HIGHER LANDBIRDS & CLAWS

[darren.naish@port.ac.uk]

Thanks to all for congrats on Will. He only woke me up twice last 
night so I suppose we're doing pretty well. Anyway, this message is a 
response to stuff from Jaime Headden and Tim Williams.

Re: manual claws in _Tynskya_. An alular claw is also present in 
_Gracilitarsus_, as the new complete specimen described by Mayr 
(2001) demonstrates. Like _Tynskya_ and _Fluvioviridavis_, 
gracilitarsids appear to be part of the 'higher landbird' assemblage but 
are otherwise Neornithes incertae sedis (or maybe Passerimorphae 
incertae sedis or such). While manual claws of some sort seem widely 
distributed in neornithines (there are a couple of good review papers 
on this - don't have the refs to hand - plus the subject has been 
discussed at length on DML before), they are mostly lacking in higher 
landbirds. I have an idea that their loss may be constrained by 
pleiotropic effects but that will have to wait to another time. 

On the subject of manual claws in neornithines, Alan Gishlick has 
asserted that hoatzin chicks don't use their claws for climbing. I 
disagree with this, having seen footage of climbing hoatzin chicks that 
can definitely be seen to be using their claws.

Incidentally, I'm especially interested in _Gracilitarsus_ because Mayr 
notes that some of its tarsometatarsal characters recall those seen in 
_Eutreptodactylus_, Baird and Vickers-Rich's 'primitive cuckoo' from 
Patagonia. Not only does Mayr's reassessment indicate that 
_Eutreptodactylus_ is not a cuckoo (contra Baird and Vickers-Rich, 
even if it is, it is not the earliest as they suggest), it also provides more 
evidence for possible interchange between Eocene European and South 
American faunas.

Further to some of Tim's comments on NW vultures: the whole thing 
about vulturids not being part of the Falconiformes s. s. still depends 
on who you ask, or what data you look at. While the molecular boys 
and girls are quite happy to have NW vultures as part of a Ciconiidae 
(Sibley and Ahlquist have storks as Ciconiinae and NW vultures as 
Cathartinae, both within Ciconiidae), some morphological studies (e.g. 
work on syringeal anatomy) support inclusion of vulturids in a 
traditional Falconiformes. Finally, while NW vultures generally don't 
kill prey, there are some published observations of turkey vultures 
killing passerines and that sort of thing.

BTW Jaime - isn't it 'cursory examination' rather than 'cursorial 
examination'.

Congrats to Steve Salisbury on the recovery of 'Elliot' (a very large 
Australian sauropod).

DARREN NAISH 
PALAEOBIOLOGY RESEARCH GROUP
School of Earth & Environmental Sciences
UNIVERSITY OF PORTSMOUTH
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