POLYPHYLETIC PICIFORMES

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

Finally recieved a copy of Olson 1983, _Evidence for a Polyphyletic 
Origin of the Piciformes.  Boy, what a great paper.

To those of you who do not know, Piciformes is the bird order that 
contains woodpeckers, toucans, honeyguides, and traditionally puffbirds 
and jamacers (Galbulae).  Two years before Olson's paper was published 
there were two cladistic analyses that supported the classical, 
monophyletic view of Piciformes.  The features given were obligate 
zygodactly ("the condition in which the fourth toe is permenently 
reversed and has an enlarged accessory articulating process (the 
"sehnenhalter") Olson 1983; 126), three-headed M.flexor hallucis longus, 
and Type VI flexor tendons.  These are the only characters holding the 
classical Piciformes together.  As Olson shows, obligate zygodactly 
occurs in cuckoos and parrots, the M.flexor hallucis longus is not 
three-headed in Galbulae, and the Type VI flexor tendons is probably 
convergent (a similiar case of convergence as Olson points out is the 
similiar branch of the M.extensor digitorum longus extending to the 
hallux in parrots and mousebirds).  

Olson shows that the suborder Galbulae actually shows more characters in 
common with the rollers, Coracii, of the order Coraciiformes.  They show 
a similiarity to coraciids in bill shape, truncate palatines, straight 
and narrow pterygiods, heavily ossified nasal septum, shape and position 
of the temporal fossae, inflated ectethemoid plate, and greatly 
exaggerated and ventrally projecting postorbital process.  The 
postorbital process takes special emphasis in Olson's mind.  The process 
is "enlarged and extends straight ventrally as far as the jugal bar" 
(Olson 1983; 130); there is a similiar short and strong postorbital 
ligament that attaches to the medial surface of the mandible just 
anterior to the articulation; the M.adductor mandibulae complex is 
narrowed, and passes through a tiny foramen in the postorbital process.  
The coracoids, humerus, down, oil gland and carpometacarpus are all 
similiar.  

Olson points out that the only features uniting the classical Piciformes 
are only deep flexor tendors.  Galbulae and Coraciiformes all show more 
similiarities to each other than Galbulae shows to Piciformes.  

Olson goes on to note the similiarities between Pici and Passeriformes: 
similiar coracoids that are slender and elongate, with the sternal end 
narrow, sternocoracoidal process reduced and procoracoid process reduced 
or absent, carpotmetacarpus, down feathers, and several myological 
characters.  

Great paper.  It is also a good introduction to birds for novices.  I 
suggest it to all.

Olson, S.L. 1983.  Evidence for a Polyphyletic Origin of the Piciformes. 
Auk 100: 126-133.

Matt Troutman

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