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CRAZY S. AMERICAN THEROPODS
_Araucanoraptor_ is big news, but it's still a _nomen dubium_. Does anyone know
where it will be published? Novas appears to be arguing that this animal is a
true relatives of Laurasian dromaeosaurids (OK, so there are other Gondwanan
dromaeosaurids I know..) - a view at odds with that of some other S. American
workers who see their animals as endemics convergent on northern forms.
If this animal is based only a foot though (is that correct? I hate all these
uncertainties), how sure can we be. I guess caution is urged. But that's an
internet problem - people speculate like crazy on preliminaries. Who cares -
However, suppose Novas's new taxon is a bona fide dromaeosaurid. This
strengthens the case for direct phyletic affinities between S. American forms
and their northern (putative) relatives. I'm unaware of any recent work on
_Secernosaurus_, but am I right in thinking that what's been published on
_Gasparinisaura_ supports this view too: i.e. because _Gasparinisaura_ is nested
within a clade of endemic Laurasian ornithopods, it is more likely to be an
immigrant from the north rather than a Gondwanan endemic?
Those of you that may be under the impression that most Gondwanan dinosaurs seem
to be descendants of Laurasian invaders, note that much evidence now indicates
the opposite - i.e. many Laurasian forms may actually be descended from
Gondwanan invaders. Early oviraptorosaurs and problematic creatures like
Gondwanan certopians (is _Notoceratops_ still a ceratopian? There's still the
Dinosaur Cove 'cf. _Leptoceratops_' ulna) and ornithomimid _Timimus_ throw
proverbial spanners into the works, and there are more surprises to come yet!
Oh yes. Alvarezsaurids appear to have originated in S. America and then spread
via N. America to Asia.
Biology has traditionally has a Northern Hemisphere bias, simply because this
is where Western civilization first sprung up, and people have assumed that all
from here is/was best. So northern groups that occur in the south must have
invaded the south and 'overrun' the weak, primitive southerners. Such views are
often false, and many fossils now show that southern taxa were as/more important
than northern ones in global patterns. e.g. Passerine birds underwent a massive
Australian radiation and then invaded northward (older view believed vice
versa), xenarthrans and South American rodents (many are not Rodentia s.s.)
underwent S. American radiation and invaded north when Panamanian isthmus
Does anyone know the current state of play re: S. American ankylosaurs?
And for those of you who keep track of such things, the name
'_Pissedoffasaurus_' is included in the current DCC newsletter as part of the
updated title for my talk. It *isn't* the title for my talk, as I'll only be
talking about alvarezsaurids, but I didn't know that when I submitted the title.
'_Pissedoffasaurus_' is an apocryphal name for _Irritator_: I'm not sure that
the rumours (according to which, it was a seriously considered name early on)
are true. Never trust rumours. I get told off for listening to them all the
_Albertosaurus_ _Albertosaurus_ _Albertosaurus_. I shall write it out a hundred
"It seemed.. darker.."