Comment on Xiaotingia by Qilong
Yes, escaping the pose constraint!
What do you think of Greg Paul's hadrosaur reconstructions and restorations, with that straight across the back of the neck to head form? They look kind of....off....to me. Do you know of a modern animal built like that?
The reconstruction is based on unpublished mummies which supposedly preserved this integument. This has since been shown to be incorrect, but the secondary reasoning used by Paul was that there was a "mammal-style" nuchal ligament (ligamentum nuchalis) that spanned the rear of the skull to the anterior dorsals. The complexity of this ligament is understated, and likely very, very different from what anyone, including Paul, restore it as. For one, it is not just one ligament, and it is bound is many branches to every single vertebra between the origin and the insertion. It is also based, as in birds, on a system of muscles that have "ligamentized" rather than just the basal ligament fibres before the appearance of muscle fibres in the system. The system is birds is very complex, and forms an array that spans the neck like an inverted truss, and keep the neck in small birds in a permanent U-shape, while in larger birds it follows the vertebral curve of the neck and is strongly associated with large ligament scars or knobs. We see this in sauropods, for example, and it implies the nuchal system was much more closely associated with the vertebral curve than apart from it, while in hadrosaurs, this is less clear.
Thanks for the info! I have seen a pic of what seems to be a corythosaur mummy that SEEMS to show the body outline. Could be wrong in what I think I see, and it shows a rather horse-like configuration, which would make sense to me.
Even bison don't have the configuration Paul shows, and their tall spine thingees are closer to the neck than in hadrosaurs. That does not prove anything, but Paul's configuration seems to me to heavily constrict a hadrosaurian's ability to move both neck and body. Usually, in nature, animals in the wild don't seem to be built to not be able to move to the best of their ability, sloths included, but of course, not including sessile animals like barnacles. In other words, most any depiction of an animal (endoskeletal) that looks like it can't move right...is wrong.
Even bison don't have the configuration Paul shows, and their tall spine thingees are closer to the neck than in hadrosaurs. That does not prove anything, but Paul's configuration seems to me to heavily constrict a hadrosaurian's ability to move both neck and body. Usually, in nature, animals in the wild don't seem to be built to not be able to move to the best of their ability, sloths included, but of course, not including sessile animals like barnacles. In other words, most any depiction of an animal (endoskeletal) that looks like it can't move right...is wrong.