tag:blogger.com,1999:blog-140938929136406282.post3717251798241556341..comments2023-11-18T15:42:20.251-05:00Comments on DinoGoss: Tall TailMatt Martyniukhttp://www.blogger.com/profile/04220900229537564466noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-140938929136406282.post-67777914659287696912010-07-14T18:33:50.436-04:002010-07-14T18:33:50.436-04:00Yeah, I saw this at SVP '09 and was very excit...Yeah, I saw this at SVP '09 and was very excited. I'm looking forward to the paper, and I'm surprised at how basal the little guy is!Zachhttps://www.blogger.com/profile/08692080707969333711noreply@blogger.comtag:blogger.com,1999:blog-140938929136406282.post-60528361298585240152010-07-13T20:58:38.791-04:002010-07-13T20:58:38.791-04:00@qilong
Good points, though I don't know if we...@qilong<br />Good points, though I don't know if we can necessarily make some of those assumptions yet. Even if Leaellynasaura is "Scutellosaurus-grade", would this necessarily rule out filaments? Armored mammals are still generally furry, for example, even (presumably) up to Megatherium sizes. Also, even if (big if) ornithischian filamentous integument is hologous with birds and/or pterosaurs, there's no reason to suspect they'd be more like vaned feathers with rachides rather than plumaceous, hair-like or pycnofibre-like structures unconnected to blood vessels. The quill-like structures of Psittacosaurus and Tianyulong may be (are porcupine quills connected to blood vessels?) but Tianyulong has standard plumaceous integument as well, apparently based on undescribed specimens. Either way, with such a long extremity, it's hard to imagine how a furry covering could be anything but a net benefit in a cold environment (as long as, as you note, the fibers aren't extremities in themselves, but I don't think there's a reason to assume they are).<br /><br />I wonder, though, would Scutellosaurus-like armor provide some insulation?Matt Martyniukhttps://www.blogger.com/profile/04220900229537564466noreply@blogger.comtag:blogger.com,1999:blog-140938929136406282.post-23199001672308590042010-07-09T14:41:00.805-04:002010-07-09T14:41:00.805-04:00Matt, awesome post.
I just want to mention that t...Matt, awesome post.<br /><br />I just want to mention that there may be some difficulties for a highly integumented Leaellynasaura. The first is the seeming similarity and potential relationship within Thyreophora, noted "shield bearers." Along with long-tailed Scutellosaurus, it may have been somewhat armored! <br /><br />The second is that polar animals are rather unlikely to try to find ways to increase their body surface area by a great amount, as this contributes more to heat loss than heat retention due to increase in how much of the body and tissue where blood flows (if, like avian feathers, blood vessels are linked to the raches) is exposed to the air. Many polar animals have short ears, short tails, short and rounded feet, etc., diminishing their relative exposure regardless of size. While this may seem antithetic to a very long tailed animal, and coating the guys in "fuzz" is just not too much beyond what's already elaborate, it seems perhaps unlikely to be as long as you depict, although very cool looking.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-140938929136406282.post-36013751825292309582010-07-06T19:42:28.069-04:002010-07-06T19:42:28.069-04:00@ Andrea
I think the main contention many people h...@ Andrea<br />I think the main contention many people have is the apparent lack of filaments in numerous lineages basal to both feathered theropods and "feathered" ornithischians. We have good, extensive skin impressions from ceratosaurs, carnosaurs (undescribed), sauropods, and hadrosaurs that show no trace of any filamentous integument. At this point we can either hypothesize that that filaments were gained once and lost at least 5 times among dinosaurs, or were gained two or three times. Parsimony leans slightly towards non-homology. It's not a huge difference, but enough that it's not nearly a solid case. We were happy to assume the filaments of pterosaurs and mammals were not homologous with feathers for years, so it's odd that finding one more filamented lineage of amniotes should suddenly start us arguing for homology.Matt Martyniukhttps://www.blogger.com/profile/04220900229537564466noreply@blogger.comtag:blogger.com,1999:blog-140938929136406282.post-31465520058808132792010-07-06T02:52:28.369-04:002010-07-06T02:52:28.369-04:00"I tend to agree with Richard Prum that the f..."I tend to agree with Richard Prum that the fuzz of ornithischians is probably not homologous with feathers."<br /><br />Interesting. Recently, Norell (in Brusatte et al.'s review of early dinosaurs) considered very likely that the ornithischian fuzzs and the proto-feathers are homologous.Andrea Cauhttps://www.blogger.com/profile/10855060597677361866noreply@blogger.comtag:blogger.com,1999:blog-140938929136406282.post-18555237077411587772010-07-05T22:54:07.736-04:002010-07-05T22:54:07.736-04:00Further proof that Leaellynasaura would make one h...Further proof that Leaellynasaura would make one heck of a cute pet.davorhttps://www.blogger.com/profile/04970830405883835452noreply@blogger.comtag:blogger.com,1999:blog-140938929136406282.post-46637105461128041852010-07-05T19:40:25.859-04:002010-07-05T19:40:25.859-04:00Yeah, I tend to agree with Richard Prum that the f...Yeah, I tend to agree with Richard Prum that the fuzz of ornithischians is probably not homologous with feathers. The whole situation would be easier to swallow if heterodontosaurids are close to marginocephalians. Normally I'd really hesitate to put fuzz on something like Leaellynasaura but the concept was too good to pass up illustrating!Matt Martyniukhttps://www.blogger.com/profile/04220900229537564466noreply@blogger.comtag:blogger.com,1999:blog-140938929136406282.post-63650201471362075522010-07-05T12:08:09.001-04:002010-07-05T12:08:09.001-04:00The new Leaellynasaura looks amazing. I suppose th...The new Leaellynasaura looks amazing. I suppose the fuzz makes more sense now that it could be closer to the base of Ornithischia, near the heterodontosaurids. (On the other hand, heterodontosaurids are being bounced around Ornithischia quite a lot.)Albertonykushttps://www.blogger.com/profile/00345306530772709064noreply@blogger.com