.<br /><br />http://www.innerbird.com/pelvic_girdle/eggs_hips/eggs_hips.htm<br /><br />http://www.innerbird.com/pelvic_girdle/run_swim_wade/run_swim_gallery.htm<br /><br />http://www.innerbird.com/pelvic_girdle/typical_hips/typical_hips.htmAnonymoushttps://www.blogger.com/profile/00700525321909666545noreply@blogger.com