[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Giant birds

>In a message dated 11/8/99 10:35:13 PM EST, bettyc@flyinggoat.com writes:
><< what about quadrepedal flightless birds like sauropods and ceratopsians?
> ;]
> -Betty >>
>Probably evolved from tree-climbing birds that couldn't fly yet.

Wait a minute.  Do you include all dinosaur groups, including ornithischians, 
under BCF (or are we really talking about BCF here)?  I thought that BCF 
referred to theropod evolution solely.  Or are we talking about something 
different.  Now, I understand that the first ornithischians are bipedal, and 
that a case could be made for a tree dwelling ancestor, but I'm not sure that 
makes them birds.

I have thought that the radical difference in hip designs implied *two 
separate* instances of bipedal evolution (I envision several protodinosaur 
groups existing, where only the ornithischians and saurischians survived).  
Personally, I can't see a saurischian evolving an ornithischian hip, even with 
a truckload of generations.  There doesn't seem to be any advantage to the 
"new" hip design.

Rob Meyerson

Politicians and diapers have one thing in common. They should both be changed 
regularly and for the same reason.