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Re: Chatterjee's Protoavis
Ian Paulsen wrote:
I haven't heard much about Chatterjee's Protoavis recently, so I assume
that it is considered invalid, am I correct?
I think it is safer to say that the status of _Protoavis_ is unresolved.
There is an opinion contrary to that of Chatterjee's that says that several
distinct taxa are represented in the sum total of material assigned to
_Protoavis_. At the current time, very few researchers concur with
Chatterjee's assessments that (1) all the material belongs to one taxon
(although more than one individual is represented), and (2) _Protoavis_ is a
true bird, more derived than _Archaeopteryx_.
We need to resolve issue (1) in order to determine if _Protoavis_ is a valid
taxon. In other words, does the type material and/or material that can be
confidently referred to _Protoavis_ show characters that can be used to
diagnose the genus _Protoavis_? Unlike the type specimen of
_Archaeopteryx_, the material assigned to _Protoavis_ is disarticulated and
poorly preserved. Until the hypodigm for _Protoavis_ is established with
more clarity, _Protoavis_ will continue to be excluded from most hypotheses
concerning the origin of flight (biomechanical, phylogenetic, or otherwise).
Mark Van Tomme wrote:
I've heard that someone who has checked Protoavis personnaly tell that
there's teratosaurian material mixed with some avian like stuff,like the
skull for exemple,
By "teratosaurian" material I would guess this someone meant rauisuchian.
Others have described the skull and neck to be possibly drepanosaurian in
nature. The skulls of drepanosaurids and _Longisquama_ are superficially
bird-like - which is why Senter (2004) gave the name "Avicephala" to the
clade containing Drepanosauridae and _Longisquama_.
The trend is to ignore this taxon as it's very difficult to obtain
authorization to see it.
So I've heard! _Protoavis_ is also ignored due to the possibly chimeric
nature of the material. One researcher has been overheard remarking: "It
seems to be a fauna, not a taxon".