RE: Koreanosaurus, new burrowing ornithopod [Meta]

[Tim Williams <tijawi@yahoo.com>]

Anthony Docimo <keenir@hotmail.com> wrote:


>  so....they can't say "based on what we have, this is who
> we think are related to _Koreanosaurus_" ?


Unless _Koreanosaurus_ is included in a phylogenetic analysis, then any 
discussion of its relationships is just hand-waving.  

 
>  yes, I know it would be best to find a dozen full and
> complete skeletons of _Koreanosaurus_. but -


But - if every dinosaur had to be known from a dozen complete skeletons before 
we could test its relationships, cladograms would be very small.  The worse 
that happens with an incompletely known specimen is that its position is weakly 
supported (in a statistical sense), and/or it can make the overall topology 
more unstable.

 
>  if nobody ever finds any more _Koreanosaurus_es than this,
> wouldn't that mean that we can't figure them into
> cladograms, because there wasn't enough material to begin
> with?     


No.  The _Koreanosaurus_ material is already more than adequate to include in 
an analysis.  If we combine the holotype, 'paratype' and other referred 
specimen (as the authors do), then we have five cervicals, seven dorsals, 17 
dorsal ribs, one caudal, both scapulae (nearly complete), both coracoids, both 
sternals, a nearly complete left humerus and part of the right (the paper 
contradicts itself as to which is which), partial radius + ulna, incomplete 
sacrum, partial left ilium and ischium, complete left femur, tibia + fibula, 
and incomplete left tarsus and metatarsus.  Not bad. 


Sure, a skull would be helpful.  And not just to provide additional characters 
for an analysis.  If the _Koreanosaurus_ postcranium is derived compared to 
(other?) hypsilophodont-grade onithopods, then who knows what changes went on 
in the skull?  _Oryctodromeus_ is regarded as a 'digging cursor', which used 
burrows for shelter and protection (including a den for raising young), but 
otherwise behaved like a typical small, bipedal ornithopod.  But if 
_Koreanosaurus_ was a digging quadruped, then perhaps the fossorial adaptations 
were employed not 
, the skull could be very interesting indeed...


Cheers

Tim