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RE: Ah ha! That's where therizinosaurs came from



Gregory Paul wrote-

> The potential link between jeholornids and therizinosaurs is much weaker
> than that between omnivoropterygids and oviraptorosaurs. The reason that
> jeholornids are interesting is because they show that long tailed herbivorous
> fliers were out and about, and were potential ancestors for neoflightless long
> tailed herbivores like basal therizinosaurs. Jeholornids make poor ancestors
> for therizinosaurs in part because they lacked tooth rows (which are
> unlikey to have reevolved although it cannot be ruled out).

If you actually suggest some synapomorphies, I could include them in the 
upcoming paravian analysis and see if they have an effect.

> Someone said I am inconsistent in rejecting cladograms that contradict the
> neoflightless hypothesis while accepting those that do. 
> ...
> Here's the thing. Are those who oppose my opposition to over reliance of
> cladistics really telling me I should be a cladist? Because if I had been so I
> would not have been able to propose the neoflightless hypothesis when Nancy
> was our 1st Lady, and only when winged microraptors were found in this
> centry would the hypothesis have been invented. Instead I got priority and the
> community was ready for the possiblity when winged dromaeosaurs turned up.
> Seriously, do you really think I should have toed the cladistic line all those
> years? And avoided the logical thinking that led to the hypothesis. Really?
> How would that work, please let me know.

I wasn't the one who made the argument, but the problem with your reasoning is 
that while your neoflightless idea seems to be at least partially right, as 
were several of your other ideas, your precladistic phylogeny also got a lot 
wrong (assuming for the moment the current consensus is right).  Protoavis has 
nothing to do with herrerasaurids, spinosaurids aren't coelophysoids, 
abelisauroids aren't megalosauroids, metriacanthosaurids are carnosaurs, 
Ornitholestes and tyrannosaurids aren't carnosaurs, ornithomimosaurs and 
oviraptorosaurs aren't avialans, Avimimus isn't particularly close to birds, 
etc..  Cladists were making some of the same mistakes, but Gauthier (1984, 
1986) got the correct position for ornithomimosaurs and oviraptorosaurs for 
instance.  So if you would have been a cladist, you might have gotten priority 
for other ideas even if your analyses didn't find basal maniraptorans to be 
bird-like.  It's not fair to point to what your intuition got right as an 
argument against cladistics without also taking into account what it got 
wrong.  The difference is that whether a cladogram's right or wrong, we can 
objectively examine the support for any topology and see which characters and 
taxa were taken into account.  But even if your intuition is right, we can't do 
anything with it.  Matthew and Brown's (1922) intuition was right that 
tyrannosaurids were coelurosaurs, but since the character evidence they 
provided doesn't actually support that conclusion (elongate quadrate well 
attached to quadratojugal, short peduncle on ilium, arctometatarsus), is it 
really justified to credit them with getting it right just because subsequent 
finds have made it most parsimonious?

> My therizinosaur paper in JVP in 84 actually was a shot at something at
> cladistic analysis -- and look at where that got me. The reason therizinosaurs
> were such a phylogenetic problem was the absence of sufficient fossils. As
> more data became available they proved to be derived theropods after all. 

Actually not true.  If you scroll down to the "Experiments with Controversial 
Taxa" section on http://home.comcast.net/~eoraptor/Gauthier%201986.htm , you'll 
see where I added Segnosauridae (based only on Segnosaurus and Erlikosaurus) to 
Gauthier's classic 1986 dinosaur analysis.  They emerged as maniraptorans just 
as they do today, even though Ornithischia and Sauropodomorpha were both OTUs.  
Your 1984 analysis was hindered by including few theropod characters, and only 
using coelophysids and dromaeosaurids as your theropod sample.  Of course, you 
could argue Gauthier's didn't include the relevent characters uniting 
segnosaurs with herbivorous dinosaurs.  But since it was a cladistic analysis, 
we could actually test that idea, whereas intuitive analyses can't be dealt 
with objectively.

Mickey Mortimer