Re: Chatterjee's Protoavis

[Tim Williams <twilliams_alpha@hotmail.com>]

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".


Tim