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Re: diplodocid radiation
> Is there any strong evidence of diplodocids present in Asia? I am
> belonging more and more convinced that Asian sauropods considered to be
> diplodocids are now being placed within the Euhelopodids or some other
> family (similar to diplodocids) as yet to be named.
There were certainly diplodocOIDs in Asia, at least in the
Cretaceous - like _Nemegtosaurus_ and _Quaesitosaurus_ (both of the
family Nemegtosauridae) and _Mongolosaurus_ (_incertae sedis_).
_Mamenchisaurus_ is now considered to be related to other Asian
sauropods like _Euhelopus_ and _Omeisaurus_, so it is certainly a
> P.S. this goes for Camarasaurids also.
_Euhelopus_ is (usually) no longer considered to be a camarasaurid.
For _Tienshanosaurus_, the material is too incomplete to be sure what
it is (one account says the hip-bones of _Tienshano_ are rather
diplodocid-like). Same goes for _Chiayusaurus_.
For _Opisthocoelicaudia_ - well, it depends on who you ask. A recent
review (by Paul Upchurch) allies it with the titanosaurids. But, the
caudal vertebrae of _O_ are opisthicoelous (the name probably gives
that away), compared to the procoelous caudals of titanosaurids (the
There seems to be some genuine titanosaurids in Asia during the
Cretaceous - mostly "_Antarctosaurus_" species. (As opposed to the
type species for _Antarcto_, which is some form of diplodocoid, not
There's no proof that _O_ is the same sauropod as _Nemegtosaurus_
though. The body-plan of _O_ is very camarasaurid-like (except for
the tail), but it's synapomorphies that count in the end, and the
affinities of _O_ are very difficult to pin down.
> ---John Schneiderman (email@example.com)