SIGH... GAVIIFORMS AGAIN

["Matthew Troutman" <m_troutman@hotmail.com>]

<<And his own tree allies loons and grebes, the two most highly modified 
living orders of diving birds {WELL, PENGUINS ASIDE], as each other's 
closest relatives, a conclusion that, I would say, few ornithologists 
share.>>

Cracraft has been holding to this bit of hooey for quite some time 
(since his classification of 1981, his Systematic Biology paper of 1982, 
his book chapter in 1988) and few people buy it.  Gaviiforms are almost 
certainly the closest sister-group to penguins, with which they share 
many characters to the exclusion of grebes.  Podicepiforms are a 
completely different ballgame.  S&A have argued that they are the 
members of an ancient lineage with not close living relatives based on 
DNA-DNA hybridization.  What interests me, is that studies of grebe 
cranial construction and cervical myology support a placement with the 
gruiforms, possibly with the sungrebes.  

Anyway, as Ron said, most people think that Cracraft is wrong in this 
case (at least he's keeping hesperornithids out of the group).  Cracraft 
is notorious for finding strange phylogenies like the linking of hawks 
(Falconiformes) and owls (Strigiformes).  (Also, to the person a few 
days ago wanted to know the genus of falconiform that kills snakes with 
its feet, it is the Secretary-bird, _Sagittarus serpentarius_.)  
Although the linking of owls to hawks is certainly more likely than a 
pelecaniform affinity for some members of falconiforms, it is not 
supported by syringeal anatomy, which, contrary to S&A, shows that New 
World vultures (Vulturidae) are not allied very closely to ciconiids 
(storks) and are included inside the falconiforms.

Sigh...  Pressing questions of avian phylogeny....

Matt Troutman 
m_troutman@hotmail.com

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