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Re: how does one...? was Re: JVP 27(1)
Cliff Green wrote:
FYI, I do not believe Steven Czerkas's claim in "dinosaurs of the
that dromaeosaurs are birds. That doesn't mean I think he should have his
name blotted out of the science for heresy.
Sorry, yes, "infamous" is probably an overstatement. I was emphasizing the
point that the volume in question has a reputation for having its
conclusions questioned and even overturned. Apologies to Cliff, or anyone
else that took offense.
The idea that dromaeosaurids may be secondarily flightless is actually not
all that radical/heretical. But Czerkas goes much further than this,
arguing that theropods are diphyletic - i.e., can be divided into one
lineage (Maniraptora) that includes birds and dromaeosaurs; and a second
lineage that includes the majority of non-avian theropods. Czerkas's
argument runs that maniraptorans (including birds) and "theropods" (the
leftovers, like carnosaurs and ceratosaurs) evolved independently from
separate basal archosaur stock. The problem is that it is very difficult to
support such a hypothesis without ignoring the multitude of shared derived
characters that all theropods have in common.
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