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Re: Why non-avian dinosaurs weren't able to survive
----- Original Message -----
From: Dann Pigdon <dannj@alphalink.com.au>
To: dinosaur@usc.edu
Sent: Tuesday, November 24, 2015 12:04 AM
Subject: Re: Why non-avian dinosaurs weren't able to survive
That's precisely what I suggested; each genus, family or superfamily likely had
it's own fatal set of
circumstances that were different to those of other genera, families or
superfamilies. A large
sauropod living close to the bolide impact site would have faced different
stresses than a small
theropod on the other side of the world.
There's no single blanket hypothesis that can completely account for all
extinctions at the end of
the Cretaceous - probably not ever for all of the dinosauria specifically.
Therefore the answer to
the original question posed in this thread is; "there's no single answer".
Non-avian dinosaurs were
simply too diverse and widespread to have all be done in by a single defining
event. Each species,
genus, family, etc likely had a different tale of woe to tell.
_________________________________________________________________________________________________
Another reason why this is largely a misleading question to ask is that
dinosaurs were not the only group of animals to not pass through the K/Pg
event. If one is going to ask why the dinosaurs didn't survive they need to
also ask why the mosasaurs, pterosaurs, plesiosaurs, ammonites, belemnites and
the rest of the 75% of life on Earth didn't survive. That includes members of
groups that only partially passed through the K/Pg event (e.g., what allowed
neornithean birds to survive the K/Pg, but not enantiornitheans? Why did
scincomorphan lizards pass through, but polyglyphanodonts did not?, etc.).
The K/Pg event was so much larger than just the end of the dinosaurs.
Jason