Re: Pegomastax, new heterodontosaurid from South Africa in new Sereno monograph (free pdf!)

[Tim Williams <tijawi@gmail.com>]

Mickey Mortimer <mickey_mortimer111@msn.com> wrote:


> In general, this is an excellent paper with numerous useful photographs and 
> illustrations (well, besides the bobble-headed Tianyulong- 
> http://www.pensoft.net/J_FILES/1/articles/2840/export.php_files/ZooKeys-226-001-g030.jpg).


Still, _Tianyulong_ is a weird little critter - with its big head,
short arms, and long legs, all quite different from
_Heterodontosaurus_.  As with many small theropods, short forelimbs do
not necessarily mean that they were useless: the hands of _Tianyulong_
were highly adapted for grasping (as in _Heterodontosaurus_), and
based on the shape/size of the deltopectoral crest and olecranon
process, the truncated forelimbs were quite strong.  The robust femur
and very long tibia initially made me wonder if _Tianyulong_ had an
avian-style, knee-based style of stride generation... but this seems
highly unlikely for an ornithischian (even one with a relatively big
head).





Cheers

Tim